xref: /openbmc/linux/drivers/net/vrf.c (revision 1b69c6d0ae90b7f1a4f61d5c8209d5cb7a55f849)
1 /*
2  * vrf.c: device driver to encapsulate a VRF space
3  *
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>
7  *
8  * Based on dummy, team and ipvlan drivers
9  *
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.
14  */
15 
16 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <linux/netdevice.h>
19 #include <linux/etherdevice.h>
20 #include <linux/ip.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>
28 
29 #include <linux/inetdevice.h>
30 #include <net/arp.h>
31 #include <net/ip.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/vrf.h>
38 
39 #define DRV_NAME	"vrf"
40 #define DRV_VERSION	"1.0"
41 
42 #define vrf_is_slave(dev)   ((dev)->flags & IFF_SLAVE)
43 
44 #define vrf_master_get_rcu(dev) \
45 	((struct net_device *)rcu_dereference(dev->rx_handler_data))
46 
47 struct pcpu_dstats {
48 	u64			tx_pkts;
49 	u64			tx_bytes;
50 	u64			tx_drps;
51 	u64			rx_pkts;
52 	u64			rx_bytes;
53 	struct u64_stats_sync	syncp;
54 };
55 
56 static struct dst_entry *vrf_ip_check(struct dst_entry *dst, u32 cookie)
57 {
58 	return dst;
59 }
60 
61 static int vrf_ip_local_out(struct sk_buff *skb)
62 {
63 	return ip_local_out(skb);
64 }
65 
66 static unsigned int vrf_v4_mtu(const struct dst_entry *dst)
67 {
68 	/* TO-DO: return max ethernet size? */
69 	return dst->dev->mtu;
70 }
71 
72 static void vrf_dst_destroy(struct dst_entry *dst)
73 {
74 	/* our dst lives forever - or until the device is closed */
75 }
76 
77 static unsigned int vrf_default_advmss(const struct dst_entry *dst)
78 {
79 	return 65535 - 40;
80 }
81 
82 static struct dst_ops vrf_dst_ops = {
83 	.family		= AF_INET,
84 	.local_out	= vrf_ip_local_out,
85 	.check		= vrf_ip_check,
86 	.mtu		= vrf_v4_mtu,
87 	.destroy	= vrf_dst_destroy,
88 	.default_advmss	= vrf_default_advmss,
89 };
90 
91 static bool is_ip_rx_frame(struct sk_buff *skb)
92 {
93 	switch (skb->protocol) {
94 	case htons(ETH_P_IP):
95 	case htons(ETH_P_IPV6):
96 		return true;
97 	}
98 	return false;
99 }
100 
101 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
102 {
103 	vrf_dev->stats.tx_errors++;
104 	kfree_skb(skb);
105 }
106 
107 /* note: already called with rcu_read_lock */
108 static rx_handler_result_t vrf_handle_frame(struct sk_buff **pskb)
109 {
110 	struct sk_buff *skb = *pskb;
111 
112 	if (is_ip_rx_frame(skb)) {
113 		struct net_device *dev = vrf_master_get_rcu(skb->dev);
114 		struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
115 
116 		u64_stats_update_begin(&dstats->syncp);
117 		dstats->rx_pkts++;
118 		dstats->rx_bytes += skb->len;
119 		u64_stats_update_end(&dstats->syncp);
120 
121 		skb->dev = dev;
122 
123 		return RX_HANDLER_ANOTHER;
124 	}
125 	return RX_HANDLER_PASS;
126 }
127 
128 static struct rtnl_link_stats64 *vrf_get_stats64(struct net_device *dev,
129 						 struct rtnl_link_stats64 *stats)
130 {
131 	int i;
132 
133 	for_each_possible_cpu(i) {
134 		const struct pcpu_dstats *dstats;
135 		u64 tbytes, tpkts, tdrops, rbytes, rpkts;
136 		unsigned int start;
137 
138 		dstats = per_cpu_ptr(dev->dstats, i);
