1 /* 2 * vrf.c: device driver to encapsulate a VRF space 3 * 4 * Copyright (c) 2015 Cumulus Networks. All rights reserved. 5 * Copyright (c) 2015 Shrijeet Mukherjee <shm@cumulusnetworks.com> 6 * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com> 7 * 8 * Based on dummy, team and ipvlan drivers 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2 of the License, or 13 * (at your option) any later version. 14 */ 15 16 #include <linux/module.h> 17 #include <linux/kernel.h> 18 #include <linux/netdevice.h> 19 #include <linux/etherdevice.h> 20 #include <linux/ip.h> 21 #include <linux/init.h> 22 #include <linux/moduleparam.h> 23 #include <linux/netfilter.h> 24 #include <linux/rtnetlink.h> 25 #include <net/rtnetlink.h> 26 #include <linux/u64_stats_sync.h> 27 #include <linux/hashtable.h> 28 29 #include <linux/inetdevice.h> 30 #include <net/arp.h> 31 #include <net/ip.h> 32 #include <net/ip_fib.h> 33 #include <net/ip6_fib.h> 34 #include <net/ip6_route.h> 35 #include <net/route.h> 36 #include <net/addrconf.h> 37 #include <net/l3mdev.h> 38 #include <net/fib_rules.h> 39 40 #define DRV_NAME "vrf" 41 #define DRV_VERSION "1.0" 42 43 #define FIB_RULE_PREF 1000 /* default preference for FIB rules */ 44 static bool add_fib_rules = true; 45 46 struct net_vrf { 47 struct rtable __rcu *rth; 48 struct rtable __rcu *rth_local; 49 struct rt6_info __rcu *rt6; 50 struct rt6_info __rcu *rt6_local; 51 u32 tb_id; 52 }; 53 54 struct pcpu_dstats { 55 u64 tx_pkts; 56 u64 tx_bytes; 57 u64 tx_drps; 58 u64 rx_pkts; 59 u64 rx_bytes; 60 u64 rx_drps; 61 struct u64_stats_sync syncp; 62 }; 63 64 static void vrf_rx_stats(struct net_device *dev, int len) 65 { 66 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); 67 68 u64_stats_update_begin(&dstats->syncp); 69 dstats->rx_pkts++; 70 dstats->rx_bytes += len; 71 u64_stats_update_end(&dstats->syncp); 72 } 73 74 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb) 75 { 76 vrf_dev->stats.tx_errors++; 77 kfree_skb(skb); 78 } 79 80 static void vrf_get_stats64(struct net_device *dev, 81 struct rtnl_link_stats64 *stats) 82 { 83 int i; 84 85 for_each_possible_cpu(i) { 86 const struct pcpu_dstats *dstats; 87 u64 tbytes, tpkts, tdrops, rbytes, rpkts; 88 unsigned int start; 89 90 dstats = per_cpu_ptr(dev->dstats, i); 91 do { 92 start = u64_stats_fetch_begin_irq(&dstats->syncp); 93 tbytes = dstats->tx_bytes; 94 tpkts = dstats->tx_pkts; 95 tdrops = dstats->tx_drps; 96 rbytes = dstats->rx_bytes; 97 rpkts = dstats->rx_pkts; 98 } while (u64_stats_fetch_retry_irq(&dstats->syncp, start)); 99 stats->tx_bytes += tbytes; 100 stats->tx_packets += tpkts; 101 stats->tx_dropped += tdrops; 102 stats->rx_bytes += rbytes; 103 stats->rx_packets += rpkts; 104 } 105 } 106 107 /* Local traffic destined to local address. Reinsert the packet to rx 108 * path, similar to loopback handling. 109 */ 110 static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev, 111 struct dst_entry *dst) 112 { 113 int len = skb->len; 114 115 skb_orphan(skb); 116 117 skb_dst_set(skb, dst); 118 skb_dst_force(skb); 119 120 /* set pkt_type to avoid skb hitting packet taps twice - 121 * once on Tx and again in Rx processing 122 */ 123 skb->pkt_type = PACKET_LOOPBACK; 124 125 skb->protocol = eth_type_trans(skb, dev); 126 127 if (likely(netif_rx(skb) == NET_RX_SUCCESS)) 128 vrf_rx_stats(dev, len); 129 else 130 this_cpu_inc(dev->dstats->rx_drps); 131 132 return NETDEV_TX_OK; 133 } 134 135 #if IS_ENABLED(CONFIG_IPV6) 136 static int vrf_ip6_local_out(struct net *net, struct sock *sk, 137 struct sk_buff *skb) 138 { 139 int err; 140 141 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, 142 sk, skb, NULL, skb_dst(skb)->dev, dst_output); 143 144 if (likely(err == 1)) 145 err = dst_output(net, sk, skb); 146 147 return err; 148 } 149 150 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, 151 struct net_device *dev) 152 { 153 const struct ipv6hdr *iph = ipv6_hdr(skb); 154 struct net *net = dev_net(skb->dev); 155 struct flowi6 fl6 = { 156 /* needed to match OIF rule */ 157 .flowi6_oif = dev->ifindex, 158 .flowi6_iif = LOOPBACK_IFINDEX, 159 .daddr = iph->daddr, 160 .saddr = iph->saddr, 161 .flowlabel = ip6_flowinfo(iph), 162 .flowi6_mark = skb->mark, 163 .flowi6_proto = iph->nexthdr, 164 .flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF, 165 }; 166 int ret = NET_XMIT_DROP; 167 struct dst_entry *dst; 168 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst; 169 170 dst = ip6_route_output(net, NULL, &fl6); 