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/sch_generic.h> 38 #include <net/netns/generic.h> 39 #include <net/netfilter/nf_conntrack.h> 40 41 #define DRV_NAME "vrf" 42 #define DRV_VERSION "1.1" 43 44 #define FIB_RULE_PREF 1000 /* default preference for FIB rules */ 45 46 #define HT_MAP_BITS 4 47 #define HASH_INITVAL ((u32)0xcafef00d) 48 49 struct vrf_map { 50 DECLARE_HASHTABLE(ht, HT_MAP_BITS); 51 spinlock_t vmap_lock; 52 53 /* shared_tables: 54 * count how many distinct tables do not comply with the strict mode 55 * requirement. 56 * shared_tables value must be 0 in order to enable the strict mode. 57 * 58 * example of the evolution of shared_tables: 59 * | time 60 * add vrf0 --> table 100 shared_tables = 0 | t0 61 * add vrf1 --> table 101 shared_tables = 0 | t1 62 * add vrf2 --> table 100 shared_tables = 1 | t2 63 * add vrf3 --> table 100 shared_tables = 1 | t3 64 * add vrf4 --> table 101 shared_tables = 2 v t4 65 * 66 * shared_tables is a "step function" (or "staircase function") 67 * and it is increased by one when the second vrf is associated to a 68 * table. 69 * 70 * at t2, vrf0 and vrf2 are bound to table 100: shared_tables = 1. 71 * 72 * at t3, another dev (vrf3) is bound to the same table 100 but the 73 * value of shared_tables is still 1. 74 * This means that no matter how many new vrfs will register on the 75 * table 100, the shared_tables will not increase (considering only 76 * table 100). 77 * 78 * at t4, vrf4 is bound to table 101, and shared_tables = 2. 79 * 80 * Looking at the value of shared_tables we can immediately know if 81 * the strict_mode can or cannot be enforced. Indeed, strict_mode 82 * can be enforced iff shared_tables = 0. 83 * 84 * Conversely, shared_tables is decreased when a vrf is de-associated 85 * from a table with exactly two associated vrfs. 86 */ 87 u32 shared_tables; 88 89 bool strict_mode; 90 }; 91 92 struct vrf_map_elem { 93 struct hlist_node hnode; 94 struct list_head vrf_list; /* VRFs registered to this table */ 95 96 u32 table_id; 97 int users; 98 int ifindex; 99 }; 100 101 static unsigned int vrf_net_id; 102 103 /* per netns vrf data */ 104 struct netns_vrf { 105 /* protected by rtnl lock */ 106 bool add_fib_rules; 107 108 struct vrf_map vmap; 109 struct ctl_table_header *ctl_hdr; 110 }; 111 112 struct net_vrf { 113 struct rtable __rcu *rth; 114 struct rt6_info __rcu *rt6; 115 #if IS_ENABLED(CONFIG_IPV6) 116 struct fib6_table *fib6_table; 117 #endif 118 u32 tb_id; 119 120 struct list_head me_list; /* entry in vrf_map_elem */ 121 int ifindex; 122 }; 123 124 struct pcpu_dstats { 125 u64 tx_pkts; 126 u64 tx_bytes; 127 u64 tx_drps; 128 u64 rx_pkts; 129 u64 rx_bytes; 130 u64 rx_drps; 131 struct u64_stats_sync syncp; 132 }; 133 134 static void vrf_rx_stats(struct net_device *dev, int len) 135 { 136 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); 137 138 u64_stats_update_begin(&dstats->syncp); 139 dstats->rx_pkts++; 140 dstats->rx_bytes += len; 141 u64_stats_update_end(&dstats->syncp); 142 } 143 144 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb) 145 { 146 vrf_dev->stats.tx_errors++; 147 kfree_skb(skb); 148 } 149 150 static void vrf_get_stats64(struct net_device *dev, 151 struct rtnl_link_stats64 *stats) 152 { 153 int i; 154 155 for_each_possible_cpu(i) { 156 const struct pcpu_dstats *dstats; 157 u64 tbytes, tpkts, tdrops, rbytes, rpkts; 158 unsigned int start; 159 160 dstats = per_cpu_ptr(dev->dstats, i); 161 do { 162 start = u64_stats_fetch_begin_irq(&dstats->syncp); 163 tbytes = dstats->tx_bytes; 164 tpkts = dstats->tx_pkts; 165 tdrops = dstats->tx_drps; 166 rbytes = dstats->rx_bytes; 167 rpkts = dstats->rx_pkts; 168 } while (u64_stats_fetch_retry_irq(&dstats->syncp, start)); 169 stats->tx_bytes += tbytes; 170 stats->tx_packets += tpkts; 171 stats->tx_dropped += tdrops; 172 stats->rx_bytes += rbytes; 173 stats->rx_packets += rpkts; 174 } 175 } 176 177 static struct vrf_map *netns_vrf_map(struct net *net) 178 { 179 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id); 180 181 return &nn_vrf->vmap; 182 } 183 184 static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev) 185 { 186 return netns_vrf_map(dev_net(dev)); 187 } 188 189 static int vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem *me) 190 { 191 struct list_head *me_head = &me->vrf_list; 192 struct net_vrf *vrf; 193 194 if (list_empty(me_head)) 195 return -ENODEV; 196 197 vrf = list_first_entry(me_head, struct net_vrf, me_list); 198 199 return vrf->ifindex; 200 } 201 202 static struct vrf_map_elem *vrf_map_elem_alloc(gfp_t flags) 203 { 204 struct vrf_map_elem *me; 205 206 me = kmalloc(sizeof(*me), flags); 207 if (!me) 208 return NULL; 209 210 return me; 211 } 212 213 static void vrf_map_elem_free(struct vrf_map_elem *me) 214 { 215 kfree(me); 216 } 217 218 static void vrf_map_elem_init(struct vrf_map_elem *me, int table_id, 219 int ifindex, int users) 220 { 221 me->table_id = table_id; 222 me->ifindex = ifindex; 223 me->users = users; 224 INIT_LIST_HEAD(&me->vrf_list); 225 } 226 227 static struct vrf_map_elem *vrf_map_lookup_elem(struct vrf_map *vmap, 228 u32 table_id) 229 { 230 struct vrf_map_elem *me; 231 u32 key; 232 233 key = jhash_1word(table_id, HASH_INITVAL); 234 hash_for_each_possible(vmap->ht, me, hnode, key) { 235 if (me->table_id == table_id) 236 return me; 237 } 238 239 return NULL; 240 } 241 242 static void vrf_map_add_elem(struct vrf_map *vmap, struct vrf_map_elem *me) 243 { 244 u32 table_id = me->table_id; 245 u32 key; 246 247 key = jhash_1word(table_id, HASH_INITVAL); 248 hash_add(vmap->ht, &me->hnode, key); 249 } 250 251 static void vrf_map_del_elem(struct vrf_map_elem *me) 252 { 253 hash_del(&me->hnode); 254 } 255 256 static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock) 257 { 258 spin_lock(&vmap->vmap_lock); 259 } 260 261 static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock) 262 { 263 spin_unlock(&vmap->vmap_lock); 264 } 265 266 /* called with rtnl lock held */ 267 static int 268 vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack) 269 { 270 struct vrf_map *vmap = netns_vrf_map_by_dev(dev); 271 struct net_vrf *vrf = netdev_priv(dev); 272 struct vrf_map_elem *new_me, *me; 273 u32 table_id = vrf->tb_id; 274 bool free_new_me = false; 275 int users; 276 int res; 277 278 /* we pre-allocate elements used in the spin-locked section (so that we 279 * keep the spinlock as short as possible). 