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 #include <net/inet_dscp.h> 41 42 #define DRV_NAME "vrf" 43 #define DRV_VERSION "1.1" 44 45 #define FIB_RULE_PREF 1000 /* default preference for FIB rules */ 46 47 #define HT_MAP_BITS 4 48 #define HASH_INITVAL ((u32)0xcafef00d) 49 50 struct vrf_map { 51 DECLARE_HASHTABLE(ht, HT_MAP_BITS); 52 spinlock_t vmap_lock; 53 54 /* shared_tables: 55 * count how many distinct tables do not comply with the strict mode 56 * requirement. 57 * shared_tables value must be 0 in order to enable the strict mode. 58 * 59 * example of the evolution of shared_tables: 60 * | time 61 * add vrf0 --> table 100 shared_tables = 0 | t0 62 * add vrf1 --> table 101 shared_tables = 0 | t1 63 * add vrf2 --> table 100 shared_tables = 1 | t2 64 * add vrf3 --> table 100 shared_tables = 1 | t3 65 * add vrf4 --> table 101 shared_tables = 2 v t4 66 * 67 * shared_tables is a "step function" (or "staircase function") 68 * and it is increased by one when the second vrf is associated to a 69 * table. 70 * 71 * at t2, vrf0 and vrf2 are bound to table 100: shared_tables = 1. 72 * 73 * at t3, another dev (vrf3) is bound to the same table 100 but the 74 * value of shared_tables is still 1. 75 * This means that no matter how many new vrfs will register on the 76 * table 100, the shared_tables will not increase (considering only 77 * table 100). 78 * 79 * at t4, vrf4 is bound to table 101, and shared_tables = 2. 80 * 81 * Looking at the value of shared_tables we can immediately know if 82 * the strict_mode can or cannot be enforced. Indeed, strict_mode 83 * can be enforced iff shared_tables = 0. 84 * 85 * Conversely, shared_tables is decreased when a vrf is de-associated 86 * from a table with exactly two associated vrfs. 87 */ 88 u32 shared_tables; 89 90 bool strict_mode; 91 }; 92 93 struct vrf_map_elem { 94 struct hlist_node hnode; 95 struct list_head vrf_list; /* VRFs registered to this table */ 96 97 u32 table_id; 98 int users; 99 int ifindex; 100 }; 101 102 static unsigned int vrf_net_id; 103 104 /* per netns vrf data */ 105 struct netns_vrf { 106 /* protected by rtnl lock */ 107 bool add_fib_rules; 108 109 struct vrf_map vmap; 110 struct ctl_table_header *ctl_hdr; 111 }; 112 113 struct net_vrf { 114 struct rtable __rcu *rth; 115 struct rt6_info __rcu *rt6; 116 #if IS_ENABLED(CONFIG_IPV6) 117 struct fib6_table *fib6_table; 118 #endif 119 u32 tb_id; 120 121 struct list_head me_list; /* entry in vrf_map_elem */ 122 int ifindex; 123 }; 124 125 static void vrf_rx_stats(struct net_device *dev, int len) 126 { 127 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); 128 129 u64_stats_update_begin(&dstats->syncp); 130 u64_stats_inc(&dstats->rx_packets); 131 u64_stats_add(&dstats->rx_bytes, len); 132 u64_stats_update_end(&dstats->syncp); 133 } 134 135 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb) 136 { 137 vrf_dev->stats.tx_errors++; 138 kfree_skb(skb); 139 } 140 141 static struct vrf_map *netns_vrf_map(struct net *net) 142 { 143 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id); 144 145 return &nn_vrf->vmap; 146 } 147 148 static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev) 149 { 150 return netns_vrf_map(dev_net(dev)); 151 } 152 153 static int vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem *me) 154 { 155 struct list_head *me_head = &me->vrf_list; 156 struct net_vrf *vrf; 157 158 if (list_empty(me_head)) 159 return -ENODEV; 160 161 vrf = list_first_entry(me_head, struct net_vrf, me_list); 162 163 return vrf->ifindex; 164 } 165 166 static struct vrf_map_elem *vrf_map_elem_alloc(gfp_t flags) 167 { 168 struct vrf_map_elem *me; 169 170 me = kmalloc(sizeof(*me), flags); 171 if (!me) 172 return NULL; 173 174 return me; 175 } 176 177 static void vrf_map_elem_free(struct vrf_map_elem *me) 178 { 179 kfree(me); 180 } 181 182 static void vrf_map_elem_init(struct vrf_map_elem *me, int table_id, 183 int ifindex, int users) 184 { 185 me->table_id = table_id; 186 me->ifindex = ifindex; 187 me->users = users; 188 INIT_LIST_HEAD(&me->vrf_list); 189 } 190 191 static struct vrf_map_elem *vrf_map_lookup_elem(struct vrf_map *vmap, 192 u32 table_id) 193 { 194 struct vrf_map_elem *me; 195 u32 key; 196 197 key = jhash_1word(table_id, HASH_INITVAL); 198 hash_for_each_possible(vmap->ht, me, hnode, key) { 199 if (me->table_id == table_id) 200 return me; 201 } 202 203 return NULL; 204 } 205 206 static void vrf_map_add_elem(struct vrf_map *vmap, struct vrf_map_elem *me) 207 { 208 u32 table_id = me->table_id; 209 u32 key; 210 211 key = jhash_1word(table_id, HASH_INITVAL); 212 hash_add(vmap->ht, &me->hnode, key); 213 } 214 215 static void vrf_map_del_elem(struct vrf_map_elem *me) 216 { 217 hash_del(&me->hnode); 218 } 219 220 static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock) 221 { 222 spin_lock(&vmap->vmap_lock); 223 } 224 225 static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock) 226 { 227 spin_unlock(&vmap->vmap_lock); 228 } 229 230 /* called with rtnl lock held */ 231 static int 232 vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack) 233 { 234 struct vrf_map *vmap = netns_vrf_map_by_dev(dev); 235 struct net_vrf *vrf = netdev_priv(dev); 236 struct vrf_map_elem *new_me, *me; 237 u32 table_id = vrf->tb_id; 238 bool free_new_me = false; 239 int users; 240 int res; 241 242 /* we pre-allocate elements used in the spin-locked section (so that we 243 * keep the spinlock as short as possible). 244 */ 245 new_me = vrf_map_elem_alloc(GFP_KERNEL); 246 if (!new_me) 247 return -ENOMEM; 248 249 vrf_map_elem_init(new_me, table_id, dev->ifindex, 0); 250 251 vrf_map_lock(vmap); 252 253 me = vrf_map_lookup_elem(vmap, table_id); 254 if (!me) { 255 me = new_me; 256 vrf_map_add_elem(vmap, me); 257 goto link_vrf; 258 } 259 260 /* we already have an entry in the vrf_map, so it means there is (at 261 * least) a vrf registered on the specific table. 