171 if (dst == dst_null) 172 goto err; 173 174 skb_dst_drop(skb); 175 176 /* if dst.dev is loopback or the VRF device again this is locally 177 * originated traffic destined to a local address. Short circuit 178 * to Rx path using our local dst 179 */ 180 if (dst->dev == net->loopback_dev || dst->dev == dev) { 181 struct net_vrf *vrf = netdev_priv(dev); 182 struct rt6_info *rt6_local; 183 184 /* release looked up dst and use cached local dst */ 185 dst_release(dst); 186 187 rcu_read_lock(); 188 189 rt6_local = rcu_dereference(vrf->rt6_local); 190 if (unlikely(!rt6_local)) { 191 rcu_read_unlock(); 192 goto err; 193 } 194 195 /* Ordering issue: cached local dst is created on newlink 196 * before the IPv6 initialization. Using the local dst 197 * requires rt6i_idev to be set so make sure it is. 198 */ 199 if (unlikely(!rt6_local->rt6i_idev)) { 200 rt6_local->rt6i_idev = in6_dev_get(dev); 201 if (!rt6_local->rt6i_idev) { 202 rcu_read_unlock(); 203 goto err; 204 } 205 } 206 207 dst = &rt6_local->dst; 208 dst_hold(dst); 209 210 rcu_read_unlock(); 211 212 return vrf_local_xmit(skb, dev, &rt6_local->dst); 213 } 214 215 skb_dst_set(skb, dst); 216 217 /* strip the ethernet header added for pass through VRF device */ 218 __skb_pull(skb, skb_network_offset(skb)); 219 220 ret = vrf_ip6_local_out(net, skb->sk, skb); 221 if (unlikely(net_xmit_eval(ret))) 222 dev->stats.tx_errors++; 223 else 224 ret = NET_XMIT_SUCCESS; 225 226 return ret; 227 err: 228 vrf_tx_error(dev, skb); 229 return NET_XMIT_DROP; 230 } 231 #else 232 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, 233 struct net_device *dev) 234 { 235 vrf_tx_error(dev, skb); 236 return NET_XMIT_DROP; 237 } 238 #endif 239 240 /* based on ip_local_out; can't use it b/c the dst is switched pointing to us */ 241 static int vrf_ip_local_out(struct net *net, struct sock *sk, 242 struct sk_buff *skb) 243 { 244 int err; 245 246 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk, 247 skb, NULL, skb_dst(skb)->dev, dst_output); 248 if (likely(err == 1)) 249 err = dst_output(net, sk, skb); 250 251 return err; 252 } 253 254 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb, 255 struct net_device *vrf_dev) 256 { 257 struct iphdr *ip4h = ip_hdr(skb); 258 int ret = NET_XMIT_DROP; 259 struct flowi4 fl4 = { 260 /* needed to match OIF rule */ 261 .flowi4_oif = vrf_dev->ifindex, 262 .flowi4_iif = LOOPBACK_IFINDEX, 263 .flowi4_tos = RT_TOS(ip4h->tos), 264 .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF, 265 .flowi4_proto = ip4h->protocol, 266 .daddr = ip4h->daddr, 267 .saddr = ip4h->saddr, 268 }; 269 struct net *net = dev_net(vrf_dev); 270 struct rtable *rt; 271 272 rt = ip_route_output_flow(net, &fl4, NULL); 273 if (IS_ERR(rt)) 274 goto err; 275 276 skb_dst_drop(skb); 277 278 /* if dst.dev is loopback or the VRF device again this is locally 279 * originated traffic destined to a local address. Short circuit 280 * to Rx path using our local dst 281 */ 282 if (rt->dst.dev == net->loopback_dev || rt->dst.dev == vrf_dev) { 283 struct net_vrf *vrf = netdev_priv(vrf_dev); 284 struct rtable *rth_local; 285 struct dst_entry *dst = NULL; 286 287 ip_rt_put(rt); 288 289 rcu_read_lock(); 290 291 rth_local = rcu_dereference(vrf->rth_local); 292 if (likely(rth_local)) { 293 dst = &rth_local->dst; 294 dst_hold(dst); 295 } 296 297 rcu_read_unlock(); 298 299 if (unlikely(!dst)) 300 goto err; 301 302 return vrf_local_xmit(skb, vrf_dev, dst); 303 } 304 305 skb_dst_set(skb, &rt->dst); 306 307 /* strip the ethernet header added for pass through VRF device */ 308 __skb_pull(skb, skb_network_offset(skb)); 309 310 if (!ip4h->saddr) { 311 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0, 312 RT_SCOPE_LINK); 313 } 314 315 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb); 316 if (unlikely(net_xmit_eval(ret))) 317 vrf_dev->stats.tx_errors++; 318 else 319 ret = NET_XMIT_SUCCESS; 320 321 out: 322 return ret; 323 err: 324 vrf_tx_error(vrf_dev, skb); 325 goto out; 326 } 327 328 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev) 329 { 330 switch (skb->protocol) { 331 case htons(ETH_P_IP): 332 return vrf_process_v4_outbound(skb, dev); 333 case htons(ETH_P_IPV6): 334 return vrf_process_v6_outbound(skb, dev); 335 default: 336 vrf_tx_error(dev, skb); 337 return NET_XMIT_DROP; 338 } 339 } 340 341 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev) 342 { 343 int len = skb->len; 344 netdev_tx_t ret = is_ip_tx_frame(skb, dev); 345 