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/flow.h> 30 #include <net/ip.h> 31 #include <net/ip_fib.h> 32 #include <net/ip6_fib.h> 33 #include <net/ip6_route.h> 34 #include <net/route.h> 35 #include <net/addrconf.h> 36 #include <net/l3mdev.h> 37 #include <net/fib_rules.h> 38 #include <net/netdev_lock.h> 39 #include <net/sch_generic.h> 40 #include <net/netns/generic.h> 41 #include <net/netfilter/nf_conntrack.h> 42 43 #define DRV_NAME "vrf" 44 #define DRV_VERSION "1.1" 45 46 #define FIB_RULE_PREF 1000 /* default preference for FIB rules */ 47 48 #define HT_MAP_BITS 4 49 #define HASH_INITVAL ((u32)0xcafef00d) 50 51 struct vrf_map { 52 DECLARE_HASHTABLE(ht, HT_MAP_BITS); 53 spinlock_t vmap_lock; 54 55 /* shared_tables: 56 * count how many distinct tables do not comply with the strict mode 57 * requirement. 58 * shared_tables value must be 0 in order to enable the strict mode. 59 * 60 * example of the evolution of shared_tables: 61 * | time 62 * add vrf0 --> table 100 shared_tables = 0 | t0 63 * add vrf1 --> table 101 shared_tables = 0 | t1 64 * add vrf2 --> table 100 shared_tables = 1 | t2 65 * add vrf3 --> table 100 shared_tables = 1 | t3 66 * add vrf4 --> table 101 shared_tables = 2 v t4 67 * 68 * shared_tables is a "step function" (or "staircase function") 69 * and it is increased by one when the second vrf is associated to a 70 * table. 71 * 72 * at t2, vrf0 and vrf2 are bound to table 100: shared_tables = 1. 73 * 74 * at t3, another dev (vrf3) is bound to the same table 100 but the 75 * value of shared_tables is still 1. 76 * This means that no matter how many new vrfs will register on the 77 * table 100, the shared_tables will not increase (considering only 78 * table 100). 79 * 80 * at t4, vrf4 is bound to table 101, and shared_tables = 2. 81 * 82 * Looking at the value of shared_tables we can immediately know if 83 * the strict_mode can or cannot be enforced. Indeed, strict_mode 84 * can be enforced iff shared_tables = 0. 85 * 86 * Conversely, shared_tables is decreased when a vrf is de-associated 87 * from a table with exactly two associated vrfs. 88 */ 89 u32 shared_tables; 90 91 bool strict_mode; 92 }; 93 94 struct vrf_map_elem { 95 struct hlist_node hnode; 96 struct list_head vrf_list; /* VRFs registered to this table */ 97 98 u32 table_id; 99 int users; 100 int ifindex; 101 }; 102 103 static unsigned int vrf_net_id; 104 105 /* per netns vrf data */ 106 struct netns_vrf { 107 /* protected by rtnl lock */ 108 bool add_fib_rules; 109 110 struct vrf_map vmap; 111 struct ctl_table_header *ctl_hdr; 112 }; 113 114 struct net_vrf { 115 struct rtable *rth; 116 struct rt6_info *rt6; 117 #if IS_ENABLED(CONFIG_IPV6) 118 struct fib6_table *fib6_table; 119 #endif 120 u32 tb_id; 121 122 struct list_head me_list; /* entry in vrf_map_elem */ 123 int ifindex; 124 }; 125 126 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb) 127 { 128 vrf_dev->stats.tx_errors++; 129 kfree_skb(skb); 130 } 131 132 static struct vrf_map *netns_vrf_map(struct net *net) 133 { 134 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id); 135 136 return &nn_vrf->vmap; 137 } 138 139 static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev) 140 { 141 return netns_vrf_map(dev_net(dev)); 142 } 143 144 static int vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem *me) 145 { 146 struct list_head *me_head = &me->vrf_list; 147 struct net_vrf *vrf; 148 149 if (list_empty(me_head)) 150 return -ENODEV; 151 152 vrf = list_first_entry(me_head, struct net_vrf, me_list); 153 154 return vrf->ifindex; 155 } 156 157 static struct vrf_map_elem *vrf_map_elem_alloc(gfp_t flags) 158 { 159 struct vrf_map_elem *me; 160 161 me = kmalloc_obj(*me, flags); 162 if (!me) 163 return NULL; 164 165 return me; 166 } 167 168 static void vrf_map_elem_free(struct vrf_map_elem *me) 169 { 170 kfree(me); 171 } 172 173 static void vrf_map_elem_init(struct vrf_map_elem *me, int table_id, 174 int ifindex, int users) 175 { 176 me->table_id = table_id; 177 me->ifindex = ifindex; 178 me->users = users; 179 INIT_LIST_HEAD(&me->vrf_list); 180 } 181 182 static struct vrf_map_elem *vrf_map_lookup_elem(struct vrf_map *vmap, 183 u32 table_id) 184 { 185 struct vrf_map_elem *me; 186 u32 key; 187 188 key = jhash_1word(table_id, HASH_INITVAL); 189 hash_for_each_possible(vmap->ht, me, hnode, key) { 190 if (me->table_id == table_id) 191 return me; 192 } 193 194 return NULL; 195 } 196 197 static void vrf_map_add_elem(struct vrf_map *vmap, struct vrf_map_elem *me) 198 { 199 u32 table_id = me->table_id; 200 u32 key; 201 202 key = jhash_1word(table_id, HASH_INITVAL); 203 hash_add(vmap->ht, &me->hnode, key); 204 } 205 206 static void vrf_map_del_elem(struct vrf_map_elem *me) 207 { 208 hash_del(&me->hnode); 209 } 210 211 static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock) 212 { 213 spin_lock(&vmap->vmap_lock); 214 } 215 216 static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock) 217 { 218 spin_unlock(&vmap->vmap_lock); 219 } 220 221 /* called with rtnl lock held */ 222 static int 223 vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack) 224 { 225 struct vrf_map *vmap = netns_vrf_map_by_dev(dev); 226 struct net_vrf *vrf = netdev_priv(dev); 227 struct vrf_map_elem *new_me, *me; 228 u32 table_id = vrf->tb_id; 229 bool free_new_me = false; 230 int users; 231 int res; 232 233 /* we pre-allocate elements used in the spin-locked section (so that we 234 * keep the spinlock as short as possible). 235 */ 236 new_me = vrf_map_elem_alloc(GFP_KERNEL); 237 if (!new_me) 238 return -ENOMEM; 239 240 vrf_map_elem_init(new_me, table_id, dev->ifindex, 0); 241 242 vrf_map_lock(vmap); 243 244 me = vrf_map_lookup_elem(vmap, table_id); 245 if (!me) { 246 me = new_me; 247 vrf_map_add_elem(vmap, me); 248 goto link_vrf; 249 } 250 251 /* we already have an entry in the vrf_map, so it means there is (at 252 * least) a vrf registered on the specific table. 