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>
38 #include <net/l3mdev.h>
40 #define DRV_NAME "vrf"
41 #define DRV_VERSION "1.0"
43 #define vrf_is_slave(dev) ((dev)->flags & IFF_SLAVE)
45 #define vrf_master_get_rcu(dev) \
46 ((struct net_device *)rcu_dereference(dev->rx_handler_data))
54 struct u64_stats_sync syncp;
57 static struct dst_entry *vrf_ip_check(struct dst_entry *dst, u32 cookie)
62 static int vrf_ip_local_out(struct sk_buff *skb)
64 return ip_local_out(skb);
67 static unsigned int vrf_v4_mtu(const struct dst_entry *dst)
69 /* TO-DO: return max ethernet size? */
73 static void vrf_dst_destroy(struct dst_entry *dst)
75 /* our dst lives forever - or until the device is closed */
78 static unsigned int vrf_default_advmss(const struct dst_entry *dst)
83 static struct dst_ops vrf_dst_ops = {
85 .local_out = vrf_ip_local_out,
86 .check = vrf_ip_check,
88 .destroy = vrf_dst_destroy,
89 .default_advmss = vrf_default_advmss,
92 static bool is_ip_rx_frame(struct sk_buff *skb)
94 switch (skb->protocol) {
96 case htons(ETH_P_IPV6):
102 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
104 vrf_dev->stats.tx_errors++;
108 /* note: already called with rcu_read_lock */
109 static rx_handler_result_t vrf_handle_frame(struct sk_buff **pskb)
111 struct sk_buff *skb = *pskb;
113 if (is_ip_rx_frame(skb)) {
114 struct net_device *dev = vrf_master_get_rcu(skb->dev);
115 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
117 u64_stats_update_begin(&dstats->syncp);
119 dstats->rx_bytes += skb->len;
120 u64_stats_update_end(&dstats->syncp);
124 return RX_HANDLER_ANOTHER;
126 return RX_HANDLER_PASS;
129 static struct rtnl_link_stats64 *vrf_get_stats64(struct net_device *dev,
130 struct rtnl_link_stats64 *stats)
134 for_each_possible_cpu(i) {
135 const struct pcpu_dstats *dstats;
136 u64 tbytes, tpkts, tdrops, rbytes, rpkts;
139 dstats = per_cpu_ptr(dev->dstats, i);
141 start = u64_stats_fetch_begin_irq(&dstats->syncp);
142 tbytes = dstats->tx_bytes;
143 tpkts = dstats->tx_pkts;
144 tdrops = dstats->tx_drps;
145 rbytes = dstats->rx_bytes;
146 rpkts = dstats->rx_pkts;
147 } while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
148 stats->tx_bytes += tbytes;
149 stats->tx_packets += tpkts;
150 stats->tx_dropped += tdrops;
151 stats->rx_bytes += rbytes;
152 stats->rx_packets += rpkts;
157 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
158 struct net_device *dev)
160 vrf_tx_error(dev, skb);
161 return NET_XMIT_DROP;
164 static int vrf_send_v4_prep(struct sk_buff *skb, struct flowi4 *fl4,
165 struct net_device *vrf_dev)
170 rt = ip_route_output_flow(dev_net(vrf_dev), fl4, NULL);
174 /* TO-DO: what about broadcast ? */
175 if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
181 skb_dst_set(skb, &rt->dst);
187 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
188 struct net_device *vrf_dev)
190 struct iphdr *ip4h = ip_hdr(skb);
191 int ret = NET_XMIT_DROP;
192 struct flowi4 fl4 = {
193 /* needed to match OIF rule */
194 .flowi4_oif = vrf_dev->ifindex,
195 .flowi4_iif = LOOPBACK_IFINDEX,
196 .flowi4_tos = RT_TOS(ip4h->tos),
197 .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_VRFSRC |
198 FLOWI_FLAG_SKIP_NH_OIF,
199 .daddr = ip4h->daddr,
202 if (vrf_send_v4_prep(skb, &fl4, vrf_dev))
206 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
210 ret = ip_local_out(skb);
211 if (unlikely(net_xmit_eval(ret)))
212 vrf_dev->stats.tx_errors++;
214 ret = NET_XMIT_SUCCESS;
219 vrf_tx_error(vrf_dev, skb);
223 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
225 /* strip the ethernet header added for pass through VRF device */