346 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) { 347 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); 348 349 u64_stats_update_begin(&dstats->syncp); 350 dstats->tx_pkts++; 351 dstats->tx_bytes += len; 352 u64_stats_update_end(&dstats->syncp); 353 } else { 354 this_cpu_inc(dev->dstats->tx_drps); 355 } 356 357 return ret; 358 } 359 360 #if IS_ENABLED(CONFIG_IPV6) 361 /* modelled after ip6_finish_output2 */ 362 static int vrf_finish_output6(struct net *net, struct sock *sk, 363 struct sk_buff *skb) 364 { 365 struct dst_entry *dst = skb_dst(skb); 366 struct net_device *dev = dst->dev; 367 struct neighbour *neigh; 368 struct in6_addr *nexthop; 369 int ret; 370 371 nf_reset(skb); 372 373 skb->protocol = htons(ETH_P_IPV6); 374 skb->dev = dev; 375 376 rcu_read_lock_bh(); 377 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr); 378 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop); 379 if (unlikely(!neigh)) 380 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false); 381 if (!IS_ERR(neigh)) { 382 sock_confirm_neigh(skb, neigh); 383 ret = neigh_output(neigh, skb); 384 rcu_read_unlock_bh(); 385 return ret; 386 } 387 rcu_read_unlock_bh(); 388 389 IP6_INC_STATS(dev_net(dst->dev), 390 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 391 kfree_skb(skb); 392 return -EINVAL; 393 } 394 395 /* modelled after ip6_output */ 396 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb) 397 { 398 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, 399 net, sk, skb, NULL, skb_dst(skb)->dev, 400 vrf_finish_output6, 401 !(IP6CB(skb)->flags & IP6SKB_REROUTED)); 402 } 403 404 /* set dst on skb to send packet to us via dev_xmit path. Allows 405 * packet to go through device based features such as qdisc, netfilter 406 * hooks and packet sockets with skb->dev set to vrf device. 407 */ 408 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev, 409 struct sock *sk, 410 struct sk_buff *skb) 411 { 412 struct net_vrf *vrf = netdev_priv(vrf_dev); 413 struct dst_entry *dst = NULL; 414 struct rt6_info *rt6; 415 416 /* don't divert link scope packets */ 417 if (rt6_need_strict(&ipv6_hdr(skb)->daddr)) 418 return skb; 419 420 rcu_read_lock(); 421 422 rt6 = rcu_dereference(vrf->rt6); 423 if (likely(rt6)) { 424 dst = &rt6->dst; 425 dst_hold(dst); 426 } 427 428 rcu_read_unlock(); 429 430 if (unlikely(!dst)) { 431 vrf_tx_error(vrf_dev, skb); 432 return NULL; 433 } 434 435 skb_dst_drop(skb); 436 skb_dst_set(skb, dst); 437 438 return skb; 439 } 440 441 /* holding rtnl */ 442 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) 443 { 444 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6); 445 struct rt6_info *rt6_local = rtnl_dereference(vrf->rt6_local); 446 struct net *net = dev_net(dev); 447 struct dst_entry *dst; 448 449 RCU_INIT_POINTER(vrf->rt6, NULL); 450 RCU_INIT_POINTER(vrf->rt6_local, NULL); 451 synchronize_rcu(); 452 453 /* move dev in dst's to loopback so this VRF device can be deleted 454 * - based on dst_ifdown 455 */ 456 if (rt6) { 457 dst = &rt6->dst; 458 dev_put(dst->dev); 459 dst->dev = net->loopback_dev; 460 dev_hold(dst->dev); 461 dst_release(dst); 462 } 463 464 if (rt6_local) { 465 if (rt6_local->rt6i_idev) { 466 in6_dev_put(rt6_local->rt6i_idev); 467 rt6_local->rt6i_idev = NULL; 468 } 469 470 dst = &rt6_local->dst; 471 dev_put(dst->dev); 472 dst->dev = net->loopback_dev; 473 dev_hold(dst->dev); 474 dst_release(dst); 475 } 476 } 477 478 static int vrf_rt6_create(struct net_device *dev) 479 { 480 int flags = DST_HOST | DST_NOPOLICY | DST_NOXFRM | DST_NOCACHE; 481 struct net_vrf *vrf = netdev_priv(dev); 482 struct net *net = dev_net(dev); 483 struct fib6_table *rt6i_table; 484 struct rt6_info *rt6, *rt6_local; 485 int rc = -ENOMEM; 486 487 /* IPv6 can be CONFIG enabled and then disabled runtime */ 488 if (!ipv6_mod_enabled()) 489 return 0; 490 491 rt6i_table = fib6_new_table(net, vrf->tb_id); 492 if (!rt6i_table) 493 goto out; 494 495 /* create a dst for routing packets out a VRF device */ 496 rt6 = ip6_dst_alloc(net, dev, flags); 497 if (!rt6) 498 goto out; 499 500 dst_hold(&rt6->dst); 501 502 rt6->rt6i_table = rt6i_table; 503 rt6->dst.output = vrf_output6; 504 505 /* create a dst for local routing - packets sent locally 506 * to local address via the VRF device as a loopback 507 */ 508 rt6_local = ip6_dst_alloc(net, dev, flags); 509 if (!rt6_local) { 510 dst_release(&rt6->dst); 511 goto out; 512 } 513 514 dst_hold(&rt6_local->dst); 515 516 