2 * vrf.c: device driver to encapsulate a VRF space
4 * Copyright (c) 2015 Cumulus Networks. All rights reserved.
5 * Copyright (c) 2015 Shrijeet Mukherjee <shm@cumulusnetworks.com>
6 * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com>
8 * Based on dummy, team and ipvlan drivers
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
16 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <linux/netdevice.h>
19 #include <linux/etherdevice.h>
21 #include <linux/init.h>
22 #include <linux/moduleparam.h>
23 #include <linux/netfilter.h>
24 #include <linux/rtnetlink.h>
25 #include <net/rtnetlink.h>
26 #include <linux/u64_stats_sync.h>
27 #include <linux/hashtable.h>
29 #include <linux/inetdevice.h>
32 #include <net/ip_fib.h>
33 #include <net/ip6_route.h>
34 #include <net/rtnetlink.h>
35 #include <net/route.h>
36 #include <net/addrconf.h>
37 #include <net/l3mdev.h>
39 #define RT_FL_TOS(oldflp4) \
40 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
42 #define DRV_NAME "vrf"
43 #define DRV_VERSION "1.0"
45 #define vrf_master_get_rcu(dev) \
46 ((struct net_device *)rcu_dereference(dev->rx_handler_data))
49 struct list_head list;
50 struct net_device *dev;
54 struct list_head all_slaves;
58 struct slave_queue queue;
69 struct u64_stats_sync syncp;
72 static struct dst_entry *vrf_ip_check(struct dst_entry *dst, u32 cookie)
77 static int vrf_ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
79 return ip_local_out(net, sk, skb);
82 static unsigned int vrf_v4_mtu(const struct dst_entry *dst)
84 /* TO-DO: return max ethernet size? */
88 static void vrf_dst_destroy(struct dst_entry *dst)
90 /* our dst lives forever - or until the device is closed */
93 static unsigned int vrf_default_advmss(const struct dst_entry *dst)
98 static struct dst_ops vrf_dst_ops = {
100 .local_out = vrf_ip_local_out,
101 .check = vrf_ip_check,
103 .destroy = vrf_dst_destroy,
104 .default_advmss = vrf_default_advmss,
107 static bool is_ip_rx_frame(struct sk_buff *skb)
109 switch (skb->protocol) {
110 case htons(ETH_P_IP):
111 case htons(ETH_P_IPV6):
117 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
119 vrf_dev->stats.tx_errors++;
123 /* note: already called with rcu_read_lock */
124 static rx_handler_result_t vrf_handle_frame(struct sk_buff **pskb)
126 struct sk_buff *skb = *pskb;
128 if (is_ip_rx_frame(skb)) {
129 struct net_device *dev = vrf_master_get_rcu(skb->dev);
130 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
132 u64_stats_update_begin(&dstats->syncp);
134 dstats->rx_bytes += skb->len;
135 u64_stats_update_end(&dstats->syncp);
139 return RX_HANDLER_ANOTHER;
141 return RX_HANDLER_PASS;
144 static struct rtnl_link_stats64 *vrf_get_stats64(struct net_device *dev,
145 struct rtnl_link_stats64 *stats)
149 for_each_possible_cpu(i) {
150 const struct pcpu_dstats *dstats;
151 u64 tbytes, tpkts, tdrops, rbytes, rpkts;
154 dstats = per_cpu_ptr(dev->dstats, i);
156 start = u64_stats_fetch_begin_irq(&dstats->syncp);
157 tbytes = dstats->tx_bytes;
158 tpkts = dstats->tx_pkts;
159 tdrops = dstats->tx_drps;
160 rbytes = dstats->rx_bytes;
161 rpkts = dstats->rx_pkts;
162 } while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
163 stats->tx_bytes += tbytes;
164 stats->tx_packets += tpkts;
165 stats->tx_dropped += tdrops;
166 stats->rx_bytes += rbytes;
167 stats->rx_packets += rpkts;
172 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
173 struct net_device *dev)
175 vrf_tx_error(dev, skb);
176 return NET_XMIT_DROP;
179 static int vrf_send_v4_prep(struct sk_buff *skb, struct flowi4 *fl4,
180 struct net_device *vrf_dev)
185 rt = ip_route_output_flow(dev_net(vrf_dev), fl4, NULL);
189 /* TO-DO: what about broadcast ? */
190 if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
196 skb_dst_set(skb, &rt->dst);
202 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
203 struct net_device *vrf_dev)
205 struct iphdr *ip4h = ip_hdr(skb);