262 */ 263 free_new_me = true; 264 if (vmap->strict_mode) { 265 /* vrfs cannot share the same table */ 266 NL_SET_ERR_MSG(extack, "Table is used by another VRF"); 267 res = -EBUSY; 268 goto unlock; 269 } 270 271 link_vrf: 272 users = ++me->users; 273 if (users == 2) 274 ++vmap->shared_tables; 275 276 list_add(&vrf->me_list, &me->vrf_list); 277 278 res = 0; 279 280 unlock: 281 vrf_map_unlock(vmap); 282 283 /* clean-up, if needed */ 284 if (free_new_me) 285 vrf_map_elem_free(new_me); 286 287 return res; 288 } 289 290 /* called with rtnl lock held */ 291 static void vrf_map_unregister_dev(struct net_device *dev) 292 { 293 struct vrf_map *vmap = netns_vrf_map_by_dev(dev); 294 struct net_vrf *vrf = netdev_priv(dev); 295 u32 table_id = vrf->tb_id; 296 struct vrf_map_elem *me; 297 int users; 298 299 vrf_map_lock(vmap); 300 301 me = vrf_map_lookup_elem(vmap, table_id); 302 if (!me) 303 goto unlock; 304 305 list_del(&vrf->me_list); 306 307 users = --me->users; 308 if (users == 1) { 309 --vmap->shared_tables; 310 } else if (users == 0) { 311 vrf_map_del_elem(me); 312 313 /* no one will refer to this element anymore */ 314 vrf_map_elem_free(me); 315 } 316 317 unlock: 318 vrf_map_unlock(vmap); 319 } 320 321 /* return the vrf device index associated with the table_id */ 322 static int vrf_ifindex_lookup_by_table_id(struct net *net, u32 table_id) 323 { 324 struct vrf_map *vmap = netns_vrf_map(net); 325 struct vrf_map_elem *me; 326 int ifindex; 327 328 vrf_map_lock(vmap); 329 330 if (!vmap->strict_mode) { 331 ifindex = -EPERM; 332 goto unlock; 333 } 334 335 me = vrf_map_lookup_elem(vmap, table_id); 336 if (!me) { 337 ifindex = -ENODEV; 338 goto unlock; 339 } 340 341 ifindex = vrf_map_elem_get_vrf_ifindex(me); 342 343 unlock: 344 vrf_map_unlock(vmap); 345 346 return ifindex; 347 } 348 349 /* by default VRF devices do not have a qdisc and are expected 350 * to be created with only a single queue. 351 */ 352 static bool qdisc_tx_is_default(const struct net_device *dev) 353 { 354 struct netdev_queue *txq; 355 struct Qdisc *qdisc; 356 357 if (dev->num_tx_queues > 1) 358 return false; 359 360 txq = netdev_get_tx_queue(dev, 0); 361 qdisc = rcu_access_pointer(txq->qdisc); 362 363 return !qdisc->enqueue; 364 } 365 366 /* Local traffic destined to local address. Reinsert the packet to rx 367 * path, similar to loopback handling. 368 */ 369 static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev, 370 struct dst_entry *dst) 371 { 372 int len = skb->len; 373 374 skb_orphan(skb); 375 376 skb_dst_set(skb, dst); 377 378 /* set pkt_type to avoid skb hitting packet taps twice - 379 * once on Tx and again in Rx processing 380 */ 381 skb->pkt_type = PACKET_LOOPBACK; 382 383 skb->protocol = eth_type_trans(skb, dev); 384 385 if (likely(__netif_rx(skb) == NET_RX_SUCCESS)) { 386 vrf_rx_stats(dev, len); 387 } else { 388 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); 389 390 u64_stats_update_begin(&dstats->syncp); 391 u64_stats_inc(&dstats->rx_drops); 392 u64_stats_update_end(&dstats->syncp); 393 } 394 395 return NETDEV_TX_OK; 396 } 397 398 static void vrf_nf_set_untracked(struct sk_buff *skb) 399 { 400 if (skb_get_nfct(skb) == 0) 401 nf_ct_set(skb, NULL, IP_CT_UNTRACKED); 402 } 403 404 static void vrf_nf_reset_ct(struct sk_buff *skb) 405 { 406 if (skb_get_nfct(skb) == IP_CT_UNTRACKED) 407 nf_reset_ct(skb); 408 } 409 410 #if IS_ENABLED(CONFIG_IPV6) 411 static int vrf_ip6_local_out(struct net *net, struct sock *sk, 412 struct sk_buff *skb) 413 { 414 int err; 415 416 vrf_nf_reset_ct(skb); 417 418 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, 419 sk, skb, NULL, skb_dst(skb)->dev, dst_output); 420 421 if (likely(err == 1)) 422 err = dst_output(net, sk, skb); 423 424 return err; 425 } 426 427 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, 428 struct net_device *dev) 429 { 430 const struct ipv6hdr *iph; 431 struct net *net = dev_net(skb->dev); 432 struct flowi6 fl6; 433 int ret = NET_XMIT_DROP; 434 struct dst_entry *dst; 435 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst; 436 437 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr))) 438 goto err; 439 440 iph = ipv6_hdr(skb); 441 442 memset(&fl6, 0, sizeof(fl6)); 443 /* needed to match OIF rule */ 444 fl6.flowi6_l3mdev = dev->ifindex; 445 fl6.flowi6_iif = LOOPBACK_IFINDEX; 446 fl6.daddr = iph->daddr; 447 fl6.saddr = iph->saddr; 448 fl6.flowlabel = ip6_flowinfo(iph); 449 fl6.flowi6_mark = skb->mark; 450 fl6.flowi6_proto = iph->nexthdr; 451 452 dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL); 453 if (IS_ERR(dst) || dst == dst_null) 454 goto err; 455 456 skb_dst_drop(skb); 457 458 /* if dst.dev is the VRF device again this is locally originated traffic 459 * destined to a local address. Short circuit to Rx path. 460 */ 461 if (dst->dev == dev) 462 return vrf_local_xmit(skb, dev, dst); 463 464 skb_dst_set(skb, dst); 465 466 /* strip the ethernet header added for pass through VRF device */ 467 __skb_pull(skb, skb_network_offset(skb)); 468 469 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); 470 ret = vrf_ip6_local_out(net, skb->sk, skb); 471 if (unlikely(net_xmit_eval(ret))) 472 dev->stats.tx_errors++; 473 else 474 ret = NET_XMIT_SUCCESS; 475 476 return ret; 477 err: 478 vrf_tx_error(dev, skb); 479 return NET_XMIT_DROP; 480 } 481 #else 482 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, 483 struct net_device *dev) 484 { 485 vrf_tx_error(dev, skb); 486 return NET_XMIT_DROP; 487 } 488 #endif 489 490 /* based on ip_local_out; can't use it b/c the dst is switched pointing to us */ 491 static int vrf_ip_local_out(struct net *net, struct sock *sk, 492 struct sk_buff *skb) 493 { 494 int err; 495 496 vrf_nf_reset_ct(skb); 497 498 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk, 499 skb, NULL, skb_dst(skb)->dev, dst_output); 500 if (likely(err == 1)) 501 err = dst_output(net, sk, skb); 502 503 return err; 504 } 505 506 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb, 507 struct net_device *vrf_dev) 508 { 509 struct iphdr *ip4h; 510 int ret = NET_XMIT_DROP; 511 struct flowi4 fl4; 512 struct net *net = dev_net(vrf_dev); 513 struct rtable *rt; 514 515 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr))) 516 goto err; 517 518 ip4h = ip_hdr(skb); 519 520 memset(&fl4, 0, sizeof(fl4)); 521 /* needed to match OIF rule */ 522 fl4.flowi4_l3mdev = vrf_dev->ifindex; 523 fl4.flowi4_iif = LOOPBACK_IFINDEX; 524 fl4.flowi4_tos = ip4h->tos & INET_DSCP_MASK; 525 fl4.flowi4_flags = FLOWI_FLAG_ANYSRC; 526 fl4.flowi4_proto = ip4h->protocol; 527 fl4.daddr = ip4h->daddr; 528 fl4.saddr = ip4h->saddr; 529 530 rt = ip_route_output_flow(net, &fl4, NULL); 531 if (IS_ERR(rt)) 532 goto err; 533 534 skb_dst_drop(skb); 535 536 /* if dst.dev is the VRF device again this is locally originated traffic 537 * destined to a local address. Short circuit to Rx path. 538 */ 539 if (rt->dst.dev == vrf_dev) 540 return vrf_local_xmit(skb, vrf_dev, &rt->dst); 541 542 skb_dst_set(skb, &rt->dst); 543 544 /* strip the ethernet header added for pass through VRF device */ 545 __skb_pull(skb, skb_network_offset(skb)); 546 547 if (!ip4h->saddr) { 548 