253 */ 254 free_new_me = true; 255 if (vmap->strict_mode) { 256 /* vrfs cannot share the same table */ 257 NL_SET_ERR_MSG(extack, "Table is used by another VRF"); 258 res = -EBUSY; 259 goto unlock; 260 } 261 262 link_vrf: 263 users = ++me->users; 264 if (users == 2) 265 ++vmap->shared_tables; 266 267 list_add(&vrf->me_list, &me->vrf_list); 268 269 res = 0; 270 271 unlock: 272 vrf_map_unlock(vmap); 273 274 /* clean-up, if needed */ 275 if (free_new_me) 276 vrf_map_elem_free(new_me); 277 278 return res; 279 } 280 281 /* called with rtnl lock held */ 282 static void vrf_map_unregister_dev(struct net_device *dev) 283 { 284 struct vrf_map *vmap = netns_vrf_map_by_dev(dev); 285 struct net_vrf *vrf = netdev_priv(dev); 286 u32 table_id = vrf->tb_id; 287 struct vrf_map_elem *me; 288 int users; 289 290 vrf_map_lock(vmap); 291 292 me = vrf_map_lookup_elem(vmap, table_id); 293 if (!me) 294 goto unlock; 295 296 list_del(&vrf->me_list); 297 298 users = --me->users; 299 if (users == 1) { 300 --vmap->shared_tables; 301 } else if (users == 0) { 302 vrf_map_del_elem(me); 303 304 /* no one will refer to this element anymore */ 305 vrf_map_elem_free(me); 306 } 307 308 unlock: 309 vrf_map_unlock(vmap); 310 } 311 312 /* return the vrf device index associated with the table_id */ 313 static int vrf_ifindex_lookup_by_table_id(struct net *net, u32 table_id) 314 { 315 struct vrf_map *vmap = netns_vrf_map(net); 316 struct vrf_map_elem *me; 317 int ifindex; 318 319 vrf_map_lock(vmap); 320 321 if (!vmap->strict_mode) { 322 ifindex = -EPERM; 323 goto unlock; 324 } 325 326 me = vrf_map_lookup_elem(vmap, table_id); 327 if (!me) { 328 ifindex = -ENODEV; 329 goto unlock; 330 } 331 332 ifindex = vrf_map_elem_get_vrf_ifindex(me); 333 334 unlock: 335 vrf_map_unlock(vmap); 336 337 return ifindex; 338 } 339 340 /* by default VRF devices do not have a qdisc and are expected 341 * to be created with only a single queue. 342 */ 343 static bool qdisc_tx_is_default(const struct net_device *dev) 344 { 345 struct netdev_queue *txq; 346 347 if (dev->num_tx_queues > 1) 348 return false; 349 350 txq = netdev_get_tx_queue(dev, 0); 351 352 return qdisc_txq_has_no_queue(txq); 353 } 354 355 /* Local traffic destined to local address. Reinsert the packet to rx 356 * path, similar to loopback handling. 357 */ 358 static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev, 359 struct dst_entry *dst) 360 { 361 unsigned int len = skb->len; 362 363 skb_orphan(skb); 364 365 skb_dst_set(skb, dst); 366 367 /* set pkt_type to avoid skb hitting packet taps twice - 368 * once on Tx and again in Rx processing 369 */ 370 skb->pkt_type = PACKET_LOOPBACK; 371 372 skb->protocol = eth_type_trans(skb, dev); 373 374 if (likely(__netif_rx(skb) == NET_RX_SUCCESS)) 375 dev_dstats_rx_add(dev, len); 376 else 377 dev_dstats_rx_dropped(dev); 378 379 return NETDEV_TX_OK; 380 } 381 382 static void vrf_nf_set_untracked(struct sk_buff *skb) 383 { 384 if (skb_get_nfct(skb) == 0) 385 nf_ct_set(skb, NULL, IP_CT_UNTRACKED); 386 } 387 388 static void vrf_nf_reset_ct(struct sk_buff *skb) 389 { 390 if (skb_get_nfct(skb) == IP_CT_UNTRACKED) 391 nf_reset_ct(skb); 392 } 393 394 #if IS_ENABLED(CONFIG_IPV6) 395 static int vrf_ip6_local_out(struct net *net, struct sock *sk, 396 struct sk_buff *skb) 397 { 398 int err; 399 400 vrf_nf_reset_ct(skb); 401 402 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, 403 sk, skb, NULL, skb_dst(skb)->dev, dst_output); 404 405 if (likely(err == 1)) 406 err = dst_output(net, sk, skb); 407 408 return err; 409 } 410 411 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, 412 struct net_device *dev) 413 { 414 const struct ipv6hdr *iph; 415 struct net *net = dev_net(skb->dev); 416 struct flowi6 fl6; 417 int ret = NET_XMIT_DROP; 418 struct dst_entry *dst; 419 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst; 420 421 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr))) 422 goto err; 423 424 iph = ipv6_hdr(skb); 425 426 memset(&fl6, 0, sizeof(fl6)); 427 /* needed to match OIF rule */ 428 fl6.flowi6_l3mdev = dev->ifindex; 429 fl6.flowi6_iif = LOOPBACK_IFINDEX; 430 fl6.daddr = iph->daddr; 431 fl6.saddr = iph->saddr; 432 fl6.flowlabel = ip6_flowinfo(iph); 433 fl6.flowi6_mark = skb->mark; 434 fl6.flowi6_proto = iph->nexthdr; 435 436 dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL); 437 if (IS_ERR(dst) || dst == dst_null) 438 goto err; 439 440 skb_dst_drop(skb); 441 442 /* if dst.dev is the VRF device again this is locally originated traffic 443 * destined to a local address. Short circuit to Rx path. 444 */ 445 if (dst->dev == dev) 446 return vrf_local_xmit(skb, dev, dst); 447 448 skb_dst_set(skb, dst); 449 450 /* strip the ethernet header added for pass through VRF device */ 451 __skb_pull(skb, skb_network_offset(skb)); 452 453 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); 454 ret = vrf_ip6_local_out(net, skb->sk, skb); 455 if (unlikely(net_xmit_eval(ret))) 456 dev->stats.tx_errors++; 457 else 458 ret = NET_XMIT_SUCCESS; 459 460 return ret; 461 err: 462 vrf_tx_error(dev, skb); 463 return NET_XMIT_DROP; 464 } 465 #else 466 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, 467 struct net_device *dev) 468 { 469 vrf_tx_error(dev, skb); 470 return NET_XMIT_DROP; 471 } 472 #endif 473 474 /* based on ip_local_out; can't use it b/c the dst is switched pointing to us */ 475 static int vrf_ip_local_out(struct net *net, struct sock *sk, 476 struct sk_buff *skb) 477 { 478 int err; 479 480 vrf_nf_reset_ct(skb); 481 482 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk, 483 skb, NULL, skb_dst(skb)->dev, dst_output); 484 if (likely(err == 1)) 485 err = dst_output(net, sk, skb); 486 487 return err; 488 } 489 490 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb, 491 struct net_device *vrf_dev) 492 { 493 struct iphdr *ip4h; 494 int ret = NET_XMIT_DROP; 495 struct flowi4 fl4; 496 struct net *net = dev_net(vrf_dev); 497 struct rtable *rt; 498 499 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr))) 500 goto err; 501 502 ip4h = ip_hdr(skb); 503 504 memset(&fl4, 0, sizeof(fl4)); 505 /* needed to match OIF rule */ 506 fl4.flowi4_l3mdev = vrf_dev->ifindex; 507 fl4.flowi4_iif = LOOPBACK_IFINDEX; 508 fl4.flowi4_dscp = ip4h_dscp(ip4h); 509 fl4.flowi4_flags = FLOWI_FLAG_ANYSRC; 510 fl4.flowi4_proto = ip4h->protocol; 511 fl4.daddr = ip4h->daddr; 512 fl4.saddr = ip4h->saddr; 513 514 rt = ip_route_output_flow(net, &fl4, NULL); 515 if (IS_ERR(rt)) 516 goto err; 517 518 skb_dst_drop(skb); 519 520 /* if dst.dev is the VRF device again this is locally originated traffic 521 * destined to a local address. Short circuit to Rx path. 522 */ 523 if (rt->dst.dev == vrf_dev) 524 return vrf_local_xmit(skb, vrf_dev, &rt->dst); 525 526 skb_dst_set(skb, &rt->dst); 