280 */ 281 new_me = vrf_map_elem_alloc(GFP_KERNEL); 282 if (!new_me) 283 return -ENOMEM; 284 285 vrf_map_elem_init(new_me, table_id, dev->ifindex, 0); 286 287 vrf_map_lock(vmap); 288 289 me = vrf_map_lookup_elem(vmap, table_id); 290 if (!me) { 291 me = new_me; 292 vrf_map_add_elem(vmap, me); 293 goto link_vrf; 294 } 295 296 /* we already have an entry in the vrf_map, so it means there is (at 297 * least) a vrf registered on the specific table. 298 */ 299 free_new_me = true; 300 if (vmap->strict_mode) { 301 /* vrfs cannot share the same table */ 302 NL_SET_ERR_MSG(extack, "Table is used by another VRF"); 303 res = -EBUSY; 304 goto unlock; 305 } 306 307 link_vrf: 308 users = ++me->users; 309 if (users == 2) 310 ++vmap->shared_tables; 311 312 list_add(&vrf->me_list, &me->vrf_list); 313 314 res = 0; 315 316 unlock: 317 vrf_map_unlock(vmap); 318 319 /* clean-up, if needed */ 320 if (free_new_me) 321 vrf_map_elem_free(new_me); 322 323 return res; 324 } 325 326 /* called with rtnl lock held */ 327 static void vrf_map_unregister_dev(struct net_device *dev) 328 { 329 struct vrf_map *vmap = netns_vrf_map_by_dev(dev); 330 struct net_vrf *vrf = netdev_priv(dev); 331 u32 table_id = vrf->tb_id; 332 struct vrf_map_elem *me; 333 int users; 334 335 vrf_map_lock(vmap); 336 337 me = vrf_map_lookup_elem(vmap, table_id); 338 if (!me) 339 goto unlock; 340 341 list_del(&vrf->me_list); 342 343 users = --me->users; 344 if (users == 1) { 345 --vmap->shared_tables; 346 } else if (users == 0) { 347 vrf_map_del_elem(me); 348 349 /* no one will refer to this element anymore */ 350 vrf_map_elem_free(me); 351 } 352 353 unlock: 354 vrf_map_unlock(vmap); 355 } 356 357 /* return the vrf device index associated with the table_id */ 358 static int vrf_ifindex_lookup_by_table_id(struct net *net, u32 table_id) 359 { 360 struct vrf_map *vmap = netns_vrf_map(net); 361 struct vrf_map_elem *me; 362 int ifindex; 363 364 vrf_map_lock(vmap); 365 366 if (!vmap->strict_mode) { 367 ifindex = -EPERM; 368 goto unlock; 369 } 370 371 me = vrf_map_lookup_elem(vmap, table_id); 372 if (!me) { 373 ifindex = -ENODEV; 374 goto unlock; 375 } 376 377 ifindex = vrf_map_elem_get_vrf_ifindex(me); 378 379 unlock: 380 vrf_map_unlock(vmap); 381 382 return ifindex; 383 } 384 385 /* by default VRF devices do not have a qdisc and are expected 386 * to be created with only a single queue. 387 */ 388 static bool qdisc_tx_is_default(const struct net_device *dev) 389 { 390 struct netdev_queue *txq; 391 struct Qdisc *qdisc; 392 393 if (dev->num_tx_queues > 1) 394 return false; 395 396 txq = netdev_get_tx_queue(dev, 0); 397 qdisc = rcu_access_pointer(txq->qdisc); 398 399 return !qdisc->enqueue; 400 } 401 402 /* Local traffic destined to local address. Reinsert the packet to rx 403 * path, similar to loopback handling. 404 */ 405 static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev, 406 struct dst_entry *dst) 407 { 408 int len = skb->len; 409 410 skb_orphan(skb); 411 412 skb_dst_set(skb, dst); 413 414 /* set pkt_type to avoid skb hitting packet taps twice - 415 * once on Tx and again in Rx processing 416 */ 417 skb->pkt_type = PACKET_LOOPBACK; 418 419 skb->protocol = eth_type_trans(skb, dev); 420 421 if (likely(__netif_rx(skb) == NET_RX_SUCCESS)) 422 vrf_rx_stats(dev, len); 423 else 424 this_cpu_inc(dev->dstats->rx_drps); 425 426 return NETDEV_TX_OK; 427 } 428 429 static void vrf_nf_set_untracked(struct sk_buff *skb) 430 { 431 if (skb_get_nfct(skb) == 0) 432 nf_ct_set(skb, NULL, IP_CT_UNTRACKED); 433 } 434 435 static void vrf_nf_reset_ct(struct sk_buff *skb) 436 { 437 if (skb_get_nfct(skb) == IP_CT_UNTRACKED) 438 nf_reset_ct(skb); 439 } 440 441 #if IS_ENABLED(CONFIG_IPV6) 442 static int vrf_ip6_local_out(struct net *net, struct sock *sk, 443 struct sk_buff *skb) 444 { 445 int err; 446 447 vrf_nf_reset_ct(skb); 448 449 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, 450 sk, skb, NULL, skb_dst(skb)->dev, dst_output); 451 452 if (likely(err == 1)) 453 err = dst_output(net, sk, skb); 454 455 return err; 456 } 457 458 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, 459 struct net_device *dev) 460 { 461 const struct ipv6hdr *iph; 462 struct net *net = dev_net(skb->dev); 463 struct flowi6 fl6; 464 int ret = NET_XMIT_DROP; 465 struct dst_entry *dst; 466 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst; 467 468 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr))) 469 goto err; 470 471 iph = ipv6_hdr(skb); 472 473 memset(&fl6, 0, sizeof(fl6)); 474 /* needed to match OIF rule */ 475 fl6.flowi6_l3mdev = dev->ifindex; 476 fl6.flowi6_iif = LOOPBACK_IFINDEX; 477 fl6.daddr = iph->daddr; 478 fl6.saddr = iph->saddr; 479 fl6.flowlabel = ip6_flowinfo(iph); 480 fl6.flowi6_mark = skb->mark; 481 fl6.flowi6_proto = iph->nexthdr; 482 483 dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL); 484 if (IS_ERR(dst) || dst == dst_null) 485 goto err; 486 487 skb_dst_drop(skb); 488 489 /* if dst.dev is the VRF device again this is locally originated traffic 490 * destined to a local address. Short circuit to Rx path. 491 */ 492 if (dst->dev == dev) 493 return vrf_local_xmit(skb, dev, dst); 494 495 skb_dst_set(skb, dst); 496 497 /* strip the ethernet header added for pass through VRF device */ 498 __skb_pull(skb, skb_network_offset(skb)); 499 500 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); 501 ret = vrf_ip6_local_out(net, skb->sk, skb); 502 if (unlikely(net_xmit_eval(ret))) 503 dev->stats.tx_errors++; 504 else 505 ret = NET_XMIT_SUCCESS; 506 507 return ret; 508 err: 509 vrf_tx_error(dev, skb); 510 return NET_XMIT_DROP; 511 } 512 #else 513 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, 514 struct net_device *dev) 515 { 516 vrf_tx_error(dev, skb); 517 return NET_XMIT_DROP; 518 } 519 #endif 520 521 /* based on ip_local_out; can't use it b/c the dst is switched pointing to us */ 522 static int vrf_ip_local_out(struct net *net, struct sock *sk, 523 struct sk_buff *skb) 524 { 525 int err; 526 527 vrf_nf_reset_ct(skb); 528 529 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk, 530 skb, NULL, skb_dst(skb)->dev, dst_output); 531 if (likely(err == 1)) 532 err = dst_output(net, sk, skb); 533 534 return err; 535 } 536 537 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb, 538 struct net_device *vrf_dev) 539 { 540 struct iphdr *ip4h; 541 int ret = NET_XMIT_DROP; 542 struct flowi4 fl4; 543 struct net *net = dev_net(vrf_dev); 544 struct rtable *rt; 545 546 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr))) 547 goto err; 548 549 ip4h = ip_hdr(skb); 550 551 memset(&fl4, 0, sizeof(fl4)); 552 /* needed to match OIF rule */ 553 fl4.flowi4_l3mdev = vrf_dev->ifindex; 554 fl4.flowi4_iif = LOOPBACK_IFINDEX; 555 fl4.flowi4_tos = RT_TOS(ip4h->tos); 556 fl4.flowi4_flags = FLOWI_FLAG_ANYSRC; 557 fl4.flowi4_proto = ip4h->protocol; 558 fl4.daddr = ip4h->daddr; 