1 /* 2 * Copyright (c) 2013 Nicira, Inc. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of version 2 of the GNU General Public 6 * License as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program; if not, write to the Free Software 15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 16 * 02110-1301, USA 17 */ 18 19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 20 21 #include <linux/capability.h> 22 #include <linux/module.h> 23 #include <linux/types.h> 24 #include <linux/kernel.h> 25 #include <linux/slab.h> 26 #include <linux/uaccess.h> 27 #include <linux/skbuff.h> 28 #include <linux/netdevice.h> 29 #include <linux/in.h> 30 #include <linux/tcp.h> 31 #include <linux/udp.h> 32 #include <linux/if_arp.h> 33 #include <linux/mroute.h> 34 #include <linux/init.h> 35 #include <linux/in6.h> 36 #include <linux/inetdevice.h> 37 #include <linux/igmp.h> 38 #include <linux/netfilter_ipv4.h> 39 #include <linux/etherdevice.h> 40 #include <linux/if_ether.h> 41 #include <linux/if_vlan.h> 42 #include <linux/rculist.h> 43 #include <linux/err.h> 44 45 #include <net/sock.h> 46 #include <net/ip.h> 47 #include <net/icmp.h> 48 #include <net/protocol.h> 49 #include <net/ip_tunnels.h> 50 #include <net/arp.h> 51 #include <net/checksum.h> 52 #include <net/dsfield.h> 53 #include <net/inet_ecn.h> 54 #include <net/xfrm.h> 55 #include <net/net_namespace.h> 56 #include <net/netns/generic.h> 57 #include <net/rtnetlink.h> 58 59 #if IS_ENABLED(CONFIG_IPV6) 60 #include <net/ipv6.h> 61 #include <net/ip6_fib.h> 62 #include <net/ip6_route.h> 63 #endif 64 65 static unsigned int ip_tunnel_hash(__be32 key, __be32 remote) 66 { 67 return hash_32((__force u32)key ^ (__force u32)remote, 68 IP_TNL_HASH_BITS); 69 } 70 71 static void __tunnel_dst_set(struct ip_tunnel_dst *idst, 72 struct dst_entry *dst) 73 { 74 struct dst_entry *old_dst; 75 76 if (dst) { 77 if (dst->flags & DST_NOCACHE) 78 dst = NULL; 79 else 80 dst_clone(dst); 81 } 82 old_dst = xchg((__force struct dst_entry **)&idst->dst, dst); 83 dst_release(old_dst); 84 } 85 86 static void tunnel_dst_set(struct ip_tunnel *t, struct dst_entry *dst) 87 { 88 __tunnel_dst_set(this_cpu_ptr(t->dst_cache), dst); 89 } 90 91 static void tunnel_dst_reset(struct ip_tunnel *t) 92 { 93 tunnel_dst_set(t, NULL); 94 } 95 96 static void tunnel_dst_reset_all(struct ip_tunnel *t) 97 { 98 int i; 99 100 for_each_possible_cpu(i) 101 __tunnel_dst_set(per_cpu_ptr(t->dst_cache, i), NULL); 102 } 103 104 static struct dst_entry *tunnel_dst_get(struct ip_tunnel *t) 105 { 106 struct dst_entry *dst; 107 108 rcu_read_lock(); 109 dst = rcu_dereference(this_cpu_ptr(t->dst_cache)->dst); 110 if (dst) 111 dst_hold(dst); 112 rcu_read_unlock(); 113 return dst; 114 } 115 116 static struct dst_entry *tunnel_dst_check(struct ip_tunnel *t, u32 cookie) 117 { 118 struct dst_entry *dst = tunnel_dst_get(t); 119 120 if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) { 121 tunnel_dst_reset(t); 122 return NULL; 123 } 124 125 return dst; 126 } 127 128 /* Often modified stats are per cpu, other are shared (netdev->stats) */ 129 struct rtnl_link_stats64 *ip_tunnel_get_stats64(struct net_device *dev, 130 struct rtnl_link_stats64 *tot) 131 { 132 int i; 133 134 for_each_possible_cpu(i) { 135 const struct pcpu_sw_netstats *tstats = 136 per_cpu_ptr(dev->tstats, i); 137 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 138 unsigned int start; 139 140 do { 141 start = u64_stats_fetch_begin_bh(&tstats->syncp); 142 rx_packets = tstats->rx_packets; 143 tx_packets = tstats->tx_packets; 144 rx_bytes = tstats->rx_bytes; 145 tx_bytes = tstats->tx_bytes; 