527 528 /* strip the ethernet header added for pass through VRF device */ 529 __skb_pull(skb, skb_network_offset(skb)); 530 531 if (!ip4h->saddr) { 532 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0, 533 RT_SCOPE_LINK); 534 } 535 536 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 537 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb); 538 if (unlikely(net_xmit_eval(ret))) 539 vrf_dev->stats.tx_errors++; 540 else 541 ret = NET_XMIT_SUCCESS; 542 543 out: 544 return ret; 545 err: 546 vrf_tx_error(vrf_dev, skb); 547 goto out; 548 } 549 550 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev) 551 { 552 switch (skb->protocol) { 553 case htons(ETH_P_IP): 554 return vrf_process_v4_outbound(skb, dev); 555 case htons(ETH_P_IPV6): 556 return vrf_process_v6_outbound(skb, dev); 557 default: 558 vrf_tx_error(dev, skb); 559 return NET_XMIT_DROP; 560 } 561 } 562 563 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev) 564 { 565 unsigned int len = skb->len; 566 netdev_tx_t ret; 567 568 ret = is_ip_tx_frame(skb, dev); 569 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) 570 dev_dstats_tx_add(dev, len); 571 else 572 dev_dstats_tx_dropped(dev); 573 574 return ret; 575 } 576 577 static void vrf_finish_direct(struct sk_buff *skb) 578 { 579 struct net_device *vrf_dev = skb->dev; 580 581 if (!list_empty(&vrf_dev->ptype_all) && 582 likely(skb_headroom(skb) >= ETH_HLEN)) { 583 struct ethhdr *eth = skb_push(skb, ETH_HLEN); 584 585 ether_addr_copy(eth->h_source, vrf_dev->dev_addr); 586 eth_zero_addr(eth->h_dest); 587 eth->h_proto = skb->protocol; 588 589 rcu_read_lock_bh(); 590 dev_queue_xmit_nit(skb, vrf_dev); 591 rcu_read_unlock_bh(); 592 593 skb_pull(skb, ETH_HLEN); 594 } 595 596 vrf_nf_reset_ct(skb); 597 } 598 599 #if IS_ENABLED(CONFIG_IPV6) 600 /* modelled after ip6_finish_output2 */ 601 static int vrf_finish_output6(struct net *net, struct sock *sk, 602 struct sk_buff *skb) 603 { 604 struct dst_entry *dst = skb_dst(skb); 605 struct net_device *dev = dst->dev; 606 const struct in6_addr *nexthop; 607 struct neighbour *neigh; 608 int ret; 609 610 vrf_nf_reset_ct(skb); 611 612 skb->protocol = htons(ETH_P_IPV6); 613 skb->dev = dev; 614 615 rcu_read_lock(); 616 nexthop = rt6_nexthop(dst_rt6_info(dst), &ipv6_hdr(skb)->daddr); 617 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop); 618 if (unlikely(!neigh)) 619 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false); 620 if (!IS_ERR(neigh)) { 621 sock_confirm_neigh(skb, neigh); 622 ret = neigh_output(neigh, skb, false); 623 rcu_read_unlock(); 624 return ret; 625 } 626 rcu_read_unlock(); 627 628 IP6_INC_STATS(dev_net(dst->dev), 629 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 630 kfree_skb(skb); 631 return -EINVAL; 632 } 633 634 /* modelled after ip6_output */ 635 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb) 636 { 637 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, 638 net, sk, skb, NULL, skb_dst(skb)->dev, 639 vrf_finish_output6, 640 !(IP6CB(skb)->flags & IP6SKB_REROUTED)); 641 } 642 643 /* set dst on skb to send packet to us via dev_xmit path. Allows 644 * packet to go through device based features such as qdisc, netfilter 645 * hooks and packet sockets with skb->dev set to vrf device. 646 */ 647 static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev, 648 struct sk_buff *skb) 649 { 650 struct net_vrf *vrf = netdev_priv(vrf_dev); 651 struct rt6_info *rt6; 652 653 rt6 = vrf->rt6; 654 dst_hold(&rt6->dst); 655 656 skb_dst_drop(skb); 657 skb_dst_set(skb, &rt6->dst); 658 659 return skb; 660 } 661 662 static int vrf_output6_direct_finish(struct net *net, struct sock *sk, 663 struct sk_buff *skb) 664 { 665 vrf_finish_direct(skb); 666 667 return vrf_ip6_local_out(net, sk, skb); 668 } 669 670 static int vrf_output6_direct(struct net *net, struct sock *sk, 671 struct sk_buff *skb) 672 { 673 int err = 1; 674 675 skb->protocol = htons(ETH_P_IPV6); 676 677 if (!(IPCB(skb)->flags & IPSKB_REROUTED)) 678 err = nf_hook(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb, 679 NULL, skb->dev, vrf_output6_direct_finish); 680 681 if (likely(err == 1)) 682 vrf_finish_direct(skb); 683 684 return err; 685 } 686 687 static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk, 688 struct sk_buff *skb) 689 { 690 int err; 691 692 err = vrf_output6_direct(net, sk, skb); 693 if (likely(err == 1)) 694 err = vrf_ip6_local_out(net, sk, skb); 695 696 return err; 697 } 698 699 static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev, 700 struct sock *sk, 701 struct sk_buff *skb) 702 { 703 struct net *net = dev_net(vrf_dev); 704 int err; 705 706 skb->dev = vrf_dev; 707 708 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, 709 skb, NULL, vrf_dev, vrf_ip6_out_direct_finish); 710 711 if (likely(err == 1)) 712 err = vrf_output6_direct(net, sk, skb); 713 714 if (likely(err == 1)) 715 return skb; 716 717 return NULL; 718 } 719 720 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev, 721 struct sock *sk, 722 struct sk_buff *skb) 723 { 724 /* don't divert link scope packets */ 725 if (rt6_need_strict(&ipv6_hdr(skb)->daddr)) 726 return skb; 727 728 vrf_nf_set_untracked(skb); 729 730 if (qdisc_tx_is_default(vrf_dev) || 731 IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) 732 return vrf_ip6_out_direct(vrf_dev, sk, skb); 733 734 return vrf_ip6_out_redirect(vrf_dev, skb); 735 } 736 737 /* holding rtnl */ 738 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) 739 { 740 struct rt6_info *rt6 = vrf->rt6; 741 742 if (rt6) { 743 dst_dev_put(&rt6->dst); 744 dst_release(&rt6->dst); 745 } 746 } 747 748 static int vrf_rt6_create(struct net_device *dev) 749 { 750 int flags = DST_NOPOLICY | DST_NOXFRM; 751 struct net_vrf *vrf = netdev_priv(dev); 752 struct net *net = dev_net(dev); 753 struct rt6_info *rt6; 754 int rc = -ENOMEM; 755 756 /* IPv6 can be CONFIG enabled and then disabled runtime */ 757 if (!ipv6_mod_enabled()) 758 return 0; 759 760 vrf->fib6_table = fib6_new_table(net, vrf->tb_id); 761 if (!vrf->fib6_table) 762 goto out; 763 764 /* create a dst for routing packets out a VRF device */ 765 rt6 = ip6_dst_alloc(net, dev, flags); 766 if (!rt6) 767 goto out; 768 769 rt6->dst.output = vrf_output6; 770 771 vrf->rt6 = rt6; 772 773 rc = 0; 774 out: 775 return rc; 776 } 777 #else 778 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev, 