559 fl4.saddr = ip4h->saddr; 560 561 rt = ip_route_output_flow(net, &fl4, NULL); 562 if (IS_ERR(rt)) 563 goto err; 564 565 skb_dst_drop(skb); 566 567 /* if dst.dev is the VRF device again this is locally originated traffic 568 * destined to a local address. Short circuit to Rx path. 569 */ 570 if (rt->dst.dev == vrf_dev) 571 return vrf_local_xmit(skb, vrf_dev, &rt->dst); 572 573 skb_dst_set(skb, &rt->dst); 574 575 /* strip the ethernet header added for pass through VRF device */ 576 __skb_pull(skb, skb_network_offset(skb)); 577 578 if (!ip4h->saddr) { 579 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0, 580 RT_SCOPE_LINK); 581 } 582 583 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 584 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb); 585 if (unlikely(net_xmit_eval(ret))) 586 vrf_dev->stats.tx_errors++; 587 else 588 ret = NET_XMIT_SUCCESS; 589 590 out: 591 return ret; 592 err: 593 vrf_tx_error(vrf_dev, skb); 594 goto out; 595 } 596 597 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev) 598 { 599 switch (skb->protocol) { 600 case htons(ETH_P_IP): 601 return vrf_process_v4_outbound(skb, dev); 602 case htons(ETH_P_IPV6): 603 return vrf_process_v6_outbound(skb, dev); 604 default: 605 vrf_tx_error(dev, skb); 606 return NET_XMIT_DROP; 607 } 608 } 609 610 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev) 611 { 612 int len = skb->len; 613 netdev_tx_t ret = is_ip_tx_frame(skb, dev); 614 615 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) { 616 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); 617 618 u64_stats_update_begin(&dstats->syncp); 619 dstats->tx_pkts++; 620 dstats->tx_bytes += len; 621 u64_stats_update_end(&dstats->syncp); 622 } else { 623 this_cpu_inc(dev->dstats->tx_drps); 624 } 625 626 return ret; 627 } 628 629 static void vrf_finish_direct(struct sk_buff *skb) 630 { 631 struct net_device *vrf_dev = skb->dev; 632 633 if (!list_empty(&vrf_dev->ptype_all) && 634 likely(skb_headroom(skb) >= ETH_HLEN)) { 635 struct ethhdr *eth = skb_push(skb, ETH_HLEN); 636 637 ether_addr_copy(eth->h_source, vrf_dev->dev_addr); 638 eth_zero_addr(eth->h_dest); 639 eth->h_proto = skb->protocol; 640 641 rcu_read_lock_bh(); 642 dev_queue_xmit_nit(skb, vrf_dev); 643 rcu_read_unlock_bh(); 644 645 skb_pull(skb, ETH_HLEN); 646 } 647 648 vrf_nf_reset_ct(skb); 649 } 650 651 #if IS_ENABLED(CONFIG_IPV6) 652 /* modelled after ip6_finish_output2 */ 653 static int vrf_finish_output6(struct net *net, struct sock *sk, 654 struct sk_buff *skb) 655 { 656 struct dst_entry *dst = skb_dst(skb); 657 struct net_device *dev = dst->dev; 658 const struct in6_addr *nexthop; 659 struct neighbour *neigh; 660 int ret; 661 662 vrf_nf_reset_ct(skb); 663 664 skb->protocol = htons(ETH_P_IPV6); 665 skb->dev = dev; 666 667 rcu_read_lock_bh(); 668 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr); 669 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop); 670 if (unlikely(!neigh)) 671 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false); 672 if (!IS_ERR(neigh)) { 673 sock_confirm_neigh(skb, neigh); 674 ret = neigh_output(neigh, skb, false); 675 rcu_read_unlock_bh(); 676 return ret; 677 } 678 rcu_read_unlock_bh(); 679 680 IP6_INC_STATS(dev_net(dst->dev), 681 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 682 kfree_skb(skb); 683 return -EINVAL; 684 } 685 686 /* modelled after ip6_output */ 687 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb) 688 { 689 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, 690 net, sk, skb, NULL, skb_dst(skb)->dev, 691 vrf_finish_output6, 692 !(IP6CB(skb)->flags & IP6SKB_REROUTED)); 693 } 694 695 /* set dst on skb to send packet to us via dev_xmit path. Allows 696 * packet to go through device based features such as qdisc, netfilter 697 * hooks and packet sockets with skb->dev set to vrf device. 698 */ 699 static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev, 700 struct sk_buff *skb) 701 { 702 struct net_vrf *vrf = netdev_priv(vrf_dev); 703 struct dst_entry *dst = NULL; 704 struct rt6_info *rt6; 705 706 rcu_read_lock(); 707 708 rt6 = rcu_dereference(vrf->rt6); 709 if (likely(rt6)) { 710 dst = &rt6->dst; 711 dst_hold(dst); 712 } 713 714 rcu_read_unlock(); 715 716 if (unlikely(!dst)) { 717 vrf_tx_error(vrf_dev, skb); 718 return NULL; 719 } 720 721 skb_dst_drop(skb); 722 skb_dst_set(skb, dst); 723 724 return skb; 725 } 726 727 static int vrf_output6_direct_finish(struct net *net, struct sock *sk, 728 struct sk_buff *skb) 729 { 730 vrf_finish_direct(skb); 731 732 return vrf_ip6_local_out(net, sk, skb); 733 } 734 735 static int vrf_output6_direct(struct net *net, struct sock *sk, 736 struct sk_buff *skb) 737 { 738 int err = 1; 739 740 skb->protocol = htons(ETH_P_IPV6); 741 742 if (!(IPCB(skb)->flags & IPSKB_REROUTED)) 743 err = nf_hook(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb, 744 NULL, skb->dev, vrf_output6_direct_finish); 745 746 if (likely(err == 1)) 747 vrf_finish_direct(skb); 748 749 return err; 750 } 751 752 static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk, 753 struct sk_buff *skb) 754 { 755 int err; 756 757 err = vrf_output6_direct(net, sk, skb); 758 if (likely(err == 1)) 759 err = vrf_ip6_local_out(net, sk, skb); 760 761 return err; 762 } 763 764 static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev, 765 struct sock *sk, 766 struct sk_buff *skb) 767 { 768 struct net *net = dev_net(vrf_dev); 769 int err; 770 771 skb->dev = vrf_dev; 772 773 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, 774 skb, NULL, vrf_dev, vrf_ip6_out_direct_finish); 775 776 if (likely(err == 1)) 777 err = vrf_output6_direct(net, sk, skb); 778 779 if (likely(err == 1)) 780 return skb; 781 782 return NULL; 783 } 784 785 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev, 786 struct sock *sk, 787 struct sk_buff *skb) 788 { 789 /* don't divert link scope packets */ 790 if (rt6_need_strict(&ipv6_hdr(skb)->daddr)) 791 return skb; 792 793 vrf_nf_set_untracked(skb); 794 795 if (qdisc_tx_is_default(vrf_dev) || 796 IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) 797 return vrf_ip6_out_direct(vrf_dev, sk, skb); 798 799 return vrf_ip6_out_redirect(vrf_dev, skb); 800 } 801 802 /* holding rtnl */ 803 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) 804 { 805 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6); 806 struct net *net = dev_net(dev); 807 struct dst_entry *dst; 808 809 RCU_INIT_POINTER(vrf->rt6, NULL); 810 synchronize_rcu(); 811 812 /* move dev in dst's to loopback so this VRF device can be deleted 813 * - based on dst_ifdown 814 */ 815 if (rt6) { 816 dst = &rt6->dst; 817 