139 		do {
140 			start = u64_stats_fetch_begin_irq(&dstats->syncp);
141 			tbytes = dstats->tx_bytes;
142 			tpkts = dstats->tx_pkts;
143 			tdrops = dstats->tx_drps;
144 			rbytes = dstats->rx_bytes;
145 			rpkts = dstats->rx_pkts;
146 		} while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
147 		stats->tx_bytes += tbytes;
148 		stats->tx_packets += tpkts;
149 		stats->tx_dropped += tdrops;
150 		stats->rx_bytes += rbytes;
151 		stats->rx_packets += rpkts;
152 	}
153 	return stats;
154 }
155 
156 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
157 					   struct net_device *dev)
158 {
159 	vrf_tx_error(dev, skb);
160 	return NET_XMIT_DROP;
161 }
162 
163 static int vrf_send_v4_prep(struct sk_buff *skb, struct flowi4 *fl4,
164 			    struct net_device *vrf_dev)
165 {
166 	struct rtable *rt;
167 	int err = 1;
168 
169 	rt = ip_route_output_flow(dev_net(vrf_dev), fl4, NULL);
170 	if (IS_ERR(rt))
171 		goto out;
172 
173 	/* TO-DO: what about broadcast ? */
174 	if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
175 		ip_rt_put(rt);
176 		goto out;
177 	}
178 
179 	skb_dst_drop(skb);
180 	skb_dst_set(skb, &rt->dst);
181 	err = 0;
182 out:
183 	return err;
184 }
185 
186 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
187 					   struct net_device *vrf_dev)
188 {
189 	struct iphdr *ip4h = ip_hdr(skb);
190 	int ret = NET_XMIT_DROP;
191 	struct flowi4 fl4 = {
192 		/* needed to match OIF rule */
193 		.flowi4_oif = vrf_dev->ifindex,
194 		.flowi4_iif = LOOPBACK_IFINDEX,
195 		.flowi4_tos = RT_TOS(ip4h->tos),
196 		.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_VRFSRC |
197 				FLOWI_FLAG_SKIP_NH_OIF,
198 		.daddr = ip4h->daddr,
199 	};
200 
201 	if (vrf_send_v4_prep(skb, &fl4, vrf_dev))
202 		goto err;
203 
204 	if (!ip4h->saddr) {
205 		ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
206 					       RT_SCOPE_LINK);
207 	}
208 
209 	ret = ip_local_out(skb);
210 	if (unlikely(net_xmit_eval(ret)))
211 		vrf_dev->stats.tx_errors++;
212 	else
213 		ret = NET_XMIT_SUCCESS;
214 
215 out:
216 	return ret;
217 err:
218 	vrf_tx_error(vrf_dev, skb);
219 	goto out;
220 }
221 
222 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
223 {
224 	/* strip the ethernet header added for pass through VRF device */
225 	__skb_pull(skb, skb_network_offset(skb));
226 
227 	switch (skb->protocol) {
228 	case htons(ETH_P_IP):
229 		return vrf_process_v4_outbound(skb, dev);
230 	case htons(ETH_P_IPV6):
231 		return vrf_process_v6_outbound(skb, dev);
232 	default:
233 		vrf_tx_error(dev, skb);
234 		return NET_XMIT_DROP;
235 	}
236 }
237 
238 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
239 {
240 	netdev_tx_t ret = is_ip_tx_frame(skb, dev);
241 
242 	if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
243 		struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
244 
245 		u64_stats_update_begin(&dstats->syncp);
246 		dstats->tx_pkts++;
247 		dstats->tx_bytes += skb->len;
248 		u64_stats_update_end(&dstats->syncp);
249 	} else {
250 		this_cpu_inc(dev->dstats->tx_drps);
251 	}
252 
253 	return ret;
254 }
255 
256 /* modelled after ip_finish_output2 */