779 struct sock *sk, 780 struct sk_buff *skb) 781 { 782 return skb; 783 } 784 785 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) 786 { 787 } 788 789 static int vrf_rt6_create(struct net_device *dev) 790 { 791 return 0; 792 } 793 #endif 794 795 /* modelled after ip_finish_output2 */ 796 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 797 { 798 struct dst_entry *dst = skb_dst(skb); 799 struct rtable *rt = dst_rtable(dst); 800 struct net_device *dev = dst->dev; 801 unsigned int hh_len = LL_RESERVED_SPACE(dev); 802 struct neighbour *neigh; 803 bool is_v6gw = false; 804 805 vrf_nf_reset_ct(skb); 806 807 /* Be paranoid, rather than too clever. */ 808 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { 809 skb = skb_expand_head(skb, hh_len); 810 if (!skb) { 811 dev->stats.tx_errors++; 812 return -ENOMEM; 813 } 814 } 815 816 rcu_read_lock(); 817 818 neigh = ip_neigh_for_gw(rt, skb, &is_v6gw); 819 if (!IS_ERR(neigh)) { 820 int ret; 821 822 sock_confirm_neigh(skb, neigh); 823 /* if crossing protocols, can not use the cached header */ 824 ret = neigh_output(neigh, skb, is_v6gw); 825 rcu_read_unlock(); 826 return ret; 827 } 828 829 rcu_read_unlock(); 830 vrf_tx_error(skb->dev, skb); 831 return -EINVAL; 832 } 833 834 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb) 835 { 836 struct net_device *dev = skb_dst(skb)->dev; 837 838 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len); 839 840 skb->dev = dev; 841 skb->protocol = htons(ETH_P_IP); 842 843 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, 844 net, sk, skb, NULL, dev, 845 vrf_finish_output, 846 !(IPCB(skb)->flags & IPSKB_REROUTED)); 847 } 848 849 /* set dst on skb to send packet to us via dev_xmit path. Allows 850 * packet to go through device based features such as qdisc, netfilter 851 * hooks and packet sockets with skb->dev set to vrf device. 852 */ 853 static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev, 854 struct sk_buff *skb) 855 { 856 struct net_vrf *vrf = netdev_priv(vrf_dev); 857 struct rtable *rth; 858 859 rth = vrf->rth; 860 dst_hold(&rth->dst); 861 862 skb_dst_drop(skb); 863 skb_dst_set(skb, &rth->dst); 864 865 return skb; 866 } 867 868 static int vrf_output_direct_finish(struct net *net, struct sock *sk, 869 struct sk_buff *skb) 870 { 871 vrf_finish_direct(skb); 872 873 return vrf_ip_local_out(net, sk, skb); 874 } 875 876 static int vrf_output_direct(struct net *net, struct sock *sk, 877 struct sk_buff *skb) 878 { 879 int err = 1; 880 881 skb->protocol = htons(ETH_P_IP); 882 883 if (!(IPCB(skb)->flags & IPSKB_REROUTED)) 884 err = nf_hook(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb, 885 NULL, skb->dev, vrf_output_direct_finish); 886 887 if (likely(err == 1)) 888 vrf_finish_direct(skb); 889 890 return err; 891 } 892 893 static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk, 894 struct sk_buff *skb) 895 { 896 int err; 897 898 err = vrf_output_direct(net, sk, skb); 899 if (likely(err == 1)) 900 err = vrf_ip_local_out(net, sk, skb); 901 902 return err; 903 } 904 905 static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev, 906 struct sock *sk, 907 struct sk_buff *skb) 908 { 909 struct net *net = dev_net(vrf_dev); 910 int err; 911 912 skb->dev = vrf_dev; 913 914 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk, 915 skb, NULL, vrf_dev, vrf_ip_out_direct_finish); 916 917 if (likely(err == 1)) 918 err = vrf_output_direct(net, sk, skb); 919 920 if (likely(err == 1)) 921 return skb; 922 923 return NULL; 924 } 925 926 static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev, 927 struct sock *sk, 928 struct sk_buff *skb) 929 { 930 /* don't divert multicast or local broadcast */ 931 if (ipv4_is_multicast(ip_hdr(skb)->daddr) || 932 ipv4_is_lbcast(ip_hdr(skb)->daddr)) 933 return skb; 934 935 vrf_nf_set_untracked(skb); 936 937 if (qdisc_tx_is_default(vrf_dev) || 938 IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) 939 return vrf_ip_out_direct(vrf_dev, sk, skb); 940 941 return vrf_ip_out_redirect(vrf_dev, skb); 942 } 943 944 /* called with rcu lock held */ 945 static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev, 946 struct sock *sk, 947 struct sk_buff *skb, 948 u16 proto) 949 { 950 switch (proto) { 951 case AF_INET: 952 return vrf_ip_out(vrf_dev, sk, skb); 953 case AF_INET6: 954 return vrf_ip6_out(vrf_dev, sk, skb); 955 } 956 957 return skb; 958 } 959 960 /* holding rtnl */ 961 static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf) 962 { 963 struct rtable *rth = vrf->rth; 964 965 dst_dev_put(&rth->dst); 966 dst_release(&rth->dst); 967 } 968 969 static int vrf_rtable_create(struct net_device *dev) 970 { 971 struct net_vrf *vrf = netdev_priv(dev); 972 struct rtable *rth; 973 974 if (!fib_new_table(dev_net(dev), vrf->tb_id)) 975 return -ENOMEM; 976 977 /* create a dst for routing packets out through a VRF device */ 978 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1); 979 if (!rth) 980 return -ENOMEM; 981 982 rth->dst.output = vrf_output; 983 984 vrf->rth = rth; 985 986 return 0; 987 } 988 989 /**************************** device handling ********************/ 990 991 /* cycle interface to flush neighbor cache and move routes across tables */ 992 static void cycle_netdev(struct net_device *dev, 993 struct netlink_ext_ack *extack) 994 { 995 unsigned int flags = dev->flags; 996 int ret; 997 998 if (!netif_running(dev)) 999 return; 1000 1001 ret = dev_change_flags(dev, flags & ~IFF_UP, extack); 1002 if (ret >= 0) 1003 ret = dev_change_flags(dev, flags, extack); 1004 1005 if (ret < 0) { 1006 netdev_err(dev, 1007 "Failed to cycle device %s; route tables might be wrong!