rt6_local->rt6i_idev = in6_dev_get(dev); 517 rt6_local->rt6i_flags = RTF_UP | RTF_NONEXTHOP | RTF_LOCAL; 518 rt6_local->rt6i_table = rt6i_table; 519 rt6_local->dst.input = ip6_input; 520 521 rcu_assign_pointer(vrf->rt6, rt6); 522 rcu_assign_pointer(vrf->rt6_local, rt6_local); 523 524 rc = 0; 525 out: 526 return rc; 527 } 528 #else 529 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev, 530 struct sock *sk, 531 struct sk_buff *skb) 532 { 533 return skb; 534 } 535 536 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) 537 { 538 } 539 540 static int vrf_rt6_create(struct net_device *dev) 541 { 542 return 0; 543 } 544 #endif 545 546 /* modelled after ip_finish_output2 */ 547 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 548 { 549 struct dst_entry *dst = skb_dst(skb); 550 struct rtable *rt = (struct rtable *)dst; 551 struct net_device *dev = dst->dev; 552 unsigned int hh_len = LL_RESERVED_SPACE(dev); 553 struct neighbour *neigh; 554 u32 nexthop; 555 int ret = -EINVAL; 556 557 nf_reset(skb); 558 559 /* Be paranoid, rather than too clever. */ 560 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { 561 struct sk_buff *skb2; 562 563 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); 564 if (!skb2) { 565 ret = -ENOMEM; 566 goto err; 567 } 568 if (skb->sk) 569 skb_set_owner_w(skb2, skb->sk); 570 571 consume_skb(skb); 572 skb = skb2; 573 } 574 575 rcu_read_lock_bh(); 576 577 nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr); 578 neigh = __ipv4_neigh_lookup_noref(dev, nexthop); 579 if (unlikely(!neigh)) 580 neigh = __neigh_create(&arp_tbl, &nexthop, dev, false); 581 if (!IS_ERR(neigh)) { 582 sock_confirm_neigh(skb, neigh); 583 ret = neigh_output(neigh, skb); 584 } 585 586 rcu_read_unlock_bh(); 587 err: 588 if (unlikely(ret < 0)) 589 vrf_tx_error(skb->dev, skb); 590 return ret; 591 } 592 593 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb) 594 { 595 struct net_device *dev = skb_dst(skb)->dev; 596 597 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len); 598 599 skb->dev = dev; 600 skb->protocol = htons(ETH_P_IP); 601 602 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, 603 net, sk, skb, NULL, dev, 604 vrf_finish_output, 605 !(IPCB(skb)->flags & IPSKB_REROUTED)); 606 } 607 608 /* set dst on skb to send packet to us via dev_xmit path. Allows 609 * packet to go through device based features such as qdisc, netfilter 610 * hooks and packet sockets with skb->dev set to vrf device. 611 */ 612 static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev, 613 struct sock *sk, 614 struct sk_buff *skb) 615 { 616 struct net_vrf *vrf = netdev_priv(vrf_dev); 617 struct dst_entry *dst = NULL; 618 struct rtable *rth; 619 620 /* don't divert multicast */ 621 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) 622 return skb; 623 624 rcu_read_lock(); 625 626 rth = rcu_dereference(vrf->rth); 627 if (likely(rth)) { 628 dst = &rth->dst; 629 dst_hold(dst); 630 } 631 632 rcu_read_unlock(); 633 634 if (unlikely(!dst)) { 635 vrf_tx_error(vrf_dev, skb); 636 return NULL; 637 } 638 639 skb_dst_drop(skb); 640 skb_dst_set(skb, dst); 641 642 return skb; 643 } 644 645 /* called with rcu lock held */ 646 static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev, 647 struct sock *sk, 648 struct sk_buff *skb, 649 u16 proto) 650 { 651 switch (proto) { 652 case AF_INET: 653 return vrf_ip_out(vrf_dev, sk, skb); 654 case AF_INET6: 655 return vrf_ip6_out(vrf_dev, sk, skb); 656 } 657 658 return skb; 659 } 660 661 /* holding rtnl */ 662 static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf) 663 { 664 struct rtable *rth = rtnl_dereference(vrf->rth); 665 struct rtable *rth_local = rtnl_dereference(vrf->rth_local); 666 struct net *net = dev_net(dev); 667 struct dst_entry *dst; 668 669 RCU_INIT_POINTER(vrf->rth, NULL); 670 RCU_INIT_POINTER(vrf->rth_local, NULL); 671 synchronize_rcu(); 672 673 /* move dev in dst's to loopback so this VRF device can be deleted 674 * - based on dst_ifdown 675 */ 676 if (rth) { 677 dst = &rth->dst; 678 dev_put(dst->dev); 679 dst->dev = net->loopback_dev; 680 dev_hold(dst->dev); 681 dst_release(dst); 682 } 683 684 if (rth_local) { 685 dst = &rth_local->dst; 686 dev_put(dst->dev); 687 dst->dev = net->loopback_dev; 688 dev_hold(dst->dev); 689 dst_release(dst); 690 } 691 } 692 693 static int vrf_rtable_create(struct net_device *dev) 694 { 695 struct net_vrf *vrf = netdev_priv(dev); 696 struct rtable *rth, *rth_local; 697 698 if (!fib_new_table(dev_net(dev), vrf->tb_id)) 699 return -ENOMEM; 700 701 /* create a dst for routing packets out through a VRF device */ 702 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1, 0); 703 if (!rth) 704 return -ENOMEM; 705 706 /* create a dst for local ingress routing - packets sent locally 707 * to local address via the VRF device as a loopback 708 */ 709 rth_local = rt_dst_alloc(dev, RTCF_LOCAL, RTN_LOCAL, 1, 1, 0); 710 if (!rth_local) { 711 dst_release(&rth->dst); 712 return -ENOMEM; 713 } 714 715 rth->dst.output = vrf_output; 716 rth->rt_table_id = vrf->tb_id; 717 718 rth_local->rt_table_id = vrf->tb_id; 719 720 rcu_assign_pointer(vrf->rth, rth); 721 rcu_assign_pointer(vrf->rth_local, rth_local); 722 723 return 0; 724 } 725 726 /**************************** device handling ********************/ 727 728 /* cycle interface to flush neighbor cache and move routes across tables */ 729 static void cycle_netdev(struct net_device *dev) 730 { 731 unsigned int flags = dev->flags; 732 int ret; 733 734 if (!netif_running(dev)) 735 return; 736 737 ret = dev_change_flags(dev, flags & ~IFF_UP); 738 if (ret >= 0) 739 ret = dev_change_flags(dev, flags); 740 741 if (ret < 0) { 742 netdev_err(dev, 743 "Failed to cycle device %s; route tables might be wrong!\n", 744 dev->name); 745 } 746 } 747 748 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev) 749 { 750 int ret; 751 752 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL); 753 if (ret < 0) 754 return ret; 755 756 port_dev->priv_flags |= IFF_L3MDEV_SLAVE; 757 cycle_netdev(port_dev); 758 759 return 0; 760 } 761 762 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev) 763 { 764 if (netif_is_l3_master(port_dev) || netif_is_l3_slave(port_dev)) 765 return -EINVAL; 766 767 return do_vrf_add_slave(dev, port_dev); 768 } 769 770 /* inverse of do_vrf_add_slave */ 771 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev) 772 { 773 netdev_upper_dev_unlink(port_dev, dev); 774 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE; 775 776 cycle_netdev(port_dev); 777 778 return 0; 779 } 780 781 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev) 782 { 783 return do_vrf_del_slave(dev, port_dev); 784 } 785 786 static void vrf_dev_uninit(struct net_device *dev) 787 { 788 struct net_vrf *vrf = netdev_priv(dev); 789 struct net_device *port_dev; 790 struct list_head *iter; 791 792 vrf_rtable_release(dev, vrf); 793 vrf_rt6_release(dev, vrf); 794 795 netdev_for_each_lower_dev(dev, port_dev, iter) 796 vrf_del_slave(dev, port_dev); 797 798 free_percpu(dev->dstats); 799 dev->dstats = NULL; 800 } 801 802 static int vrf_dev_init(struct net_device *dev) 803 { 804 struct net_vrf *vrf = netdev_priv(dev); 805 806 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats); 807 if (!dev->dstats) 808 goto out_nomem; 809 810 /* create the default dst which points back to us */ 811 if (vrf_rtable_create(dev) != 0) 812 goto out_stats; 813 814 if (vrf_rt6_create(dev) != 0) 815 goto out_rth; 816 817 dev->flags = IFF_MASTER | IFF_NOARP; 818 819 /* MTU is irrelevant for VRF device; set to 64k similar to lo */ 820 dev->mtu = 64 * 1024; 821 822 /* similarly, oper state is irrelevant; set to up to avoid confusion */ 823 dev->operstate = IF_OPER_UP; 824 netdev_lockdep_set_classes(dev); 825 return 0; 826 827 out_rth: 828 vrf_rtable_release(dev, vrf); 829 out_stats: 830 free_percpu(dev->dstats); 831 dev->dstats = NULL; 832 out_nomem: 833 return -ENOMEM; 834 } 835 836 static const struct net_device_ops vrf_netdev_ops = { 837 .ndo_init = vrf_dev_init, 838 .ndo_uninit = vrf_dev_uninit, 839 .ndo_start_xmit = vrf_xmit, 840 .ndo_get_stats64 = vrf_get_stats64, 841 .ndo_add_slave = vrf_add_slave, 842 .ndo_del_slave = vrf_del_slave, 843 }; 844 845 static u32 vrf_fib_table(const struct net_device *dev) 846 { 847 struct net_vrf *vrf = netdev_priv(dev); 848 849 return vrf->tb_id; 850 } 851 852 static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) 853 { 854 return 0; 855 } 856 857 static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook, 858 struct sk_buff *skb, 859 struct net_device *dev) 860 { 861 struct net *net = dev_net(dev); 862 863 if (NF_HOOK(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) < 0) 864 skb = NULL; /* kfree_skb(skb) handled by nf code */ 865 866 return skb; 867 } 868 869 #if IS_ENABLED(CONFIG_IPV6) 870 /* neighbor handling is done with actual device; do not want 871 * to flip skb->dev for those ndisc packets. This really fails 872 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is 873 * a start. 