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0, 549 RT_SCOPE_LINK); 550 } 551 552 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 553 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb); 554 if (unlikely(net_xmit_eval(ret))) 555 vrf_dev->stats.tx_errors++; 556 else 557 ret = NET_XMIT_SUCCESS; 558 559 out: 560 return ret; 561 err: 562 vrf_tx_error(vrf_dev, skb); 563 goto out; 564 } 565 566 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev) 567 { 568 switch (skb->protocol) { 569 case htons(ETH_P_IP): 570 return vrf_process_v4_outbound(skb, dev); 571 case htons(ETH_P_IPV6): 572 return vrf_process_v6_outbound(skb, dev); 573 default: 574 vrf_tx_error(dev, skb); 575 return NET_XMIT_DROP; 576 } 577 } 578 579 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev) 580 { 581 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); 582 583 int len = skb->len; 584 netdev_tx_t ret = is_ip_tx_frame(skb, dev); 585 586 u64_stats_update_begin(&dstats->syncp); 587 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) { 588 589 u64_stats_inc(&dstats->tx_packets); 590 u64_stats_add(&dstats->tx_bytes, len); 591 } else { 592 u64_stats_inc(&dstats->tx_drops); 593 } 594 u64_stats_update_end(&dstats->syncp); 595 596 return ret; 597 } 598 599 static void vrf_finish_direct(struct sk_buff *skb) 600 { 601 struct net_device *vrf_dev = skb->dev; 602 603 if (!list_empty(&vrf_dev->ptype_all) && 604 likely(skb_headroom(skb) >= ETH_HLEN)) { 605 struct ethhdr *eth = skb_push(skb, ETH_HLEN); 606 607 ether_addr_copy(eth->h_source, vrf_dev->dev_addr); 608 eth_zero_addr(eth->h_dest); 609 eth->h_proto = skb->protocol; 610 611 rcu_read_lock_bh(); 612 dev_queue_xmit_nit(skb, vrf_dev); 613 rcu_read_unlock_bh(); 614 615 skb_pull(skb, ETH_HLEN); 616 } 617 618 vrf_nf_reset_ct(skb); 619 } 620 621 #if IS_ENABLED(CONFIG_IPV6) 622 /* modelled after ip6_finish_output2 */ 623 static int vrf_finish_output6(struct net *net, struct sock *sk, 624 struct sk_buff *skb) 625 { 626 struct dst_entry *dst = skb_dst(skb); 627 struct net_device *dev = dst->dev; 628 const struct in6_addr *nexthop; 629 struct neighbour *neigh; 630 int ret; 631 632 vrf_nf_reset_ct(skb); 633 634 skb->protocol = htons(ETH_P_IPV6); 635 skb->dev = dev; 636 637 rcu_read_lock(); 638 nexthop = rt6_nexthop(dst_rt6_info(dst), &ipv6_hdr(skb)->daddr); 639 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop); 640 if (unlikely(!neigh)) 641 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false); 642 if (!IS_ERR(neigh)) { 643 sock_confirm_neigh(skb, neigh); 644 ret = neigh_output(neigh, skb, false); 645 rcu_read_unlock(); 646 return ret; 647 } 648 rcu_read_unlock(); 649 650 IP6_INC_STATS(dev_net(dst->dev), 651 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 652 kfree_skb(skb); 653 return -EINVAL; 654 } 655 656 /* modelled after ip6_output */ 657 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb) 658 { 659 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, 660 net, sk, skb, NULL, skb_dst(skb)->dev, 661 vrf_finish_output6, 662 !(IP6CB(skb)->flags & IP6SKB_REROUTED)); 663 } 664 665 /* set dst on skb to send packet to us via dev_xmit path. Allows 666 * packet to go through device based features such as qdisc, netfilter 667 * hooks and packet sockets with skb->dev set to vrf device. 668 */ 669 static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev, 670 struct sk_buff *skb) 671 { 672 struct net_vrf *vrf = netdev_priv(vrf_dev); 673 struct dst_entry *dst = NULL; 674 struct rt6_info *rt6; 675 676 rcu_read_lock(); 677 678 rt6 = rcu_dereference(vrf->rt6); 679 if (likely(rt6)) { 680 dst = &rt6->dst; 681 dst_hold(dst); 682 } 683 684 rcu_read_unlock(); 685 686 if (unlikely(!dst)) { 687 vrf_tx_error(vrf_dev, skb); 688 return NULL; 689 } 690 691 skb_dst_drop(skb); 692 skb_dst_set(skb, dst); 693 694 return skb; 695 } 696 697 static int vrf_output6_direct_finish(struct net *net, struct sock *sk, 698 struct sk_buff *skb) 699 { 700 vrf_finish_direct(skb); 701 702 return vrf_ip6_local_out(net, sk, skb); 703 } 704 705 static int vrf_output6_direct(struct net *net, struct sock *sk, 706 struct sk_buff *skb) 707 { 708 int err = 1; 709 710 skb->protocol = htons(ETH_P_IPV6); 711 712 if (!(IPCB(skb)->flags & IPSKB_REROUTED)) 713 err = nf_hook(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb, 714 NULL, skb->dev, vrf_output6_direct_finish); 715 716 if (likely(err == 1)) 717 vrf_finish_direct(skb); 718 719 return err; 720 } 721 722 static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk, 723 struct sk_buff *skb) 724 { 725 int err; 726 727 err = vrf_output6_direct(net, sk, skb); 728 if (likely(err == 1)) 729 err = vrf_ip6_local_out(net, sk, skb); 730 731 return err; 732 } 733 734 static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev, 735 struct sock *sk, 736 struct sk_buff *skb) 737 { 738 struct net *net = dev_net(vrf_dev); 739 int err; 740 741 skb->dev = vrf_dev; 742 743 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, 744 skb, NULL, vrf_dev, vrf_ip6_out_direct_finish); 745 746 if (likely(err == 1)) 747 err = vrf_output6_direct(net, sk, skb); 748 749 if (likely(err == 1)) 750 return skb; 751 752 return NULL; 753 } 754 755 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev, 756 struct sock *sk, 757 struct sk_buff *skb) 758 { 759 /* don't divert link scope packets */ 760 if (rt6_need_strict(&ipv6_hdr(skb)->daddr)) 761 return skb; 762 763 vrf_nf_set_untracked(skb); 764 765 if (qdisc_tx_is_default(vrf_dev) || 766 IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) 767 return vrf_ip6_out_direct(vrf_dev, sk, skb); 768 769 return vrf_ip6_out_redirect(vrf_dev, skb); 770 } 771 772 /* holding rtnl */ 773 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) 774 { 775 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6); 776 struct net *net = dev_net(dev); 777 struct dst_entry *dst; 778 779 RCU_INIT_POINTER(vrf->rt6, NULL); 780 synchronize_rcu(); 781 782 /* move dev in dst's to loopback so this VRF device can be deleted 783 * - based on dst_ifdown 784 */ 785 if (rt6) { 786 dst = &rt6->dst; 787 netdev_ref_replace(dst->dev, net->loopback_dev, 788 &dst->dev_tracker, GFP_KERNEL); 789 dst->dev = net->loopback_dev; 790 dst_release(dst); 791 } 792 } 793 794 static int vrf_rt6_create(struct net_device *dev) 795 { 796 int flags = DST_NOPOLICY | DST_NOXFRM; 797 struct net_vrf *vrf = netdev_priv(dev); 798 struct net *net = dev_net(dev); 799 struct rt6_info *rt6; 800 int rc = -ENOMEM; 801 802 /* IPv6 can be CONFIG enabled and then disabled