\n", 1008 dev->name); 1009 } 1010 } 1011 1012 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev, 1013 struct netlink_ext_ack *extack) 1014 { 1015 int ret; 1016 1017 /* do not allow loopback device to be enslaved to a VRF. 1018 * The vrf device acts as the loopback for the vrf. 1019 */ 1020 if (port_dev == dev_net(dev)->loopback_dev) { 1021 NL_SET_ERR_MSG(extack, 1022 "Can not enslave loopback device to a VRF"); 1023 return -EOPNOTSUPP; 1024 } 1025 1026 port_dev->priv_flags |= IFF_L3MDEV_SLAVE; 1027 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack); 1028 if (ret < 0) 1029 goto err; 1030 1031 cycle_netdev(port_dev, extack); 1032 1033 return 0; 1034 1035 err: 1036 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE; 1037 synchronize_net(); 1038 return ret; 1039 } 1040 1041 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev, 1042 struct netlink_ext_ack *extack) 1043 { 1044 if (netif_is_l3_master(port_dev)) { 1045 NL_SET_ERR_MSG(extack, 1046 "Can not enslave an L3 master device to a VRF"); 1047 return -EINVAL; 1048 } 1049 1050 if (netif_is_l3_slave(port_dev)) 1051 return -EINVAL; 1052 1053 return do_vrf_add_slave(dev, port_dev, extack); 1054 } 1055 1056 /* inverse of do_vrf_add_slave */ 1057 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev, 1058 bool needs_sync) 1059 { 1060 netdev_upper_dev_unlink(port_dev, dev); 1061 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE; 1062 /* Make sure that concurrent RCU readers that identified the device 1063 * as a VRF port see a VRF master or no master at all. 1064 */ 1065 if (needs_sync) 1066 synchronize_net(); 1067 1068 cycle_netdev(port_dev, NULL); 1069 1070 return 0; 1071 } 1072 1073 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev) 1074 { 1075 return do_vrf_del_slave(dev, port_dev, true); 1076 } 1077 1078 static void vrf_dev_uninit(struct net_device *dev) 1079 { 1080 struct net_vrf *vrf = netdev_priv(dev); 1081 1082 vrf_rtable_release(dev, vrf); 1083 vrf_rt6_release(dev, vrf); 1084 } 1085 1086 static int vrf_dev_init(struct net_device *dev) 1087 { 1088 struct net_vrf *vrf = netdev_priv(dev); 1089 1090 /* create the default dst which points back to us */ 1091 if (vrf_rtable_create(dev) != 0) 1092 goto out_nomem; 1093 1094 if (vrf_rt6_create(dev) != 0) 1095 goto out_rth; 1096 1097 dev->flags = IFF_MASTER | IFF_NOARP; 1098 1099 /* similarly, oper state is irrelevant; set to up to avoid confusion */ 1100 dev->operstate = IF_OPER_UP; 1101 netdev_lockdep_set_classes(dev); 1102 return 0; 1103 1104 out_rth: 1105 vrf_rtable_release(dev, vrf); 1106 out_nomem: 1107 return -ENOMEM; 1108 } 1109 1110 static const struct net_device_ops vrf_netdev_ops = { 1111 .ndo_init = vrf_dev_init, 1112 .ndo_uninit = vrf_dev_uninit, 1113 .ndo_start_xmit = vrf_xmit, 1114 .ndo_set_mac_address = eth_mac_addr, 1115 .ndo_add_slave = vrf_add_slave, 1116 .ndo_del_slave = vrf_del_slave, 1117 }; 1118 1119 static u32 vrf_fib_table(const struct net_device *dev) 1120 { 1121 struct net_vrf *vrf = netdev_priv(dev); 1122 1123 return vrf->tb_id; 1124 } 1125 1126 static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) 1127 { 1128 kfree_skb(skb); 1129 return 0; 1130 } 1131 1132 static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook, 1133 struct sk_buff *skb, 1134 struct net_device *dev) 1135 { 1136 struct net *net = dev_net(dev); 1137 1138 if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1) 1139 skb = NULL; /* kfree_skb(skb) handled by nf code */ 1140 1141 return skb; 1142 } 1143 1144 static int vrf_prepare_mac_header(struct sk_buff *skb, 1145 struct net_device *vrf_dev, u16 proto) 1146 { 1147 struct ethhdr *eth; 1148 int err; 1149 1150 /* in general, we do not know if there is enough space in the head of 1151 * the packet for hosting the mac header. 1152 */ 1153 err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev)); 1154 if (unlikely(err)) 1155 /* no space in the skb head */ 1156 return -ENOBUFS; 1157 1158 __skb_push(skb, ETH_HLEN); 1159 eth = (struct ethhdr *)skb->data; 1160 1161 skb_reset_mac_header(skb); 1162 skb_reset_mac_len(skb); 1163 1164 /* we set the ethernet destination and the source addresses to the 1165 * address of the VRF device. 1166 */ 1167 ether_addr_copy(eth->h_dest, vrf_dev->dev_addr); 1168 ether_addr_copy(eth->h_source, vrf_dev->dev_addr); 1169 eth->h_proto = htons(proto); 1170 1171 /* the destination address of the Ethernet frame corresponds to the 1172 * address set on the VRF interface; therefore, the packet is intended 1173 * to be processed locally. 1174 */ 1175 skb->protocol = eth->h_proto; 1176 skb->pkt_type = PACKET_HOST; 1177 1178 skb_pull_inline(skb, ETH_HLEN); 1179 1180 return 0; 1181 } 1182 1183 /* prepare and add the mac header to the packet if it was not set previously. 1184 * In this way, packet sniffers such as tcpdump can parse the packet correctly. 1185 * If the mac header was already set, the original mac header is left 1186 * untouched and the function returns immediately. 1187 */ 1188 static int vrf_add_mac_header_if_unset(struct sk_buff *skb, 1189 struct net_device *vrf_dev, 1190 u16 proto, struct net_device *orig_dev) 1191 { 1192 if (skb_mac_header_was_set(skb) && dev_has_header(orig_dev)) 1193 return 0; 1194 1195 return vrf_prepare_mac_header(skb, vrf_dev, proto); 1196 } 1197 1198 #if IS_ENABLED(CONFIG_IPV6) 1199 /* neighbor handling is done with actual device; do not want 1200 * to flip skb->dev for those ndisc packets. This really fails 1201 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is 1202 * a start. 1203 */ 1204 static bool ipv6_ndisc_frame(const struct sk_buff *skb) 1205 { 1206 const struct ipv6hdr *iph = ipv6_hdr(skb); 1207 bool rc = false; 1208 1209 if (iph->nexthdr == NEXTHDR_ICMP) { 1210 const struct icmp6hdr *icmph; 1211 struct icmp6hdr _icmph; 1212 1213 icmph = skb_header_pointer(skb, sizeof(*iph), 1214 sizeof(_icmph), &_icmph); 1215 if (!icmph) 1216 goto out; 1217 1218 switch (icmph->icmp6_type) { 1219 case NDISC_ROUTER_SOLICITATION: 1220 case NDISC_ROUTER_ADVERTISEMENT: 1221 case NDISC_NEIGHBOUR_SOLICITATION: 1222 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1223 case NDISC_REDIRECT: 1224 rc = true; 1225 break; 1226 } 1227 } 1228 1229 out: 1230 return rc; 1231 } 1232 1233 static struct rt6_info *vrf_ip6_route_lookup(struct net *net, 1234 const struct net_device *dev, 1235 struct flowi6 *fl6, 1236 int ifindex, 1237 const struct sk_buff *skb, 1238 int flags) 1239 { 1240 struct net_vrf *vrf = netdev_priv(dev); 1241 1242 return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags); 1243 } 1244 1245 static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev, 1246 int ifindex) 1247 { 1248 const struct ipv6hdr *iph = ipv6_hdr(skb); 1249 struct flowi6 fl6 = { 1250 .flowi6_iif = ifindex, 1251 .flowi6_mark = skb->mark, 1252 .flowi6_proto = iph->nexthdr, 1253 .daddr = iph->daddr, 1254 .saddr = iph->saddr, 1255 .flowlabel = ip6_flowinfo(iph), 1256 }; 1257 struct net *net = dev_net(vrf_dev); 1258 struct rt6_info *rt6; 1259 1260 skb_dst_drop(skb); 1261 1262 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb, 1263 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE); 1264 if (unlikely(!rt6)) 1265 return; 1266 1267 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst)) 1268 return; 1269 1270 skb_dst_set(skb, &rt6->dst); 1271 } 1272 1273 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, 1274 struct sk_buff *skb) 1275 { 1276 int orig_iif = skb->skb_iif; 1277 bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr); 1278 bool is_ndisc = ipv6_ndisc_frame(skb); 1279 1280 /* loopback, multicast & non-ND link-local traffic; do not push through 1281 * packet taps again. Reset pkt_type for upper layers to process skb. 1282 * For non-loopback strict packets, determine the dst using the original 1283 * ifindex. 