257 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
258 {
259 	struct dst_entry *dst = skb_dst(skb);
260 	struct rtable *rt = (struct rtable *)dst;
261 	struct net_device *dev = dst->dev;
262 	unsigned int hh_len = LL_RESERVED_SPACE(dev);
263 	struct neighbour *neigh;
264 	u32 nexthop;
265 	int ret = -EINVAL;
266 
267 	/* Be paranoid, rather than too clever. */
268 	if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
269 		struct sk_buff *skb2;
270 
271 		skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
272 		if (!skb2) {
273 			ret = -ENOMEM;
274 			goto err;
275 		}
276 		if (skb->sk)
277 			skb_set_owner_w(skb2, skb->sk);
278 
279 		consume_skb(skb);
280 		skb = skb2;
281 	}
282 
283 	rcu_read_lock_bh();
284 
285 	nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr);
286 	neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
287 	if (unlikely(!neigh))
288 		neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
289 	if (!IS_ERR(neigh))
290 		ret = dst_neigh_output(dst, neigh, skb);
291 
292 	rcu_read_unlock_bh();
293 err:
294 	if (unlikely(ret < 0))
295 		vrf_tx_error(skb->dev, skb);
296 	return ret;
297 }
298 
299 static int vrf_output(struct sock *sk, struct sk_buff *skb)
300 {
301 	struct net_device *dev = skb_dst(skb)->dev;
302 	struct net *net = dev_net(dev);
303 
304 	IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
305 
306 	skb->dev = dev;
307 	skb->protocol = htons(ETH_P_IP);
308 
309 	return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
310 			    net, sk, skb, NULL, dev,
311 			    vrf_finish_output,
312 			    !(IPCB(skb)->flags & IPSKB_REROUTED));
313 }
314 
315 static void vrf_rtable_destroy(struct net_vrf *vrf)
316 {
317 	struct dst_entry *dst = (struct dst_entry *)vrf->rth;
318 
319 	dst_destroy(dst);
320 	vrf->rth = NULL;
321 }
322 
323 static struct rtable *vrf_rtable_create(struct net_device *dev)
324 {
325 	struct net_vrf *vrf = netdev_priv(dev);
326 	struct rtable *rth;
327 
328 	rth = dst_alloc(&vrf_dst_ops, dev, 2,
329 			DST_OBSOLETE_NONE,
330 			(DST_HOST | DST_NOPOLICY | DST_NOXFRM));
331 	if (rth) {
332 		rth->dst.output	= vrf_output;
333 		rth->rt_genid	= rt_genid_ipv4(dev_net(dev));
334 		rth->rt_flags	= 0;
335 		rth->rt_type	= RTN_UNICAST;
336 		rth->rt_is_input = 0;
337 		rth->rt_iif	= 0;
338 		rth->rt_pmtu	= 0;
339 		rth->rt_gateway	= 0;
340 		rth->rt_uses_gateway = 0;
341 		rth->rt_table_id = vrf->tb_id;
342 		INIT_LIST_HEAD(&rth->rt_uncached);
343 		rth->rt_uncached_list = NULL;
344 	}
345 
346 	return rth;
347 }
348 
349 /**************************** device handling ********************/
350 
351 /* cycle interface to flush neighbor cache and move routes across tables */
352 static void cycle_netdev(struct net_device *dev)
353 {
354 	unsigned int flags = dev->flags;
355 	int ret;
356 
357 	if (!netif_running(dev))
358 		return;
359 
360 	ret = dev_change_flags(dev, flags & ~IFF_UP);
361 	if (ret >= 0)
362 		ret = dev_change_flags(dev, flags);
363 
364 	if (ret < 0) {
365 		netdev_err(dev,
366 			   "Failed to cycle device %s; route tables might be wrong!\n",
367 			   dev->name);