runtime */ 803 if (!ipv6_mod_enabled()) 804 return 0; 805 806 vrf->fib6_table = fib6_new_table(net, vrf->tb_id); 807 if (!vrf->fib6_table) 808 goto out; 809 810 /* create a dst for routing packets out a VRF device */ 811 rt6 = ip6_dst_alloc(net, dev, flags); 812 if (!rt6) 813 goto out; 814 815 rt6->dst.output = vrf_output6; 816 817 rcu_assign_pointer(vrf->rt6, rt6); 818 819 rc = 0; 820 out: 821 return rc; 822 } 823 #else 824 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev, 825 struct sock *sk, 826 struct sk_buff *skb) 827 { 828 return skb; 829 } 830 831 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) 832 { 833 } 834 835 static int vrf_rt6_create(struct net_device *dev) 836 { 837 return 0; 838 } 839 #endif 840 841 /* modelled after ip_finish_output2 */ 842 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 843 { 844 struct dst_entry *dst = skb_dst(skb); 845 struct rtable *rt = dst_rtable(dst); 846 struct net_device *dev = dst->dev; 847 unsigned int hh_len = LL_RESERVED_SPACE(dev); 848 struct neighbour *neigh; 849 bool is_v6gw = false; 850 851 vrf_nf_reset_ct(skb); 852 853 /* Be paranoid, rather than too clever. */ 854 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { 855 skb = skb_expand_head(skb, hh_len); 856 if (!skb) { 857 dev->stats.tx_errors++; 858 return -ENOMEM; 859 } 860 } 861 862 rcu_read_lock(); 863 864 neigh = ip_neigh_for_gw(rt, skb, &is_v6gw); 865 if (!IS_ERR(neigh)) { 866 int ret; 867 868 sock_confirm_neigh(skb, neigh); 869 /* if crossing protocols, can not use the cached header */ 870 ret = neigh_output(neigh, skb, is_v6gw); 871 rcu_read_unlock(); 872 return ret; 873 } 874 875 rcu_read_unlock(); 876 vrf_tx_error(skb->dev, skb); 877 return -EINVAL; 878 } 879 880 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb) 881 { 882 struct net_device *dev = skb_dst(skb)->dev; 883 884 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len); 885 886 skb->dev = dev; 887 skb->protocol = htons(ETH_P_IP); 888 889 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, 890 net, sk, skb, NULL, dev, 891 vrf_finish_output, 892 !(IPCB(skb)->flags & IPSKB_REROUTED)); 893 } 894 895 /* set dst on skb to send packet to us via dev_xmit path. Allows 896 * packet to go through device based features such as qdisc, netfilter 897 * hooks and packet sockets with skb->dev set to vrf device. 898 */ 899 static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev, 900 struct sk_buff *skb) 901 { 902 struct net_vrf *vrf = netdev_priv(vrf_dev); 903 struct dst_entry *dst = NULL; 904 struct rtable *rth; 905 906 rcu_read_lock(); 907 908 rth = rcu_dereference(vrf->rth); 909 if (likely(rth)) { 910 dst = &rth->dst; 911 dst_hold(dst); 912 } 913 914 rcu_read_unlock(); 915 916 if (unlikely(!dst)) { 917 vrf_tx_error(vrf_dev, skb); 918 return NULL; 919 } 920 921 skb_dst_drop(skb); 922 skb_dst_set(skb, dst); 923 924 return skb; 925 } 926 927 static int vrf_output_direct_finish(struct net *net, struct sock *sk, 928 struct sk_buff *skb) 929 { 930 vrf_finish_direct(skb); 931 932 return vrf_ip_local_out(net, sk, skb); 933 } 934 935 static int vrf_output_direct(struct net *net, struct sock *sk, 936 struct sk_buff *skb) 937 { 938 int err = 1; 939 940 skb->protocol = htons(ETH_P_IP); 941 942 if (!(IPCB(skb)->flags & IPSKB_REROUTED)) 943 err = nf_hook(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb, 944 NULL, skb->dev, vrf_output_direct_finish); 945 946 if (likely(err == 1)) 947 vrf_finish_direct(skb); 948 949 return err; 950 } 951 952 static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk, 953 struct sk_buff *skb) 954 { 955 int err; 956 957 err = vrf_output_direct(net, sk, skb); 958 if (likely(err == 1)) 959 err = vrf_ip_local_out(net, sk, skb); 960 961 return err; 962 } 963 964 static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev, 965 struct sock *sk, 966 struct sk_buff *skb) 967 { 968 struct net *net = dev_net(vrf_dev); 969 int err; 970 971 skb->dev = vrf_dev; 972 973 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk, 974 skb, NULL, vrf_dev, vrf_ip_out_direct_finish); 975 976 if (likely(err == 1)) 977 err = vrf_output_direct(net, sk, skb); 978 979 if (likely(err == 1)) 980 return skb; 981 982 return NULL; 983 } 984 985 static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev, 986 struct sock *sk, 987 struct sk_buff *skb) 988 { 989 /* don't divert multicast or local broadcast */ 990 if (ipv4_is_multicast(ip_hdr(skb)->daddr) || 991 ipv4_is_lbcast(ip_hdr(skb)->daddr)) 992 return skb; 993 994 vrf_nf_set_untracked(skb); 995 996 if (qdisc_tx_is_default(vrf_dev) || 997 IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) 998 return vrf_ip_out_direct(vrf_dev, sk, skb); 999 1000 return vrf_ip_out_redirect(vrf_dev, skb); 1001 } 1002 1003 /* called with rcu lock held */ 1004 static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev, 1005 struct sock *sk, 1006 struct sk_buff *skb, 1007 u16 proto) 1008 { 1009 switch (proto) { 1010 case AF_INET: 1011 return vrf_ip_out(vrf_dev, sk, skb); 1012 case AF_INET6: 1013 return vrf_ip6_out(vrf_dev, sk, skb); 1014 } 1015 1016 return skb; 1017 } 1018 1019 /* holding rtnl */ 1020 static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf) 1021 { 1022 struct rtable *rth = rtnl_dereference(vrf->rth); 1023 struct net *net = dev_net(dev); 1024 struct dst_entry *dst; 1025 1026 RCU_INIT_POINTER(vrf->rth, NULL); 1027 synchronize_rcu(); 1028 1029 /* move dev in dst's to loopback so this VRF device can be deleted 1030 * - based on dst_ifdown 1031 */ 1032 if (rth) { 1033 dst = &rth->dst; 1034 netdev_ref_replace(dst->dev, net->loopback_dev, 1035 &dst->dev_tracker, GFP_KERNEL); 1036 dst->dev = net->loopback_dev; 1037 dst_release(dst); 1038 } 1039 } 1040 1041 static int vrf_rtable_create(struct net_device *dev) 1042 { 1043 struct net_vrf *vrf = netdev_priv(dev); 1044 struct rtable *rth; 1045 1046 if (!fib_new_table(dev_net(dev), vrf->tb_id)) 1047 return -ENOMEM; 1048 1049 /* create a dst for routing packets out through a VRF device */ 1050 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1); 1051 if (!rth) 1052 return -ENOMEM; 1053 1054 rth->dst.output = vrf_output; 1055 1056 rcu_assign_pointer(vrf->rth, rth); 1057 1058 return 0; 1059 } 1060 1061 /**************************** device handling ********************/ 1062 1063 /* cycle interface to flush neighbor cache and move routes across tables */ 1064 static void cycle_netdev(struct net_device *dev, 1065 struct netlink_ext_ack *extack) 1066 { 1067 unsigned int flags = dev->flags; 1068 int ret; 1069 1070 if (!netif_running(dev)) 1071 return; 1072 1073 ret = dev_change_flags(dev, flags & ~IFF_UP, extack); 1074 if (ret >= 0) 1075 ret = dev_change_flags(dev, flags, extack); 1076 1077 if (ret < 0) { 1078 netdev_err(dev, 1079 "Failed to cycle device %s; route tables might be wrong!