874 */ 875 static bool ipv6_ndisc_frame(const struct sk_buff *skb) 876 { 877 const struct ipv6hdr *iph = ipv6_hdr(skb); 878 bool rc = false; 879 880 if (iph->nexthdr == NEXTHDR_ICMP) { 881 const struct icmp6hdr *icmph; 882 struct icmp6hdr _icmph; 883 884 icmph = skb_header_pointer(skb, sizeof(*iph), 885 sizeof(_icmph), &_icmph); 886 if (!icmph) 887 goto out; 888 889 switch (icmph->icmp6_type) { 890 case NDISC_ROUTER_SOLICITATION: 891 case NDISC_ROUTER_ADVERTISEMENT: 892 case NDISC_NEIGHBOUR_SOLICITATION: 893 case NDISC_NEIGHBOUR_ADVERTISEMENT: 894 case NDISC_REDIRECT: 895 rc = true; 896 break; 897 } 898 } 899 900 out: 901 return rc; 902 } 903 904 static struct rt6_info *vrf_ip6_route_lookup(struct net *net, 905 const struct net_device *dev, 906 struct flowi6 *fl6, 907 int ifindex, 908 int flags) 909 { 910 struct net_vrf *vrf = netdev_priv(dev); 911 struct fib6_table *table = NULL; 912 struct rt6_info *rt6; 913 914 rcu_read_lock(); 915 916 /* fib6_table does not have a refcnt and can not be freed */ 917 rt6 = rcu_dereference(vrf->rt6); 918 if (likely(rt6)) 919 table = rt6->rt6i_table; 920 921 rcu_read_unlock(); 922 923 if (!table) 924 return NULL; 925 926 return ip6_pol_route(net, table, ifindex, fl6, flags); 927 } 928 929 static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev, 930 int ifindex) 931 { 932 const struct ipv6hdr *iph = ipv6_hdr(skb); 933 struct flowi6 fl6 = { 934 .daddr = iph->daddr, 935 .saddr = iph->saddr, 936 .flowlabel = ip6_flowinfo(iph), 937 .flowi6_mark = skb->mark, 938 .flowi6_proto = iph->nexthdr, 939 .flowi6_iif = ifindex, 940 }; 941 struct net *net = dev_net(vrf_dev); 942 struct rt6_info *rt6; 943 944 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, 945 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE); 946 if (unlikely(!rt6)) 947 return; 948 949 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst)) 950 return; 951 952 skb_dst_set(skb, &rt6->dst); 953 } 954 955 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, 956 struct sk_buff *skb) 957 { 958 int orig_iif = skb->skb_iif; 959 bool need_strict; 960 961 /* loopback traffic; do not push through packet taps again. 962 * Reset pkt_type for upper layers to process skb 963 */ 964 if (skb->pkt_type == PACKET_LOOPBACK) { 965 skb->dev = vrf_dev; 966 skb->skb_iif = vrf_dev->ifindex; 967 IP6CB(skb)->flags |= IP6SKB_L3SLAVE; 968 skb->pkt_type = PACKET_HOST; 969 goto out; 970 } 971 972 /* if packet is NDISC or addressed to multicast or link-local 973 * then keep the ingress interface 974 */ 975 need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr); 976 if (!ipv6_ndisc_frame(skb) && !need_strict) { 977 vrf_rx_stats(vrf_dev, skb->len); 978 skb->dev = vrf_dev; 979 skb->skb_iif = vrf_dev->ifindex; 980 981 skb_push(skb, skb->mac_len); 982 dev_queue_xmit_nit(skb, vrf_dev); 983 skb_pull(skb, skb->mac_len); 984 985 IP6CB(skb)->flags |= IP6SKB_L3SLAVE; 986 } 987 988 if (need_strict) 989 vrf_ip6_input_dst(skb, vrf_dev, orig_iif); 990 991 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev); 992 out: 993 return skb; 994 } 995 996 #else 997 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, 998 struct sk_buff *skb) 999 { 1000 return skb; 1001 } 1002 #endif 1003 1004 static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev, 1005 struct sk_buff *skb) 1006 { 1007 skb->dev = vrf_dev; 1008 skb->skb_iif = vrf_dev->ifindex; 1009 IPCB(skb)->flags |= IPSKB_L3SLAVE; 1010 1011 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) 1012 goto out; 1013 1014 /* loopback traffic; do not push through packet taps again. 1015 * Reset pkt_type for upper layers to process skb 1016 */ 1017 if (skb->pkt_type == PACKET_LOOPBACK) { 1018 skb->pkt_type = PACKET_HOST; 1019 goto out; 1020 } 1021 1022 vrf_rx_stats(vrf_dev, skb->len); 1023 1024 skb_push(skb, skb->mac_len); 1025 dev_queue_xmit_nit(skb, vrf_dev); 1026 skb_pull(skb, skb->mac_len); 1027 1028 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev); 1029 out: 1030 return skb; 1031 } 1032 1033 /* called with rcu lock held */ 1034 static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev, 1035 struct sk_buff *skb, 1036 u16 proto) 1037 { 1038 switch (proto) { 1039 case AF_INET: 1040 return vrf_ip_rcv(vrf_dev, skb); 1041 case AF_INET6: 1042 return vrf_ip6_rcv(vrf_dev, skb); 1043 } 1044 1045 return skb; 1046 } 1047 1048 #if IS_ENABLED(CONFIG_IPV6) 1049 /* send to