1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * vrf.c: device driver to encapsulate a VRF space 4 * 5 * Copyright (c) 2015 Cumulus Networks. All rights reserved. 6 * Copyright (c) 2015 Shrijeet Mukherjee <shm@cumulusnetworks.com> 7 * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com> 8 * 9 * Based on dummy, team and ipvlan drivers 10 */ 11 12 #include <linux/ethtool.h> 13 #include <linux/module.h> 14 #include <linux/kernel.h> 15 #include <linux/netdevice.h> 16 #include <linux/etherdevice.h> 17 #include <linux/ip.h> 18 #include <linux/init.h> 19 #include <linux/moduleparam.h> 20 #include <linux/netfilter.h> 21 #include <linux/rtnetlink.h> 22 #include <net/rtnetlink.h> 23 #include <linux/u64_stats_sync.h> 24 #include <linux/hashtable.h> 25 #include <linux/spinlock_types.h> 26 27 #include <linux/inetdevice.h> 28 #include <net/arp.h> 29 #include <net/ip.h> 30 #include <net/ip_fib.h> 31 #include <net/ip6_fib.h> 32 #include <net/ip6_route.h> 33 #include <net/route.h> 34 #include <net/addrconf.h> 35 #include <net/l3mdev.h> 36 #include <net/fib_rules.h> 37 #include <net/netns/generic.h> 38 39 #define DRV_NAME "vrf" 40 #define DRV_VERSION "1.1" 41 42 #define FIB_RULE_PREF 1000 /* default preference for FIB rules */ 43 44 #define HT_MAP_BITS 4 45 #define HASH_INITVAL ((u32)0xcafef00d) 46 47 struct vrf_map { 48 DECLARE_HASHTABLE(ht, HT_MAP_BITS); 49 spinlock_t vmap_lock; 50 51 /* shared_tables: 52 * count how many distinct tables do not comply with the strict mode 53 * requirement. 54 * shared_tables value must be 0 in order to enable the strict mode. 55 * 56 * example of the evolution of shared_tables: 57 * | time 58 * add vrf0 --> table 100 shared_tables = 0 | t0 59 * add vrf1 --> table 101 shared_tables = 0 | t1 60 * add vrf2 --> table 100 shared_tables = 1 | t2 61 * add vrf3 --> table 100 shared_tables = 1 | t3 62 * add vrf4 --> table 101 shared_tables = 2 v t4 63 * 64 * shared_tables is a "step function" (or "staircase function") 65 * and it is increased by one when the second vrf is associated to a 66 * table. 67 * 68 * at t2, vrf0 and vrf2 are bound to table 100: shared_tables = 1. 69 * 70 * at t3, another dev (vrf3) is bound to the same table 100 but the 71 * value of shared_tables is still 1. 72 * This means that no matter how many new vrfs will register on the 73 * table 100, the shared_tables will not increase (considering only 74 * table 100). 75 * 76 * at t4, vrf4 is bound to table 101, and shared_tables = 2. 77 * 78 * Looking at the value of shared_tables we can immediately know if 79 * the strict_mode can or cannot be enforced. Indeed, strict_mode 80 * can be enforced iff shared_tables = 0. 81 * 82 * Conversely, shared_tables is decreased when a vrf is de-associated 83 * from a table with exactly two associated vrfs. 84 */ 85 u32 shared_tables; 86 87 bool strict_mode; 88 }; 89 90 struct vrf_map_elem { 91 struct hlist_node hnode; 92 struct list_head vrf_list; /* VRFs registered to this table */ 93 94 u32 table_id; 95 int users; 96 int ifindex; 97 }; 98 99 static unsigned int vrf_net_id; 100 101 /* per netns vrf data */ 102 struct netns_vrf { 103 /* protected by rtnl lock */ 104 bool add_fib_rules; 105 106 struct vrf_map vmap; 107 struct ctl_table_header *ctl_hdr; 108 }; 109 110 struct net_vrf { 111 struct rtable __rcu *rth; 112 struct rt6_info __rcu *rt6; 113 #if IS_ENABLED(CONFIG_IPV6) 114 struct fib6_table *fib6_table; 115 #endif 116 u32 tb_id; 117 118 struct list_head me_list; /* entry in vrf_map_elem */ 119 int ifindex; 120 }; 121 122 struct pcpu_dstats { 123 u64 tx_pkts; 124 u64 tx_bytes; 125 u64 tx_drps; 126 u64 rx_pkts; 127 u64 rx_bytes; 128 u64 rx_drps; 129 struct u64_stats_sync syncp; 130 }; 131 132 static void vrf_rx_stats(struct net_device *dev, int len) 133 { 134 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); 135 136 u64_stats_update_begin(&dstats->syncp); 137 dstats->rx_pkts++; 138 dstats->rx_bytes += len; 139 u64_stats_update_end(&dstats->syncp); 140 } 141 142 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb) 143 { 144 vrf_dev->stats.tx_errors++; 145 kfree_skb(skb); 146 } 147 148 static void vrf_get_stats64(struct net_device *dev, 149 struct rtnl_link_stats64 *stats) 150 { 151 int i; 152 153 for_each_possible_cpu(i) { 154 const struct pcpu_dstats *dstats; 155 u64 tbytes, tpkts, tdrops, rbytes, rpkts; 156 unsigned int start; 157 158 dstats = per_cpu_ptr(dev->dstats, i); 159 do { 160 start = u64_stats_fetch_begin_irq(&dstats->syncp); 161 tbytes = dstats->tx_bytes; 162 tpkts = dstats->tx_pkts; 163 tdrops = dstats->tx_drps; 164 rbytes = dstats->rx_bytes; 165 rpkts = dstats->rx_pkts; 166 } while (u64_stats_fetch_retry_irq(&dstats->syncp, start)); 167 stats->tx_bytes += tbytes; 168 stats->tx_packets += tpkts; 169 stats->tx_dropped += tdrops; 170 stats->rx_bytes += rbytes; 171 stats->rx_packets += rpkts; 172 } 173 } 174 175 static struct vrf_map *netns_vrf_map(struct net *net) 176 { 177 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id); 178 179 return &nn_vrf->vmap; 180 } 181 182 static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev) 183 { 184 return netns_vrf_map(dev_net(dev)); 185 } 186 187 static int vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem *me) 188 { 189 struct list_head *me_head = &me->vrf_list; 190 struct net_vrf *vrf; 191 192 if (list_empty(me_head)) 193 return -ENODEV; 194 195 vrf = list_first_entry(me_head, struct net_vrf, me_list); 196 197 return vrf->ifindex; 198 } 199 200 static struct vrf_map_elem *vrf_map_elem_alloc(gfp_t flags) 201 { 202 struct vrf_map_elem *me; 203 204 me = kmalloc(sizeof(*me), flags); 205 if (!me) 206 return NULL; 207 208 return me; 209 } 210 211 static void vrf_map_elem_free(struct vrf_map_elem *me) 212 { 213 kfree(me); 214 } 215 216 static void vrf_map_elem_init(struct vrf_map_elem *me, int table_id, 217 int ifindex, int users) 218 { 219 me->table_id = table_id; 220 me->ifindex = ifindex; 221 me->users = users; 222 INIT_LIST_HEAD(&me->vrf_list); 223 } 224 225 static struct vrf_map_elem *vrf_map_lookup_elem(struct vrf_map *vmap, 226 u32 table_id) 227 { 228 struct vrf_map_elem *me; 229 u32 key; 230 231 key = jhash_1word(table_id, HASH_INITVAL); 232 hash_for_each_possible(vmap->ht, me, hnode, key) { 233 if (me->table_id == table_id) 234 return me; 235 } 236 237 return NULL; 238 } 239 240 static void vrf_map_add_elem(struct vrf_map *vmap, struct vrf_map_elem *me) 241 { 242 u32 table_id = me->table_id; 243 u32 key; 244 245 key = jhash_1word(table_id, HASH_INITVAL); 246 hash_add(vmap->ht, &me->hnode, key); 247 } 248 249 static void vrf_map_del_elem(struct vrf_map_elem *me) 250 { 251 hash_del(&me->hnode); 252 } 253 254 static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock) 255 { 256 spin_lock(&vmap->vmap_lock); 257 } 258 259 static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock) 260 { 261 spin_unlock(&vmap->vmap_lock); 262 } 263 264 /* called with rtnl lock held */ 265 static int 266 vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack) 267 { 268 struct vrf_map *vmap = netns_vrf_map_by_dev(dev); 269 struct net_vrf *vrf = netdev_priv(dev); 270 struct vrf_map_elem *new_me, *me; 271 u32 table_id = vrf->tb_id; 272 bool free_new_me = false; 273 int users; 274 int res; 275 276 /* we pre-allocate elements used in the spin-locked section (so that we 277 * keep the spinlock as short as possibile). 