1284 */ 1285 if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) { 1286 skb->dev = vrf_dev; 1287 skb->skb_iif = vrf_dev->ifindex; 1288 IP6CB(skb)->flags |= IP6SKB_L3SLAVE; 1289 1290 if (skb->pkt_type == PACKET_LOOPBACK) 1291 skb->pkt_type = PACKET_HOST; 1292 else 1293 vrf_ip6_input_dst(skb, vrf_dev, orig_iif); 1294 1295 goto out; 1296 } 1297 1298 /* if packet is NDISC then keep the ingress interface */ 1299 if (!is_ndisc) { 1300 struct net_device *orig_dev = skb->dev; 1301 1302 dev_dstats_rx_add(vrf_dev, skb->len); 1303 skb->dev = vrf_dev; 1304 skb->skb_iif = vrf_dev->ifindex; 1305 1306 if (!list_empty(&vrf_dev->ptype_all)) { 1307 int err; 1308 1309 err = vrf_add_mac_header_if_unset(skb, vrf_dev, 1310 ETH_P_IPV6, 1311 orig_dev); 1312 if (likely(!err)) { 1313 skb_push(skb, skb->mac_len); 1314 dev_queue_xmit_nit(skb, vrf_dev); 1315 skb_pull(skb, skb->mac_len); 1316 } 1317 } 1318 1319 IP6CB(skb)->flags |= IP6SKB_L3SLAVE; 1320 } 1321 1322 if (need_strict) 1323 vrf_ip6_input_dst(skb, vrf_dev, orig_iif); 1324 1325 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev); 1326 out: 1327 return skb; 1328 } 1329 1330 #else 1331 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, 1332 struct sk_buff *skb) 1333 { 1334 return skb; 1335 } 1336 #endif 1337 1338 static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev, 1339 struct sk_buff *skb) 1340 { 1341 struct net_device *orig_dev = skb->dev; 1342 1343 skb->dev = vrf_dev; 1344 skb->skb_iif = vrf_dev->ifindex; 1345 IPCB(skb)->flags |= IPSKB_L3SLAVE; 1346 1347 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) 1348 goto out; 1349 1350 /* loopback traffic; do not push through packet taps again. 1351 * Reset pkt_type for upper layers to process skb 1352 */ 1353 if (skb->pkt_type == PACKET_LOOPBACK) { 1354 skb->pkt_type = PACKET_HOST; 1355 goto out; 1356 } 1357 1358 dev_dstats_rx_add(vrf_dev, skb->len); 1359 1360 if (!list_empty(&vrf_dev->ptype_all)) { 1361 int err; 1362 1363 err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP, 1364 orig_dev); 1365 if (likely(!err)) { 1366 skb_push(skb, skb->mac_len); 1367 dev_queue_xmit_nit(skb, vrf_dev); 1368 skb_pull(skb, skb->mac_len); 1369 } 1370 } 1371 1372 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev); 1373 out: 1374 return skb; 1375 } 1376 1377 /* called with rcu lock held */ 1378 static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev, 1379 struct sk_buff *skb, 1380 u16 proto) 1381 { 1382 switch (proto) { 1383 case AF_INET: 1384 return vrf_ip_rcv(vrf_dev, skb); 1385 case AF_INET6: 1386 return vrf_ip6_rcv(vrf_dev, skb); 1387 } 1388 1389 return skb; 1390 } 1391 1392 #if IS_ENABLED(CONFIG_IPV6) 1393 /* send to link-local or multicast address via interface enslaved to 1394 * VRF device. Force lookup to VRF table without changing flow struct 1395 * Note: Caller to this function must hold rcu_read_lock() and no refcnt 1396 * is taken on the dst by this function. 1397 */ 1398 static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev, 1399 struct flowi6 *fl6) 1400 { 1401 struct net *net = dev_net(dev); 1402 int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF; 1403 struct dst_entry *dst = NULL; 1404 struct rt6_info *rt; 1405 1406 /* VRF device does not have a link-local address and 1407 * sending packets to link-local or mcast addresses over 1408 * a VRF device does not make sense 1409 */ 1410 if (fl6->flowi6_oif == dev->ifindex) { 1411 dst = &net->ipv6.ip6_null_entry->dst; 1412 return dst; 1413 } 1414 1415 if (!ipv6_addr_any(&fl6->saddr)) 1416 flags |= RT6_LOOKUP_F_HAS_SADDR; 1417 1418 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags); 1419 if (rt) 1420 dst = &rt->dst; 1421 1422 return dst; 1423 } 1424 #endif 1425 1426 static const struct l3mdev_ops vrf_l3mdev_ops = { 1427 .l3mdev_fib_table = vrf_fib_table, 1428 .l3mdev_l3_rcv = vrf_l3_rcv, 1429 .l3mdev_l3_out = vrf_l3_out, 1430 #if IS_ENABLED(CONFIG_IPV6) 1431 .l3mdev_link_scope_lookup = vrf_link_scope_lookup, 1432 #endif 1433 }; 1434 1435 static void vrf_get_drvinfo(struct net_device *dev, 1436 struct ethtool_drvinfo *info) 1437 { 1438 strscpy(info->driver, DRV_NAME, sizeof(info->driver)); 1439 strscpy(info->version, DRV_VERSION, sizeof(info->version)); 1440 } 1441 1442 static const struct ethtool_ops vrf_ethtool_ops = { 1443 .get_drvinfo = vrf_get_drvinfo, 1444 }; 1445 1446 static inline size_t vrf_fib_rule_nl_size(void) 1447 { 1448 size_t sz; 1449 1450 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)); 1451 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */ 1452 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */ 1453 sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */ 1454 1455 return sz; 1456 } 1457 1458 static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it) 1459 { 1460 struct fib_rule_hdr *frh; 1461 struct nlmsghdr *nlh; 1462 struct sk_buff *skb; 1463 int err; 1464 1465 if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) && 1466 !ipv6_mod_enabled()) 1467 return 0; 1468 1469 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL); 1470 if (!skb) 1471 return -ENOMEM; 1472 1473 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0); 1474 if (!nlh) 1475 goto nla_put_failure; 1476 1477 /* rule only needs to appear once */ 1478 nlh->nlmsg_flags |= NLM_F_EXCL; 1479 1480 frh = nlmsg_data(nlh); 1481 memset(frh, 0, sizeof(*frh)); 1482 frh->family = family; 1483 frh->action = FR_ACT_TO_TBL; 1484 1485 if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL)) 1486 goto nla_put_failure; 1487 1488 if (nla_put_u8(skb, FRA_L3MDEV, 1)) 1489 goto nla_put_failure; 1490 1491 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF)) 1492 goto nla_put_failure; 1493 1494 nlmsg_end(skb, nlh); 1495 1496 if (add_it) { 1497 err = fib_newrule(dev_net(dev), skb, nlh, NULL, true); 1498 if (err == -EEXIST) 1499 err = 0; 1500 } else { 1501 err = fib_delrule(dev_net(dev), skb, nlh, NULL, true); 1502 if (err == -ENOENT) 1503 err = 0; 1504 } 1505 nlmsg_free(skb); 1506 1507 return err; 1508 1509 nla_put_failure: 1510 nlmsg_free(skb); 1511 1512 return -EMSGSIZE; 1513 } 1514 1515 static int vrf_add_fib_rules(const struct net_device *dev) 1516 { 1517 int err; 1518 1519 err = vrf_fib_rule(dev, AF_INET, true); 1520 if (err < 0) 1521 goto out_err; 1522 1523 err = vrf_fib_rule(dev, AF_INET6, true); 1524 if (err < 0) 1525 goto ipv6_err; 1526 1527 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES) 1528 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true); 1529 if (err < 0) 1530 goto ipmr_err; 1531 #endif 1532 1533 #if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES) 1534 err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, true); 1535 if (err < 0) 1536 goto ip6mr_err; 1537 #endif 1538 1539 return 0; 1540 1541 #if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES) 1542 ip6mr_err: 1543 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, false); 1544 #endif 1545 1546 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES) 1547 ipmr_err: 1548 vrf_fib_rule(dev, AF_INET6, false); 1549 #endif 1550 1551 ipv6_err: 1552 vrf_fib_rule(dev, AF_INET, false); 1553 1554 out_err: 1555 netdev_err(dev, "Failed to add FIB rules.\n"); 1556 return err; 1557 } 1558 1559 static void vrf_setup(struct net_device *dev) 1560 { 1561 ether_setup(dev); 1562 1563 /* Initialize the device structure. */ 1564 dev->netdev_ops = &vrf_netdev_ops; 1565 dev->l3mdev_ops = &vrf_l3mdev_ops; 1566 dev->ethtool_ops = &vrf_ethtool_ops; 1567 dev->needs_free_netdev = true; 1568 1569 /* Fill in device structure with ethernet-generic values. */ 1570 eth_hw_addr_random(dev); 1571 1572 /* don't acquire vrf device's netif_tx_lock when transmitting */ 1573 dev->lltx = true; 1574 1575 /* don't allow vrf devices to change network namespaces. */ 1576 dev->netns_immutable = true; 1577 1578 /* does not make sense for a VLAN to be added to a vrf device */ 1579 dev->features |= NETIF_F_VLAN_CHALLENGED; 1580 1581 /* enable offload features */ 1582 dev->features |= NETIF_F_GSO_SOFTWARE; 1583 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC; 1584 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA; 1585 1586 dev->hw_features = dev->features; 1587 dev->hw_enc_features = dev->features; 1588 1589 /* default to no qdisc; user can add if desired */ 1590 dev->priv_flags |= IFF_NO_QUEUE; 1591 dev->priv_flags |= IFF_NO_RX_HANDLER; 1592 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1593 1594 /* VRF devices do not care about MTU, but if the MTU is set 1595 * too low then the ipv4 and ipv6 protocols are disabled 1596 * which breaks networking. 1597 */ 1598 dev->min_mtu = IPV6_MIN_MTU; 1599 dev->max_mtu = IP6_MAX_MTU; 1600 dev->mtu = dev->max_mtu; 1601 1602 dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS; 1603 } 1604 1605 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[], 1606 struct netlink_ext_ack *extack) 1607 { 1608 if (tb[IFLA_ADDRESS]) { 1609 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) { 1610 NL_SET_ERR_MSG(extack, "Invalid hardware address"); 1611 return -EINVAL; 1612 } 1613 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) { 1614 NL_SET_ERR_MSG(extack, "Invalid hardware address"); 1615 return -EADDRNOTAVAIL; 1616 } 1617 } 1618 return 0; 1619 } 1620 1621 static void vrf_dellink(struct net_device *dev, struct list_head *head) 1622 { 1623 struct net_device *port_dev; 1624 struct list_head *iter; 1625 1626 netdev_for_each_lower_dev(dev, port_dev, iter) 1627 do_vrf_del_slave(dev, port_dev, false); 1628 1629 vrf_map_unregister_dev(dev); 1630 1631 unregister_netdevice_queue(dev, head); 1632 } 1633 1634 static int vrf_newlink(struct net_device *dev, 1635 struct rtnl_newlink_params *params, 1636 struct netlink_ext_ack *extack) 1637 { 1638 struct net_vrf *vrf = netdev_priv(dev); 1639 struct nlattr **data = params->data; 1640 struct netns_vrf *nn_vrf; 1641 bool *add_fib_rules; 1642 struct net *net; 1643 int err; 1644 1645 if (!data || !data[IFLA_VRF_TABLE]) { 1646 NL_SET_ERR_MSG(extack, "VRF table id is missing"); 1647 return -EINVAL; 1648 } 1649 1650 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]); 1651 if (vrf->tb_id == RT_TABLE_UNSPEC) { 1652 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE], 1653 "Invalid VRF table id"); 1654 return -EINVAL; 1655 } 1656 1657 dev->priv_flags |= IFF_L3MDEV_MASTER; 1658 1659 err = register_netdevice(dev); 1660 if (err) 1661 goto out; 1662 1663 /* mapping between table_id and vrf; 1664 * note: such binding could not be done in the dev init function 1665 * because dev->ifindex id is not available yet. 1666 */ 1667 vrf->ifindex = dev->ifindex; 1668 1669 err = vrf_map_register_dev(dev, extack); 1670 if (err) { 1671 unregister_netdevice(dev); 1672 goto out; 1673 } 1674 1675 net = dev_net(dev); 1676 nn_vrf = net_generic(net, vrf_net_id); 1677 1678 add_fib_rules = &nn_vrf->add_fib_rules; 1679 if (*add_fib_rules) { 1680 err = vrf_add_fib_rules(dev); 1681 if (err) { 1682 vrf_map_unregister_dev(dev); 1683 unregister_netdevice(dev); 1684 goto out; 1685 } 1686 *add_fib_rules = false; 1687 } 1688 1689 out: 1690 return err; 1691 } 1692 1693 static size_t vrf_nl_getsize(const struct net_device *dev) 1694 { 1695 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */ 1696 } 1697 1698 static int vrf_fillinfo(struct sk_buff *skb, 1699 const struct net_device *dev) 1700 { 1701 struct net_vrf *vrf = netdev_priv(dev); 1702 1703 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id); 1704 } 1705 1706 static size_t vrf_get_slave_size(const struct net_device *bond_dev, 1707 const struct net_device *slave_dev) 1708 { 1709 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */ 1710 } 1711 1712 static int vrf_fill_slave_info(struct sk_buff *skb, 1713 const struct net_device *vrf_dev, 1714 const struct net_device *slave_dev) 1715 { 1716 struct net_vrf *vrf = netdev_priv(vrf_dev); 1717 1718 