368 	}
369 }
370 
371 static struct slave *__vrf_find_slave_dev(struct slave_queue *queue,
372 					  struct net_device *dev)
373 {
374 	struct list_head *head = &queue->all_slaves;
375 	struct slave *slave;
376 
377 	list_for_each_entry(slave, head, list) {
378 		if (slave->dev == dev)
379 			return slave;
380 	}
381 
382 	return NULL;
383 }
384 
385 /* inverse of __vrf_insert_slave */
386 static void __vrf_remove_slave(struct slave_queue *queue, struct slave *slave)
387 {
388 	list_del(&slave->list);
389 }
390 
391 static void __vrf_insert_slave(struct slave_queue *queue, struct slave *slave)
392 {
393 	list_add(&slave->list, &queue->all_slaves);
394 }
395 
396 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
397 {
398 	struct net_vrf_dev *vrf_ptr = kmalloc(sizeof(*vrf_ptr), GFP_KERNEL);
399 	struct slave *slave = kzalloc(sizeof(*slave), GFP_KERNEL);
400 	struct net_vrf *vrf = netdev_priv(dev);
401 	struct slave_queue *queue = &vrf->queue;
402 	int ret = -ENOMEM;
403 
404 	if (!slave || !vrf_ptr)
405 		goto out_fail;
406 
407 	slave->dev = port_dev;
408 	vrf_ptr->ifindex = dev->ifindex;
409 	vrf_ptr->tb_id = vrf->tb_id;
410 
411 	/* register the packet handler for slave ports */
412 	ret = netdev_rx_handler_register(port_dev, vrf_handle_frame, dev);
413 	if (ret) {
414 		netdev_err(port_dev,
415 			   "Device %s failed to register rx_handler\n",
416 			   port_dev->name);
417 		goto out_fail;
418 	}
419 
420 	ret = netdev_master_upper_dev_link(port_dev, dev);
421 	if (ret < 0)
422 		goto out_unregister;
423 
424 	port_dev->flags |= IFF_SLAVE;
425 	__vrf_insert_slave(queue, slave);
426 	rcu_assign_pointer(port_dev->vrf_ptr, vrf_ptr);
427 	cycle_netdev(port_dev);
428 
429 	return 0;
430 
431 out_unregister:
432 	netdev_rx_handler_unregister(port_dev);
433 out_fail:
434 	kfree(vrf_ptr);
435 	kfree(slave);
436 	return ret;
437 }
438 
439 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
440 {
441 	if (netif_is_l3_master(port_dev) || vrf_is_slave(port_dev))
442 		return -EINVAL;
443 
444 	return do_vrf_add_slave(dev, port_dev);
445 }
446 
447 /* inverse of do_vrf_add_slave */
448 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
449 {
450 	struct net_vrf_dev *vrf_ptr = rtnl_dereference(port_dev->vrf_ptr);
451 	struct net_vrf *vrf = netdev_priv(dev);
452 	struct slave_queue *queue = &vrf->queue;
453 	struct slave *slave;
454 
455 	RCU_INIT_POINTER(port_dev->vrf_ptr, NULL);
456 
457 	netdev_upper_dev_unlink(port_dev, dev);
458 	port_dev->flags &= ~IFF_SLAVE;
459 
460 	netdev_rx_handler_unregister(port_dev);
461 
462 	/* after netdev_rx_handler_unregister for synchronize_rcu */
463 	kfree(vrf_ptr);
464 
465 	cycle_netdev(port_dev);
466 
467 	slave = __vrf_find_slave_dev(queue, port_dev);
468 	if (slave)
469 		__vrf_remove_slave(queue, slave);
470 
471 	kfree(slave);
472 
473 	return 0;
474 }
475 
476 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
477 {
478 	return do_vrf_del_slave(dev, port_dev);
479 }
480 
481 static void vrf_dev_uninit(struct net_device *dev)
482 {
483 	struct net_vrf *vrf = netdev_priv(dev);
484 	struct slave_queue *queue = &vrf->queue;