278 */ 279 new_me = vrf_map_elem_alloc(GFP_KERNEL); 280 if (!new_me) 281 return -ENOMEM; 282 283 vrf_map_elem_init(new_me, table_id, dev->ifindex, 0); 284 285 vrf_map_lock(vmap); 286 287 me = vrf_map_lookup_elem(vmap, table_id); 288 if (!me) { 289 me = new_me; 290 vrf_map_add_elem(vmap, me); 291 goto link_vrf; 292 } 293 294 /* we already have an entry in the vrf_map, so it means there is (at 295 * least) a vrf registered on the specific table. 296 */ 297 free_new_me = true; 298 if (vmap->strict_mode) { 299 /* vrfs cannot share the same table */ 300 NL_SET_ERR_MSG(extack, "Table is used by another VRF"); 301 res = -EBUSY; 302 goto unlock; 303 } 304 305 link_vrf: 306 users = ++me->users; 307 if (users == 2) 308 ++vmap->shared_tables; 309 310 list_add(&vrf->me_list, &me->vrf_list); 311 312 res = 0; 313 314 unlock: 315 vrf_map_unlock(vmap); 316 317 /* clean-up, if needed */ 318 if (free_new_me) 319 vrf_map_elem_free(new_me); 320 321 return res; 322 } 323 324 /* called with rtnl lock held */ 325 static void vrf_map_unregister_dev(struct net_device *dev) 326 { 327 struct vrf_map *vmap = netns_vrf_map_by_dev(dev); 328 struct net_vrf *vrf = netdev_priv(dev); 329 u32 table_id = vrf->tb_id; 330 struct vrf_map_elem *me; 331 int users; 332 333 vrf_map_lock(vmap); 334 335 me = vrf_map_lookup_elem(vmap, table_id); 336 if (!me) 337 goto unlock; 338 339 list_del(&vrf->me_list); 340 341 users = --me->users; 342 if (users == 1) { 343 --vmap->shared_tables; 344 } else if (users == 0) { 345 vrf_map_del_elem(me); 346 347 /* no one will refer to this element anymore */ 348 vrf_map_elem_free(me); 349 } 350 351 unlock: 352 vrf_map_unlock(vmap); 353 } 354 355 /* return the vrf device index associated with the table_id */ 356 static int vrf_ifindex_lookup_by_table_id(struct net *net, u32 table_id) 357 { 358 struct vrf_map *vmap = netns_vrf_map(net); 359 struct vrf_map_elem *me; 360 int ifindex; 361 362 vrf_map_lock(vmap); 363 364 if (!vmap->strict_mode) { 365 ifindex = -EPERM; 366 goto unlock; 367 } 368 369 me = vrf_map_lookup_elem(vmap, table_id); 370 if (!me) { 371 ifindex = -ENODEV; 372 goto unlock; 373 } 374 375 ifindex = vrf_map_elem_get_vrf_ifindex(me); 376 377 unlock: 378 vrf_map_unlock(vmap); 379 380 return ifindex; 381 } 382 383 /* by default VRF devices do not have a qdisc and are expected 384 * to be created with only a single queue. 385 */ 386 static bool qdisc_tx_is_default(const struct net_device *dev) 387 { 388 struct netdev_queue *txq; 389 struct Qdisc *qdisc; 390 391 if (dev->num_tx_queues > 1) 392 return false; 393 394 txq = netdev_get_tx_queue(dev, 0); 395 qdisc = rcu_access_pointer(txq->qdisc); 396 397 return !qdisc->enqueue; 398 } 399 400 /* Local traffic destined to local address. Reinsert the packet to rx 401 * path, similar to loopback handling. 402 */ 403 static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev, 404 struct dst_entry *dst) 405 { 406 int len = skb->len; 407 408 skb_orphan(skb); 409 410 skb_dst_set(skb, dst); 411 412 /* set pkt_type to avoid skb hitting packet taps twice - 413 * once on Tx and again in Rx processing 414 */ 415 skb->pkt_type = PACKET_LOOPBACK; 416 417 skb->protocol = eth_type_trans(skb, dev); 418 419 if (likely(netif_rx(skb) == NET_RX_SUCCESS)) 420 vrf_rx_stats(dev, len); 421 else 422 this_cpu_inc(dev->dstats->rx_drps); 423 424 return NETDEV_TX_OK; 425 } 426 427 #if IS_ENABLED(CONFIG_IPV6) 428 static int vrf_ip6_local_out(struct net *net, struct sock *sk, 429 struct sk_buff *skb) 430 { 431 int err; 432 433 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, 434 sk, skb, NULL, skb_dst(skb)->dev, dst_output); 435 436 if (likely(err == 1)) 437 err = dst_output(net, sk, skb); 438 439 return err; 440 } 441 442 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, 443 struct net_device *dev) 444 { 445 const struct ipv6hdr *iph; 446 struct net *net = dev_net(skb->dev); 447 struct flowi6 fl6; 448 int ret = NET_XMIT_DROP; 449 struct dst_entry *dst; 450 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst; 451 452 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr))) 453 goto err; 454 455 iph = ipv6_hdr(skb); 456 457 memset(&fl6, 0, sizeof(fl6)); 458 /* needed to match OIF rule */ 459 fl6.flowi6_oif = dev->ifindex; 460 fl6.flowi6_iif = LOOPBACK_IFINDEX; 461 fl6.daddr = iph->daddr; 462 fl6.saddr = iph->saddr; 463 fl6.flowlabel = ip6_flowinfo(iph); 464 fl6.flowi6_mark = skb->mark; 465 fl6.flowi6_proto = iph->nexthdr; 466 fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF; 467 468 dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL); 469 if (IS_ERR(dst) || dst == dst_null) 470 goto err; 471 472 skb_dst_drop(skb); 473 474 /* if dst.dev is loopback or the VRF device again this is locally 475 * originated traffic destined to a local address. Short circuit 476 * to Rx path 477 */ 478 if (dst->dev == dev) 479 return vrf_local_xmit(skb, dev, dst); 480 481 skb_dst_set(skb, dst); 482 483 /* strip the ethernet header added for pass through VRF device */ 484 __skb_pull(skb, skb_network_offset(skb)); 485 486 ret = vrf_ip6_local_out(net, skb->sk, skb); 487 if (unlikely(net_xmit_eval(ret))) 488 dev->stats.tx_errors++; 489 else 490 ret = NET_XMIT_SUCCESS; 491 492 return ret; 493 err: 494 vrf_tx_error(dev, skb); 495 return NET_XMIT_DROP; 496 } 497 #else 498 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, 499 struct net_device *dev) 500 { 501 vrf_tx_error(dev, skb); 502 return NET_XMIT_DROP; 503 } 504 #endif 505 506 /* based on ip_local_out; can't use it b/c the dst is switched pointing to us */ 507 static int vrf_ip_local_out(struct net *net, struct sock *sk, 508 struct sk_buff *skb) 509 { 510 int err; 511 512 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk, 513 skb, NULL, skb_dst(skb)->dev, dst_output); 514 if (likely(err == 1)) 515 err = dst_output(net, sk, skb); 516 517 return err; 518 } 519 520 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb, 521 struct net_device *vrf_dev) 522 { 523 struct iphdr *ip4h; 524 int ret = NET_XMIT_DROP; 525 struct flowi4 fl4; 526 struct net *net = dev_net(vrf_dev); 527 struct rtable *rt; 528 529 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr))) 530 goto err; 531 532 ip4h = ip_hdr(skb); 533 534 memset(&fl4, 0, sizeof(fl4)); 535 /* needed to match OIF rule */ 536 fl4.flowi4_oif = vrf_dev->ifindex; 537 fl4.flowi4_iif = LOOPBACK_IFINDEX; 538 fl4.flowi4_tos = RT_TOS(ip4h->tos); 539 fl4.