xref: /openbmc/linux/drivers/net/vrf.c (revision 32981ea5)
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_fib.h>
34 #include <net/ip6_route.h>
35 #include <net/route.h>
36 #include <net/addrconf.h>
37 #include <net/l3mdev.h>
38 
39 #define RT_FL_TOS(oldflp4) \
40 	((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
41 
42 #define DRV_NAME	"vrf"
43 #define DRV_VERSION	"1.0"
44 
45 struct net_vrf {
46 	struct rtable __rcu	*rth;
47 	struct rt6_info	__rcu	*rt6;
48 	u32                     tb_id;
49 };
50 
51 struct pcpu_dstats {
52 	u64			tx_pkts;
53 	u64			tx_bytes;
54 	u64			tx_drps;
55 	u64			rx_pkts;
56 	u64			rx_bytes;
57 	struct u64_stats_sync	syncp;
58 };
59 
60 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
61 {
62 	vrf_dev->stats.tx_errors++;
63 	kfree_skb(skb);
64 }
65 
66 static struct rtnl_link_stats64 *vrf_get_stats64(struct net_device *dev,
67 						 struct rtnl_link_stats64 *stats)
68 {
69 	int i;
70 
71 	for_each_possible_cpu(i) {
72 		const struct pcpu_dstats *dstats;
73 		u64 tbytes, tpkts, tdrops, rbytes, rpkts;
74 		unsigned int start;
75 
76 		dstats = per_cpu_ptr(dev->dstats, i);
77 		do {
78 			start = u64_stats_fetch_begin_irq(&dstats->syncp);
79 			tbytes = dstats->tx_bytes;
80 			tpkts = dstats->tx_pkts;
81 			tdrops = dstats->tx_drps;
82 			rbytes = dstats->rx_bytes;
83 			rpkts = dstats->rx_pkts;
84 		} while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
85 		stats->tx_bytes += tbytes;
86 		stats->tx_packets += tpkts;
87 		stats->tx_dropped += tdrops;
88 		stats->rx_bytes += rbytes;
89 		stats->rx_packets += rpkts;
90 	}
91 	return stats;
92 }
93 
94 #if IS_ENABLED(CONFIG_IPV6)
95 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
96 					   struct net_device *dev)
97 {
98 	const struct ipv6hdr *iph = ipv6_hdr(skb);
99 	struct net *net = dev_net(skb->dev);
100 	struct flowi6 fl6 = {
101 		/* needed to match OIF rule */
102 		.flowi6_oif = dev->ifindex,
103 		.flowi6_iif = LOOPBACK_IFINDEX,
104 		.daddr = iph->daddr,
105 		.saddr = iph->saddr,
106 		.flowlabel = ip6_flowinfo(iph),
107 		.flowi6_mark = skb->mark,
108 		.flowi6_proto = iph->nexthdr,
109 		.flowi6_flags = FLOWI_FLAG_L3MDEV_SRC | FLOWI_FLAG_SKIP_NH_OIF,
110 	};
111 	int ret = NET_XMIT_DROP;
112 	struct dst_entry *dst;
113 	struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
114 
115 	dst = ip6_route_output(net, NULL, &fl6);
116 	if (dst == dst_null)
117 		goto err;
118 
119 	skb_dst_drop(skb);
120 	skb_dst_set(skb, dst);
121 
122 	ret = ip6_local_out(net, skb->sk, skb);
123 	if (unlikely(net_xmit_eval(ret)))
124 		dev->stats.tx_errors++;
125 	else
126 		ret = NET_XMIT_SUCCESS;
127 
128 	return ret;
129 err:
130 	vrf_tx_error(dev, skb);
131 	return NET_XMIT_DROP;
132 }
133 #else
134 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
135 					   struct net_device *dev)
136 {
137 	vrf_tx_error(dev, skb);
138 	return NET_XMIT_DROP;
139 }
140 #endif
141 
142 static int vrf_send_v4_prep(struct sk_buff *skb, struct flowi4 *fl4,
143 			    struct net_device *vrf_dev)
144 {
145 	struct rtable *rt;
146 	int err = 1;
147 
148 	rt = ip_route_output_flow(dev_net(vrf_dev), fl4, NULL);
149 	if (IS_ERR(rt))
150 		goto out;
151 
152 	/* TO-DO: what about broadcast ? */
153 	if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
154 		ip_rt_put(rt);
155 		goto out;
156 	}
157 
158 	skb_dst_drop(skb);
159 	skb_dst_set(skb, &rt->dst);
160 	err = 0;
161 out:
162 	return err;
163 }
164 
165 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
166 					   struct net_device *vrf_dev)
167 {
168 	struct iphdr *ip4h = ip_hdr(skb);
169 	int ret = NET_XMIT_DROP;
170 	struct flowi4 fl4 = {
171 		/* needed to match OIF rule */
172 		.flowi4_oif = vrf_dev->ifindex,
173 		.flowi4_iif = LOOPBACK_IFINDEX,
174 		.flowi4_tos = RT_TOS(ip4h->tos),
175 		.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_L3MDEV_SRC |
176 				FLOWI_FLAG_SKIP_NH_OIF,
177 		.daddr = ip4h->daddr,
178 	};
179 
180 	if (vrf_send_v4_prep(skb, &fl4, vrf_dev))
181 		goto err;
182 
183 	if (!ip4h->saddr) {
184 		ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
185 					       RT_SCOPE_LINK);
186 	}
187 
188 	ret = ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
189 	if (unlikely(net_xmit_eval(ret)))
190 		vrf_dev->stats.tx_errors++;
191 	else
192 		ret = NET_XMIT_SUCCESS;
193 
194 out:
195 	return ret;
196 err:
197 	vrf_tx_error(vrf_dev, skb);
198 	goto out;
199 }
200 
201 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
202 {
203 	/* strip the ethernet header added for pass through VRF device */
204 	__skb_pull(skb, skb_network_offset(skb));
205 
206 	switch (skb->protocol) {
207 	case htons(ETH_P_IP):