226 __skb_pull(skb, skb_network_offset(skb));
228 switch (skb->protocol) {
229 case htons(ETH_P_IP):
230 return vrf_process_v4_outbound(skb, dev);
231 case htons(ETH_P_IPV6):
232 return vrf_process_v6_outbound(skb, dev);
234 vrf_tx_error(dev, skb);
235 return NET_XMIT_DROP;
239 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
241 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
243 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
244 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
246 u64_stats_update_begin(&dstats->syncp);
248 dstats->tx_bytes += skb->len;
249 u64_stats_update_end(&dstats->syncp);
251 this_cpu_inc(dev->dstats->tx_drps);
257 /* modelled after ip_finish_output2 */
258 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
260 struct dst_entry *dst = skb_dst(skb);
261 struct rtable *rt = (struct rtable *)dst;
262 struct net_device *dev = dst->dev;
263 unsigned int hh_len = LL_RESERVED_SPACE(dev);
264 struct neighbour *neigh;
268 /* Be paranoid, rather than too clever. */
269 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
270 struct sk_buff *skb2;
272 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
278 skb_set_owner_w(skb2, skb->sk);
286 nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr);
287 neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
288 if (unlikely(!neigh))
289 neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
291 ret = dst_neigh_output(dst, neigh, skb);
293 rcu_read_unlock_bh();
295 if (unlikely(ret < 0))
296 vrf_tx_error(skb->dev, skb);
300 static int vrf_output(struct sock *sk, struct sk_buff *skb)
302 struct net_device *dev = skb_dst(skb)->dev;
303 struct net *net = dev_net(dev);
305 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
308 skb->protocol = htons(ETH_P_IP);
310 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
311 net, sk, skb, NULL, dev,
313 !(IPCB(skb)->flags & IPSKB_REROUTED));
316 static void vrf_rtable_destroy(struct net_vrf *vrf)
318 struct dst_entry *dst = (struct dst_entry *)vrf->rth;
324 static struct rtable *vrf_rtable_create(struct net_device *dev)
326 struct net_vrf *vrf = netdev_priv(dev);
329 rth = dst_alloc(&vrf_dst_ops, dev, 2,
331 (DST_HOST | DST_NOPOLICY | DST_NOXFRM));
333 rth->dst.output = vrf_output;
334 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
336 rth->rt_type = RTN_UNICAST;
337 rth->rt_is_input = 0;
341 rth->rt_uses_gateway = 0;
342 rth->rt_table_id = vrf->tb_id;
343 INIT_LIST_HEAD(&rth->rt_uncached);
344 rth->rt_uncached_list = NULL;
350 /**************************** device handling ********************/
352 /* cycle interface to flush neighbor cache and move routes across tables */
353 static void cycle_netdev(struct net_device *dev)
355 unsigned int flags = dev->flags;
358 if (!netif_running(dev))
361 ret = dev_change_flags(dev, flags & ~IFF_UP);
363 ret = dev_change_flags(dev, flags);
367 "Failed to cycle device %s; route tables might be wrong!\n",
372 static struct slave *__vrf_find_slave_dev(struct slave_queue *queue,
373 struct net_device *dev)
375 struct list_head *head = &queue->all_slaves;
378 list_for_each_entry(slave, head, list) {
379 if (slave->dev == dev)
386 /* inverse of __vrf_insert_slave */
387 static void __vrf_remove_slave(struct slave_queue *queue, struct slave *slave)
389 list_del(&slave->list);
392 static void __vrf_insert_slave(struct slave_queue *queue, struct slave *slave)
394 list_add(&slave->list, &queue->all_slaves);
397 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
399 struct net_vrf_dev *vrf_ptr = kmalloc(sizeof(*vrf_ptr), GFP_KERNEL);