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF; 540 fl4.flowi4_proto = ip4h->protocol; 541 fl4.daddr = ip4h->daddr; 542 fl4.saddr = ip4h->saddr; 543 544 rt = ip_route_output_flow(net, &fl4, NULL); 545 if (IS_ERR(rt)) 546 goto err; 547 548 skb_dst_drop(skb); 549 550 /* if dst.dev is loopback or the VRF device again this is locally 551 * originated traffic destined to a local address. Short circuit 552 * to Rx path 553 */ 554 if (rt->dst.dev == vrf_dev) 555 return vrf_local_xmit(skb, vrf_dev, &rt->dst); 556 557 skb_dst_set(skb, &rt->dst); 558 559 /* strip the ethernet header added for pass through VRF device */ 560 __skb_pull(skb, skb_network_offset(skb)); 561 562 if (!ip4h->saddr) { 563 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0, 564 RT_SCOPE_LINK); 565 } 566 567 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb); 568 if (unlikely(net_xmit_eval(ret))) 569 vrf_dev->stats.tx_errors++; 570 else 571 ret = NET_XMIT_SUCCESS; 572 573 out: 574 return ret; 575 err: 576 vrf_tx_error(vrf_dev, skb); 577 goto out; 578 } 579 580 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev) 581 { 582 switch (skb->protocol) { 583 case htons(ETH_P_IP): 584 return vrf_process_v4_outbound(skb, dev); 585 case htons(ETH_P_IPV6): 586 return vrf_process_v6_outbound(skb, dev); 587 default: 588 vrf_tx_error(dev, skb); 589 return NET_XMIT_DROP; 590 } 591 } 592 593 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev) 594 { 595 int len = skb->len; 596 netdev_tx_t ret = is_ip_tx_frame(skb, dev); 597 598 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) { 599 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); 600 601 u64_stats_update_begin(&dstats->syncp); 602 dstats->tx_pkts++; 603 dstats->tx_bytes += len; 604 u64_stats_update_end(&dstats->syncp); 605 } else { 606 this_cpu_inc(dev->dstats->tx_drps); 607 } 608 609 return ret; 610 } 611 612 static void vrf_finish_direct(struct sk_buff *skb) 613 { 614 struct net_device *vrf_dev = skb->dev; 615 616 if (!list_empty(&vrf_dev->ptype_all) && 617 likely(skb_headroom(skb) >= ETH_HLEN)) { 618 struct ethhdr *eth = skb_push(skb, ETH_HLEN); 619 620 ether_addr_copy(eth->h_source, vrf_dev->dev_addr); 621 eth_zero_addr(eth->h_dest); 622 eth->h_proto = skb->protocol; 623 624 rcu_read_lock_bh(); 625 dev_queue_xmit_nit(skb, vrf_dev); 626 rcu_read_unlock_bh(); 627 628 skb_pull(skb, ETH_HLEN); 629 } 630 631 /* reset skb device */ 632 nf_reset_ct(skb); 633 } 634 635 #if IS_ENABLED(CONFIG_IPV6) 636 /* modelled after ip6_finish_output2 */ 637 static int vrf_finish_output6(struct net *net, struct sock *sk, 638 struct sk_buff *skb) 639 { 640 struct dst_entry *dst = skb_dst(skb); 641 struct net_device *dev = dst->dev; 642 const struct in6_addr *nexthop; 643 struct neighbour *neigh; 644 int ret; 645 646 nf_reset_ct(skb); 647 648 skb->protocol = htons(ETH_P_IPV6); 649 skb->dev = dev; 650 651 rcu_read_lock_bh(); 652 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr); 653 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop); 654 if (unlikely(!neigh)) 655 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false); 656 if (!IS_ERR(neigh)) { 657 sock_confirm_neigh(skb, neigh); 658 ret = neigh_output(neigh, skb, false); 659 rcu_read_unlock_bh(); 660 return ret; 661 } 662 rcu_read_unlock_bh(); 663 664 IP6_INC_STATS(dev_net(dst->dev), 665 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 666 kfree_skb(skb); 667 return -EINVAL; 668 } 669 670 /* modelled after ip6_output */ 671 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb) 672 { 673 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, 674 net, sk, skb, NULL, skb_dst(skb)->dev, 675 vrf_finish_output6, 676 !(IP6CB(skb)->flags & IP6SKB_REROUTED)); 677 } 678 679 /* set dst on skb to send packet to us via dev_xmit path. Allows 680 * packet to go through device based features such as qdisc, netfilter 681 * hooks and packet sockets with skb->dev set to vrf device. 682 */ 683 static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev, 684 struct sk_buff *skb) 685 { 686 struct net_vrf *vrf = netdev_priv(vrf_dev); 687 struct dst_entry *dst = NULL; 688 struct rt6_info *rt6; 689 690 rcu_read_lock(); 691 692 rt6 = rcu_dereference(vrf->rt6); 693 if (likely(rt6)) { 694 dst = &rt6->dst; 695 dst_hold(dst); 696 } 697 698 rcu_read_unlock(); 699 700 if (unlikely(!dst)) { 701 vrf_tx_error(vrf_dev, skb); 702 return NULL; 703 } 704 705 skb_dst_drop(skb); 706 skb_dst_set(skb, dst); 707 708 return skb; 709 } 710 711 static int vrf_output6_direct_finish(struct net *net, struct sock *sk, 712 struct sk_buff *skb) 713 { 714 vrf_finish_direct(skb); 715 716 return vrf_ip6_local_out(net, sk, skb); 717 } 718 719 static int vrf_output6_direct(struct net *net, struct sock *sk, 720 struct sk_buff *skb) 721 { 722 int err = 1; 723 724 skb->protocol = htons(ETH_P_IPV6); 725 726 if (!(IPCB(skb)->flags & IPSKB_REROUTED)) 727 err = nf_hook(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb, 728 NULL, skb->dev, vrf_output6_direct_finish); 729 730 if (likely(err == 1)) 731 vrf_finish_direct(skb); 732 733 return err; 734 } 735 736 static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk, 737 struct sk_buff *skb) 738 { 739 int err; 740 741 err = vrf_output6_direct(net, sk, skb); 742 if (likely(err == 1)) 743 err = vrf_ip6_local_out(net, sk, skb); 744 745 return err; 746 } 747 748 static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev, 749 struct sock *sk, 750 struct sk_buff *skb) 751 { 752 struct net *net = dev_net(vrf_dev); 753 int err; 754 755 skb->dev = vrf_dev; 756 757 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, 758 skb, NULL, vrf_dev, vrf_ip6_out_direct_finish); 759 760 if (likely(err == 1)) 761 err = vrf_output6_direct(net, sk, skb); 762 763 if (likely(err == 1)) 764 return skb; 765 766 return NULL; 767 } 768 769 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev, 770 struct sock *sk, 771 struct sk_buff *skb) 772 { 773 /* don't divert link scope packets */ 774 if (rt6_need_strict(&ipv6_hdr(skb)->daddr)) 775 return skb; 776 777 if (qdisc_tx_is_default(vrf_dev) || 778 IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) 779 return vrf_ip6_out_direct(vrf_dev, sk, skb); 780 781 return vrf_ip6_out_redirect(vrf_dev, skb); 782 } 783 784 /* holding rtnl */ 785 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) 786 { 787 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6); 