206 int ret = NET_XMIT_DROP;
207 struct flowi4 fl4 = {
208 /* needed to match OIF rule */
209 .flowi4_oif = vrf_dev->ifindex,
210 .flowi4_iif = LOOPBACK_IFINDEX,
211 .flowi4_tos = RT_TOS(ip4h->tos),
212 .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_L3MDEV_SRC |
213 FLOWI_FLAG_SKIP_NH_OIF,
214 .daddr = ip4h->daddr,
217 if (vrf_send_v4_prep(skb, &fl4, vrf_dev))
221 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
225 ret = ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
226 if (unlikely(net_xmit_eval(ret)))
227 vrf_dev->stats.tx_errors++;
229 ret = NET_XMIT_SUCCESS;
234 vrf_tx_error(vrf_dev, skb);
238 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
240 /* strip the ethernet header added for pass through VRF device */
241 __skb_pull(skb, skb_network_offset(skb));
243 switch (skb->protocol) {
244 case htons(ETH_P_IP):
245 return vrf_process_v4_outbound(skb, dev);
246 case htons(ETH_P_IPV6):
247 return vrf_process_v6_outbound(skb, dev);
249 vrf_tx_error(dev, skb);
250 return NET_XMIT_DROP;
254 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
256 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
258 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
259 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
261 u64_stats_update_begin(&dstats->syncp);
263 dstats->tx_bytes += skb->len;
264 u64_stats_update_end(&dstats->syncp);
266 this_cpu_inc(dev->dstats->tx_drps);
272 /* modelled after ip_finish_output2 */
273 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
275 struct dst_entry *dst = skb_dst(skb);
276 struct rtable *rt = (struct rtable *)dst;
277 struct net_device *dev = dst->dev;
278 unsigned int hh_len = LL_RESERVED_SPACE(dev);
279 struct neighbour *neigh;
283 /* Be paranoid, rather than too clever. */
284 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
285 struct sk_buff *skb2;
287 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
293 skb_set_owner_w(skb2, skb->sk);
301 nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr);
302 neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
303 if (unlikely(!neigh))
304 neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
306 ret = dst_neigh_output(dst, neigh, skb);
308 rcu_read_unlock_bh();
310 if (unlikely(ret < 0))
311 vrf_tx_error(skb->dev, skb);
315 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
317 struct net_device *dev = skb_dst(skb)->dev;
319 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
322 skb->protocol = htons(ETH_P_IP);
324 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
325 net, sk, skb, NULL, dev,
327 !(IPCB(skb)->flags & IPSKB_REROUTED));
330 static void vrf_rtable_destroy(struct net_vrf *vrf)
332 struct dst_entry *dst = (struct dst_entry *)vrf->rth;
338 static struct rtable *vrf_rtable_create(struct net_device *dev)
340 struct net_vrf *vrf = netdev_priv(dev);
343 rth = dst_alloc(&vrf_dst_ops, dev, 2,
345 (DST_HOST | DST_NOPOLICY | DST_NOXFRM));
347 rth->dst.output = vrf_output;
348 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
350 rth->rt_type = RTN_UNICAST;
351 rth->rt_is_input = 0;
355 rth->rt_uses_gateway = 0;
356 rth->rt_table_id = vrf->tb_id;
357 INIT_LIST_HEAD(&rth->rt_uncached);
358 rth->rt_uncached_list = NULL;
364 /**************************** device handling ********************/
366 /* cycle interface to flush neighbor cache and move routes across tables */
367 static void cycle_netdev(struct net_device *dev)
369 unsigned int flags = dev->flags;
372 if (!netif_running(dev))
375 ret = dev_change_flags(dev, flags & ~IFF_UP);
377 ret = dev_change_flags(dev, flags);
381 "Failed to cycle device %s; route tables might be wrong!\n",
386 static struct slave *__vrf_find_slave_dev(struct slave_queue *queue,
387 struct net_device *dev)
389 struct list_head *head = &queue->all_slaves;
392 list_for_each_entry(slave, head, list) {
393 if (slave->dev == dev)