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id)) 1719 return -EMSGSIZE; 1720 1721 return 0; 1722 } 1723 1724 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = { 1725 [IFLA_VRF_TABLE] = { .type = NLA_U32 }, 1726 }; 1727 1728 static struct rtnl_link_ops vrf_link_ops __read_mostly = { 1729 .kind = DRV_NAME, 1730 .priv_size = sizeof(struct net_vrf), 1731 1732 .get_size = vrf_nl_getsize, 1733 .policy = vrf_nl_policy, 1734 .validate = vrf_validate, 1735 .fill_info = vrf_fillinfo, 1736 1737 .get_slave_size = vrf_get_slave_size, 1738 .fill_slave_info = vrf_fill_slave_info, 1739 1740 .newlink = vrf_newlink, 1741 .dellink = vrf_dellink, 1742 .setup = vrf_setup, 1743 .maxtype = IFLA_VRF_MAX, 1744 }; 1745 1746 static int vrf_device_event(struct notifier_block *unused, 1747 unsigned long event, void *ptr) 1748 { 1749 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1750 1751 /* only care about unregister events to drop slave references */ 1752 if (event == NETDEV_UNREGISTER) { 1753 struct net_device *vrf_dev; 1754 1755 if (!netif_is_l3_slave(dev)) 1756 goto out; 1757 1758 vrf_dev = netdev_master_upper_dev_get(dev); 1759 do_vrf_del_slave(vrf_dev, dev, false); 1760 } 1761 out: 1762 return NOTIFY_DONE; 1763 } 1764 1765 static struct notifier_block vrf_notifier_block __read_mostly = { 1766 .notifier_call = vrf_device_event, 1767 }; 1768 1769 static int vrf_map_init(struct vrf_map *vmap) 1770 { 1771 spin_lock_init(&vmap->vmap_lock); 1772 hash_init(vmap->ht); 1773 1774 vmap->strict_mode = false; 1775 1776 return 0; 1777 } 1778 1779 #ifdef CONFIG_SYSCTL 1780 static bool vrf_strict_mode(struct vrf_map *vmap) 1781 { 1782 bool strict_mode; 1783 1784 vrf_map_lock(vmap); 1785 strict_mode = vmap->strict_mode; 1786 vrf_map_unlock(vmap); 1787 1788 return strict_mode; 1789 } 1790 1791 static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode) 1792 { 1793 bool *cur_mode; 1794 int res = 0; 1795 1796 vrf_map_lock(vmap); 1797 1798 cur_mode = &vmap->strict_mode; 1799 if (*cur_mode == new_mode) 1800 goto unlock; 1801 1802 if (*cur_mode) { 1803 /* disable strict mode */ 1804 *cur_mode = false; 1805 } else { 1806 if (vmap->shared_tables) { 1807 /* we cannot allow strict_mode because there are some 1808 * vrfs that share one or more tables. 1809 */ 1810 res = -EBUSY; 1811 goto unlock; 1812 } 1813 1814 /* no tables are shared among vrfs, so we can go back 1815 * to 1:1 association between a vrf with its table. 1816 */ 1817 *cur_mode = true; 1818 } 1819 1820 unlock: 1821 vrf_map_unlock(vmap); 1822 1823 return res; 1824 } 1825 1826 static int vrf_shared_table_handler(const struct ctl_table *table, int write, 1827 void *buffer, size_t *lenp, loff_t *ppos) 1828 { 1829 struct net *net = (struct net *)table->extra1; 1830 struct vrf_map *vmap = netns_vrf_map(net); 1831 int proc_strict_mode = 0; 1832 struct ctl_table tmp = { 1833 .procname = table->procname, 1834 .data = &proc_strict_mode, 1835 .maxlen = sizeof(int), 1836 .mode = table->mode, 1837 .extra1 = SYSCTL_ZERO, 1838 .extra2 = SYSCTL_ONE, 1839 }; 1840 int ret; 1841 1842 if (!write) 1843 proc_strict_mode = vrf_strict_mode(vmap); 1844 1845 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 1846 1847 if (write && ret == 0) 1848 ret = vrf_strict_mode_change(vmap, (bool)proc_strict_mode); 1849 1850 return ret; 1851 } 1852 1853 static const struct ctl_table vrf_table[] = { 1854 { 1855 .procname = "strict_mode", 1856 .data = NULL, 1857 .maxlen = sizeof(int), 1858 .mode = 0644, 1859 .proc_handler = vrf_shared_table_handler, 1860 /* set by the vrf_netns_init */ 1861 .extra1 = NULL, 1862 }, 1863 }; 1864 1865 static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf) 1866 { 1867 struct ctl_table *table; 1868 1869 table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL); 1870 if (!table) 1871 return -ENOMEM; 1872 1873 /* init the extra1 parameter with the reference to current netns */ 1874 table[0].extra1 = net; 1875 1876 nn_vrf->ctl_hdr = register_net_sysctl_sz(net, "net/vrf", table, 1877 ARRAY_SIZE(vrf_table)); 1878 if (!nn_vrf->ctl_hdr) { 1879 kfree(table); 1880 return -ENOMEM; 1881 } 1882 1883 return 0; 1884 } 1885 1886 static void vrf_netns_exit_sysctl(struct net *net) 1887 { 1888 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id); 1889 const struct ctl_table *table; 1890 1891 table = nn_vrf->ctl_hdr->ctl_table_arg; 1892 unregister_net_sysctl_table(nn_vrf->ctl_hdr); 1893 kfree(table); 1894 } 1895 #else 1896 static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf) 1897 { 1898 return 0; 1899 } 1900 1901 static void vrf_netns_exit_sysctl(struct net *net) 1902 { 1903 } 1904 #endif 1905 1906 /* Initialize per network namespace state */ 1907 static int __net_init vrf_netns_init(struct net *net) 1908 { 1909 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id); 1910 1911 nn_vrf->add_fib_rules = true; 1912 vrf_map_init(&nn_vrf->vmap); 1913 1914 return vrf_netns_init_sysctl(net, nn_vrf); 1915 } 1916 1917 static void __net_exit vrf_netns_exit(struct net *net) 1918 { 1919 vrf_netns_exit_sysctl(net); 1920 } 1921 1922 static struct pernet_operations vrf_net_ops __net_initdata = { 1923 .init = vrf_netns_init, 1924 .exit = vrf_netns_exit, 1925 .id = &vrf_net_id, 1926 .size = sizeof(struct netns_vrf), 1927 }; 1928 1929 static int __init vrf_init_module(void) 1930 { 1931 int rc; 1932 1933 rc = register_netdevice_notifier(&vrf_notifier_block); 1934 if (rc < 0) 1935 return rc; 1936 1937 rc = register_pernet_subsys(&vrf_net_ops); 1938 if (rc < 0) 1939 goto error; 1940 1941 rc = l3mdev_table_lookup_register(L3MDEV_TYPE_VRF, 1942 vrf_ifindex_lookup_by_table_id); 1943 if (rc < 0) 1944 goto unreg_pernet; 1945 1946 rc = rtnl_link_register(&vrf_link_ops); 1947 if (rc < 0) 1948 goto table_lookup_unreg; 1949 1950 return 0; 1951 1952 table_lookup_unreg: 1953 l3mdev_table_lookup_unregister(L3MDEV_TYPE_VRF, 1954 vrf_ifindex_lookup_by_table_id); 1955 1956 unreg_pernet: 1957 unregister_pernet_subsys(&vrf_net_ops); 1958 1959 error: 1960 unregister_netdevice_notifier(&vrf_notifier_block); 1961 return rc; 1962 } 1963 1964 module_init(vrf_init_module); 1965 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern"); 1966 MODULE_DESCRIPTION("Device driver to instantiate VRF domains"); 1967 MODULE_LICENSE("GPL"); 1968 MODULE_ALIAS_RTNL_LINK(DRV_NAME); 1969 MODULE_VERSION(DRV_VERSION); 1970