400 struct slave *slave = kzalloc(sizeof(*slave), GFP_KERNEL);
401 struct net_vrf *vrf = netdev_priv(dev);
402 struct slave_queue *queue = &vrf->queue;
405 if (!slave || !vrf_ptr)
408 slave->dev = port_dev;
409 vrf_ptr->ifindex = dev->ifindex;
410 vrf_ptr->tb_id = vrf->tb_id;
412 /* register the packet handler for slave ports */
413 ret = netdev_rx_handler_register(port_dev, vrf_handle_frame, dev);
416 "Device %s failed to register rx_handler\n",
421 ret = netdev_master_upper_dev_link(port_dev, dev);
425 port_dev->flags |= IFF_SLAVE;
426 __vrf_insert_slave(queue, slave);
427 rcu_assign_pointer(port_dev->vrf_ptr, vrf_ptr);
428 cycle_netdev(port_dev);
433 netdev_rx_handler_unregister(port_dev);
440 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
442 if (netif_is_l3_master(port_dev) || vrf_is_slave(port_dev))
445 return do_vrf_add_slave(dev, port_dev);
448 /* inverse of do_vrf_add_slave */
449 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
451 struct net_vrf_dev *vrf_ptr = rtnl_dereference(port_dev->vrf_ptr);
452 struct net_vrf *vrf = netdev_priv(dev);
453 struct slave_queue *queue = &vrf->queue;
456 RCU_INIT_POINTER(port_dev->vrf_ptr, NULL);
458 netdev_upper_dev_unlink(port_dev, dev);
459 port_dev->flags &= ~IFF_SLAVE;
461 netdev_rx_handler_unregister(port_dev);
463 /* after netdev_rx_handler_unregister for synchronize_rcu */
466 cycle_netdev(port_dev);
468 slave = __vrf_find_slave_dev(queue, port_dev);
470 __vrf_remove_slave(queue, slave);
477 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
479 return do_vrf_del_slave(dev, port_dev);
482 static void vrf_dev_uninit(struct net_device *dev)
484 struct net_vrf *vrf = netdev_priv(dev);
485 struct slave_queue *queue = &vrf->queue;
486 struct list_head *head = &queue->all_slaves;
487 struct slave *slave, *next;
489 vrf_rtable_destroy(vrf);
491 list_for_each_entry_safe(slave, next, head, list)
492 vrf_del_slave(dev, slave->dev);
494 free_percpu(dev->dstats);
498 static int vrf_dev_init(struct net_device *dev)
500 struct net_vrf *vrf = netdev_priv(dev);
502 INIT_LIST_HEAD(&vrf->queue.all_slaves);
504 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
508 /* create the default dst which points back to us */
509 vrf->rth = vrf_rtable_create(dev);
513 dev->flags = IFF_MASTER | IFF_NOARP;
518 free_percpu(dev->dstats);
524 static const struct net_device_ops vrf_netdev_ops = {
525 .ndo_init = vrf_dev_init,
526 .ndo_uninit = vrf_dev_uninit,
527 .ndo_start_xmit = vrf_xmit,
528 .ndo_get_stats64 = vrf_get_stats64,
529 .ndo_add_slave = vrf_add_slave,
530 .ndo_del_slave = vrf_del_slave,
533 static u32 vrf_fib_table(const struct net_device *dev)
535 struct net_vrf *vrf = netdev_priv(dev);
540 static struct rtable *vrf_get_rtable(const struct net_device *dev,
541 const struct flowi4 *fl4)
543 struct rtable *rth = NULL;
545 if (!(fl4->flowi4_flags & FLOWI_FLAG_VRFSRC)) {
546 struct net_vrf *vrf = netdev_priv(dev);
549 atomic_inc(&rth->dst.__refcnt);
555 static const struct l3mdev_ops vrf_l3mdev_ops = {
556 .l3mdev_fib_table = vrf_fib_table,
557 .l3mdev_get_rtable = vrf_get_rtable,
560 static void vrf_get_drvinfo(struct net_device *dev,
561 struct ethtool_drvinfo *info)
563 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
564 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
567 static const struct ethtool_ops vrf_ethtool_ops = {
568 .get_drvinfo = vrf_get_drvinfo,
571 static void vrf_setup(struct net_device *dev)
575 /* Initialize the device structure. */
576 dev->netdev_ops = &vrf_netdev_ops;
577 dev->l3mdev_ops = &vrf_l3mdev_ops;
578 dev->ethtool_ops = &vrf_ethtool_ops;