788 struct net *net = dev_net(dev); 789 struct dst_entry *dst; 790 791 RCU_INIT_POINTER(vrf->rt6, NULL); 792 synchronize_rcu(); 793 794 /* move dev in dst's to loopback so this VRF device can be deleted 795 * - based on dst_ifdown 796 */ 797 if (rt6) { 798 dst = &rt6->dst; 799 dev_put(dst->dev); 800 dst->dev = net->loopback_dev; 801 dev_hold(dst->dev); 802 dst_release(dst); 803 } 804 } 805 806 static int vrf_rt6_create(struct net_device *dev) 807 { 808 int flags = DST_NOPOLICY | DST_NOXFRM; 809 struct net_vrf *vrf = netdev_priv(dev); 810 struct net *net = dev_net(dev); 811 struct rt6_info *rt6; 812 int rc = -ENOMEM; 813 814 /* IPv6 can be CONFIG enabled and then disabled runtime */ 815 if (!ipv6_mod_enabled()) 816 return 0; 817 818 vrf->fib6_table = fib6_new_table(net, vrf->tb_id); 819 if (!vrf->fib6_table) 820 goto out; 821 822 /* create a dst for routing packets out a VRF device */ 823 rt6 = ip6_dst_alloc(net, dev, flags); 824 if (!rt6) 825 goto out; 826 827 rt6->dst.output = vrf_output6; 828 829 rcu_assign_pointer(vrf->rt6, rt6); 830 831 rc = 0; 832 out: 833 return rc; 834 } 835 #else 836 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev, 837 struct sock *sk, 838 struct sk_buff *skb) 839 { 840 return skb; 841 } 842 843 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) 844 { 845 } 846 847 static int vrf_rt6_create(struct net_device *dev) 848 { 849 return 0; 850 } 851 #endif 852 853 /* modelled after ip_finish_output2 */ 854 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 855 { 856 struct dst_entry *dst = skb_dst(skb); 857 struct rtable *rt = (struct rtable *)dst; 858 struct net_device *dev = dst->dev; 859 unsigned int hh_len = LL_RESERVED_SPACE(dev); 860 struct neighbour *neigh; 861 bool is_v6gw = false; 862 int ret = -EINVAL; 863 864 nf_reset_ct(skb); 865 866 /* Be paranoid, rather than too clever. */ 867 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { 868 struct sk_buff *skb2; 869 870 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); 871 if (!skb2) { 872 ret = -ENOMEM; 873 goto err; 874 } 875 if (skb->sk) 876 skb_set_owner_w(skb2, skb->sk); 877 878 consume_skb(skb); 879 skb = skb2; 880 } 881 882 rcu_read_lock_bh(); 883 884 neigh = ip_neigh_for_gw(rt, skb, &is_v6gw); 885 if (!IS_ERR(neigh)) { 886 sock_confirm_neigh(skb, neigh); 887 /* if crossing protocols, can not use the cached header */ 888 ret = neigh_output(neigh, skb, is_v6gw); 889 rcu_read_unlock_bh(); 890 return ret; 891 } 892 893 rcu_read_unlock_bh(); 894 err: 895 vrf_tx_error(skb->dev, skb); 896 return ret; 897 } 898 899 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb) 900 { 901 struct net_device *dev = skb_dst(skb)->dev; 902 903 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len); 904 905 skb->dev = dev; 906 skb->protocol = htons(ETH_P_IP); 907 908 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, 909 net, sk, skb, NULL, dev, 910 vrf_finish_output, 911 !(IPCB(skb)->flags & IPSKB_REROUTED)); 912 } 913 914 /* set dst on skb to send packet to us via dev_xmit path. Allows 915 * packet to go through device based features such as qdisc, netfilter 916 * hooks and packet sockets with skb->dev set to vrf device. 917 */ 918 static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev, 919 struct sk_buff *skb) 920 { 921 struct net_vrf *vrf = netdev_priv(vrf_dev); 922 struct dst_entry *dst = NULL; 923 struct rtable *rth; 924 925 rcu_read_lock(); 926 927 rth = rcu_dereference(vrf->rth); 928 if (likely(rth)) { 929 dst = &rth->dst; 930 dst_hold(dst); 931 } 932 933 rcu_read_unlock(); 934 935 if (unlikely(!dst)) { 936 vrf_tx_error(vrf_dev, skb); 937 return NULL; 938 } 939 940 skb_dst_drop(skb); 941 skb_dst_set(skb, dst); 942 943 return skb; 944 } 945 946 static int vrf_output_direct_finish(struct net *net, struct sock *sk, 947 struct sk_buff *skb) 948 { 949 vrf_finish_direct(skb); 950 951 return vrf_ip_local_out(net, sk, skb); 952 } 953 954 static int vrf_output_direct(struct net *net, struct sock *sk, 955 struct sk_buff *skb) 956 { 957 int err = 1; 958 959 skb->protocol = htons(ETH_P_IP); 960 961 if (!(IPCB(skb)->flags & IPSKB_REROUTED)) 962 err = nf_hook(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb, 963 NULL, skb->dev, vrf_output_direct_finish); 964 965 if (likely(err == 1)) 966 vrf_finish_direct(skb); 967 968 return err; 969 } 970 971 static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk, 972 struct sk_buff *skb) 973 { 974 int err; 975 976 err = vrf_output_direct(net, sk, skb); 977 if (likely(err == 1)) 978 err = vrf_ip_local_out(net, sk, skb); 979 980 return err; 981 } 982 983 static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev, 984 struct sock *sk, 985 struct sk_buff *skb) 986 { 987 struct net *net = dev_net(vrf_dev); 988 int err; 989 990 skb->dev = vrf_dev; 991 992 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk, 993 skb, NULL, vrf_dev, vrf_ip_out_direct_finish); 994 995 if (likely(err == 1)) 996 err = vrf_output_direct(net, sk, skb); 997 998 if (likely(err == 1)) 999 return skb; 1000 1001 return NULL; 1002 } 1003 1004 static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev, 1005 struct sock *sk, 1006 struct sk_buff *skb) 1007 { 1008 /* don't divert multicast or local broadcast */ 1009 if (ipv4_is_multicast(ip_hdr(skb)->daddr) || 1010 ipv4_is_lbcast(ip_hdr(skb)->daddr)) 1011 return skb; 1012 1013 if (qdisc_tx_is_default(vrf_dev) || 1014 IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) 1015 return vrf_ip_out_direct(vrf_dev, sk, skb); 1016 1017 return vrf_ip_out_redirect(vrf_dev, skb); 1018 } 1019 1020 /* called with rcu lock held */ 1021 static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev, 1022 struct sock *sk, 1023 struct sk_buff *skb, 1024 u16 proto) 1025 { 1026 switch (proto) { 1027 case AF_INET: 1028 return vrf_ip_out(vrf_dev, sk, skb); 1029 case AF_INET6: 1030 return vrf_ip6_out(vrf_dev, sk, skb); 1031 } 1032 1033 return skb; 1034 } 1035 1036 /* holding rtnl */ 1037 static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf) 1038 { 1039 struct rtable *rth = rtnl_dereference(vrf->rth); 1040 struct net *net = dev_net(dev); 1041 struct dst_entry *dst; 1042 1043 RCU_INIT_POINTER(vrf->rth, NULL); 1044 synchronize_rcu(); 1045 1046 /* move dev in dst's to loopback so this VRF device can be deleted 1047 * - based on dst_ifdown 1048 */ 1049 if (rth) { 1050 dst = &rth->dst; 1051 dev_put(dst->dev); 1052 dst->dev = net->loopback_dev; 1053 dev_hold(dst->dev); 1054 dst_release(dst); 1055 } 1056 } 1057 1058 static int vrf_rtable_create(struct net_device *dev) 1059 { 1060 struct net_vrf *vrf = netdev_priv(dev); 1061 struct rtable *rth; 1062 1063 if (!fib_new_table(dev_net(dev), vrf->tb_id)) 1064 return -ENOMEM; 1065 1066 /* create a dst for routing packets out through a VRF device */ 1067 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1); 1068 if (!rth) 1069 return -ENOMEM; 1070 1071 rth->dst.output = vrf_output; 1072 1073 rcu_assign_pointer(vrf->rth, rth); 1074 1075 return 0; 1076 } 1077 1078 /**************************** device handling ********************/ 1079 1080 /* cycle interface to flush neighbor cache and move routes across tables */ 1081 static void cycle_netdev(struct net_device *dev, 1082 struct netlink_ext_ack *extack) 1083 { 1084 unsigned int flags = dev->flags; 1085 int ret; 1086 1087 if (!netif_running(dev)) 1088 return; 1089 1090 ret = dev_change_flags(dev, flags & ~IFF_UP, extack); 1091 if (ret >= 0) 1092 ret = dev_change_flags(dev, flags, extack); 1093 1094 if (ret < 0) { 1095 netdev_err(dev, 1096 "Failed to cycle device %s; route tables might be wrong!