146 } while (u64_stats_fetch_retry_bh(&tstats->syncp, start)); 147 148 tot->rx_packets += rx_packets; 149 tot->tx_packets += tx_packets; 150 tot->rx_bytes += rx_bytes; 151 tot->tx_bytes += tx_bytes; 152 } 153 154 tot->multicast = dev->stats.multicast; 155 156 tot->rx_crc_errors = dev->stats.rx_crc_errors; 157 tot->rx_fifo_errors = dev->stats.rx_fifo_errors; 158 tot->rx_length_errors = dev->stats.rx_length_errors; 159 tot->rx_frame_errors = dev->stats.rx_frame_errors; 160 tot->rx_errors = dev->stats.rx_errors; 161 162 tot->tx_fifo_errors = dev->stats.tx_fifo_errors; 163 tot->tx_carrier_errors = dev->stats.tx_carrier_errors; 164 tot->tx_dropped = dev->stats.tx_dropped; 165 tot->tx_aborted_errors = dev->stats.tx_aborted_errors; 166 tot->tx_errors = dev->stats.tx_errors; 167 168 tot->collisions = dev->stats.collisions; 169 170 return tot; 171 } 172 EXPORT_SYMBOL_GPL(ip_tunnel_get_stats64); 173 174 static bool ip_tunnel_key_match(const struct ip_tunnel_parm *p, 175 __be16 flags, __be32 key) 176 { 177 if (p->i_flags & TUNNEL_KEY) { 178 if (flags & TUNNEL_KEY) 179 return key == p->i_key; 180 else 181 /* key expected, none present */ 182 return false; 183 } else 184 return !(flags & TUNNEL_KEY); 185 } 186 187 /* Fallback tunnel: no source, no destination, no key, no options 188 189 Tunnel hash table: 190 We require exact key match i.e. if a key is present in packet 191 it will match only tunnel with the same key; if it is not present, 192 it will match only keyless tunnel. 193 194 All keysless packets, if not matched configured keyless tunnels 195 will match fallback tunnel. 196 Given src, dst and key, find appropriate for input tunnel. 197 */ 198 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, 199 int link, __be16 flags, 200 __be32 remote, __be32 local, 201 __be32 key) 202 { 203 unsigned int hash; 204 struct ip_tunnel *t, *cand = NULL; 205 struct hlist_head *head; 206 207 hash = ip_tunnel_hash(key, remote); 208 head = &itn->tunnels[hash]; 209 210 hlist_for_each_entry_rcu(t, head, hash_node) { 211 if (local != t->parms.iph.saddr || 212 remote != t->parms.iph.daddr || 213 !(t->dev->flags & IFF_UP)) 214 continue; 215 216 if (!ip_tunnel_key_match(&t->parms, flags, key)) 217 continue; 218 219 if (t->parms.link == link) 220 return t; 221 else 222 cand = t; 223 } 224 225 hlist_for_each_entry_rcu(t, head, hash_node) { 226 if (remote != t->parms.iph.daddr || 227 !(t->dev->flags & IFF_UP)) 228 continue; 229 230 if (!ip_tunnel_key_match(&t->parms, flags, key)) 231 continue; 232 233 if (t->parms.link == link) 234 return t; 235 else if (!cand) 236 cand = t; 237 } 238 239 hash = ip_tunnel_hash(key, 0); 240 head = &itn->tunnels[hash]; 241 242 hlist_for_each_entry_rcu(t, head, hash_node) { 243 if ((local != t->parms.iph.saddr && 244 (local != t->parms.iph.daddr || 245 !ipv4_is_multicast(local))) || 246 !(t->dev->flags & IFF_UP)) 247 continue; 248 249 if (!ip_tunnel_key_match(&t->parms, flags, key)) 250 continue; 251 252 if (t->parms.link == link) 253 return t; 254 else if (!cand) 255 cand = t; 256 } 257 258 if (flags & TUNNEL_NO_KEY) 259 goto skip_key_lookup; 260 261 hlist_for_each_entry_rcu(t, head, hash_node) { 262 if (t->parms.i_key != key || 263 !