dev_replace_track(dst->dev, net->loopback_dev, 818 &dst->dev_tracker, GFP_KERNEL); 819 dst->dev = net->loopback_dev; 820 dst_release(dst); 821 } 822 } 823 824 static int vrf_rt6_create(struct net_device *dev) 825 { 826 int flags = DST_NOPOLICY | DST_NOXFRM; 827 struct net_vrf *vrf = netdev_priv(dev); 828 struct net *net = dev_net(dev); 829 struct rt6_info *rt6; 830 int rc = -ENOMEM; 831 832 /* IPv6 can be CONFIG enabled and then disabled runtime */ 833 if (!ipv6_mod_enabled()) 834 return 0; 835 836 vrf->fib6_table = fib6_new_table(net, vrf->tb_id); 837 if (!vrf->fib6_table) 838 goto out; 839 840 /* create a dst for routing packets out a VRF device */ 841 rt6 = ip6_dst_alloc(net, dev, flags); 842 if (!rt6) 843 goto out; 844 845 rt6->dst.output = vrf_output6; 846 847 rcu_assign_pointer(vrf->rt6, rt6); 848 849 rc = 0; 850 out: 851 return rc; 852 } 853 #else 854 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev, 855 struct sock *sk, 856 struct sk_buff *skb) 857 { 858 return skb; 859 } 860 861 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) 862 { 863 } 864 865 static int vrf_rt6_create(struct net_device *dev) 866 { 867 return 0; 868 } 869 #endif 870 871 /* modelled after ip_finish_output2 */ 872 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 873 { 874 struct dst_entry *dst = skb_dst(skb); 875 struct rtable *rt = (struct rtable *)dst; 876 struct net_device *dev = dst->dev; 877 unsigned int hh_len = LL_RESERVED_SPACE(dev); 878 struct neighbour *neigh; 879 bool is_v6gw = false; 880 881 vrf_nf_reset_ct(skb); 882 883 /* Be paranoid, rather than too clever. */ 884 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { 885 skb = skb_expand_head(skb, hh_len); 886 if (!skb) { 887 dev->stats.tx_errors++; 888 return -ENOMEM; 889 } 890 } 891 892 rcu_read_lock_bh(); 893 894 neigh = ip_neigh_for_gw(rt, skb, &is_v6gw); 895 if (!IS_ERR(neigh)) { 896 int ret; 897 898 sock_confirm_neigh(skb, neigh); 899 /* if crossing protocols, can not use the cached header */ 900 ret = neigh_output(neigh, skb, is_v6gw); 901 rcu_read_unlock_bh(); 902 return ret; 903 } 904 905 rcu_read_unlock_bh(); 906 vrf_tx_error(skb->dev, skb); 907 return -EINVAL; 908 } 909 910 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb) 911 { 912 struct net_device *dev = skb_dst(skb)->dev; 913 914 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len); 915 916 skb->dev = dev; 917 skb->protocol = htons(ETH_P_IP); 918 919 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, 920 net, sk, skb, NULL, dev, 921 vrf_finish_output, 922 !(IPCB(skb)->flags & IPSKB_REROUTED)); 923 } 924 925 /* set dst on skb to send packet to us via dev_xmit path. Allows 926 * packet to go through device based features such as qdisc, netfilter 927 * hooks and packet sockets with skb->dev set to vrf device. 928 */ 929 static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev, 930 struct sk_buff *skb) 931 { 932 struct net_vrf *vrf = netdev_priv(vrf_dev); 933 struct dst_entry *dst = NULL; 934 struct rtable *rth; 935 936 rcu_read_lock(); 937 938 rth = rcu_dereference(vrf->rth); 939 if (likely(rth)) { 940 dst = &rth->dst; 941 dst_hold(dst); 942 } 943 944 rcu_read_unlock(); 945 946 if (unlikely(!dst)) { 947 vrf_tx_error(vrf_dev, skb); 948 return NULL; 949 } 950 951 skb_dst_drop(skb); 952 skb_dst_set(skb, dst); 953 954 return skb; 955 } 956 957 static int vrf_output_direct_finish(struct net *net, struct sock *sk, 958 struct sk_buff *skb) 959 { 960 vrf_finish_direct(skb); 961 962 return vrf_ip_local_out(net, sk, skb); 963 } 964 965 static int vrf_output_direct(struct net *net, struct sock *sk, 966 struct sk_buff *skb) 967 { 968 int err = 1; 969 970 skb->protocol = htons(ETH_P_IP); 971 972 if (!(IPCB(skb)->flags & IPSKB_REROUTED)) 973 err = nf_hook(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb, 974 NULL, skb->dev, vrf_output_direct_finish); 975 976 if (likely(err == 1)) 977 vrf_finish_direct(skb); 978 979 return err; 980 } 981 982 static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk, 983 struct sk_buff *skb) 984 { 985 int err; 986 987 err = vrf_output_direct(net, sk, skb); 988 if (likely(err == 1)) 989 err = vrf_ip_local_out(net, sk, skb); 990 991 return err; 992 } 993 994 static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev, 995 struct sock *sk, 996 struct sk_buff *skb) 997 { 998 struct net *net = dev_net(vrf_dev); 999 int err; 1000 1001 skb->dev = vrf_dev; 1002 1003 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk, 1004 skb, NULL, vrf_dev, vrf_ip_out_direct_finish); 1005 1006 if (likely(err == 1)) 1007 err = vrf_output_direct(net, sk, skb); 1008 1009 if (likely(err == 1)) 1010 return skb; 1011 1012 return NULL; 1013 } 1014 1015 static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev, 1016 struct sock *sk, 1017 struct sk_buff *skb) 1018 { 1019 /* don't divert multicast or local broadcast */ 1020 if (ipv4_is_multicast(ip_hdr(skb)->daddr) || 1021 ipv4_is_lbcast(ip_hdr(skb)->daddr)) 1022 return skb; 1023 1024 vrf_nf_set_untracked(skb); 1025 1026 if (qdisc_tx_is_default(vrf_dev) || 1027 IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) 1028 return vrf_ip_out_direct(vrf_dev, sk, skb); 1029 1030 return vrf_ip_out_redirect(vrf_dev, skb); 1031 } 1032 1033 /* called with rcu lock held */ 1034 static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev, 1035 struct sock *sk, 1036 struct sk_buff *skb, 1037 u16 proto) 1038 { 1039 switch (proto) { 1040 case AF_INET: 1041 return vrf_ip_out(vrf_dev, sk, skb); 1042 case AF_INET6: 1043 return vrf_ip6_out(vrf_dev, sk, skb); 1044 } 1045 1046 return skb; 1047 } 1048 1049 /* holding rtnl */ 1050 static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf) 1051 { 1052 struct rtable *rth = rtnl_dereference(vrf->rth); 1053 struct net *net = dev_net(dev); 1054 struct dst_entry *dst; 1055 1056 RCU_INIT_POINTER(vrf->rth, NULL); 1057 synchronize_rcu(); 1058 1059 /* move dev in dst's to loopback so this VRF device can be deleted 1060 * - based on dst_ifdown 1061 */ 1062 if (rth) { 1063 dst = &rth->dst; 1064 dev_replace_track(dst->dev, net->loopback_dev, 1065 &dst->dev_tracker, GFP_KERNEL); 1066 dst->dev = net->loopback_dev; 1067 dst_release(dst); 1068 } 1069 } 1070 1071 static int vrf_rtable_create(struct net_device *dev) 1072 { 1073 struct net_vrf *vrf = netdev_priv(dev); 1074 struct rtable *rth; 1075 1076 if (!fib_new_table(dev_net(dev), vrf->tb_id)) 1077 return -ENOMEM; 1078 1079 /* create a dst for routing packets out through a VRF device */ 1080 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1); 1081 if (!rth) 1082 return -ENOMEM; 1083 1084 rth->dst.output = vrf_output; 1085 1086 rcu_assign_pointer(vrf->rth, rth); 1087 1088 return 0; 1089 } 1090 1091 /**************************** device handling ********************/ 1092 1093 /* cycle interface to flush neighbor cache and move routes across tables */ 1094 static void cycle_netdev(struct net_device *dev, 1095 struct netlink_ext_ack *extack) 1096 { 1097 unsigned int flags = dev->flags; 1098 int ret; 1099 1100 if (!netif_running(dev)) 1101 return; 1102 1103 ret = dev_change_flags(dev, flags & ~IFF_UP, extack); 1104 if (ret >= 0) 1105 ret = dev_change_flags(dev, flags, extack); 1106 1107 if (ret < 0) { 1108 netdev_err(dev, 1109 "Failed to cycle device %s; route tables might be wrong!