400 /* inverse of __vrf_insert_slave */
401 static void __vrf_remove_slave(struct slave_queue *queue, struct slave *slave)
403 list_del(&slave->list);
406 static void __vrf_insert_slave(struct slave_queue *queue, struct slave *slave)
408 list_add(&slave->list, &queue->all_slaves);
411 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
413 struct slave *slave = kzalloc(sizeof(*slave), GFP_KERNEL);
414 struct net_vrf *vrf = netdev_priv(dev);
415 struct slave_queue *queue = &vrf->queue;
421 slave->dev = port_dev;
423 /* register the packet handler for slave ports */
424 ret = netdev_rx_handler_register(port_dev, vrf_handle_frame, dev);
427 "Device %s failed to register rx_handler\n",
432 ret = netdev_master_upper_dev_link(port_dev, dev);
436 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
437 __vrf_insert_slave(queue, slave);
438 cycle_netdev(port_dev);
443 netdev_rx_handler_unregister(port_dev);
449 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
451 if (netif_is_l3_master(port_dev) || netif_is_l3_slave(port_dev))
454 return do_vrf_add_slave(dev, port_dev);
457 /* inverse of do_vrf_add_slave */
458 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
460 struct net_vrf *vrf = netdev_priv(dev);
461 struct slave_queue *queue = &vrf->queue;
464 netdev_upper_dev_unlink(port_dev, dev);
465 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
467 netdev_rx_handler_unregister(port_dev);
469 cycle_netdev(port_dev);
471 slave = __vrf_find_slave_dev(queue, port_dev);
473 __vrf_remove_slave(queue, slave);
480 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
482 return do_vrf_del_slave(dev, port_dev);
485 static void vrf_dev_uninit(struct net_device *dev)
487 struct net_vrf *vrf = netdev_priv(dev);
488 struct slave_queue *queue = &vrf->queue;
489 struct list_head *head = &queue->all_slaves;
490 struct slave *slave, *next;
492 vrf_rtable_destroy(vrf);
494 list_for_each_entry_safe(slave, next, head, list)
495 vrf_del_slave(dev, slave->dev);
497 free_percpu(dev->dstats);
501 static int vrf_dev_init(struct net_device *dev)
503 struct net_vrf *vrf = netdev_priv(dev);
505 INIT_LIST_HEAD(&vrf->queue.all_slaves);
507 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
511 /* create the default dst which points back to us */
512 vrf->rth = vrf_rtable_create(dev);
516 dev->flags = IFF_MASTER | IFF_NOARP;
521 free_percpu(dev->dstats);
527 static const struct net_device_ops vrf_netdev_ops = {
528 .ndo_init = vrf_dev_init,
529 .ndo_uninit = vrf_dev_uninit,
530 .ndo_start_xmit = vrf_xmit,
531 .ndo_get_stats64 = vrf_get_stats64,
532 .ndo_add_slave = vrf_add_slave,
533 .ndo_del_slave = vrf_del_slave,
536 static u32 vrf_fib_table(const struct net_device *dev)
538 struct net_vrf *vrf = netdev_priv(dev);
543 static struct rtable *vrf_get_rtable(const struct net_device *dev,
544 const struct flowi4 *fl4)
546 struct rtable *rth = NULL;
548 if (!(fl4->flowi4_flags & FLOWI_FLAG_L3MDEV_SRC)) {
549 struct net_vrf *vrf = netdev_priv(dev);
552 atomic_inc(&rth->dst.__refcnt);
558 /* called under rcu_read_lock */
559 static void vrf_get_saddr(struct net_device *dev, struct flowi4 *fl4)
561 struct fib_result res = { .tclassid = 0 };
562 struct net *net = dev_net(dev);
563 u32 orig_tos = fl4->flowi4_tos;
564 u8 flags = fl4->flowi4_flags;
565 u8 scope = fl4->flowi4_scope;
566 u8 tos = RT_FL_TOS(fl4);
568 if (unlikely(!fl4->daddr))
571 fl4->flowi4_flags |= FLOWI_FLAG_SKIP_NH_OIF;
572 fl4->flowi4_iif = LOOPBACK_IFINDEX;
573 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
574 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
575 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
577 if (!fib_lookup(net, fl4, &res, 0)) {
578 if (res.type == RTN_LOCAL)
579 fl4->saddr = res.fi->fib_prefsrc ? : fl4->daddr;
581 fib_select_path(net, &res, fl4, -1);
584 fl4->flowi4_flags = flags;
585 fl4->flowi4_tos = orig_tos;