\n", 1080 dev->name); 1081 } 1082 } 1083 1084 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev, 1085 struct netlink_ext_ack *extack) 1086 { 1087 int ret; 1088 1089 /* do not allow loopback device to be enslaved to a VRF. 1090 * The vrf device acts as the loopback for the vrf. 1091 */ 1092 if (port_dev == dev_net(dev)->loopback_dev) { 1093 NL_SET_ERR_MSG(extack, 1094 "Can not enslave loopback device to a VRF"); 1095 return -EOPNOTSUPP; 1096 } 1097 1098 port_dev->priv_flags |= IFF_L3MDEV_SLAVE; 1099 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack); 1100 if (ret < 0) 1101 goto err; 1102 1103 cycle_netdev(port_dev, extack); 1104 1105 return 0; 1106 1107 err: 1108 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE; 1109 return ret; 1110 } 1111 1112 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev, 1113 struct netlink_ext_ack *extack) 1114 { 1115 if (netif_is_l3_master(port_dev)) { 1116 NL_SET_ERR_MSG(extack, 1117 "Can not enslave an L3 master device to a VRF"); 1118 return -EINVAL; 1119 } 1120 1121 if (netif_is_l3_slave(port_dev)) 1122 return -EINVAL; 1123 1124 return do_vrf_add_slave(dev, port_dev, extack); 1125 } 1126 1127 /* inverse of do_vrf_add_slave */ 1128 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev) 1129 { 1130 netdev_upper_dev_unlink(port_dev, dev); 1131 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE; 1132 1133 cycle_netdev(port_dev, NULL); 1134 1135 return 0; 1136 } 1137 1138 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev) 1139 { 1140 return do_vrf_del_slave(dev, port_dev); 1141 } 1142 1143 static void vrf_dev_uninit(struct net_device *dev) 1144 { 1145 struct net_vrf *vrf = netdev_priv(dev); 1146 1147 vrf_rtable_release(dev, vrf); 1148 vrf_rt6_release(dev, vrf); 1149 } 1150 1151 static int vrf_dev_init(struct net_device *dev) 1152 { 1153 struct net_vrf *vrf = netdev_priv(dev); 1154 1155 /* create the default dst which points back to us */ 1156 if (vrf_rtable_create(dev) != 0) 1157 goto out_nomem; 1158 1159 if (vrf_rt6_create(dev) != 0) 1160 goto out_rth; 1161 1162 dev->flags = IFF_MASTER | IFF_NOARP; 1163 1164 /* similarly, oper state is irrelevant; set to up to avoid confusion */ 1165 dev->operstate = IF_OPER_UP; 1166 netdev_lockdep_set_classes(dev); 1167 return 0; 1168 1169 out_rth: 1170 vrf_rtable_release(dev, vrf); 1171 out_nomem: 1172 return -ENOMEM; 1173 } 1174 1175 static const struct net_device_ops vrf_netdev_ops = { 1176 .ndo_init = vrf_dev_init, 1177 .ndo_uninit = vrf_dev_uninit, 1178 .ndo_start_xmit = vrf_xmit, 1179 .ndo_set_mac_address = eth_mac_addr, 1180 .ndo_add_slave = vrf_add_slave, 1181 .ndo_del_slave = vrf_del_slave, 1182 }; 1183 1184 static u32 vrf_fib_table(const struct net_device *dev) 1185 { 1186 struct net_vrf *vrf = netdev_priv(dev); 1187 1188 return vrf->tb_id; 1189 } 1190 1191 static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) 1192 { 1193 kfree_skb(skb); 1194 return 0; 1195 } 1196 1197 static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook, 1198 struct sk_buff *skb, 1199 struct net_device *dev) 1200 { 1201 struct net *net = dev_net(dev); 1202 1203 if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1) 1204 skb = NULL; /* kfree_skb(skb) handled by nf code */ 1205 1206 return skb; 1207 } 1208 1209 static int vrf_prepare_mac_header(struct sk_buff *skb, 1210 struct net_device *vrf_dev, u16 proto) 1211 { 1212 struct ethhdr *eth; 1213 int err; 1214 1215 /* in general, we do not know if there is enough space in the head of 1216 * the packet for hosting the mac header. 1217 */ 1218 err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev)); 1219 if (unlikely(err)) 1220 /* no space in the skb head */ 1221 return -ENOBUFS; 1222 1223 __skb_push(skb, ETH_HLEN); 1224 eth = (struct ethhdr *)skb->data; 1225 1226 skb_reset_mac_header(skb); 1227 skb_reset_mac_len(skb); 1228 1229 /* we set the ethernet destination and the source addresses to the 1230 * address of the VRF device. 1231 */ 1232 ether_addr_copy(eth->h_dest, vrf_dev->dev_addr); 1233 ether_addr_copy(eth->h_source, vrf_dev->dev_addr); 1234 eth->h_proto = htons(proto); 1235 1236 /* the destination address of the Ethernet frame corresponds to the 1237 * address set on the VRF interface; therefore, the packet is intended 1238 * to be processed locally. 1239 */ 1240 skb->protocol = eth->h_proto; 1241 skb->pkt_type = PACKET_HOST; 1242 1243 skb_postpush_rcsum(skb, skb->data, ETH_HLEN); 1244 1245 skb_pull_inline(skb, ETH_HLEN); 1246 1247 return 0; 1248 } 1249 1250 /* prepare and add the mac header to the packet if it was not set previously. 1251 * In this way, packet sniffers such as tcpdump can parse the packet correctly. 1252 * If the mac header was already set, the original mac header is left 1253 * untouched and the function returns immediately. 1254 */ 1255 static int vrf_add_mac_header_if_unset(struct sk_buff *skb, 1256 struct net_device *vrf_dev, 1257 u16 proto, struct net_device *orig_dev) 1258 { 1259 if (skb_mac_header_was_set(skb) && dev_has_header(orig_dev)) 1260 return 0; 1261 1262 return vrf_prepare_mac_header(skb, vrf_dev, proto); 1263 } 1264 1265 #if IS_ENABLED(CONFIG_IPV6) 1266 /* neighbor handling is done with actual device; do not want 1267 * to flip skb->dev for those ndisc packets. This really fails 1268 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is 1269 * a start. 