\n", 1110 dev->name); 1111 } 1112 } 1113 1114 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev, 1115 struct netlink_ext_ack *extack) 1116 { 1117 int ret; 1118 1119 /* do not allow loopback device to be enslaved to a VRF. 1120 * The vrf device acts as the loopback for the vrf. 1121 */ 1122 if (port_dev == dev_net(dev)->loopback_dev) { 1123 NL_SET_ERR_MSG(extack, 1124 "Can not enslave loopback device to a VRF"); 1125 return -EOPNOTSUPP; 1126 } 1127 1128 port_dev->priv_flags |= IFF_L3MDEV_SLAVE; 1129 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack); 1130 if (ret < 0) 1131 goto err; 1132 1133 cycle_netdev(port_dev, extack); 1134 1135 return 0; 1136 1137 err: 1138 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE; 1139 return ret; 1140 } 1141 1142 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev, 1143 struct netlink_ext_ack *extack) 1144 { 1145 if (netif_is_l3_master(port_dev)) { 1146 NL_SET_ERR_MSG(extack, 1147 "Can not enslave an L3 master device to a VRF"); 1148 return -EINVAL; 1149 } 1150 1151 if (netif_is_l3_slave(port_dev)) 1152 return -EINVAL; 1153 1154 return do_vrf_add_slave(dev, port_dev, extack); 1155 } 1156 1157 /* inverse of do_vrf_add_slave */ 1158 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev) 1159 { 1160 netdev_upper_dev_unlink(port_dev, dev); 1161 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE; 1162 1163 cycle_netdev(port_dev, NULL); 1164 1165 return 0; 1166 } 1167 1168 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev) 1169 { 1170 return do_vrf_del_slave(dev, port_dev); 1171 } 1172 1173 static void vrf_dev_uninit(struct net_device *dev) 1174 { 1175 struct net_vrf *vrf = netdev_priv(dev); 1176 1177 vrf_rtable_release(dev, vrf); 1178 vrf_rt6_release(dev, vrf); 1179 1180 free_percpu(dev->dstats); 1181 dev->dstats = NULL; 1182 } 1183 1184 static int vrf_dev_init(struct net_device *dev) 1185 { 1186 struct net_vrf *vrf = netdev_priv(dev); 1187 1188 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats); 1189 if (!dev->dstats) 1190 goto out_nomem; 1191 1192 /* create the default dst which points back to us */ 1193 if (vrf_rtable_create(dev) != 0) 1194 goto out_stats; 1195 1196 if (vrf_rt6_create(dev) != 0) 1197 goto out_rth; 1198 1199 dev->flags = IFF_MASTER | IFF_NOARP; 1200 1201 /* similarly, oper state is irrelevant; set to up to avoid confusion */ 1202 dev->operstate = IF_OPER_UP; 1203 netdev_lockdep_set_classes(dev); 1204 return 0; 1205 1206 out_rth: 1207 vrf_rtable_release(dev, vrf); 1208 out_stats: 1209 free_percpu(dev->dstats); 1210 dev->dstats = NULL; 1211 out_nomem: 1212 return -ENOMEM; 1213 } 1214 1215 static const struct net_device_ops vrf_netdev_ops = { 1216 .ndo_init = vrf_dev_init, 1217 .ndo_uninit = vrf_dev_uninit, 1218 .ndo_start_xmit = vrf_xmit, 1219 .ndo_set_mac_address = eth_mac_addr, 1220 .ndo_get_stats64 = vrf_get_stats64, 1221 .ndo_add_slave = vrf_add_slave, 1222 .ndo_del_slave = vrf_del_slave, 1223 }; 1224 1225 static u32 vrf_fib_table(const struct net_device *dev) 1226 { 1227 struct net_vrf *vrf = netdev_priv(dev); 1228 1229 return vrf->tb_id; 1230 } 1231 1232 static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) 1233 { 1234 kfree_skb(skb); 1235 return 0; 1236 } 1237 1238 static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook, 1239 struct sk_buff *skb, 1240 struct net_device *dev) 1241 { 1242 struct net *net = dev_net(dev); 1243 1244 if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1) 1245 skb = NULL; /* kfree_skb(skb) handled by nf code */ 1246 1247 return skb; 1248 } 1249 1250 static int vrf_prepare_mac_header(struct sk_buff *skb, 1251 struct net_device *vrf_dev, u16 proto) 1252 { 1253 struct ethhdr *eth; 1254 int err; 1255 1256 /* in general, we do not know if there is enough space in the head of 1257 * the packet for hosting the mac header. 1258 */ 1259 err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev)); 1260 if (unlikely(err)) 1261 /* no space in the skb head */ 1262 return -ENOBUFS; 1263 1264 __skb_push(skb, ETH_HLEN); 1265 eth = (struct ethhdr *)skb->data; 1266 1267 skb_reset_mac_header(skb); 1268 1269 /* we set the ethernet destination and the source addresses to the 1270 * address of the VRF device. 1271 */ 1272 ether_addr_copy(eth->h_dest, vrf_dev->dev_addr); 1273 ether_addr_copy(eth->h_source, vrf_dev->dev_addr); 1274 eth->h_proto = htons(proto); 1275 1276 /* the destination address of the Ethernet frame corresponds to the 1277 * address set on the VRF interface; therefore, the packet is intended 1278 * to be processed locally. 1279 */ 1280 skb->protocol = eth->h_proto; 1281 skb->pkt_type = PACKET_HOST; 1282 1283 skb_postpush_rcsum(skb, skb->data, ETH_HLEN); 1284 1285 skb_pull_inline(skb, ETH_HLEN); 1286 1287 return 0; 1288 } 1289 1290 /* prepare and add the mac header to the packet if it was not set previously. 1291 * In this way, packet sniffers such as tcpdump can parse the packet correctly. 1292 * If the mac header was already set, the original mac header is left 1293 * untouched and the function returns immediately. 1294 */ 1295 static int vrf_add_mac_header_if_unset(struct sk_buff *skb, 1296 struct net_device *vrf_dev, 1297 u16 proto) 1298 { 1299 if (skb_mac_header_was_set(skb)) 1300 return 0; 1301 1302 return vrf_prepare_mac_header(skb, vrf_dev, proto); 1303 } 1304 1305 #if IS_ENABLED(CONFIG_IPV6) 1306 /* neighbor handling is done with actual device; do not want 1307 * to flip skb->dev for those ndisc packets. This really fails 1308 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is 1309 * a start. 