586 fl4->flowi4_scope = scope;
589 static const struct l3mdev_ops vrf_l3mdev_ops = {
590 .l3mdev_fib_table = vrf_fib_table,
591 .l3mdev_get_rtable = vrf_get_rtable,
592 .l3mdev_get_saddr = vrf_get_saddr,
595 static void vrf_get_drvinfo(struct net_device *dev,
596 struct ethtool_drvinfo *info)
598 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
599 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
602 static const struct ethtool_ops vrf_ethtool_ops = {
603 .get_drvinfo = vrf_get_drvinfo,
606 static void vrf_setup(struct net_device *dev)
610 /* Initialize the device structure. */
611 dev->netdev_ops = &vrf_netdev_ops;
612 dev->l3mdev_ops = &vrf_l3mdev_ops;
613 dev->ethtool_ops = &vrf_ethtool_ops;
614 dev->destructor = free_netdev;
616 /* Fill in device structure with ethernet-generic values. */
617 eth_hw_addr_random(dev);
619 /* don't acquire vrf device's netif_tx_lock when transmitting */
620 dev->features |= NETIF_F_LLTX;
622 /* don't allow vrf devices to change network namespaces. */
623 dev->features |= NETIF_F_NETNS_LOCAL;
626 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[])
628 if (tb[IFLA_ADDRESS]) {
629 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
631 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
632 return -EADDRNOTAVAIL;
637 static void vrf_dellink(struct net_device *dev, struct list_head *head)
639 unregister_netdevice_queue(dev, head);
642 static int vrf_newlink(struct net *src_net, struct net_device *dev,
643 struct nlattr *tb[], struct nlattr *data[])
645 struct net_vrf *vrf = netdev_priv(dev);
648 if (!data || !data[IFLA_VRF_TABLE])
651 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
653 dev->priv_flags |= IFF_L3MDEV_MASTER;
655 err = register_netdevice(dev);
666 static size_t vrf_nl_getsize(const struct net_device *dev)
668 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
671 static int vrf_fillinfo(struct sk_buff *skb,
672 const struct net_device *dev)
674 struct net_vrf *vrf = netdev_priv(dev);
676 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
679 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
680 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
683 static struct rtnl_link_ops vrf_link_ops __read_mostly = {
685 .priv_size = sizeof(struct net_vrf),
687 .get_size = vrf_nl_getsize,
688 .policy = vrf_nl_policy,
689 .validate = vrf_validate,
690 .fill_info = vrf_fillinfo,
692 .newlink = vrf_newlink,
693 .dellink = vrf_dellink,
695 .maxtype = IFLA_VRF_MAX,
698 static int vrf_device_event(struct notifier_block *unused,
699 unsigned long event, void *ptr)
701 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
703 /* only care about unregister events to drop slave references */
704 if (event == NETDEV_UNREGISTER) {
705 struct net_device *vrf_dev;
707 if (!netif_is_l3_slave(dev))
710 vrf_dev = netdev_master_upper_dev_get(dev);
711 vrf_del_slave(vrf_dev, dev);
717 static struct notifier_block vrf_notifier_block __read_mostly = {
718 .notifier_call = vrf_device_event,
721 static int __init vrf_init_module(void)
725 vrf_dst_ops.kmem_cachep =
726 kmem_cache_create("vrf_ip_dst_cache",
727 sizeof(struct rtable), 0,
731 if (!vrf_dst_ops.kmem_cachep)
734 register_netdevice_notifier(&vrf_notifier_block);
736 rc = rtnl_link_register(&vrf_link_ops);
743 unregister_netdevice_notifier(&vrf_notifier_block);
744 kmem_cache_destroy(vrf_dst_ops.kmem_cachep);
748 static void __exit vrf_cleanup_module(void)
750 rtnl_link_unregister(&vrf_link_ops);
751 unregister_netdevice_notifier(&vrf_notifier_block);
752 kmem_cache_destroy(vrf_dst_ops.kmem_cachep);
755 module_init(vrf_init_module);
756 module_exit(vrf_cleanup_module);
757 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
758 MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
759 MODULE_LICENSE("GPL");
760 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
761 MODULE_VERSION(DRV_VERSION);