1270 */ 1271 static bool ipv6_ndisc_frame(const struct sk_buff *skb) 1272 { 1273 const struct ipv6hdr *iph = ipv6_hdr(skb); 1274 bool rc = false; 1275 1276 if (iph->nexthdr == NEXTHDR_ICMP) { 1277 const struct icmp6hdr *icmph; 1278 struct icmp6hdr _icmph; 1279 1280 icmph = skb_header_pointer(skb, sizeof(*iph), 1281 sizeof(_icmph), &_icmph); 1282 if (!icmph) 1283 goto out; 1284 1285 switch (icmph->icmp6_type) { 1286 case NDISC_ROUTER_SOLICITATION: 1287 case NDISC_ROUTER_ADVERTISEMENT: 1288 case NDISC_NEIGHBOUR_SOLICITATION: 1289 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1290 case NDISC_REDIRECT: 1291 rc = true; 1292 break; 1293 } 1294 } 1295 1296 out: 1297 return rc; 1298 } 1299 1300 static struct rt6_info *vrf_ip6_route_lookup(struct net *net, 1301 const struct net_device *dev, 1302 struct flowi6 *fl6, 1303 int ifindex, 1304 const struct sk_buff *skb, 1305 int flags) 1306 { 1307 struct net_vrf *vrf = netdev_priv(dev); 1308 1309 return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags); 1310 } 1311 1312 static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev, 1313 int ifindex) 1314 { 1315 const struct ipv6hdr *iph = ipv6_hdr(skb); 1316 struct flowi6 fl6 = { 1317 .flowi6_iif = ifindex, 1318 .flowi6_mark = skb->mark, 1319 .flowi6_proto = iph->nexthdr, 1320 .daddr = iph->daddr, 1321 .saddr = iph->saddr, 1322 .flowlabel = ip6_flowinfo(iph), 1323 }; 1324 struct net *net = dev_net(vrf_dev); 1325 struct rt6_info *rt6; 1326 1327 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb, 1328 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE); 1329 if (unlikely(!rt6)) 1330 return; 1331 1332 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst)) 1333 return; 1334 1335 skb_dst_set(skb, &rt6->dst); 1336 } 1337 1338 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, 1339 struct sk_buff *skb) 1340 { 1341 int orig_iif = skb->skb_iif; 1342 bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr); 1343 bool is_ndisc = ipv6_ndisc_frame(skb); 1344 1345 /* loopback, multicast & non-ND link-local traffic; do not push through 1346 * packet taps again. Reset pkt_type for upper layers to process skb. 1347 * For non-loopback strict packets, determine the dst using the original 1348 * ifindex. 1349 */ 1350 if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) { 1351 skb->dev = vrf_dev; 1352 skb->skb_iif = vrf_dev->ifindex; 1353 IP6CB(skb)->flags |= IP6SKB_L3SLAVE; 1354 1355 if (skb->pkt_type == PACKET_LOOPBACK) 1356 skb->pkt_type = PACKET_HOST; 1357 else 1358 vrf_ip6_input_dst(skb, vrf_dev, orig_iif); 1359 1360 goto out; 1361 } 1362 1363 /* if packet is NDISC then keep the ingress interface */ 1364 if (!is_ndisc) { 1365 struct net_device *orig_dev = skb->dev; 1366 1367 vrf_rx_stats(vrf_dev, skb->len); 1368 skb->dev = vrf_dev; 1369 skb->skb_iif = vrf_dev->ifindex; 1370 1371 if (!list_empty(&vrf_dev->ptype_all)) { 1372 int err; 1373 1374 err = vrf_add_mac_header_if_unset(skb, vrf_dev, 1375 ETH_P_IPV6, 1376 orig_dev); 1377 if (likely(!err)) { 1378 skb_push(skb, skb->mac_len); 1379 dev_queue_xmit_nit(skb, vrf_dev); 1380 skb_pull(skb, skb->mac_len); 1381 } 1382 } 1383 1384 IP6CB(skb)->flags |= IP6SKB_L3SLAVE; 1385 } 1386 1387 if (need_strict) 1388 vrf_ip6_input_dst(skb, vrf_dev, orig_iif); 1389 1390 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev); 1391 out: 1392 return skb; 1393 } 1394 1395 #else 1396 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, 1397 struct sk_buff *skb) 1398 { 1399 return skb; 1400 } 1401 #endif 1402 1403 static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev, 1404 struct sk_buff *skb) 1405 { 1406 struct net_device *orig_dev = skb->dev; 1407 1408 skb->dev = vrf_dev; 1409 skb->skb_iif = vrf_dev->ifindex; 1410 IPCB(skb)->flags |= IPSKB_L3SLAVE; 1411 1412 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) 1413 goto out; 1414 1415 /* loopback traffic; do not push through packet taps again. 1416 * Reset pkt_type for upper layers to process skb 1417 */ 1418 if (skb->pkt_type == PACKET_LOOPBACK) { 1419 skb->pkt_type = PACKET_HOST; 1420 goto out; 1421 } 1422 1423 vrf_rx_stats(vrf_dev, skb->len); 1424 1425 if (!list_empty(&vrf_dev->ptype_all)) { 1426 int err; 1427 1428 err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP, 1429 orig_dev); 1430 if (likely(!err)) { 1431 skb_push(skb, skb->mac_len); 1432 dev_queue_xmit_nit(skb, vrf_dev); 1433 skb_pull(skb, skb->mac_len); 1434 } 1435 } 1436 1437 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev); 1438 out: 1439 return skb; 1440 } 1441 1442 /* called with rcu lock held */ 1443 static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev, 1444 struct sk_buff *skb, 1445 u16 proto) 1446 { 1447 switch (proto) { 1448 case AF_INET: 1449 return vrf_ip_rcv(vrf_dev, skb); 1450 case AF_INET6: 1451 return vrf_ip6_rcv(vrf_dev, skb); 1452 } 1453 1454 return skb; 1455 } 1456 1457 #if IS_ENABLED(CONFIG_IPV6) 1458 /* send to link-local or multicast address via interface enslaved to 1459 * VRF device. Force lookup to VRF table without changing flow struct 1460 * Note: Caller to this function must hold rcu_read_lock() and no refcnt 1461 * is taken on the dst by this function. 1462 */ 1463 static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev, 1464 struct flowi6 *fl6) 1465 { 1466 struct net *net = dev_net(dev); 1467 int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF; 1468 struct dst_entry *dst = NULL; 1469 struct rt6_info *rt; 1470 1471 /* VRF device does not have a link-local address and 1472 * sending packets to link-local or mcast addresses over 1473 * a VRF device does not make sense 1474 */ 1475 if (fl6->flowi6_oif == dev->ifindex) { 1476 dst = &net->ipv6.ip6_null_entry->dst; 1477 return dst; 1478 } 1479 1480 if (!ipv6_addr_any(&fl6->saddr)) 1481 flags |= RT6_LOOKUP_F_HAS_SADDR; 1482 1483 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags); 1484 if (rt) 1485 dst = &rt->dst; 1486 1487 return dst; 1488 } 1489 #endif 1490 1491 static const struct l3mdev_ops vrf_l3mdev_ops = { 1492 .l3mdev_fib_table = vrf_fib_table, 1493 .l3mdev_l3_rcv = vrf_l3_rcv, 1494 .l3mdev_l3_out = vrf_l3_out, 1495 #if IS_ENABLED(CONFIG_IPV6) 1496 .l3mdev_link_scope_lookup = vrf_link_scope_lookup, 1497 #endif 1498 }; 1499 1500 static void vrf_get_drvinfo(struct net_device *dev, 1501 struct ethtool_drvinfo *info) 1502 { 1503 strscpy(info->driver, DRV_NAME, sizeof(info->driver)); 1504 strscpy(info->version, DRV_VERSION, sizeof(info->version)); 1505 } 1506 1507 static const struct ethtool_ops vrf_ethtool_ops = { 1508 .get_drvinfo = vrf_get_drvinfo, 1509 }; 1510 1511 static inline size_t vrf_fib_rule_nl_size(void) 1512 { 1513 size_t sz; 1514 1515 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)); 1516 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */ 1517 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */ 1518 sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */ 1519 1520 return sz; 1521 } 1522 1523 static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it) 1524 { 1525 struct fib_rule_hdr *frh; 1526 struct nlmsghdr *nlh; 1527 struct sk_buff *skb; 1528 int err; 1529 1530 if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) && 1531 !ipv6_mod_enabled()) 1532 return 0; 1533 1534 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL); 1535 if (!skb) 1536 return -ENOMEM; 1537 1538 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0); 