1310 */ 1311 static bool ipv6_ndisc_frame(const struct sk_buff *skb) 1312 { 1313 const struct ipv6hdr *iph = ipv6_hdr(skb); 1314 bool rc = false; 1315 1316 if (iph->nexthdr == NEXTHDR_ICMP) { 1317 const struct icmp6hdr *icmph; 1318 struct icmp6hdr _icmph; 1319 1320 icmph = skb_header_pointer(skb, sizeof(*iph), 1321 sizeof(_icmph), &_icmph); 1322 if (!icmph) 1323 goto out; 1324 1325 switch (icmph->icmp6_type) { 1326 case NDISC_ROUTER_SOLICITATION: 1327 case NDISC_ROUTER_ADVERTISEMENT: 1328 case NDISC_NEIGHBOUR_SOLICITATION: 1329 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1330 case NDISC_REDIRECT: 1331 rc = true; 1332 break; 1333 } 1334 } 1335 1336 out: 1337 return rc; 1338 } 1339 1340 static struct rt6_info *vrf_ip6_route_lookup(struct net *net, 1341 const struct net_device *dev, 1342 struct flowi6 *fl6, 1343 int ifindex, 1344 const struct sk_buff *skb, 1345 int flags) 1346 { 1347 struct net_vrf *vrf = netdev_priv(dev); 1348 1349 return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags); 1350 } 1351 1352 static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev, 1353 int ifindex) 1354 { 1355 const struct ipv6hdr *iph = ipv6_hdr(skb); 1356 struct flowi6 fl6 = { 1357 .flowi6_iif = ifindex, 1358 .flowi6_mark = skb->mark, 1359 .flowi6_proto = iph->nexthdr, 1360 .daddr = iph->daddr, 1361 .saddr = iph->saddr, 1362 .flowlabel = ip6_flowinfo(iph), 1363 }; 1364 struct net *net = dev_net(vrf_dev); 1365 struct rt6_info *rt6; 1366 1367 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb, 1368 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE); 1369 if (unlikely(!rt6)) 1370 return; 1371 1372 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst)) 1373 return; 1374 1375 skb_dst_set(skb, &rt6->dst); 1376 } 1377 1378 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, 1379 struct sk_buff *skb) 1380 { 1381 int orig_iif = skb->skb_iif; 1382 bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr); 1383 bool is_ndisc = ipv6_ndisc_frame(skb); 1384 1385 /* loopback, multicast & non-ND link-local traffic; do not push through 1386 * packet taps again. Reset pkt_type for upper layers to process skb. 1387 * For strict packets with a source LLA, determine the dst using the 1388 * original ifindex. 1389 */ 1390 if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) { 1391 skb->dev = vrf_dev; 1392 skb->skb_iif = vrf_dev->ifindex; 1393 IP6CB(skb)->flags |= IP6SKB_L3SLAVE; 1394 1395 if (skb->pkt_type == PACKET_LOOPBACK) 1396 skb->pkt_type = PACKET_HOST; 1397 else if (ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL) 1398 vrf_ip6_input_dst(skb, vrf_dev, orig_iif); 1399 1400 goto out; 1401 } 1402 1403 /* if packet is NDISC then keep the ingress interface */ 1404 if (!is_ndisc) { 1405 vrf_rx_stats(vrf_dev, skb->len); 1406 skb->dev = vrf_dev; 1407 skb->skb_iif = vrf_dev->ifindex; 1408 1409 if (!list_empty(&vrf_dev->ptype_all)) { 1410 int err; 1411 1412 err = vrf_add_mac_header_if_unset(skb, vrf_dev, 1413 ETH_P_IPV6); 1414 if (likely(!err)) { 1415 skb_push(skb, skb->mac_len); 1416 dev_queue_xmit_nit(skb, vrf_dev); 1417 skb_pull(skb, skb->mac_len); 1418 } 1419 } 1420 1421 IP6CB(skb)->flags |= IP6SKB_L3SLAVE; 1422 } 1423 1424 if (need_strict) 1425 vrf_ip6_input_dst(skb, vrf_dev, orig_iif); 1426 1427 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev); 1428 out: 1429 return skb; 1430 } 1431 1432 #else 1433 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, 1434 struct sk_buff *skb) 1435 { 1436 return skb; 1437 } 1438 #endif 1439 1440 static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev, 1441 struct sk_buff *skb) 1442 { 1443 skb->dev = vrf_dev; 1444 skb->skb_iif = vrf_dev->ifindex; 1445 IPCB(skb)->flags |= IPSKB_L3SLAVE; 1446 1447 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) 1448 goto out; 1449 1450 /* loopback traffic; do not push through packet taps again. 1451 * Reset pkt_type for upper layers to process skb 1452 */ 1453 if (skb->pkt_type == PACKET_LOOPBACK) { 1454 skb->pkt_type = PACKET_HOST; 1455 goto out; 1456 } 1457 1458 vrf_rx_stats(vrf_dev, skb->len); 1459 1460 if (!list_empty(&vrf_dev->ptype_all)) { 1461 int err; 1462 1463 err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP); 1464 if (likely(!err)) { 1465 skb_push(skb, skb->mac_len); 1466 dev_queue_xmit_nit(skb, vrf_dev); 1467 skb_pull(skb, skb->mac_len); 1468 } 1469 } 1470 1471 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev); 1472 out: 1473 return skb; 1474 } 1475 1476 /* called with rcu lock held */ 1477 static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev, 1478 struct sk_buff *skb, 1479 u16 proto) 1480 { 1481 switch (proto) { 1482 case AF_INET: 1483 return vrf_ip_rcv(vrf_dev, skb); 1484 case AF_INET6: 1485 return vrf_ip6_rcv(vrf_dev, skb); 1486 } 1487 1488 return skb; 1489 } 1490 1491 #if IS_ENABLED(CONFIG_IPV6) 1492 /* send to link-local or multicast address via interface enslaved to 1493 * VRF device. Force lookup to VRF table without changing flow struct 1494 * Note: Caller to this function must hold rcu_read_lock() and no refcnt 1495 * is taken on the dst by this function. 1496 */ 1497 static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev, 1498 struct flowi6 *fl6) 1499 { 1500 struct net *net = dev_net(dev); 1501 int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF; 1502 struct dst_entry *dst = NULL; 1503 struct rt6_info *rt; 1504 1505 /* VRF device does not have a link-local address and 1506 * sending packets to link-local or mcast addresses over 1507 * a VRF device does not make sense 1508 */ 1509 if (fl6->flowi6_oif == dev->ifindex) { 1510 dst = &net->ipv6.ip6_null_entry->dst; 1511 return dst; 1512 } 1513 1514 if (!ipv6_addr_any(&fl6->saddr)) 1515 flags |= RT6_LOOKUP_F_HAS_SADDR; 1516 1517 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags); 1518 if (rt) 1519 dst = &rt->dst; 1520 1521 return dst; 1522 } 1523 #endif 1524 1525 static const struct l3mdev_ops vrf_l3mdev_ops = { 1526 .l3mdev_fib_table = vrf_fib_table, 1527 .l3mdev_l3_rcv = vrf_l3_rcv, 1528 .l3mdev_l3_out = vrf_l3_out, 1529 #if IS_ENABLED(CONFIG_IPV6) 1530 .l3mdev_link_scope_lookup = vrf_link_scope_lookup, 1531 #endif 1532 }; 1533 1534 static void vrf_get_drvinfo(struct net_device *dev, 1535 struct ethtool_drvinfo *info) 1536 { 1537 strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); 1538 strlcpy(info->version, DRV_VERSION, sizeof(info->version)); 1539 } 1540 1541 static const struct ethtool_ops vrf_ethtool_ops = { 1542 .get_drvinfo = vrf_get_drvinfo, 1543 }; 1544 1545 static inline size_t vrf_fib_rule_nl_size(void) 1546 { 1547 size_t sz; 1548 1549 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)); 1550 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */ 1551 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */ 1552 sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */ 1553 1554 return sz; 1555 } 1556 1557 static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it) 1558 { 1559 struct fib_rule_hdr *frh; 1560 struct nlmsghdr *nlh; 1561 struct sk_buff *skb; 1562 int err; 1563 1564 if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) && 1565 !ipv6_mod_enabled()) 1566 return 0; 1567 1568 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL); 1569 if (!skb) 1570 return -ENOMEM; 1571 1572 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0); 1573 if (!nlh) 1574 goto nla_put_failure; 1575 1576 /* rule only needs to appear once */ 1577 nlh->nlmsg_flags |= NLM_F_EXCL; 1578 1579 frh = nlmsg_data(nlh); 1580 memset(frh, 0, sizeof(*frh)); 1581 frh->family = family; 1582 frh->action = FR_ACT_TO_TBL; 1583 1584 if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL)) 1585 goto nla_put_failure; 1586 1587 if (nla_put_u8(skb, FRA_L3MDEV, 1)) 1588 goto nla_put_failure; 1589 1590 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF)) 1591 goto nla_put_failure; 1592 1593 nlmsg_end(skb, nlh); 1594 1595 /* fib_nl_{new,del}rule handling looks for net from skb->sk */ 1596 skb->sk = dev_net(dev)->rtnl; 1597 if (add_it) { 1598 err = fib_nl_newrule(skb, nlh, NULL); 1599 if (err == -EEXIST) 1600 err = 0; 1601 } else { 1602 err = fib_nl_delrule(skb, nlh, NULL); 1603 if (err == -ENOENT) 1604 err = 0; 1605 } 1606 nlmsg_free(skb); 1607 1608 return err; 1609 1610 nla_put_failure: 1611 nlmsg_free(skb); 1612 1613 return -EMSGSIZE; 1614 } 1615 1616 static int vrf_add_fib_rules(const struct net_device *dev) 1617 { 1618 int err; 1619 1620 err = vrf_fib_rule(dev, AF_INET, true); 1621 if (err < 0) 1622 goto out_err; 1623 1624 err = vrf_fib_rule(dev, AF_INET6, true); 1625 if (err < 0) 1626 goto ipv6_err; 1627 1628 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES) 1629 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true); 1630 if (err < 0) 1631 goto ipmr_err; 1632 #endif 1633 1634 #if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES) 1635 err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, true); 1636 if (err < 0) 1637 goto ip6mr_err; 1638 #endif 1639 1640 return 0; 1641 1642 #if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES) 1643 ip6mr_err: 1644 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, false); 1645 #endif 1646 1647 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES) 1648 ipmr_err: 1649 vrf_fib_rule(dev, AF_INET6, false); 1650 #endif 1651 1652 ipv6_err: 1653 vrf_fib_rule(dev, AF_INET, false); 1654 1655 out_err: 1656 netdev_err(dev, "Failed to add FIB rules.\n"); 1657 return err; 1658 } 1659 1660 static void vrf_setup(struct net_device *dev) 1661 { 1662 ether_setup(dev); 1663 1664 /* Initialize the device structure. */ 1665 dev->netdev_ops = &vrf_netdev_ops; 1666 dev->l3mdev_ops = &vrf_l3mdev_ops; 1667 dev->ethtool_ops = &vrf_ethtool_ops; 1668 dev->needs_free_netdev = true; 1669 1670 /* Fill in device structure with ethernet-generic values. */ 1671 eth_hw_addr_random(dev); 1672 1673 /* don't acquire vrf device's netif_tx_lock when transmitting */ 1674 dev->features |= NETIF_F_LLTX; 1675 1676 /* don't allow vrf devices to change network namespaces. */ 1677 dev->features |= NETIF_F_NETNS_LOCAL; 1678 1679 /* does not make sense for a VLAN to be added to a vrf device */ 1680 dev->features |= NETIF_F_VLAN_CHALLENGED; 1681 1682 /* enable offload features */ 1683 dev->features |= NETIF_F_GSO_SOFTWARE; 1684 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC; 1685 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA; 1686 1687 dev->hw_features = dev->features; 1688 dev->hw_enc_features = dev->features; 1689 1690 /* default to no qdisc; user can add if desired */ 1691 dev->priv_flags |= IFF_NO_QUEUE; 1692 dev->priv_flags |= IFF_NO_RX_HANDLER; 1693 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1694 1695 /* VRF devices do not care about MTU, but if the MTU is set 1696 * too low then the ipv4 and ipv6 protocols are disabled 1697 * which breaks networking. 1698 */ 1699 dev->min_mtu = IPV6_MIN_MTU; 1700 dev->max_mtu = IP6_MAX_MTU; 1701 dev->mtu = dev->max_mtu; 1702 } 1703 1704 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[], 1705 struct netlink_ext_ack *extack) 1706 { 1707 if (tb[IFLA_ADDRESS]) { 1708 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) { 1709 NL_SET_ERR_MSG(extack, "Invalid hardware address"); 1710 return -EINVAL; 1711 } 1712 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) { 1713 NL_SET_ERR_MSG(extack, "Invalid hardware address"); 1714 return -EADDRNOTAVAIL; 1715 } 1716 } 1717 return 0; 1718 } 1719 1720 static void vrf_dellink(struct net_device *dev, struct list_head *head) 1721 { 1722 struct net_device *port_dev; 1723 struct list_head *iter; 1724 1725 netdev_for_each_lower_dev(dev, port_dev, iter) 1726 vrf_del_slave(dev, port_dev); 1727 1728 vrf_map_unregister_dev(dev); 1729 1730 unregister_netdevice_queue(dev, head); 1731 } 1732 1733 static int vrf_newlink(struct net *src_net, struct net_device *dev, 1734 struct nlattr *tb[], struct nlattr *data[], 1735 struct netlink_ext_ack *extack) 1736 { 1737 struct net_vrf *vrf = netdev_priv(dev); 1738 struct netns_vrf *nn_vrf; 1739 bool *add_fib_rules; 1740 struct net *net; 1741 int err; 1742 1743 if (!data || !data[IFLA_VRF_TABLE]) { 1744 NL_SET_ERR_MSG(extack, "VRF table id is missing"); 1745 return -EINVAL; 1746 } 1747 1748 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]); 1749 if (vrf->tb_id == RT_TABLE_UNSPEC) { 1750 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE], 1751 "Invalid VRF table id"); 1752 return -EINVAL; 1753 } 1754 1755 dev->priv_flags |= IFF_L3MDEV_MASTER; 1756 1757 err = register_netdevice(dev); 1758 if (err) 1759 goto out; 1760 1761 /* mapping between table_id and vrf; 1762 * note: such binding could not be done in the dev init function 1763 * because dev->ifindex id is not available yet. 1764 */ 1765 vrf->ifindex = dev->ifindex; 1766 1767 err = vrf_map_register_dev(dev, extack); 1768 if (err) { 1769 unregister_netdevice(dev); 1770 goto out; 1771 } 1772 1773 net = dev_net(dev); 1774 nn_vrf = net_generic(net, vrf_net_id); 1775 1776 add_fib_rules = &nn_vrf->add_fib_rules; 1777 if (*add_fib_rules) { 1778 err = vrf_add_fib_rules(dev); 1779 if (err) { 1780 vrf_map_unregister_dev(dev); 1781 unregister_netdevice(dev); 1782 goto out; 1783 } 1784 *add_fib_rules = false; 1785 } 1786 1787 out: 1788 return err; 1789 } 1790 1791 static size_t vrf_nl_getsize(const struct net_device *dev) 1792 { 1793 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */ 1794 } 1795 1796 static int vrf_fillinfo(struct sk_buff *skb, 1797 const struct net_device *dev) 1798 { 1799 struct net_vrf *vrf = netdev_priv(dev); 1800 1801 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id); 1802 } 1803 1804 static size_t vrf_get_slave_size(const