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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * vrf.c: device driver to encapsulate a VRF space4 *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 drivers10 */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 448#define HASH_INITVAL ((u32)0xcafef00d)49 50struct 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 mode56 * 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 * | time61 * add vrf0 --> table 100 shared_tables = 0 | t062 * add vrf1 --> table 101 shared_tables = 0 | t163 * add vrf2 --> table 100 shared_tables = 1 | t264 * add vrf3 --> table 100 shared_tables = 1 | t365 * add vrf4 --> table 101 shared_tables = 2 v t466 *67 * shared_tables is a "step function" (or "staircase function")68 * and it is increased by one when the second vrf is associated to a69 * 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 the74 * value of shared_tables is still 1.75 * This means that no matter how many new vrfs will register on the76 * table 100, the shared_tables will not increase (considering only77 * 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 if82 * the strict_mode can or cannot be enforced. Indeed, strict_mode83 * can be enforced iff shared_tables = 0.84 *85 * Conversely, shared_tables is decreased when a vrf is de-associated86 * from a table with exactly two associated vrfs.87 */88 u32 shared_tables;89 90 bool strict_mode;91};92 93struct 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 102static unsigned int vrf_net_id;103 104/* per netns vrf data */105struct 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 113struct 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#endif119 u32 tb_id;120 121 struct list_head me_list; /* entry in vrf_map_elem */122 int ifindex;123};124 125static 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 135static 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 141static 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 148static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev)149{150 return netns_vrf_map(dev_net(dev));151}152 153static 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 166static 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 177static void vrf_map_elem_free(struct vrf_map_elem *me)178{179 kfree(me);180}181 182static 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 191static 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 206static 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 215static void vrf_map_del_elem(struct vrf_map_elem *me)216{217 hash_del(&me->hnode);218}219 220static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock)221{222 spin_lock(&vmap->vmap_lock);223}224 225static 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 */231static int232vrf_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 we243 * 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 (at261 * 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 271link_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 280unlock: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 */291static 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 317unlock:318 vrf_map_unlock(vmap);319}320 321/* return the vrf device index associated with the table_id */322static 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 343unlock:344 vrf_map_unlock(vmap);345 346 return ifindex;347}348 349/* by default VRF devices do not have a qdisc and are expected350 * to be created with only a single queue.351 */352static 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 rx367 * path, similar to loopback handling.368 */369static 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 processing380 */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 398static 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 404static 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)411static 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 427static 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 traffic459 * 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 else474 ret = NET_XMIT_SUCCESS;475 476 return ret;477err:478 vrf_tx_error(dev, skb);479 return NET_XMIT_DROP;480}481#else482static 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#endif489 490/* based on ip_local_out; can't use it b/c the dst is switched pointing to us */491static 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 506static 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 traffic537 * 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 else557 ret = NET_XMIT_SUCCESS;558 559out:560 return ret;561err:562 vrf_tx_error(vrf_dev, skb);563 goto out;564}565 566static 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 579static 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 599static 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 */623static 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 */657static 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. Allows666 * packet to go through device based features such as qdisc, netfilter667 * hooks and packet sockets with skb->dev set to vrf device.668 */669static 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 697static 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 705static 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 722static 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 734static 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 755static 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 */773static 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 deleted783 * - based on dst_ifdown784 */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 794static 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;820out:821 return rc;822}823#else824static 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 831static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)832{833}834 835static int vrf_rt6_create(struct net_device *dev)836{837 return 0;838}839#endif840 841/* modelled after ip_finish_output2 */842static 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 880static 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. Allows896 * packet to go through device based features such as qdisc, netfilter897 * hooks and packet sockets with skb->dev set to vrf device.898 */899static 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 927static 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 935static 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 952static 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 964static 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 985static 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 */1004static 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 */1020static 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 deleted1030 * - based on dst_ifdown1031 */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 1041static 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 */1064static 