\n", 1097 dev->name); 1098 } 1099 } 1100 1101 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev, 1102 struct netlink_ext_ack *extack) 1103 { 1104 int ret; 1105 1106 /* do not allow loopback device to be enslaved to a VRF. 1107 * The vrf device acts as the loopback for the vrf. 1108 */ 1109 if (port_dev == dev_net(dev)->loopback_dev) { 1110 NL_SET_ERR_MSG(extack, 1111 "Can not enslave loopback device to a VRF"); 1112 return -EOPNOTSUPP; 1113 } 1114 1115 port_dev->priv_flags |= IFF_L3MDEV_SLAVE; 1116 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack); 1117 if (ret < 0) 1118 goto err; 1119 1120 cycle_netdev(port_dev, extack); 1121 1122 return 0; 1123 1124 err: 1125 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE; 1126 return ret; 1127 } 1128 1129 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev, 1130 struct netlink_ext_ack *extack) 1131 { 1132 if (netif_is_l3_master(port_dev)) { 1133 NL_SET_ERR_MSG(extack, 1134 "Can not enslave an L3 master device to a VRF"); 1135 return -EINVAL; 1136 } 1137 1138 if (netif_is_l3_slave(port_dev)) 1139 return -EINVAL; 1140 1141 return do_vrf_add_slave(dev, port_dev, extack); 1142 } 1143 1144 /* inverse of do_vrf_add_slave */ 1145 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev) 1146 { 1147 netdev_upper_dev_unlink(port_dev, dev); 1148 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE; 1149 1150 cycle_netdev(port_dev, NULL); 1151 1152 return 0; 1153 } 1154 1155 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev) 1156 { 1157 return do_vrf_del_slave(dev, port_dev); 1158 } 1159 1160 static void vrf_dev_uninit(struct net_device *dev) 1161 { 1162 struct net_vrf *vrf = netdev_priv(dev); 1163 1164 vrf_rtable_release(dev, vrf); 1165 vrf_rt6_release(dev, vrf); 1166 1167 free_percpu(dev->dstats); 1168 dev->dstats = NULL; 1169 } 1170 1171 static int vrf_dev_init(struct net_device *dev) 1172 { 1173 struct net_vrf *vrf = netdev_priv(dev); 1174 1175 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats); 1176 if (!dev->dstats) 1177 goto out_nomem; 1178 1179 /* create the default dst which points back to us */ 1180 if (vrf_rtable_create(dev) != 0) 1181 goto out_stats; 1182 1183 if (vrf_rt6_create(dev) != 0) 1184 goto out_rth; 1185 1186 dev->flags = IFF_MASTER | IFF_NOARP; 1187 1188 /* MTU is irrelevant for VRF device; set to 64k similar to lo */ 1189 dev->mtu = 64 * 1024; 1190 1191 /* similarly, oper state is irrelevant; set to up to avoid confusion */ 1192 dev->operstate = IF_OPER_UP; 1193 netdev_lockdep_set_classes(dev); 1194 return 0; 1195 1196 out_rth: 1197 vrf_rtable_release(dev, vrf); 1198 out_stats: 1199 free_percpu(dev->dstats); 1200 dev->dstats = NULL; 1201 out_nomem: 1202 return -ENOMEM; 1203 } 1204 1205 static const struct net_device_ops vrf_netdev_ops = { 1206 .ndo_init = vrf_dev_init, 1207 .ndo_uninit = vrf_dev_uninit, 1208 .ndo_start_xmit = vrf_xmit, 1209 .ndo_set_mac_address = eth_mac_addr, 1210 .ndo_get_stats64 = vrf_get_stats64, 1211 .ndo_add_slave = vrf_add_slave, 1212 .ndo_del_slave = vrf_del_slave, 1213 }; 1214 1215 static u32 vrf_fib_table(const struct net_device *dev) 1216 { 1217 struct net_vrf *vrf = netdev_priv(dev); 1218 1219 return vrf->tb_id; 1220 } 1221 1222 static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) 1223 { 1224 kfree_skb(skb); 1225 return 0; 1226 } 1227 1228 static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook, 1229 struct sk_buff *skb, 1230 struct net_device *dev) 1231 { 1232 struct net *net = dev_net(dev); 1233 1234 if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1) 1235 skb = NULL; /* kfree_skb(skb) handled by nf code */ 1236 1237 return skb; 1238 } 1239 1240 static int vrf_prepare_mac_header(struct sk_buff *skb, 1241 struct net_device *vrf_dev, u16 proto) 1242 { 1243 struct ethhdr *eth; 1244 int err; 1245 1246 /* in general, we do not know if there is enough space in the head of 1247 * the packet for hosting the mac header. 1248 */ 1249 err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev)); 1250 if (unlikely(err)) 1251 /* no space in the skb head */ 1252 return -ENOBUFS; 1253 1254 __skb_push(skb, ETH_HLEN); 1255 eth = (struct ethhdr *)skb->data; 1256 1257 skb_reset_mac_header(skb); 1258 1259 /* we set the ethernet destination and the source addresses to the 1260 * address of the VRF device. 1261 */ 1262 ether_addr_copy(eth->h_dest, vrf_dev->dev_addr); 1263 ether_addr_copy(eth->h_source, vrf_dev->dev_addr); 1264 eth->h_proto = htons(proto); 1265 1266 /* the destination address of the Ethernet frame corresponds to the 1267 * address set on the VRF interface; therefore, the packet is intended 1268 * to be processed locally. 1269 */ 1270 skb->protocol = eth->h_proto; 1271 skb->pkt_type = PACKET_HOST; 1272 1273 skb_postpush_rcsum(skb, skb->data, ETH_HLEN); 1274 1275 skb_pull_inline(skb, ETH_HLEN); 1276 1277 return 0; 1278 } 1279 1280 /* prepare and add the mac header to the packet if it was not set previously. 1281 * In this way, packet sniffers such as tcpdump can parse the packet correctly. 1282 * If the mac header was already set, the original mac header is left 1283 * untouched and the function returns immediately. 1284 */ 1285 static int vrf_add_mac_header_if_unset(struct sk_buff *skb, 1286 struct net_device *vrf_dev, 1287 u16 proto) 1288 { 1289 if (skb_mac_header_was_set(skb)) 1290 return 0; 1291 1292 return vrf_prepare_mac_header(skb, vrf_dev, proto); 1293 } 1294 1295 #if IS_ENABLED(CONFIG_IPV6) 1296 /* neighbor handling is done with actual device; do not want 1297 * to flip skb->dev for those ndisc packets. This really fails 1298 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is 1299 * a start. 