link-local or multicast address via interface enslaved to 1050 * VRF device. Force lookup to VRF table without changing flow struct 1051 */ 1052 static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev, 1053 struct flowi6 *fl6) 1054 { 1055 struct net *net = dev_net(dev); 1056 int flags = RT6_LOOKUP_F_IFACE; 1057 struct dst_entry *dst = NULL; 1058 struct rt6_info *rt; 1059 1060 /* VRF device does not have a link-local address and 1061 * sending packets to link-local or mcast addresses over 1062 * a VRF device does not make sense 1063 */ 1064 if (fl6->flowi6_oif == dev->ifindex) { 1065 dst = &net->ipv6.ip6_null_entry->dst; 1066 dst_hold(dst); 1067 return dst; 1068 } 1069 1070 if (!ipv6_addr_any(&fl6->saddr)) 1071 flags |= RT6_LOOKUP_F_HAS_SADDR; 1072 1073 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, flags); 1074 if (rt) 1075 dst = &rt->dst; 1076 1077 return dst; 1078 } 1079 #endif 1080 1081 static const struct l3mdev_ops vrf_l3mdev_ops = { 1082 .l3mdev_fib_table = vrf_fib_table, 1083 .l3mdev_l3_rcv = vrf_l3_rcv, 1084 .l3mdev_l3_out = vrf_l3_out, 1085 #if IS_ENABLED(CONFIG_IPV6) 1086 .l3mdev_link_scope_lookup = vrf_link_scope_lookup, 1087 #endif 1088 }; 1089 1090 static void vrf_get_drvinfo(struct net_device *dev, 1091 struct ethtool_drvinfo *info) 1092 { 1093 strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); 1094 strlcpy(info->version, DRV_VERSION, sizeof(info->version)); 1095 } 1096 1097 static const struct ethtool_ops vrf_ethtool_ops = { 1098 .get_drvinfo = vrf_get_drvinfo, 1099 }; 1100 1101 static inline size_t vrf_fib_rule_nl_size(void) 1102 { 1103 size_t sz; 1104 1105 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)); 1106 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */ 1107 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */ 1108 1109 return sz; 1110 } 1111 1112 static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it) 1113 { 1114 struct fib_rule_hdr *frh; 1115 struct nlmsghdr *nlh; 1116 struct sk_buff *skb; 1117 int err; 1118 1119 if (family == AF_INET6 && !ipv6_mod_enabled()) 1120 return 0; 1121 1122 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL); 1123 if (!skb) 1124 return -ENOMEM; 1125 1126 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0); 1127 if (!nlh) 1128 goto nla_put_failure; 1129 1130 /* rule only needs to appear once */ 1131 nlh->nlmsg_flags |= NLM_F_EXCL; 1132 1133 frh = nlmsg_data(nlh); 1134 memset(frh, 0, sizeof(*frh)); 1135 frh->family = family; 1136 frh->action = FR_ACT_TO_TBL; 1137 1138 if (nla_put_u32(skb, FRA_L3MDEV, 1)) 1139 goto nla_put_failure; 1140 1141 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF)) 1142 goto nla_put_failure; 1143 1144 nlmsg_end(skb, nlh); 1145 1146 /* fib_nl_{new,del}rule handling looks for net from skb->sk */ 1147 skb->sk = dev_net(dev)->rtnl; 1148 if (add_it) { 1149 err = fib_nl_newrule(skb, nlh); 1150 if (err == -EEXIST) 1151 err = 0; 1152 } else { 1153 err = fib_nl_delrule(skb, nlh); 1154 if (err == -ENOENT) 1155 err = 0; 1156 } 1157 nlmsg_free(skb); 1158 1159 return err; 1160 1161 nla_put_failure: 1162 nlmsg_free(skb); 1163 1164 return -EMSGSIZE; 1165 } 1166 1167 static int vrf_add_fib_rules(const struct net_device *dev) 1168 { 1169 int err; 1170 1171 err = vrf_fib_rule(dev, AF_INET, true); 1172 if (err < 0) 1173 goto out_err; 1174 1175 err = vrf_fib_rule(dev, AF_INET6, true); 1176 if (err < 0) 1177 goto ipv6_err; 1178 1179 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES) 1180 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true); 1181 if (err < 0) 1182 goto ipmr_err; 1183 #endif 1184 1185 return 0; 1186 1187 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES) 1188 ipmr_err: 1189 vrf_fib_rule(dev, AF_INET6, false); 1190 #endif 1191 1192 ipv6_err: 1193 vrf_fib_rule(dev, AF_INET, false); 1194 1195 out_err: 1196 netdev_err(dev, "Failed to add FIB rules.