1539 if (!nlh) 1540 goto nla_put_failure; 1541 1542 /* rule only needs to appear once */ 1543 nlh->nlmsg_flags |= NLM_F_EXCL; 1544 1545 frh = nlmsg_data(nlh); 1546 memset(frh, 0, sizeof(*frh)); 1547 frh->family = family; 1548 frh->action = FR_ACT_TO_TBL; 1549 1550 if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL)) 1551 goto nla_put_failure; 1552 1553 if (nla_put_u8(skb, FRA_L3MDEV, 1)) 1554 goto nla_put_failure; 1555 1556 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF)) 1557 goto nla_put_failure; 1558 1559 nlmsg_end(skb, nlh); 1560 1561 /* fib_nl_{new,del}rule handling looks for net from skb->sk */ 1562 skb->sk = dev_net(dev)->rtnl; 1563 if (add_it) { 1564 err = fib_nl_newrule(skb, nlh, NULL); 1565 if (err == -EEXIST) 1566 err = 0; 1567 } else { 1568 err = fib_nl_delrule(skb, nlh, NULL); 1569 if (err == -ENOENT) 1570 err = 0; 1571 } 1572 nlmsg_free(skb); 1573 1574 return err; 1575 1576 nla_put_failure: 1577 nlmsg_free(skb); 1578 1579 return -EMSGSIZE; 1580 } 1581 1582 static int vrf_add_fib_rules(const struct net_device *dev) 1583 { 1584 int err; 1585 1586 err = vrf_fib_rule(dev, AF_INET, true); 1587 if (err < 0) 1588 goto out_err; 1589 1590 err = vrf_fib_rule(dev, AF_INET6, true); 1591 if (err < 0) 1592 goto ipv6_err; 1593 1594 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES) 1595 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true); 1596 if (err < 0) 1597 goto ipmr_err; 1598 #endif 1599 1600 #if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES) 1601 err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, true); 1602 if (err < 0) 1603 goto ip6mr_err; 1604 #endif 1605 1606 return 0; 1607 1608 #if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES) 1609 ip6mr_err: 1610 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, false); 1611 #endif 1612 1613 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES) 1614 ipmr_err: 1615 vrf_fib_rule(dev, AF_INET6, false); 1616 #endif 1617 1618 ipv6_err: 1619 vrf_fib_rule(dev, AF_INET, false); 1620 1621 out_err: 1622 netdev_err(dev, "Failed to add FIB rules.\n"); 1623 return err; 1624 } 1625 1626 static void vrf_setup(struct net_device *dev) 1627 { 1628 ether_setup(dev); 1629 1630 /* Initialize the device structure. */ 1631 dev->netdev_ops = &vrf_netdev_ops; 1632 dev->l3mdev_ops = &vrf_l3mdev_ops; 1633 dev->ethtool_ops = &vrf_ethtool_ops; 1634 dev->needs_free_netdev = true; 1635 1636 /* Fill in device structure with ethernet-generic values. */ 1637 eth_hw_addr_random(dev); 1638 1639 /* don't acquire vrf device's netif_tx_lock when transmitting */ 1640 dev->lltx = true; 1641 1642 /* don't allow vrf devices to change network namespaces. */ 1643 dev->netns_local = true; 1644 1645 /* does not make sense for a VLAN to be added to a vrf device */ 1646 dev->features |= NETIF_F_VLAN_CHALLENGED; 1647 1648 /* enable offload features */ 1649 dev->features |= NETIF_F_GSO_SOFTWARE; 1650 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC; 1651 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA; 1652 1653 dev->hw_features = dev->features; 1654 dev->hw_enc_features = dev->features; 1655 1656 /* default to no qdisc; user can add if desired */ 1657 dev->priv_flags |= IFF_NO_QUEUE; 1658 dev->priv_flags |= IFF_NO_RX_HANDLER; 1659 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1660 1661 /* VRF devices do not care about MTU, but if the MTU is set 1662 * too low then the ipv4 and ipv6 protocols are disabled 1663 * which breaks networking. 1664 */ 1665 dev->min_mtu = IPV6_MIN_MTU; 1666 dev->max_mtu = IP6_MAX_MTU; 1667 dev->mtu = dev->max_mtu; 1668 1669 dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS; 1670 } 1671 1672 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[], 1673 struct netlink_ext_ack *extack) 1674 { 1675 if (tb[IFLA_ADDRESS]) { 1676 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) { 1677 NL_SET_ERR_MSG(extack, "Invalid hardware address"); 1678 return -EINVAL; 1679 } 1680 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) { 1681 NL_SET_ERR_MSG(extack, "Invalid hardware address"); 1682 return -EADDRNOTAVAIL; 1683 } 1684 } 1685 return 0; 1686 } 1687 1688 static void vrf_dellink(struct net_device *dev, struct list_head *head) 1689 { 1690 struct net_device *port_dev; 1691 struct list_head *iter; 1692 1693 netdev_for_each_lower_dev(dev, port_dev, iter) 1694 vrf_del_slave(dev, port_dev); 1695 1696 vrf_map_unregister_dev(dev); 1697 1698 unregister_netdevice_queue(dev, head); 1699 } 1700 1701 static int vrf_newlink(struct net *src_net, struct net_device *dev, 1702 struct nlattr *tb[], struct nlattr *data[], 1703 struct netlink_ext_ack *extack) 1704 { 1705 struct net_vrf *vrf = netdev_priv(dev); 1706 struct netns_vrf *nn_vrf; 1707 bool *add_fib_rules; 1708 struct net *net; 1709 int err; 1710 1711 if (!data || !data[IFLA_VRF_TABLE]) { 1712 NL_SET_ERR_MSG(extack, "VRF table id is missing"); 1713 return -EINVAL; 1714 } 1715 1716 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]); 1717 if (vrf->tb_id == RT_TABLE_UNSPEC) { 1718 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE], 1719 "Invalid VRF table id"); 1720 return -EINVAL; 1721 } 1722 1723 dev->priv_flags |= IFF_L3MDEV_MASTER; 1724 1725 err = register_netdevice(dev); 1726 if (err) 1727 goto out; 1728 1729 /* mapping between table_id and vrf; 1730 * note: such binding could not be done in the dev init function 1731 * because dev->ifindex id is not available yet. 1732 */ 1733 vrf->ifindex = dev->ifindex; 1734 1735 err = vrf_map_register_dev(dev, extack); 1736 if (err) { 1737 unregister_netdevice(dev); 1738 goto out; 1739 } 1740 1741 net = dev_net(dev); 1742 nn_vrf = net_generic(net, vrf_net_id); 1743 1744 add_fib_rules = &nn_vrf->add_fib_rules; 1745 if (*add_fib_rules) { 1746 err = vrf_add_fib_rules(dev); 1747 if (err) { 1748 vrf_map_unregister_dev(dev); 1749 unregister_netdevice(dev); 1750 goto out; 1751 } 1752 *add_fib_rules = false; 1753 } 1754 1755 out: 1756 return err; 1757 } 1758 1759 static size_t vrf_nl_getsize(const struct net_device *dev) 1760 { 1761 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */ 1762 } 1763 1764 static int vrf_fillinfo(struct sk_buff *skb, 1765 const struct net_device *dev) 1766 { 1767 struct net_vrf *vrf = netdev_priv(dev); 1768 1769 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id); 1770 } 1771 1772 static size_t vrf_get_slave_size(const struct net_device *bond_dev, 1773 const struct net_device *slave_dev) 1774 { 1775 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */ 1776 } 1777 1778 static int vrf_fill_slave_info(struct sk_buff *skb, 1779 const struct net_device *vrf_dev, 1780 const struct net_device *slave_dev) 1781 { 1782 struct net_vrf *vrf = netdev_priv(vrf_dev); 1783 1784 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id)) 1785 return -EMSGSIZE; 1786 1787 return 0; 1788 } 1789 1790 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = { 1791 [IFLA_VRF_TABLE] = { .type = NLA_U32 }, 1792 }; 1793 1794 static struct rtnl_link_ops vrf_link_ops __read_mostly = { 1795 .kind = DRV_NAME, 1796 .priv_size = sizeof(struct net_vrf), 1797 1798 .get_size = vrf_nl_getsize, 1799 .policy = vrf_nl_policy, 1800 .validate = vrf_validate, 1801 .fill_info = vrf_fillinfo, 1802 1803 .get_slave_size = vrf_get_slave_size, 1804 .fill_slave_info = vrf_fill_slave_info, 1805 1806 .newlink = vrf_newlink, 1807 .dellink = vrf_dellink, 1808 .setup = vrf_setup, 1809 .maxtype = IFLA_VRF_MAX, 1810 }; 1811 1812 static int vrf_device_event(struct notifier_block *unused, 1813 unsigned long event, void *ptr) 1814 { 1815 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1816 1817 /* only care about unregister events to drop slave references */ 1818 if (event == NETDEV_UNREGISTER) { 1819 struct net_device *vrf_dev; 1820 1821 if (!netif_is_l3_slave(dev)) 1822 goto out; 1823 1824 vrf_dev = netdev_master_upper_dev_get(dev); 1825 vrf_del_slave(vrf_dev, dev); 1826 } 1827 out: 1828 return NOTIFY_DONE; 1829 } 1830 1831 static struct notifier_block vrf_notifier_block __read_mostly = { 1832 .notifier_call = vrf_device_event, 1833 }; 1834 1835 static int vrf_map_init(struct vrf_map *vmap) 1836 { 1837 spin_lock_init(&vmap->vmap_lock); 1838 hash_init(vmap->ht); 1839 1840 vmap->strict_mode = false; 1841 1842 return 0; 1843 } 1844 1845 #ifdef CONFIG_SYSCTL 1846 static bool vrf_strict_mode(struct vrf_map *vmap) 1847 { 1848 bool strict_mode; 1849 1850 vrf_map_lock(vmap); 1851 strict_mode = vmap->strict_mode; 1852 vrf_map_unlock(vmap); 1853 1854 return strict_mode; 1855 } 1856 1857 static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode) 1858 { 1859 bool *cur_mode; 1860 int res = 0; 1861 1862 vrf_map_lock(vmap); 1863 1864 cur_mode = &vmap->strict_mode; 1865 if (*cur_mode == new_mode) 1866 goto unlock; 1867 1868 if (*cur_mode) { 1869 /* disable strict mode */ 1870 *cur_mode = false; 1871 } else { 1872 if (vmap->shared_tables) { 1873 /* we cannot allow strict_mode because there are some 1874 * vrfs that share one or more tables. 1875 */ 1876 res = -EBUSY; 1877 goto unlock; 1878 } 1879 1880 /* no tables are shared among vrfs, so we can go back 1881 * to 1:1 association between a vrf with its table. 1882 */ 1883 *cur_mode = true; 1884 } 1885 1886 unlock: 1887 vrf_map_unlock(vmap); 1888 1889 return res; 1890 } 1891 1892 static int vrf_shared_table_handler(const struct ctl_table *table, int write, 1893 void *buffer, size_t *lenp, loff_t *ppos) 1894 { 1895 struct net *net = (struct net *)table->extra1; 1896 struct vrf_map *vmap = netns_vrf_map(net); 1897 int proc_strict_mode = 0; 1898 struct ctl_table tmp = { 1899 .procname = table->procname, 1900 .data = &proc_strict_mode, 1901 .maxlen = sizeof(int), 1902 .mode = table->mode, 1903 .extra1 = SYSCTL_ZERO, 1904 .extra2 = SYSCTL_ONE, 1905 }; 1906 int ret; 1907 1908 if (!write) 1909 proc_strict_mode = vrf_strict_mode(vmap); 1910 1911 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 1912 1913 if (write && ret == 0) 1914 ret = vrf_strict_mode_change(vmap, (bool)proc_strict_mode); 1915 1916 return ret; 1917 } 1918 1919 static const struct ctl_table vrf_table[] = { 1920 { 1921 .procname = "strict_mode", 1922 .data = NULL, 1923 .maxlen = sizeof(int), 1924 .mode = 0644, 1925 .proc_handler = vrf_shared_table_handler, 1926 /* set by the vrf_netns_init */ 1927 .extra1 = NULL, 1928 }, 1929 }; 1930 1931 static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf) 1932 { 1933 struct ctl_table *table; 1934 1935 table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL); 1936 if (!table) 1937 return -ENOMEM; 1938 1939 /* init the extra1 parameter with the reference to current netns */ 1940 table[0].extra1 = net; 1941 1942 nn_vrf->ctl_hdr = register_net_sysctl_sz(net, "net/vrf", table, 1943 ARRAY_SIZE(vrf_table)); 1944 if (!nn_vrf->ctl_hdr) { 1945 kfree(table); 1946 return -ENOMEM; 1947 } 1948 1949 return 0; 1950 } 1951 1952 static void vrf_netns_exit_sysctl(struct net *net) 1953 { 1954 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id); 1955 const struct ctl_table *table; 1956 1957 table = nn_vrf->ctl_hdr->ctl_table_arg; 1958 unregister_net_sysctl_table(nn_vrf->ctl_hdr); 1959 kfree(table); 1960 } 1961 #else 1962 static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf) 1963 { 1964 return 0; 1965 } 1966 1967 static void vrf_netns_exit_sysctl(struct net *net) 1968 { 1969 } 1970 #endif 1971 1972 /* Initialize per network namespace state */ 1973 static int __net_init vrf_netns_init(struct net *net) 1974 { 1975 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id); 1976 1977 nn_vrf->add_fib_rules = true; 1978 vrf_map_init(&nn_vrf->vmap); 1979 1980 return vrf_netns_init_sysctl(net, nn_vrf); 1981 } 1982 1983 static void __net_exit vrf_netns_exit(struct net *net) 1984 { 1985 vrf_netns_exit_sysctl(net); 1986 } 1987 1988 static struct pernet_operations vrf_net_ops __net_initdata = { 1989 .init = vrf_netns_init, 1990 .exit = vrf_netns_exit, 1991 .id = &vrf_net_id, 1992 .size = sizeof(struct netns_vrf), 1993 }; 1994 1995 static int __init vrf_init_module(void) 1996 { 1997 int rc; 1998 1999 register_netdevice_notifier(&vrf_notifier_block); 2000 2001 rc = register_pernet_subsys(&vrf_net_ops); 2002 if (rc < 0) 2003 goto error; 2004 2005 rc = l3mdev_table_lookup_register(L3MDEV_TYPE_VRF, 2006 vrf_ifindex_lookup_by_table_id); 2007 if (rc < 0) 2008 goto unreg_pernet; 2009 2010 rc = rtnl_link_register(&vrf_link_ops); 2011 if (rc < 0) 2012 goto table_lookup_unreg; 2013 2014 return 0; 2015 2016 table_lookup_unreg: 2017 l3mdev_table_lookup_unregister(L3MDEV_TYPE_VRF, 2018 vrf_ifindex_lookup_by_table_id); 2019 2020 unreg_pernet: 2021 unregister_pernet_subsys(&vrf_net_ops); 2022 2023 error: 2024 unregister_netdevice_notifier(&vrf_notifier_block); 2025 return rc; 2026 } 2027 2028 module_init(vrf_init_module); 2029 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern"); 2030 MODULE_DESCRIPTION("Device driver to instantiate VRF domains"); 2031 MODULE_LICENSE("GPL"); 2032 MODULE_ALIAS_RTNL_LINK(DRV_NAME); 2033 MODULE_VERSION(DRV_VERSION); 2034