1300 */ 1301 static bool ipv6_ndisc_frame(const struct sk_buff *skb) 1302 { 1303 const struct ipv6hdr *iph = ipv6_hdr(skb); 1304 bool rc = false; 1305 1306 if (iph->nexthdr == NEXTHDR_ICMP) { 1307 const struct icmp6hdr *icmph; 1308 struct icmp6hdr _icmph; 1309 1310 icmph = skb_header_pointer(skb, sizeof(*iph), 1311 sizeof(_icmph), &_icmph); 1312 if (!icmph) 1313 goto out; 1314 1315 switch (icmph->icmp6_type) { 1316 case NDISC_ROUTER_SOLICITATION: 1317 case NDISC_ROUTER_ADVERTISEMENT: 1318 case NDISC_NEIGHBOUR_SOLICITATION: 1319 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1320 case NDISC_REDIRECT: 1321 rc = true; 1322 break; 1323 } 1324 } 1325 1326 out: 1327 return rc; 1328 } 1329 1330 static struct rt6_info *vrf_ip6_route_lookup(struct net *net, 1331 const struct net_device *dev, 1332 struct flowi6 *fl6, 1333 int ifindex, 1334 const struct sk_buff *skb, 1335 int flags) 1336 { 1337 struct net_vrf *vrf = netdev_priv(dev); 1338 1339 return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags); 1340 } 1341 1342 static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev, 1343 int ifindex) 1344 { 1345 const struct ipv6hdr *iph = ipv6_hdr(skb); 1346 struct flowi6 fl6 = { 1347 .flowi6_iif = ifindex, 1348 .flowi6_mark = skb->mark, 1349 .flowi6_proto = iph->nexthdr, 1350 .daddr = iph->daddr, 1351 .saddr = iph->saddr, 1352 .flowlabel = ip6_flowinfo(iph), 1353 }; 1354 struct net *net = dev_net(vrf_dev); 1355 struct rt6_info *rt6; 1356 1357 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb, 1358 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE); 1359 if (unlikely(!rt6)) 1360 return; 1361 1362 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst)) 1363 return; 1364 1365 skb_dst_set(skb, &rt6->dst); 1366 } 1367 1368 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, 1369 struct sk_buff *skb) 1370 { 1371 int orig_iif = skb->skb_iif; 1372 bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr); 1373 bool is_ndisc = ipv6_ndisc_frame(skb); 1374 bool is_ll_src; 1375 1376 /* loopback, multicast & non-ND link-local traffic; do not push through 1377 * packet taps again. Reset pkt_type for upper layers to process skb. 1378 * for packets with lladdr src, however, skip so that the dst can be 1379 * determine at input using original ifindex in the case that daddr 1380 * needs strict 1381 */ 1382 is_ll_src = ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL; 1383 if (skb->pkt_type == PACKET_LOOPBACK || 1384 (need_strict && !is_ndisc && !is_ll_src)) { 1385 skb->dev = vrf_dev; 1386 skb->skb_iif = vrf_dev->ifindex; 1387 IP6CB(skb)->flags |= IP6SKB_L3SLAVE; 1388 if (skb->pkt_type == PACKET_LOOPBACK) 1389 skb->pkt_type = PACKET_HOST; 1390 goto out; 1391 } 1392 1393 /* if packet is NDISC then keep the ingress interface */ 1394 if (!is_ndisc) { 1395 vrf_rx_stats(vrf_dev, skb->len); 1396 skb->dev = vrf_dev; 1397 skb->skb_iif = vrf_dev->ifindex; 1398 1399 if (!list_empty(&vrf_dev->ptype_all)) { 1400 int err; 1401 1402 err = vrf_add_mac_header_if_unset(skb, vrf_dev, 1403 ETH_P_IPV6); 1404 if (likely(!err)) { 1405 skb_push(skb, skb->mac_len); 1406 dev_queue_xmit_nit(skb, vrf_dev); 1407 skb_pull(skb, skb->mac_len); 1408 } 1409 } 1410 1411 IP6CB(skb)->flags |= IP6SKB_L3SLAVE; 1412 } 1413 1414 if (need_strict) 1415 vrf_ip6_input_dst(skb, vrf_dev, orig_iif); 1416 1417 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev); 1418 out: 1419 return skb; 1420 } 1421 1422 #else 1423 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, 1424 struct sk_buff *skb) 1425 { 1426 return skb; 1427 } 1428 #endif 1429 1430 static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev, 1431 struct sk_buff *skb) 1432 { 1433 skb->dev = vrf_dev; 1434 skb->skb_iif = vrf_dev->ifindex; 1435 IPCB(skb)->flags |= IPSKB_L3SLAVE; 1436 1437 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) 1438 goto out; 1439 1440 /* loopback traffic; do not push through packet taps again. 1441 * Reset pkt_type for upper layers to process skb 1442 */ 1443 if (skb->pkt_type == PACKET_LOOPBACK) { 1444 skb->pkt_type = PACKET_HOST; 1445 goto out; 1446 } 1447 1448 vrf_rx_stats(vrf_dev, skb->len); 1449 1450 if (!list_empty(&vrf_dev->ptype_all)) { 1451 int err; 1452 1453 err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP); 1454 if (likely(!err)) { 1455 skb_push(skb, skb->mac_len); 1456 dev_queue_xmit_nit(skb, vrf_dev); 1457 skb_pull(skb, skb->mac_len); 1458 } 1459 } 1460 1461 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev); 1462 out: 1463 return skb; 1464 } 1465 1466 /* called with rcu lock held */ 1467 static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev, 1468 struct sk_buff *skb, 1469 u16 proto) 1470 { 1471 switch (proto) { 1472 case AF_INET: 1473 return vrf_ip_rcv(vrf_dev, skb); 1474 case AF_INET6: 1475 return vrf_ip6_rcv(vrf_dev, skb); 1476 } 1477 1478 return skb; 1479 } 1480 1481 #if IS_ENABLED(CONFIG_IPV6) 1482 /* send to link-local or multicast address via interface enslaved to 1483 * VRF device. Force lookup to VRF table without changing flow struct 1484 * Note: Caller to this function must hold rcu_read_lock() and no refcnt 1485 * is taken on the dst by this function. 1486 */ 1487 static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev, 1488 struct flowi6 *fl6) 1489 { 1490 struct net *net = dev_net(dev); 1491 int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF; 1492 struct dst_entry *dst = NULL; 1493 struct rt6_info *rt; 1494 1495 /* VRF device does not have a link-local address and 1496 * sending packets to link-local or mcast addresses over 1497 * a VRF device does not make sense 1498 */ 1499 if (fl6->flowi6_oif == dev->ifindex) { 1500 dst = &net->ipv6.ip6_null_entry->dst; 1501 return dst; 1502 } 1503 1504 if (!ipv6_addr_any(&fl6->saddr)) 1505 flags |= RT6_LOOKUP_F_HAS_SADDR; 1506 1507 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags); 1508 if (rt) 1509 dst = &rt->dst; 1510 1511 return dst; 1512 } 1513 #endif 1514 1515 static const struct l3mdev_ops vrf_l3mdev_ops = { 1516 .l3mdev_fib_table = vrf_fib_table, 1517 .l3mdev_l3_rcv = vrf_l3_rcv, 1518 .l3mdev_l3_out = vrf_l3_out, 1519 #if IS_ENABLED(CONFIG_IPV6) 1520 .l3mdev_link_scope_lookup = vrf_link_scope_lookup, 1521 #endif 1522 }; 1523 1524 static void vrf_get_drvinfo(struct net_device *dev, 1525 struct ethtool_drvinfo *info) 1526 { 1527 strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); 1528 strlcpy(info->version, DRV_VERSION, sizeof(info->version)); 1529 } 1530 1531 static const struct ethtool_ops vrf_ethtool_ops = { 1532 .get_drvinfo = vrf_get_drvinfo, 1533 }; 1534 1535 static inline size_t vrf_fib_rule_nl_size(void) 1536 { 1537 size_t sz; 1538 1539 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)); 1540 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */ 1541 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */ 1542 sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */ 1543 1544 return sz; 1545 } 1546 1547 static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it) 1548 { 1549 struct fib_rule_hdr *frh; 1550 struct nlmsghdr *nlh; 1551 struct sk_buff *skb; 1552 int err; 1553 1554 if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) && 1555 !ipv6_mod_enabled()) 1556 return 0; 1557 1558 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL); 1559 if (!skb) 1560 return -ENOMEM; 1561 1562 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0); 1563 if (!nlh) 1564 goto nla_put_failure; 1565 1566 /* rule only needs to appear once */ 1567 nlh->nlmsg_flags |= NLM_F_EXCL; 1568 1569 frh = nlmsg_data(nlh); 1570 memset(frh, 0, sizeof(*frh)); 1571 frh->family = family; 1572 frh->action = FR_ACT_TO_TBL; 1573 1574 if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL)) 1575 goto nla_put_failure; 1576 1577 if (nla_put_u8(skb, FRA_L3MDEV, 1)) 1578 goto nla_put_failure; 1579 1580 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF)) 1581 goto nla_put_failure; 1582 1583 nlmsg_end(skb, nlh); 1584 1585 /* fib_nl_{new,del}rule handling looks for net from skb->sk */ 1586 skb->sk = dev_net(dev)->rtnl; 1587 if (add_it) { 1588 err = fib_nl_newrule(skb, nlh, NULL); 1589 if (err == -EEXIST) 1590 err = 0; 1591 } else { 1592 err = fib_nl_delrule(skb, nlh, NULL); 1593 if (err == -ENOENT) 1594 err = 0; 1595 } 1596 nlmsg_free(skb); 1597 1598 return err; 1599 1600 nla_put_failure: 1601 nlmsg_free(skb); 1602 1603 return -EMSGSIZE; 1604 } 1605 1606 static int vrf_add_fib_rules(const struct net_device *dev) 1607 { 1608 int err; 1609 1610 err = vrf_fib_rule(dev, AF_INET, true); 1611 if (err < 0) 1612 goto out_err; 1613 1614 err = vrf_fib_rule(dev, AF_INET6, true); 1615 if (err < 0) 1616 goto ipv6_err; 1617 1618 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES) 1619 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true); 1620 if (err < 0) 1621 goto ipmr_err; 1622 #endif 1623 1624 #if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES) 1625 err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, true); 1626 if (err < 0) 1627 goto ip6mr_err; 1628 #endif 1629 1630 return 0; 1631 1632 #if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES) 1633 ip6mr_err: 1634 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, false); 1635 #endif 1636 1637 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES) 1638 ipmr_err: 1639 vrf_fib_rule(dev, AF_INET6, false); 1640 #endif 1641 1642 ipv6_err: 1643 vrf_fib_rule(dev, AF_INET, false); 1644 1645 out_err: 1646 netdev_err(dev, "Failed to add FIB rules.\n"); 1647 return err; 1648 } 1649 1650 static void vrf_setup(struct net_device *dev) 1651 { 1652 ether_setup(dev); 1653 1654 /* Initialize the device structure. */ 1655 dev->netdev_ops = &vrf_netdev_ops; 1656 dev->l3mdev_ops = &vrf_l3mdev_ops; 1657 dev->ethtool_ops = &vrf_ethtool_ops; 1658 dev->needs_free_netdev = true; 1659 1660 /* Fill in device structure with ethernet-generic values. */ 1661 eth_hw_addr_random(dev); 1662 1663 /* don't acquire vrf device's netif_tx_lock when transmitting */ 1664 dev->features |= NETIF_F_LLTX; 1665 1666 /* don't allow vrf devices to change network namespaces. */ 1667 dev->features |= NETIF_F_NETNS_LOCAL; 1668 1669 /* does not make sense for a VLAN to be added to a vrf device */ 1670 dev->features |= NETIF_F_VLAN_CHALLENGED; 1671 1672 /* enable offload features */ 1673 dev->features |= NETIF_F_GSO_SOFTWARE; 1674 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC; 1675 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA; 1676 1677 dev->hw_features = dev->features; 1678 dev->hw_enc_features = dev->features; 1679 1680 /* default to no qdisc; user can add if desired */ 1681 dev->priv_flags |= IFF_NO_QUEUE; 1682 dev->priv_flags |= IFF_NO_RX_HANDLER; 1683 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1684 1685 /* VRF devices do not care about MTU, but if the MTU is set 1686 * too low then the ipv4 and ipv6 protocols are disabled 1687 * which breaks networking. 1688 */ 1689 dev->min_mtu = IPV6_MIN_MTU; 1690 dev->max_mtu = ETH_MAX_MTU; 1691 } 1692 1693 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[], 1694 struct netlink_ext_ack *extack) 1695 { 1696 if (tb[IFLA_ADDRESS]) { 1697 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) { 1698 NL_SET_ERR_MSG(extack, "Invalid hardware address"); 1699 return -EINVAL; 1700 } 1701 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) { 1702 NL_SET_ERR_MSG(extack, "Invalid hardware address"); 1703 return -EADDRNOTAVAIL; 1704 } 1705 } 1706 return 0; 1707 } 1708 1709 static void vrf_dellink(struct net_device *dev, struct list_head *head) 1710 { 1711 struct net_device *port_dev; 1712 struct list_head *iter; 1713 1714 netdev_for_each_lower_dev(dev, port_dev, iter) 1715 vrf_del_slave(dev, port_dev); 1716 1717 vrf_map_unregister_dev(dev); 1718 1719 unregister_netdevice_queue(dev, head); 1720 } 1721 1722 static int vrf_newlink(struct net *src_net, struct net_device *dev, 1723 struct nlattr *tb[], struct nlattr *data[], 1724 struct netlink_ext_ack *extack) 1725 { 1726 struct net_vrf *vrf = netdev_priv(dev); 1727 struct netns_vrf *nn_vrf; 1728 bool *add_fib_rules; 1729 struct net *net; 1730 int err; 1731 1732 if (!data || !data[IFLA_VRF_TABLE]) { 1733 NL_SET_ERR_MSG(extack, "VRF table id is missing"); 1734 return -EINVAL; 1735 } 1736 1737 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]); 1738 if (vrf->tb_id == RT_TABLE_UNSPEC) { 1739 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE], 1740 "Invalid VRF table id"); 1741 return -EINVAL; 1742 } 1743 1744 dev->priv_flags |= IFF_L3MDEV_MASTER; 1745 1746 err = register_netdevice(dev); 1747 if (err) 1748 goto out; 1749 1750 /* mapping between table_id and vrf; 1751 * note: such binding could not be done in the dev init function 1752 * because dev->ifindex id is not available yet. 1753 */ 1754 vrf->ifindex = dev->ifindex; 1755 1756 err = vrf_map_register_dev(dev, extack); 1757 if (err) { 1758 unregister_netdevice(dev); 1759 goto out; 1760 } 1761 1762 net = dev_net(dev); 1763 nn_vrf = net_generic(net, vrf_net_id); 1764 1765 add_fib_rules = &nn_vrf->add_fib_rules; 1766 if (*add_fib_rules) { 1767 err = vrf_add_fib_rules(dev); 1768 if (err) { 1769 vrf_map_unregister_dev(dev); 1770 unregister_netdevice(dev); 1771 goto out; 1772 } 1773 *add_fib_rules = false; 1774 } 1775 1776 out: 1777 return err; 1778 } 1779 1780 static size_t vrf_nl_getsize(const struct net_device *dev) 1781 { 1782 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */ 1783 } 1784 1785 static int vrf_fillinfo(struct sk_buff *skb, 1786 const struct net_device *dev) 1787 { 1788 struct net_vrf *vrf = netdev_priv(dev); 1789 1790 