485 	struct list_head *head = &queue->all_slaves;
486 	struct slave *slave, *next;
487 
488 	vrf_rtable_destroy(vrf);
489 
490 	list_for_each_entry_safe(slave, next, head, list)
491 		vrf_del_slave(dev, slave->dev);
492 
493 	free_percpu(dev->dstats);
494 	dev->dstats = NULL;
495 }
496 
497 static int vrf_dev_init(struct net_device *dev)
498 {
499 	struct net_vrf *vrf = netdev_priv(dev);
500 
501 	INIT_LIST_HEAD(&vrf->queue.all_slaves);
502 
503 	dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
504 	if (!dev->dstats)
505 		goto out_nomem;
506 
507 	/* create the default dst which points back to us */
508 	vrf->rth = vrf_rtable_create(dev);
509 	if (!vrf->rth)
510 		goto out_stats;
511 
512 	dev->flags = IFF_MASTER | IFF_NOARP;
513 
514 	return 0;
515 
516 out_stats:
517 	free_percpu(dev->dstats);
518 	dev->dstats = NULL;
519 out_nomem:
520 	return -ENOMEM;
521 }
522 
523 static const struct net_device_ops vrf_netdev_ops = {
524 	.ndo_init		= vrf_dev_init,
525 	.ndo_uninit		= vrf_dev_uninit,
526 	.ndo_start_xmit		= vrf_xmit,
527 	.ndo_get_stats64	= vrf_get_stats64,
528 	.ndo_add_slave		= vrf_add_slave,
529 	.ndo_del_slave		= vrf_del_slave,
530 };
531 
532 static void vrf_get_drvinfo(struct net_device *dev,
533 			    struct ethtool_drvinfo *info)
534 {
535 	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
536 	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
537 }
538 
539 static const struct ethtool_ops vrf_ethtool_ops = {
540 	.get_drvinfo	= vrf_get_drvinfo,
541 };
542 
543 static void vrf_setup(struct net_device *dev)
544 {
545 	ether_setup(dev);
546 
547 	/* Initialize the device structure. */
548 	dev->netdev_ops = &vrf_netdev_ops;
549 	dev->ethtool_ops = &vrf_ethtool_ops;
550 	dev->destructor = free_netdev;
551 
552 	/* Fill in device structure with ethernet-generic values. */
553 	eth_hw_addr_random(dev);
554 
555 	/* don't acquire vrf device's netif_tx_lock when transmitting */
556 	dev->features |= NETIF_F_LLTX;
557 
558 	/* don't allow vrf devices to change network namespaces. */
559 	dev->features |= NETIF_F_NETNS_LOCAL;
560 }
561 
562 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[])
563 {
564 	if (tb[IFLA_ADDRESS]) {
565 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
566 			return -EINVAL;
567 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
568 			return -EADDRNOTAVAIL;
569 	}
570 	return 0;
571 }
572 
573 static void vrf_dellink(struct net_device *dev, struct list_head *head)
574 {
575 	struct net_vrf_dev *vrf_ptr = rtnl_dereference(dev->vrf_ptr);
576 
577 	RCU_INIT_POINTER(dev->vrf_ptr, NULL);
578 	kfree_rcu(vrf_ptr, rcu);
579 	unregister_netdevice_queue(dev, head);
580 }
581 
582 static int vrf_newlink(struct net *src_net, struct net_device *dev,
583 		       struct nlattr *tb[], struct nlattr *data[])
584 {
585 	struct net_vrf *vrf = netdev_priv(dev);
586 	struct net_vrf_dev *vrf_ptr;
587 	int err;
588 
589 	if (!data || !data[IFLA_VRF_TABLE])
590 		return -EINVAL;
591 
592 	vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
593 
594 	dev->priv_flags |= IFF_L3MDEV_MASTER;
595 
596 	err = -ENOMEM;