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 1084static 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 1107err:1108 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;1109 return ret;1110}1111 1112static 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 */1128static 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 1138static 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 1143static 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 1151static 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 1169out_rth:1170 vrf_rtable_release(dev, vrf);1171out_nomem:1172 return -ENOMEM;1173}1174 1175static 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 1184static 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 1191static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)1192{1193 kfree_skb(skb);1194 return 0;1195}1196 1197static 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 1209static 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 of1216 * 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 the1230 * 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 the1237 * address set on the VRF interface; therefore, the packet is intended1238 * 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 left1253 * untouched and the function returns immediately.1254 */1255static 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 want1267 * to flip skb->dev for those ndisc packets. This really fails1268 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is1269 * a start.1270 */1271static 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 1296out:1297 return rc;1298}1299 1300static 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 1312static 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 1338static 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 through1346 * packet taps again. Reset pkt_type for upper layers to process skb.1347 * For non-loopback strict packets, determine the dst using the original1348 * 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 else1358 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);1391out:1392 return skb;1393}1394 1395#else1396static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,1397 struct sk_buff *skb)1398{1399 return skb;1400}1401#endif1402 1403static 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 skb1417 */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);1438out:1439 return skb;1440}1441 1442/* called with rcu lock held */1443static 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 to1459 * VRF device. Force lookup to VRF table without changing flow struct1460 * Note: Caller to this function must hold rcu_read_lock() and no refcnt1461 * is taken on the dst by this function.1462 */1463static 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 and1472 * sending packets to link-local or mcast addresses over1473 * a VRF device does not make sense1474 */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#endif1490 1491static 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#endif1498};1499 1500static 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 1507static const struct ethtool_ops vrf_ethtool_ops = {1508 .get_drvinfo = vrf_get_drvinfo,1509};1510 1511static 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 1523static 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 1576nla_put_failure:1577 nlmsg_free(skb);1578 1579 return -EMSGSIZE;1580}1581 1582static 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#endif1599 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#endif1605 1606 return 0;1607 1608#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)1609ip6mr_err:1610 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, false);1611#endif1612 1613#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)1614ipmr_err:1615 vrf_fib_rule(dev, AF_INET6, false);1616#endif1617 1618ipv6_err:1619 vrf_fib_rule(dev, AF_INET, false);1620 1621out_err:1622 netdev_err(dev, "Failed to add FIB rules.\n");1623 return err;1624}1625 1626static 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 set1662 * too low then the ipv4 and ipv6 protocols are disabled1663 * 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 1672static 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 1688static 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 1701static 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 function1731 * 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 1755out:1756 return err;1757}1758 1759static size_t vrf_nl_getsize(const struct net_device *dev)1760{1761 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */1762}1763 1764static 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 1772static 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 1778static 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 1790static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {1791 [IFLA_VRF_TABLE] = { .type = NLA_U32 },1792};1793 1794static 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 1812static 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 }1827out:1828 return NOTIFY_DONE;1829}1830 1831static struct notifier_block vrf_notifier_block __read_mostly = {1832 .notifier_call = vrf_device_event,1833};1834 1835static 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_SYSCTL1846static 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 1857static 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 some1874 * 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 back1881 * to 1:1 association between a vrf with its table.1882 */1883 *cur_mode = true;1884 }1885 1886unlock:1887 vrf_map_unlock(vmap);1888 1889 return res;1890}1891 1892static 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 1919static 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 1931static 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 1952static 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#else1962static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)1963{1964 return 0;1965}1966 1967static void vrf_netns_exit_sysctl(struct net *net)1968{1969}1970#endif1971 1972/* Initialize per network namespace state */1973static 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 1983static void __net_exit vrf_netns_exit(struct net *net)1984{1985 vrf_netns_exit_sysctl(net);1986}1987 1988static 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 1995static 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 2016table_lookup_unreg:2017 l3mdev_table_lookup_unregister(L3MDEV_TYPE_VRF,2018 vrf_ifindex_lookup_by_table_id);2019 2020unreg_pernet:2021 unregister_pernet_subsys(&vrf_net_ops);2022 2023error:2024 unregister_netdevice_notifier(&vrf_notifier_block);2025 return rc;2026}2027 2028module_init(vrf_init_module);2029MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");2030MODULE_DESCRIPTION("Device driver to instantiate VRF domains");2031MODULE_LICENSE("GPL");2032MODULE_ALIAS_RTNL_LINK(DRV_NAME);2033MODULE_VERSION(DRV_VERSION);2034