(t->dev->flags & IFF_UP)) 264 continue; 265 266 if (t->parms.link == link) 267 return t; 268 else if (!cand) 269 cand = t; 270 } 271 272 skip_key_lookup: 273 if (cand) 274 return cand; 275 276 if (itn->fb_tunnel_dev && itn->fb_tunnel_dev->flags & IFF_UP) 277 return netdev_priv(itn->fb_tunnel_dev); 278 279 280 return NULL; 281 } 282 EXPORT_SYMBOL_GPL(ip_tunnel_lookup); 283 284 static struct hlist_head *ip_bucket(struct ip_tunnel_net *itn, 285 struct ip_tunnel_parm *parms) 286 { 287 unsigned int h; 288 __be32 remote; 289 290 if (parms->iph.daddr && !ipv4_is_multicast(parms->iph.daddr)) 291 remote = parms->iph.daddr; 292 else 293 remote = 0; 294 295 h = ip_tunnel_hash(parms->i_key, remote); 296 return &itn->tunnels[h]; 297 } 298 299 static void ip_tunnel_add(struct ip_tunnel_net *itn, struct ip_tunnel *t) 300 { 301 struct hlist_head *head = ip_bucket(itn, &t->parms); 302 303 hlist_add_head_rcu(&t->hash_node, head); 304 } 305 306 static void ip_tunnel_del(struct ip_tunnel *t) 307 { 308 hlist_del_init_rcu(&t->hash_node); 309 } 310 311 static struct ip_tunnel *ip_tunnel_find(struct ip_tunnel_net *itn, 312 struct ip_tunnel_parm *parms, 313 int type) 314 { 315 __be32 remote = parms->iph.daddr; 316 __be32 local = parms->iph.saddr; 317 __be32 key = parms->i_key; 318 int link = parms->link; 319 struct ip_tunnel *t = NULL; 320 struct hlist_head *head = ip_bucket(itn, parms); 321 322 hlist_for_each_entry_rcu(t, head, hash_node) { 323 if (local == t->parms.iph.saddr && 324 remote == t->parms.iph.daddr && 325 key == t->parms.i_key && 326 link == t->parms.link && 327 type == t->dev->type) 328 break; 329 } 330 return t; 331 } 332 333 static struct net_device *__ip_tunnel_create(struct net *net, 334 const struct rtnl_link_ops *ops, 335 struct ip_tunnel_parm *parms) 336 { 337 int err; 338 struct ip_tunnel *tunnel; 339 struct net_device *dev; 340 char name[IFNAMSIZ]; 341 342 if (parms->name[0]) 343 strlcpy(name, parms->name, IFNAMSIZ); 344 else { 345 if (strlen(ops->kind) > (IFNAMSIZ - 3)) { 346 err = -E2BIG; 347 goto failed; 348 } 349 strlcpy(name, ops->kind, IFNAMSIZ); 350 strncat(name, "%d", 2); 351 } 352 353 ASSERT_RTNL(); 354 dev = alloc_netdev(ops->priv_size, name, ops->setup); 355 if (!dev) { 356 err = -ENOMEM; 357 goto failed; 358 } 359 dev_net_set(dev, net); 360 361 dev->rtnl_link_ops = ops; 362 363 tunnel = netdev_priv(dev); 364 tunnel->parms = *parms; 365 tunnel->net = net; 366 367 err = register_netdevice(dev); 368 if (err) 369 goto failed_free; 370 371 return dev; 372 373 failed_free: 374 free_netdev(dev); 375 failed: 376 return ERR_PTR(err); 377 } 378 379 static inline void init_tunnel_flow(struct flowi4 *fl4, 380 int proto, 381 __be32 daddr, __be32 saddr, 382 __be32 key, __u8 tos, int oif) 383 { 384 memset(fl4, 0, sizeof(*fl4)); 385 fl4->flowi4_oif = oif; 386 fl4->daddr = daddr; 387 fl4->saddr = saddr; 388 fl4->flowi4_tos = tos; 389 fl4->flowi4_proto = proto; 390 fl4->fl4_gre_key = key; 391 } 392 393 static int ip_tunnel_bind_dev(struct net_device *dev) 394 { 395 struct net_device *tdev = NULL; 396 struct ip_tunnel *tunnel = netdev_priv(dev); 397 const struct iphdr *iph; 398 int hlen = LL_MAX_HEADER; 399 int mtu = ETH_DATA_LEN; 400 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 401 402 iph = &tunnel->parms.iph; 403 404 /* Guess output device to choose reasonable mtu and needed_headroom */ 405 if (iph->daddr) { 406 struct flowi4 fl4; 407 struct rtable *rt; 408 409 init_tunnel_flow(&fl4, iph->protocol, iph->daddr, 410 iph->saddr, tunnel->parms.o_key, 411 RT_TOS(iph->tos), tunnel->parms.link); 412 rt = ip_route_output_key(tunnel->net, &fl4); 413 414 if (!IS_ERR(rt)) { 415 tdev = rt->dst.dev; 416 tunnel_dst_set(tunnel, &rt->dst); 417 ip_rt_put(rt); 418 } 419 if (dev->type != ARPHRD_ETHER) 420 dev->flags |= IFF_POINTOPOINT; 421 } 422 423 if (!tdev && tunnel->parms.link) 424 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link); 425 426 if (tdev) { 427 hlen = tdev->hard_header_len + tdev->needed_headroom; 428 mtu = tdev->mtu; 429 } 430 dev->iflink = tunnel->parms.link; 431 432 dev->needed_headroom = t_hlen + hlen; 433 mtu -= (dev->hard_header_len + t_hlen); 434 435 if (mtu < 68) 436 mtu = 68; 437 438 return mtu; 439 } 440 441 static struct ip_tunnel *ip_tunnel_create(struct net *net, 442 struct ip_tunnel_net *itn, 443 struct ip_tunnel_parm *parms) 444 { 445 struct ip_tunnel *nt, *fbt; 446 struct net_device *dev; 447 448 BUG_ON(!itn->fb_tunnel_dev); 449 fbt = netdev_priv(itn->fb_tunnel_dev); 450 dev = __ip_tunnel_create(net, itn->fb_tunnel_dev->rtnl_link_ops, parms); 451 if (IS_ERR(dev)) 452 return NULL; 453 454 dev->mtu = ip_tunnel_bind_dev(dev); 455 456 nt = netdev_priv(dev); 457 ip_tunnel_add(itn, nt); 458 return nt; 459 } 460 461 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, 462 const struct tnl_ptk_info *tpi, bool log_ecn_error) 463 { 464 struct pcpu_sw_netstats *tstats; 465 const struct iphdr *iph = ip_hdr(skb); 466 int err; 467 468 #ifdef CONFIG_NET_IPGRE_BROADCAST 469 if (ipv4_is_multicast(iph->daddr)) { 470 /* Looped back packet, drop it! */ 471 if (rt_is_output_route(skb_rtable(skb))) 472 goto drop; 473 tunnel->dev->stats.multicast++; 474 skb->pkt_type = PACKET_BROADCAST; 475 } 476 #endif 477 478 if ((!(tpi->flags&TUNNEL_CSUM) && (tunnel->parms.i_flags&TUNNEL_CSUM)) || 479 ((tpi->flags&TUNNEL_CSUM) && !(tunnel->parms.i_flags&TUNNEL_CSUM))) { 480 tunnel->dev->stats.rx_crc_errors++; 481 tunnel->dev->stats.rx_errors++; 482 goto drop; 483 } 484 485 if (tunnel->parms.i_flags&TUNNEL_SEQ) { 486 if (!(tpi->flags&TUNNEL_SEQ) || 487 (tunnel->i_seqno && (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) { 488 tunnel->dev->stats.rx_fifo_errors++; 489 tunnel->dev->stats.rx_errors++; 490 goto drop; 491 } 492 tunnel->i_seqno = ntohl(tpi->seq) + 1; 493 } 494 495 err = IP_ECN_decapsulate(iph, skb); 496 if (unlikely(err)) { 497 if (log_ecn_error) 498 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", 499 &iph->saddr, iph->tos); 500 if (err > 1) { 501 ++tunnel->dev->stats.rx_frame_errors; 502 ++tunnel->dev->stats.rx_errors; 503 goto drop; 504 } 505 } 506 507 tstats = this_cpu_ptr(tunnel->dev->tstats); 508 u64_stats_update_begin(&tstats->syncp); 509 tstats->rx_packets++; 510 tstats->rx_bytes += skb->len; 511 u64_stats_update_end(&tstats->syncp); 512 513 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev))); 514 515 if (tunnel->dev->type == ARPHRD_ETHER) { 516 skb->protocol = eth_type_trans(skb, tunnel->dev); 517 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN); 518 } else { 519 skb->dev = tunnel->dev; 520 } 521 522 gro_cells_receive(&tunnel->gro_cells, skb); 523 return 0; 524 525 drop: 526 kfree_skb(skb); 527 return 0; 528 } 529 EXPORT_SYMBOL_GPL(ip_tunnel_rcv); 530 531 static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, 532 struct rtable *rt, __be16 df) 533 { 534 struct ip_tunnel *tunnel = netdev_priv(dev); 535 int pkt_size = skb->len - tunnel->hlen - dev->hard_header_len; 536 int mtu; 537 538 if (df) 539 mtu = dst_mtu(&rt->dst) - dev->hard_header_len 540 - sizeof(struct iphdr) - tunnel->hlen; 541 else 542 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; 543 544 if (skb_dst(skb)) 545 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); 546 547 if (skb->protocol == htons(ETH_P_IP)) { 548 if (!skb_is_gso(skb) && 549 (df & htons(IP_DF)) && mtu < pkt_size) { 550 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 551 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); 552 return -E2BIG; 553 } 554 } 555 #if IS_ENABLED(CONFIG_IPV6) 556 else if (skb->protocol == htons(ETH_P_IPV6)) { 557 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb); 558 559 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && 560 mtu >= IPV6_MIN_MTU) { 561 if ((tunnel->parms.iph.daddr && 562 !ipv4_is_multicast(tunnel->parms.iph.daddr)) || 563 rt6->rt6i_dst.plen == 128) { 564 rt6->rt6i_flags |= RTF_MODIFIED; 565 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu); 566 } 567 } 568 569 if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU && 570 mtu < pkt_size) { 571 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 572 return -E2BIG; 573 } 574 } 575 #endif 576 return 0; 577 } 578 579 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 580 const struct iphdr *tnl_params, const u8 protocol) 581 { 582 struct ip_tunnel *tunnel = netdev_priv(dev); 583 const struct iphdr *inner_iph; 584 struct flowi4 fl4; 585 u8 tos, ttl; 586 __be16 df; 587 struct rtable *rt = NULL; /* Route to the other host */ 588 unsigned int max_headroom; /* The extra header space needed */ 589 __be32 dst; 590 int err; 591 bool connected = true; 592 593 inner_iph = (const struct iphdr *)skb_inner_network_header(skb); 594 595 dst = tnl_params->daddr; 596 if (dst == 0) { 597 /* NBMA tunnel */ 598 599 if (skb_dst(skb) == NULL) { 600 dev->stats.tx_fifo_errors++; 601 goto tx_error; 602 } 603 604 if (skb->protocol == htons(ETH_P_IP)) { 605 rt = skb_rtable(skb); 606 dst = rt_nexthop(rt, inner_iph->daddr); 607 } 608 #if IS_ENABLED(CONFIG_IPV6) 609 else if (skb->protocol == htons(ETH_P_IPV6)) { 610 const struct in6_addr *addr6; 611 struct neighbour *neigh; 612 bool do_tx_error_icmp; 613 int addr_type; 614 615 neigh = dst_neigh_lookup(skb_dst(skb), 616 &ipv6_hdr(skb)->daddr); 617 if (neigh == NULL) 618 goto tx_error; 619 620 addr6 = (const struct in6_addr *)&neigh->primary_key; 621 addr_type = ipv6_addr_type(addr6); 622 623 if (addr_type == IPV6_ADDR_ANY) { 624 addr6 = &ipv6_hdr(skb)->daddr; 625 addr_type = ipv6_addr_type(addr6); 626 } 627 628 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 629 do_tx_error_icmp = true; 630 else { 631 do_tx_error_icmp = false; 632 dst = addr6->s6_addr32[3]; 633 } 634 neigh_release(neigh); 635 if (do_tx_error_icmp) 636 goto tx_error_icmp; 637 } 638 #endif 639 else 640 goto tx_error; 641 642 connected = false; 643 } 644 645 tos = tnl_params->tos; 646 if (tos & 0x1) { 647 tos &= ~0x1; 648 if (skb->protocol == htons(ETH_P_IP)) { 649 tos = inner_iph->tos; 650 connected = false; 651 } else if (skb->protocol == htons(ETH_P_IPV6)) { 652 tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph); 653 connected = false; 654 } 655 } 656 657 init_tunnel_flow(&fl4, protocol, dst, tnl_params->saddr, 658 tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link); 659 660 if (connected) 661 rt = (struct rtable *)tunnel_dst_check(tunnel, 0); 662 663 if (!rt) { 664 rt = ip_route_output_key(tunnel->net, &fl4); 665 666 if (IS_ERR(rt)) { 667 dev->stats.tx_carrier_errors++; 668 goto tx_error; 669 } 670 if (connected) 671 tunnel_dst_set(tunnel, &rt->dst); 672 } 673 674 if (rt->dst.dev == dev) { 675 ip_rt_put(rt); 676 dev->stats.collisions++; 677 goto tx_error; 678 } 679 680 if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off)) { 681 ip_rt_put(rt); 682 goto tx_error; 683 } 684 685 if (tunnel->err_count > 0) { 686 if (time_before(jiffies, 687 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 688 tunnel->err_count--; 689 690 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 691 dst_link_failure(skb); 692 } else 693 tunnel->err_count = 0; 694 } 695 696 tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); 