579 dev->destructor = free_netdev;
581 /* Fill in device structure with ethernet-generic values. */
582 eth_hw_addr_random(dev);
584 /* don't acquire vrf device's netif_tx_lock when transmitting */
585 dev->features |= NETIF_F_LLTX;
587 /* don't allow vrf devices to change network namespaces. */
588 dev->features |= NETIF_F_NETNS_LOCAL;
591 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[])
593 if (tb[IFLA_ADDRESS]) {
594 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
596 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
597 return -EADDRNOTAVAIL;
602 static void vrf_dellink(struct net_device *dev, struct list_head *head)
604 struct net_vrf_dev *vrf_ptr = rtnl_dereference(dev->vrf_ptr);
606 RCU_INIT_POINTER(dev->vrf_ptr, NULL);
607 kfree_rcu(vrf_ptr, rcu);
608 unregister_netdevice_queue(dev, head);
611 static int vrf_newlink(struct net *src_net, struct net_device *dev,
612 struct nlattr *tb[], struct nlattr *data[])
614 struct net_vrf *vrf = netdev_priv(dev);
615 struct net_vrf_dev *vrf_ptr;
618 if (!data || !data[IFLA_VRF_TABLE])
621 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
623 dev->priv_flags |= IFF_L3MDEV_MASTER;
626 vrf_ptr = kmalloc(sizeof(*dev->vrf_ptr), GFP_KERNEL);
630 vrf_ptr->ifindex = dev->ifindex;
631 vrf_ptr->tb_id = vrf->tb_id;
633 err = register_netdevice(dev);
637 rcu_assign_pointer(dev->vrf_ptr, vrf_ptr);
647 static size_t vrf_nl_getsize(const struct net_device *dev)
649 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
652 static int vrf_fillinfo(struct sk_buff *skb,
653 const struct net_device *dev)
655 struct net_vrf *vrf = netdev_priv(dev);
657 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
660 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
661 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
664 static struct rtnl_link_ops vrf_link_ops __read_mostly = {
666 .priv_size = sizeof(struct net_vrf),
668 .get_size = vrf_nl_getsize,
669 .policy = vrf_nl_policy,
670 .validate = vrf_validate,
671 .fill_info = vrf_fillinfo,
673 .newlink = vrf_newlink,
674 .dellink = vrf_dellink,
676 .maxtype = IFLA_VRF_MAX,
679 static int vrf_device_event(struct notifier_block *unused,
680 unsigned long event, void *ptr)
682 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
684 /* only care about unregister events to drop slave references */
685 if (event == NETDEV_UNREGISTER) {
686 struct net_vrf_dev *vrf_ptr = rtnl_dereference(dev->vrf_ptr);
687 struct net_device *vrf_dev;
689 if (!vrf_ptr || netif_is_l3_master(dev))
692 vrf_dev = netdev_master_upper_dev_get(dev);
693 vrf_del_slave(vrf_dev, dev);
699 static struct notifier_block vrf_notifier_block __read_mostly = {
700 .notifier_call = vrf_device_event,
703 static int __init vrf_init_module(void)
707 vrf_dst_ops.kmem_cachep =
708 kmem_cache_create("vrf_ip_dst_cache",
709 sizeof(struct rtable), 0,
713 if (!vrf_dst_ops.kmem_cachep)
716 register_netdevice_notifier(&vrf_notifier_block);
718 rc = rtnl_link_register(&vrf_link_ops);
725 unregister_netdevice_notifier(&vrf_notifier_block);
726 kmem_cache_destroy(vrf_dst_ops.kmem_cachep);
730 static void __exit vrf_cleanup_module(void)
732 rtnl_link_unregister(&vrf_link_ops);
733 unregister_netdevice_notifier(&vrf_notifier_block);
734 kmem_cache_destroy(vrf_dst_ops.kmem_cachep);
737 module_init(vrf_init_module);
738 module_exit(vrf_cleanup_module);
739 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
740 MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
741 MODULE_LICENSE("GPL");
742 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
743 MODULE_VERSION(DRV_VERSION);