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id); 1791 } 1792 1793 static size_t vrf_get_slave_size(const struct net_device *bond_dev, 1794 const struct net_device *slave_dev) 1795 { 1796 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */ 1797 } 1798 1799 static int vrf_fill_slave_info(struct sk_buff *skb, 1800 const struct net_device *vrf_dev, 1801 const struct net_device *slave_dev) 1802 { 1803 struct net_vrf *vrf = netdev_priv(vrf_dev); 1804 1805 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id)) 1806 return -EMSGSIZE; 1807 1808 return 0; 1809 } 1810 1811 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = { 1812 [IFLA_VRF_TABLE] = { .type = NLA_U32 }, 1813 }; 1814 1815 static struct rtnl_link_ops vrf_link_ops __read_mostly = { 1816 .kind = DRV_NAME, 1817 .priv_size = sizeof(struct net_vrf), 1818 1819 .get_size = vrf_nl_getsize, 1820 .policy = vrf_nl_policy, 1821 .validate = vrf_validate, 1822 .fill_info = vrf_fillinfo, 1823 1824 .get_slave_size = vrf_get_slave_size, 1825 .fill_slave_info = vrf_fill_slave_info, 1826 1827 .newlink = vrf_newlink, 1828 .dellink = vrf_dellink, 1829 .setup = vrf_setup, 1830 .maxtype = IFLA_VRF_MAX, 1831 }; 1832 1833 static int vrf_device_event(struct notifier_block *unused, 1834 unsigned long event, void *ptr) 1835 { 1836 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1837 1838 /* only care about unregister events to drop slave references */ 1839 if (event == NETDEV_UNREGISTER) { 1840 struct net_device *vrf_dev; 1841 1842 if (!netif_is_l3_slave(dev)) 1843 goto out; 1844 1845 vrf_dev = netdev_master_upper_dev_get(dev); 1846 vrf_del_slave(vrf_dev, dev); 1847 } 1848 out: 1849 return NOTIFY_DONE; 1850 } 1851 1852 static struct notifier_block vrf_notifier_block __read_mostly = { 1853 .notifier_call = vrf_device_event, 1854 }; 1855 1856 static int vrf_map_init(struct vrf_map *vmap) 1857 { 1858 spin_lock_init(&vmap->vmap_lock); 1859 hash_init(vmap->ht); 1860 1861 vmap->strict_mode = false; 1862 1863 return 0; 1864 } 1865 1866 #ifdef CONFIG_SYSCTL 1867 static bool vrf_strict_mode(struct vrf_map *vmap) 1868 { 1869 bool strict_mode; 1870 1871 vrf_map_lock(vmap); 1872 strict_mode = vmap->strict_mode; 1873 vrf_map_unlock(vmap); 1874 1875 return strict_mode; 1876 } 1877 1878 static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode) 1879 { 1880 bool *cur_mode; 1881 int res = 0; 1882 1883 vrf_map_lock(vmap); 1884 1885 cur_mode = &vmap->strict_mode; 1886 if (*cur_mode == new_mode) 1887 goto unlock; 1888 1889 if (*cur_mode) { 1890 /* disable strict mode */ 1891 *cur_mode = false; 1892 } else { 1893 if (vmap->shared_tables) { 1894 /* we cannot allow strict_mode because there are some 1895 * vrfs that share one or more tables. 1896 */ 1897 res = -EBUSY; 1898 goto unlock; 1899 } 1900 1901 /* no tables are shared among vrfs, so we can go back 1902 * to 1:1 association between a vrf with its table. 1903 */ 1904 *cur_mode = true; 1905 } 1906 1907 unlock: 1908 vrf_map_unlock(vmap); 1909 1910 return res; 1911 } 1912 1913 static int vrf_shared_table_handler(struct ctl_table *table, int write, 1914 void *buffer, size_t *lenp, loff_t *ppos) 1915 { 1916 struct net *net = (struct net *)table->extra1; 1917 struct vrf_map *vmap = netns_vrf_map(net); 1918 int proc_strict_mode = 0; 1919 struct ctl_table tmp = { 1920 .procname = table->procname, 1921 .data = &proc_strict_mode, 1922 .maxlen = sizeof(int), 1923 .mode = table->mode, 1924 .extra1 = SYSCTL_ZERO, 1925 .extra2 = SYSCTL_ONE, 1926 }; 1927 int ret; 1928 1929 if (!write) 1930 proc_strict_mode = vrf_strict_mode(vmap); 1931 1932 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 1933 1934 if (write && ret == 0) 1935 ret = vrf_strict_mode_change(vmap, (bool)proc_strict_mode); 1936 1937 return ret; 1938 } 1939 1940 static const struct ctl_table vrf_table[] = { 1941 { 1942 .procname = "strict_mode", 1943 .data = NULL, 1944 .maxlen = sizeof(int), 1945 .mode = 0644, 1946 .proc_handler = vrf_shared_table_handler, 1947 /* set by the vrf_netns_init */ 1948 .extra1 = NULL, 1949 }, 1950 { }, 1951 }; 1952 1953 static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf) 1954 { 1955 struct ctl_table *table; 1956 1957 table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL); 1958 if (!table) 1959 return -ENOMEM; 1960 1961 /* init the extra1 parameter with the reference to current netns */ 1962 table[0].extra1 = net; 1963 1964 nn_vrf->ctl_hdr = register_net_sysctl(net, "net/vrf", table); 1965 if (!nn_vrf->ctl_hdr) { 1966 kfree(table); 1967 return -ENOMEM; 1968 } 1969 1970 return 0; 1971 } 1972 1973 static void vrf_netns_exit_sysctl(struct net *net) 1974 { 1975 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id); 1976 struct ctl_table *table; 1977 1978 table = nn_vrf->ctl_hdr->ctl_table_arg; 1979 unregister_net_sysctl_table(nn_vrf->ctl_hdr); 1980 kfree(table); 1981 } 1982 #else 1983 static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf) 1984 { 1985 return 0; 1986 } 1987 1988 static void vrf_netns_exit_sysctl(struct net *net) 1989 { 1990 } 1991 #endif 1992 1993 /* Initialize per network namespace state */ 1994 static int __net_init vrf_netns_init(struct net *net) 1995 { 1996 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id); 1997 1998 nn_vrf->add_fib_rules = true; 1999 vrf_map_init(&nn_vrf->vmap); 2000 2001 return vrf_netns_init_sysctl(net, nn_vrf); 2002 } 2003 2004 static void __net_exit vrf_netns_exit(struct net *net) 2005 { 2006 vrf_netns_exit_sysctl(net); 2007 } 2008 2009 static struct pernet_operations vrf_net_ops __net_initdata = { 2010 .init = vrf_netns_init, 2011 .exit = vrf_netns_exit, 2012 .id = &vrf_net_id, 2013 .size = sizeof(struct netns_vrf), 2014 }; 2015 2016 static int __init vrf_init_module(void) 2017 { 2018 int rc; 2019 2020 register_netdevice_notifier(&vrf_notifier_block); 2021 2022 rc = register_pernet_subsys(&vrf_net_ops); 2023 if (rc < 0) 2024 goto error; 2025 2026 rc = l3mdev_table_lookup_register(L3MDEV_TYPE_VRF, 2027 vrf_ifindex_lookup_by_table_id); 2028 if (rc < 0) 2029 goto unreg_pernet; 2030 2031 rc = rtnl_link_register(&vrf_link_ops); 2032 if (rc < 0) 2033 goto table_lookup_unreg; 2034 2035 return 0; 2036 2037 table_lookup_unreg: 2038 l3mdev_table_lookup_unregister(L3MDEV_TYPE_VRF, 2039 vrf_ifindex_lookup_by_table_id); 2040 2041 unreg_pernet: 2042 unregister_pernet_subsys(&vrf_net_ops); 2043 2044 error: 2045 unregister_netdevice_notifier(&vrf_notifier_block); 2046 return rc; 2047 } 2048 2049 module_init(vrf_init_module); 2050 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern"); 2051 MODULE_DESCRIPTION("Device driver to instantiate VRF domains"); 2052 MODULE_LICENSE("GPL"); 2053 MODULE_ALIAS_RTNL_LINK(DRV_NAME); 2054 MODULE_VERSION(DRV_VERSION); 2055