697 ttl = tnl_params->ttl; 698 if (ttl == 0) { 699 if (skb->protocol == htons(ETH_P_IP)) 700 ttl = inner_iph->ttl; 701 #if IS_ENABLED(CONFIG_IPV6) 702 else if (skb->protocol == htons(ETH_P_IPV6)) 703 ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit; 704 #endif 705 else 706 ttl = ip4_dst_hoplimit(&rt->dst); 707 } 708 709 df = tnl_params->frag_off; 710 if (skb->protocol == htons(ETH_P_IP)) 711 df |= (inner_iph->frag_off&htons(IP_DF)); 712 713 max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr) 714 + rt->dst.header_len; 715 if (max_headroom > dev->needed_headroom) 716 dev->needed_headroom = max_headroom; 717 718 if (skb_cow_head(skb, dev->needed_headroom)) { 719 dev->stats.tx_dropped++; 720 kfree_skb(skb); 721 return; 722 } 723 724 err = iptunnel_xmit(rt, skb, fl4.saddr, fl4.daddr, protocol, 725 tos, ttl, df, !net_eq(tunnel->net, dev_net(dev))); 726 iptunnel_xmit_stats(err, &dev->stats, dev->tstats); 727 728 return; 729 730 #if IS_ENABLED(CONFIG_IPV6) 731 tx_error_icmp: 732 dst_link_failure(skb); 733 #endif 734 tx_error: 735 dev->stats.tx_errors++; 736 kfree_skb(skb); 737 } 738 EXPORT_SYMBOL_GPL(ip_tunnel_xmit); 739 740 static void ip_tunnel_update(struct ip_tunnel_net *itn, 741 struct ip_tunnel *t, 742 struct net_device *dev, 743 struct ip_tunnel_parm *p, 744 bool set_mtu) 745 { 746 ip_tunnel_del(t); 747 t->parms.iph.saddr = p->iph.saddr; 748 t->parms.iph.daddr = p->iph.daddr; 749 t->parms.i_key = p->i_key; 750 t->parms.o_key = p->o_key; 751 if (dev->type != ARPHRD_ETHER) { 752 memcpy(dev->dev_addr, &p->iph.saddr, 4); 753 memcpy(dev->broadcast, &p->iph.daddr, 4); 754 } 755 ip_tunnel_add(itn, t); 756 757 t->parms.iph.ttl = p->iph.ttl; 758 t->parms.iph.tos = p->iph.tos; 759 t->parms.iph.frag_off = p->iph.frag_off; 760 761 if (t->parms.link != p->link) { 762 int mtu; 763 764 t->parms.link = p->link; 765 mtu = ip_tunnel_bind_dev(dev); 766 if (set_mtu) 767 dev->mtu = mtu; 768 } 769 tunnel_dst_reset_all(t); 770 netdev_state_change(dev); 771 } 772 773 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd) 774 { 775 int err = 0; 776 struct ip_tunnel *t; 777 struct net *net = dev_net(dev); 778 struct ip_tunnel *tunnel = netdev_priv(dev); 779 struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id); 780 781 BUG_ON(!itn->fb_tunnel_dev); 782 switch (cmd) { 783 case SIOCGETTUNNEL: 784 t = NULL; 785 if (dev == itn->fb_tunnel_dev) 786 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); 787 if (t == NULL) 788 t = netdev_priv(dev); 789 memcpy(p, &t->parms, sizeof(*p)); 790 break; 791 792 case SIOCADDTUNNEL: 793 case SIOCCHGTUNNEL: 794 err = -EPERM; 795 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 796 goto done; 797 if (p->iph.ttl) 798 p->iph.frag_off |= htons(IP_DF); 799 if (!(p->i_flags&TUNNEL_KEY)) 800 p->i_key = 0; 801 if (!(p->o_flags&TUNNEL_KEY)) 802 p->o_key = 0; 803 804 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); 805 806 if (!t && (cmd == SIOCADDTUNNEL)) 807 t = ip_tunnel_create(net, itn, p); 808 809 if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 810 if (t != NULL) { 811 if (t->dev != dev) { 812 err = -EEXIST; 813 break; 814 } 815 } else { 816 unsigned int nflags = 0; 817 818 if (ipv4_is_multicast(p->iph.daddr)) 819 nflags = IFF_BROADCAST; 820 else if (p->iph.daddr) 821 nflags = IFF_POINTOPOINT; 822 823 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) { 824 err = -EINVAL; 825 break; 826 } 827 828 t = netdev_priv(dev); 829 } 830 } 831 832 if (t) { 833 err = 0; 834 ip_tunnel_update(itn, t, dev, p, true); 835 } else 836 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 