struct net_device *bond_dev, 1805 const struct net_device *slave_dev) 1806 { 1807 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */ 1808 } 1809 1810 static int vrf_fill_slave_info(struct sk_buff *skb, 1811 const struct net_device *vrf_dev, 1812 const struct net_device *slave_dev) 1813 { 1814 struct net_vrf *vrf = netdev_priv(vrf_dev); 1815 1816 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id)) 1817 return -EMSGSIZE; 1818 1819 return 0; 1820 } 1821 1822 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = { 1823 [IFLA_VRF_TABLE] = { .type = NLA_U32 }, 1824 }; 1825 1826 static struct rtnl_link_ops vrf_link_ops __read_mostly = { 1827 .kind = DRV_NAME, 1828 .priv_size = sizeof(struct net_vrf), 1829 1830 .get_size = vrf_nl_getsize, 1831 .policy = vrf_nl_policy, 1832 .validate = vrf_validate, 1833 .fill_info = vrf_fillinfo, 1834 1835 .get_slave_size = vrf_get_slave_size, 1836 .fill_slave_info = vrf_fill_slave_info, 1837 1838 .newlink = vrf_newlink, 1839 .dellink = vrf_dellink, 1840 .setup = vrf_setup, 1841 .maxtype = IFLA_VRF_MAX, 1842 }; 1843 1844 static int vrf_device_event(struct notifier_block *unused, 1845 unsigned long event, void *ptr) 1846 { 1847 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1848 1849 /* only care about unregister events to drop slave references */ 1850 if (event == NETDEV_UNREGISTER) { 1851 struct net_device *vrf_dev; 1852 1853 if (!netif_is_l3_slave(dev)) 1854 goto out; 1855 1856 vrf_dev = netdev_master_upper_dev_get(dev); 1857 vrf_del_slave(vrf_dev, dev); 1858 } 1859 out: 1860 return NOTIFY_DONE; 1861 } 1862 1863 static struct notifier_block vrf_notifier_block __read_mostly = { 1864 .notifier_call = vrf_device_event, 1865 }; 1866 1867 static int vrf_map_init(struct vrf_map *vmap) 1868 { 1869 spin_lock_init(&vmap->vmap_lock); 1870 hash_init(vmap->ht); 1871 1872 vmap->strict_mode = false; 1873 1874 return 0; 1875 } 1876 1877 #ifdef CONFIG_SYSCTL 1878 static bool vrf_strict_mode(struct vrf_map *vmap) 1879 { 1880 bool strict_mode; 1881 1882 vrf_map_lock(vmap); 1883 strict_mode = vmap->strict_mode; 1884 vrf_map_unlock(vmap); 1885 1886 return strict_mode; 1887 } 1888 1889 static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode) 1890 { 1891 bool *cur_mode; 1892 int res = 0; 1893 1894 vrf_map_lock(vmap); 1895 1896 cur_mode = &vmap->strict_mode; 1897 if (*cur_mode == new_mode) 1898 goto unlock; 1899 1900 if (*cur_mode) { 1901 /* disable strict mode */ 1902 *cur_mode = false; 1903 } else { 1904 if (vmap->shared_tables) { 1905 /* we cannot allow strict_mode because there are some 1906 * vrfs that share one or more tables. 1907 */ 1908 res = -EBUSY; 1909 goto unlock; 1910 } 1911 1912 /* no tables are shared among vrfs, so we can go back 1913 * to 1:1 association between a vrf with its table. 1914 */ 1915 *cur_mode = true; 1916 } 1917 1918 unlock: 1919 vrf_map_unlock(vmap); 1920 1921 return res; 1922 } 1923 1924 static int vrf_shared_table_handler(struct ctl_table *table, int write, 1925 void *buffer, size_t *lenp, loff_t *ppos) 1926 { 1927 struct net *net = (struct net *)table->extra1; 1928 struct vrf_map *vmap = netns_vrf_map(net); 1929 int proc_strict_mode = 0; 1930 struct ctl_table tmp = { 1931 .procname = table->procname, 1932 .data = &proc_strict_mode, 1933 .maxlen = sizeof(int), 1934 .mode = table->mode, 1935 .extra1 = SYSCTL_ZERO, 1936 .extra2 = SYSCTL_ONE, 1937 }; 1938 int ret; 1939 1940 if (!write) 1941 proc_strict_mode = vrf_strict_mode(vmap); 1942 1943 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 1944 1945 if (write && ret == 0) 1946 ret = vrf_strict_mode_change(vmap, (bool)proc_strict_mode); 1947 1948 return ret; 1949 } 1950 1951 static const struct ctl_table vrf_table[] = { 1952 { 1953 .procname = "strict_mode", 1954 .data = NULL, 1955 .maxlen = sizeof(int), 1956 .mode = 0644, 1957 .proc_handler = vrf_shared_table_handler, 1958 /* set by the vrf_netns_init */ 1959 .extra1 = NULL, 1960 }, 1961 { }, 1962 }; 1963 1964 static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf) 1965 { 1966 struct ctl_table *table; 1967 1968 table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL); 1969 if (!table) 1970 return -ENOMEM; 1971 1972 /* init the extra1 parameter with the reference to current netns */ 1973 table[0].extra1 = net; 1974 1975 nn_vrf->ctl_hdr = register_net_sysctl(net, "net/vrf", table); 1976 if (!nn_vrf->ctl_hdr) { 1977 kfree(table); 1978 return -ENOMEM; 1979 } 1980 1981 return 0; 1982 } 1983 1984 static void vrf_netns_exit_sysctl(struct net *net) 1985 { 1986 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id); 1987 struct ctl_table *table; 1988 1989 table = nn_vrf->ctl_hdr->ctl_table_arg; 1990 unregister_net_sysctl_table(nn_vrf->ctl_hdr); 1991 kfree(table); 1992 } 1993 #else 1994 static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf) 1995 { 1996 return 0; 1997 } 1998 1999 static void vrf_netns_exit_sysctl(struct net *net) 2000 { 2001 } 2002 #endif 2003 2004 /* Initialize per network namespace state */ 2005 static int __net_init vrf_netns_init(struct net *net) 2006 { 2007 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id); 2008 2009 nn_vrf->add_fib_rules = true; 2010 vrf_map_init(&nn_vrf->vmap); 2011 2012 return vrf_netns_init_sysctl(net, nn_vrf); 2013 } 2014 2015 static void __net_exit vrf_netns_exit(struct net *net) 2016 { 2017 vrf_netns_exit_sysctl(net); 2018 } 2019 2020 static struct pernet_operations vrf_net_ops __net_initdata = { 2021 .init = vrf_netns_init, 2022 .exit = vrf_netns_exit, 2023 .id = &vrf_net_id, 2024 .size = sizeof(struct netns_vrf), 2025 }; 2026 2027 static int __init vrf_init_module(void) 2028 { 2029 int rc; 2030 2031 register_netdevice_notifier(&vrf_notifier_block); 2032 2033 rc = register_pernet_subsys(&vrf_net_ops); 2034 if (rc < 0) 2035 goto error; 2036 2037 rc = l3mdev_table_lookup_register(L3MDEV_TYPE_VRF, 2038 vrf_ifindex_lookup_by_table_id); 2039 if (rc < 0) 2040 goto unreg_pernet; 2041 2042 rc = rtnl_link_register(&vrf_link_ops); 2043 if (rc < 0) 2044 goto table_lookup_unreg; 2045 2046 return 0; 2047 2048 table_lookup_unreg: 2049 l3mdev_table_lookup_unregister(L3MDEV_TYPE_VRF, 2050 vrf_ifindex_lookup_by_table_id); 2051 2052 unreg_pernet: 2053 unregister_pernet_subsys(&vrf_net_ops); 2054 2055 error: 2056 unregister_netdevice_notifier(&vrf_notifier_block); 2057 return rc; 2058 } 2059 2060 module_init(vrf_init_module); 2061 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern"); 2062 MODULE_DESCRIPTION("Device driver to instantiate VRF domains"); 2063 MODULE_LICENSE("GPL"); 2064 MODULE_ALIAS_RTNL_LINK(DRV_NAME); 2065 MODULE_VERSION(DRV_VERSION); 2066