597 	vrf_ptr = kmalloc(sizeof(*dev->vrf_ptr), GFP_KERNEL);
598 	if (!vrf_ptr)
599 		goto out_fail;
600 
601 	vrf_ptr->ifindex = dev->ifindex;
602 	vrf_ptr->tb_id = vrf->tb_id;
603 
604 	err = register_netdevice(dev);
605 	if (err < 0)
606 		goto out_fail;
607 
608 	rcu_assign_pointer(dev->vrf_ptr, vrf_ptr);
609 
610 	return 0;
611 
612 out_fail:
613 	kfree(vrf_ptr);
614 	free_netdev(dev);
615 	return err;
616 }
617 
618 static size_t vrf_nl_getsize(const struct net_device *dev)
619 {
620 	return nla_total_size(sizeof(u32));  /* IFLA_VRF_TABLE */
621 }
622 
623 static int vrf_fillinfo(struct sk_buff *skb,
624 			const struct net_device *dev)
625 {
626 	struct net_vrf *vrf = netdev_priv(dev);
627 
628 	return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
629 }
630 
631 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
632 	[IFLA_VRF_TABLE] = { .type = NLA_U32 },
633 };
634 
635 static struct rtnl_link_ops vrf_link_ops __read_mostly = {
636 	.kind		= DRV_NAME,
637 	.priv_size	= sizeof(struct net_vrf),
638 
639 	.get_size	= vrf_nl_getsize,
640 	.policy		= vrf_nl_policy,
641 	.validate	= vrf_validate,
642 	.fill_info	= vrf_fillinfo,
643 
644 	.newlink	= vrf_newlink,
645 	.dellink	= vrf_dellink,
646 	.setup		= vrf_setup,
647 	.maxtype	= IFLA_VRF_MAX,
648 };
649 
650 static int vrf_device_event(struct notifier_block *unused,
651 			    unsigned long event, void *ptr)
652 {
653 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
654 
655 	/* only care about unregister events to drop slave references */
656 	if (event == NETDEV_UNREGISTER) {
657 		struct net_vrf_dev *vrf_ptr = rtnl_dereference(dev->vrf_ptr);
658 		struct net_device *vrf_dev;
659 
660 		if (!vrf_ptr || netif_is_l3_master(dev))
661 			goto out;
662 
663 		vrf_dev = netdev_master_upper_dev_get(dev);
664 		vrf_del_slave(vrf_dev, dev);
665 	}
666 out:
667 	return NOTIFY_DONE;
668 }
669 
670 static struct notifier_block vrf_notifier_block __read_mostly = {
671 	.notifier_call = vrf_device_event,
672 };
673 
674 static int __init vrf_init_module(void)
675 {
676 	int rc;
677 
678 	vrf_dst_ops.kmem_cachep =
679 		kmem_cache_create("vrf_ip_dst_cache",
680 				  sizeof(struct rtable), 0,
681 				  SLAB_HWCACHE_ALIGN,
682 				  NULL);
683 
684 	if (!vrf_dst_ops.kmem_cachep)
685 		return -ENOMEM;
686 
687 	register_netdevice_notifier(&vrf_notifier_block);
688 
689 	rc = rtnl_link_register(&vrf_link_ops);
690 	if (rc < 0)
691 		goto error;
692 
693 	return 0;
694 
695 error:
696 	unregister_netdevice_notifier(&vrf_notifier_block);
697 	kmem_cache_destroy(vrf_dst_ops.kmem_cachep);
698 	return rc;
699 }
700 
701 static void __exit vrf_cleanup_module(void)
702 {
703 	rtnl_link_unregister(&vrf_link_ops);
704 	unregister_netdevice_notifier(&vrf_notifier_block);
705 	kmem_cache_destroy(vrf_dst_ops.kmem_cachep);
706 }
707 
708 module_init(vrf_init_module);
709 module_exit(vrf_cleanup_module);
710 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
711 MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
712 MODULE_LICENSE("GPL");
713 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
714 MODULE_VERSION(DRV_VERSION);
715