837 break; 838 839 case SIOCDELTUNNEL: 840 err = -EPERM; 841 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 842 goto done; 843 844 if (dev == itn->fb_tunnel_dev) { 845 err = -ENOENT; 846 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); 847 if (t == NULL) 848 goto done; 849 err = -EPERM; 850 if (t == netdev_priv(itn->fb_tunnel_dev)) 851 goto done; 852 dev = t->dev; 853 } 854 unregister_netdevice(dev); 855 err = 0; 856 break; 857 858 default: 859 err = -EINVAL; 860 } 861 862 done: 863 return err; 864 } 865 EXPORT_SYMBOL_GPL(ip_tunnel_ioctl); 866 867 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 868 { 869 struct ip_tunnel *tunnel = netdev_priv(dev); 870 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 871 872 if (new_mtu < 68 || 873 new_mtu > 0xFFF8 - dev->hard_header_len - t_hlen) 874 return -EINVAL; 875 dev->mtu = new_mtu; 876 return 0; 877 } 878 EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu); 879 880 static void ip_tunnel_dev_free(struct net_device *dev) 881 { 882 struct ip_tunnel *tunnel = netdev_priv(dev); 883 884 gro_cells_destroy(&tunnel->gro_cells); 885 free_percpu(tunnel->dst_cache); 886 free_percpu(dev->tstats); 887 free_netdev(dev); 888 } 889 890 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head) 891 { 892 struct ip_tunnel *tunnel = netdev_priv(dev); 893 struct ip_tunnel_net *itn; 894 895 itn = net_generic(tunnel->net, tunnel->ip_tnl_net_id); 896 897 if (itn->fb_tunnel_dev != dev) { 898 ip_tunnel_del(netdev_priv(dev)); 899 unregister_netdevice_queue(dev, head); 900 } 901 } 902 EXPORT_SYMBOL_GPL(ip_tunnel_dellink); 903 904 int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id, 905 struct rtnl_link_ops *ops, char *devname) 906 { 907 struct ip_tunnel_net *itn = net_generic(net, ip_tnl_net_id); 908 struct ip_tunnel_parm parms; 909 unsigned int i; 910 911 for (i = 0; i < IP_TNL_HASH_SIZE; i++) 912 INIT_HLIST_HEAD(&itn->tunnels[i]); 913 914 if (!ops) { 915 itn->fb_tunnel_dev = NULL; 916 return 0; 917 } 918 919 memset(&parms, 0, sizeof(parms)); 920 if (devname) 921 strlcpy(parms.name, devname, IFNAMSIZ); 922 923 rtnl_lock(); 924 itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, &parms); 925 /* FB netdevice is special: we have one, and only one per netns. 926 * Allowing to move it to another netns is clearly unsafe. 927 */ 928 if (!IS_ERR(itn->fb_tunnel_dev)) { 929 itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 930 ip_tunnel_add(itn, netdev_priv(itn->fb_tunnel_dev)); 931 } 932 rtnl_unlock(); 933 934 return PTR_ERR_OR_ZERO(itn->fb_tunnel_dev); 935 } 936 EXPORT_SYMBOL_GPL(ip_tunnel_init_net); 937 938 static void ip_tunnel_destroy(struct ip_tunnel_net *itn, struct list_head *head, 939 struct rtnl_link_ops *ops) 940 { 941 struct net *net = dev_net(itn->fb_tunnel_dev); 942 struct net_device *dev, *aux; 943 int h; 944 945 for_each_netdev_safe(net, dev, aux) 946 if (dev->rtnl_link_ops == ops) 947 unregister_netdevice_queue(dev, head); 948 949 for (h = 0; h < IP_TNL_HASH_SIZE; h++) { 950 struct ip_tunnel *t; 951 struct hlist_node *n; 952 struct hlist_head *thead = &itn->tunnels[h]; 953 954 hlist_for_each_entry_safe(t, n, thead, hash_node) 955 /* If dev is in the same netns, it has already 956 * been added to the list by the previous loop. 957 */ 958 if (!net_eq(dev_net(t->dev), net)) 959 unregister_netdevice_queue(t->dev, head); 960 } 961 } 962 963 void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops) 964 { 965 LIST_HEAD(list); 966 967 rtnl_lock(); 968 ip_tunnel_destroy(itn, &list, ops); 969 unregister_netdevice_many(&list); 970 rtnl_unlock(); 