\n"); 1197 return err; 1198 } 1199 1200 static void vrf_setup(struct net_device *dev) 1201 { 1202 ether_setup(dev); 1203 1204 /* Initialize the device structure. */ 1205 dev->netdev_ops = &vrf_netdev_ops; 1206 dev->l3mdev_ops = &vrf_l3mdev_ops; 1207 dev->ethtool_ops = &vrf_ethtool_ops; 1208 dev->destructor = free_netdev; 1209 1210 /* Fill in device structure with ethernet-generic values. */ 1211 eth_hw_addr_random(dev); 1212 1213 /* don't acquire vrf device's netif_tx_lock when transmitting */ 1214 dev->features |= NETIF_F_LLTX; 1215 1216 /* don't allow vrf devices to change network namespaces. */ 1217 dev->features |= NETIF_F_NETNS_LOCAL; 1218 1219 /* does not make sense for a VLAN to be added to a vrf device */ 1220 dev->features |= NETIF_F_VLAN_CHALLENGED; 1221 1222 /* enable offload features */ 1223 dev->features |= NETIF_F_GSO_SOFTWARE; 1224 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM; 1225 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA; 1226 1227 dev->hw_features = dev->features; 1228 dev->hw_enc_features = dev->features; 1229 1230 /* default to no qdisc; user can add if desired */ 1231 dev->priv_flags |= IFF_NO_QUEUE; 1232 } 1233 1234 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[]) 1235 { 1236 if (tb[IFLA_ADDRESS]) { 1237 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1238 return -EINVAL; 1239 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1240 return -EADDRNOTAVAIL; 1241 } 1242 return 0; 1243 } 1244 1245 static void vrf_dellink(struct net_device *dev, struct list_head *head) 1246 { 1247 unregister_netdevice_queue(dev, head); 1248 } 1249 1250 static int vrf_newlink(struct net *src_net, struct net_device *dev, 1251 struct nlattr *tb[], struct nlattr *data[]) 1252 { 1253 struct net_vrf *vrf = netdev_priv(dev); 1254 int err; 1255 1256 if (!data || !data[IFLA_VRF_TABLE]) 1257 return -EINVAL; 1258 1259 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]); 1260 if (vrf->tb_id == RT_TABLE_UNSPEC) 1261 return -EINVAL; 1262 1263 dev->priv_flags |= IFF_L3MDEV_MASTER; 1264 1265 err = register_netdevice(dev); 1266 if (err) 1267 goto out; 1268 1269 if (add_fib_rules) { 1270 err = vrf_add_fib_rules(dev); 1271 if (err) { 1272 unregister_netdevice(dev); 1273 goto out; 1274 } 1275 add_fib_rules = false; 1276 } 1277 1278 out: 1279 return err; 1280 } 1281 1282 static size_t vrf_nl_getsize(const struct net_device *dev) 1283 { 1284 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */ 1285 } 1286 1287 static int vrf_fillinfo(struct sk_buff *skb, 1288 const struct net_device *dev) 1289 { 1290 struct net_vrf *vrf = netdev_priv(dev); 1291 1292 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id); 1293 } 1294 1295 static size_t vrf_get_slave_size(const struct net_device *bond_dev, 1296 const struct net_device *slave_dev) 1297 { 1298 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */ 1299 } 1300 1301 static int vrf_fill_slave_info(struct sk_buff *skb, 1302 const struct net_device *vrf_dev, 1303 const struct net_device *slave_dev) 1304 { 1305 struct net_vrf *vrf = netdev_priv(vrf_dev); 1306 1307 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id)) 1308 return -EMSGSIZE; 1309 1310 return 0; 1311 } 1312 1313 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = { 1314 [IFLA_VRF_TABLE] = { .type = NLA_U32 }, 1315 }; 1316 1317 static struct rtnl_link_ops vrf_link_ops __read_mostly = { 1318 .kind = DRV_NAME, 1319 .priv_size = sizeof(struct net_vrf), 1320 1321 .get_size = vrf_nl_getsize, 1322 .policy = vrf_nl_policy, 1323 .validate = vrf_validate, 1324 .fill_info = vrf_fillinfo, 1325 1326 .get_slave_size = vrf_get_slave_size, 1327 .fill_slave_info = vrf_fill_slave_info, 1328 1329 .newlink = vrf_newlink, 1330 .dellink = vrf_dellink, 1331 .setup = vrf_setup, 1332 .maxtype = IFLA_VRF_MAX, 1333 }; 1334 1335 static int vrf_device_event(struct notifier_block *unused, 1336 unsigned long event, void *ptr) 1337 { 1338 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1339 1340 /* only care about unregister events to drop slave references */ 1341 if (event == NETDEV_UNREGISTER) { 1342 struct net_device *vrf_dev; 1343 1344 if (!netif_is_l3_slave(dev)) 1345 goto out; 1346 1347 vrf_dev = netdev_master_upper_dev_get(dev); 1348 vrf_del_slave(vrf_dev, dev); 1349 } 1350 out: 1351 return NOTIFY_DONE; 1352 } 1353 1354 static struct notifier_block vrf_notifier_block __read_mostly = { 1355 .notifier_call = vrf_device_event, 1356 }; 1357 1358 static int __init vrf_init_module(void) 1359 { 1360 int rc; 1361 1362 register_netdevice_notifier(&vrf_notifier_block); 1363 1364 rc = rtnl_link_register(&vrf_link_ops); 1365 if (rc < 0) 1366 goto error; 1367 1368 return 0; 1369 1370 error: 1371 unregister_netdevice_notifier(&vrf_notifier_block); 1372 return rc; 1373 } 1374 1375 module_init(vrf_init_module); 1376 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern"); 1377 MODULE_DESCRIPTION("Device driver to instantiate VRF domains"); 1378 MODULE_LICENSE("GPL"); 1379 MODULE_ALIAS_RTNL_LINK(DRV_NAME); 1380 MODULE_VERSION(DRV_VERSION); 1381