971 } 972 EXPORT_SYMBOL_GPL(ip_tunnel_delete_net); 973 974 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], 975 struct ip_tunnel_parm *p) 976 { 977 struct ip_tunnel *nt; 978 struct net *net = dev_net(dev); 979 struct ip_tunnel_net *itn; 980 int mtu; 981 int err; 982 983 nt = netdev_priv(dev); 984 itn = net_generic(net, nt->ip_tnl_net_id); 985 986 if (ip_tunnel_find(itn, p, dev->type)) 987 return -EEXIST; 988 989 nt->net = net; 990 nt->parms = *p; 991 err = register_netdevice(dev); 992 if (err) 993 goto out; 994 995 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS]) 996 eth_hw_addr_random(dev); 997 998 mtu = ip_tunnel_bind_dev(dev); 999 if (!tb[IFLA_MTU]) 1000 dev->mtu = mtu; 1001 1002 ip_tunnel_add(itn, nt); 1003 1004 out: 1005 return err; 1006 } 1007 EXPORT_SYMBOL_GPL(ip_tunnel_newlink); 1008 1009 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[], 1010 struct ip_tunnel_parm *p) 1011 { 1012 struct ip_tunnel *t; 1013 struct ip_tunnel *tunnel = netdev_priv(dev); 1014 struct net *net = tunnel->net; 1015 struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id); 1016 1017 if (dev == itn->fb_tunnel_dev) 1018 return -EINVAL; 1019 1020 t = ip_tunnel_find(itn, p, dev->type); 1021 1022 if (t) { 1023 if (t->dev != dev) 1024 return -EEXIST; 1025 } else { 1026 t = tunnel; 1027 1028 if (dev->type != ARPHRD_ETHER) { 1029 unsigned int nflags = 0; 1030 1031 if (ipv4_is_multicast(p->iph.daddr)) 1032 nflags = IFF_BROADCAST; 1033 else if (p->iph.daddr) 1034 nflags = IFF_POINTOPOINT; 1035 1036 if ((dev->flags ^ nflags) & 1037 (IFF_POINTOPOINT | IFF_BROADCAST)) 1038 return -EINVAL; 1039 } 1040 } 1041 1042 ip_tunnel_update(itn, t, dev, p, !tb[IFLA_MTU]); 1043 return 0; 1044 } 1045 EXPORT_SYMBOL_GPL(ip_tunnel_changelink); 1046 1047 int ip_tunnel_init(struct net_device *dev) 1048 { 1049 struct ip_tunnel *tunnel = netdev_priv(dev); 1050 struct iphdr *iph = &tunnel->parms.iph; 1051 int i, err; 1052 1053 dev->destructor = ip_tunnel_dev_free; 1054 dev->tstats = alloc_percpu(struct pcpu_sw_netstats); 1055 if (!dev->tstats) 1056 return -ENOMEM; 1057 1058 for_each_possible_cpu(i) { 1059 struct pcpu_sw_netstats *ipt_stats; 1060 ipt_stats = per_cpu_ptr(dev->tstats, i); 1061 u64_stats_init(&ipt_stats->syncp); 1062 } 1063 1064 tunnel->dst_cache = alloc_percpu(struct ip_tunnel_dst); 1065 if (!tunnel->dst_cache) { 1066 free_percpu(dev->tstats); 1067 return -ENOMEM; 1068 } 1069 1070 err = gro_cells_init(&tunnel->gro_cells, dev); 1071 if (err) { 1072 free_percpu(tunnel->dst_cache); 1073 free_percpu(dev->tstats); 1074 return err; 1075 } 1076 1077 tunnel->dev = dev; 1078 tunnel->net = dev_net(dev); 1079 strcpy(tunnel->parms.name, dev->name); 1080 iph->version = 4; 1081 iph->ihl = 5; 1082 1083 return 0; 1084 } 1085 EXPORT_SYMBOL_GPL(ip_tunnel_init); 1086 1087 void ip_tunnel_uninit(struct net_device *dev) 1088 { 1089 struct ip_tunnel *tunnel = netdev_priv(dev); 1090 struct net *net = tunnel->net; 1091 struct ip_tunnel_net *itn; 1092 1093 itn = net_generic(net, tunnel->ip_tnl_net_id); 1094 /* fb_tunnel_dev will be unregisted in net-exit call. */ 1095 if (itn->fb_tunnel_dev != dev) 1096 ip_tunnel_del(netdev_priv(dev)); 1097 1098 tunnel_dst_reset_all(tunnel); 1099 } 1100 EXPORT_SYMBOL_GPL(ip_tunnel_uninit); 1101 1102 /* Do least required initialization, rest of init is done in tunnel_init call */ 1103 void ip_tunnel_setup(struct net_device *dev, int net_id) 1104 { 1105 struct ip_tunnel *tunnel = netdev_priv(dev); 1106 tunnel->ip_tnl_net_id = net_id; 1107 } 1108 EXPORT_SYMBOL_GPL(ip_tunnel_setup); 1109 1110 MODULE_LICENSE("GPL"); 1111