208 		return vrf_process_v4_outbound(skb, dev);
209 	case htons(ETH_P_IPV6):
210 		return vrf_process_v6_outbound(skb, dev);
211 	default:
212 		vrf_tx_error(dev, skb);
213 		return NET_XMIT_DROP;
214 	}
215 }
216 
217 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
218 {
219 	netdev_tx_t ret = is_ip_tx_frame(skb, dev);
220 
221 	if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
222 		struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
223 
224 		u64_stats_update_begin(&dstats->syncp);
225 		dstats->tx_pkts++;
226 		dstats->tx_bytes += skb->len;
227 		u64_stats_update_end(&dstats->syncp);
228 	} else {
229 		this_cpu_inc(dev->dstats->tx_drps);
230 	}
231 
232 	return ret;
233 }
234 
235 #if IS_ENABLED(CONFIG_IPV6)
236 /* modelled after ip6_finish_output2 */
237 static int vrf_finish_output6(struct net *net, struct sock *sk,
238 			      struct sk_buff *skb)
239 {
240 	struct dst_entry *dst = skb_dst(skb);
241 	struct net_device *dev = dst->dev;
242 	struct neighbour *neigh;
243 	struct in6_addr *nexthop;
244 	int ret;
245 
246 	skb->protocol = htons(ETH_P_IPV6);
247 	skb->dev = dev;
248 
249 	rcu_read_lock_bh();
250 	nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
251 	neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
252 	if (unlikely(!neigh))
253 		neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
254 	if (!IS_ERR(neigh)) {
255 		ret = dst_neigh_output(dst, neigh, skb);
256 		rcu_read_unlock_bh();
257 		return ret;
258 	}
259 	rcu_read_unlock_bh();
260 
261 	IP6_INC_STATS(dev_net(dst->dev),
262 		      ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
263 	kfree_skb(skb);
264 	return -EINVAL;
265 }
266 
267 /* modelled after ip6_output */
268 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
269 {
270 	return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
271 			    net, sk, skb, NULL, skb_dst(skb)->dev,
272 			    vrf_finish_output6,
273 			    !(IP6CB(skb)->flags & IP6SKB_REROUTED));
274 }
275 
276 /* holding rtnl */
277 static void vrf_rt6_release(struct net_vrf *vrf)
278 {
279 	struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
280 
281 	rcu_assign_pointer(vrf->rt6, NULL);
282 
283 	if (rt6)
284 		dst_release(&rt6->dst);
285 }
286 
287 static int vrf_rt6_create(struct net_device *dev)
288 {
289 	struct net_vrf *vrf = netdev_priv(dev);
290 	struct net *net = dev_net(dev);
291 	struct fib6_table *rt6i_table;
292 	struct rt6_info *rt6;
293 	int rc = -ENOMEM;
294 
295 	rt6i_table = fib6_new_table(net, vrf->tb_id);
296 	if (!rt6i_table)
297 		goto out;
298 
299 	rt6 = ip6_dst_alloc(net, dev,
300 			    DST_HOST | DST_NOPOLICY | DST_NOXFRM | DST_NOCACHE);
301 	if (!rt6)
302 		goto out;
303 
304 	dst_hold(&rt6->dst);
305 
306 	rt6->rt6i_table = rt6i_table;
307 	rt6->dst.output	= vrf_output6;
308 	rcu_assign_pointer(vrf->rt6, rt6);
309 
310 	rc = 0;
311 out:
312 	return rc;
313 }
314 #else
315 static void vrf_rt6_release(struct net_vrf *vrf)
316 {
317 }
318 
319 static int vrf_rt6_create(struct net_device *dev)
320 {
321 	return 0;
322 }
323 #endif
324 
325 /* modelled after ip_finish_output2 */
326 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
327 {
328 	struct dst_entry *dst = skb_dst(skb);
329 	struct rtable *rt = (struct rtable *)dst;
330 	struct net_device *dev = dst->dev;
331 	unsigned int hh_len = LL_RESERVED_SPACE(dev);
332 	struct neighbour *neigh;
333 	u32 nexthop;
334 	int ret = -EINVAL;
335 
336 	/* Be paranoid, rather than too clever. */
337 	if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
338 		struct sk_buff *skb2;
339 
340 		skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
341 		if (!skb2) {
342 			ret = -ENOMEM;
343 			goto err;
344 		}
345 		if (skb->sk)
346 			skb_set_owner_w(skb2, skb->sk);
347 
348 		consume_skb(skb);
349 		skb = skb2;
350 	}
351 
352 	rcu_read_lock_bh();
353 
354 	nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr);
355 	neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
356 	if (unlikely(!neigh))
357 		neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
358 	if (!IS_ERR(neigh))
359 		ret = dst_neigh_output(dst, neigh, skb);
360 
361 	rcu_read_unlock_bh();
362 err:
363 	if (unlikely(ret < 0))
364 		vrf_tx_error(skb->dev, skb);
365 	return ret;
366 }
367 
368 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
369 {
370 	struct net_device *dev = skb_dst(skb)->dev;
371 
372 	IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
373 
374 	skb->dev = dev;
375 	skb->protocol = htons(ETH_P_IP);
376 
377 	return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
378 			    net, sk, skb, NULL, dev,
379 			    vrf_finish_output,
380 			    !(IPCB(skb)->flags & IPSKB_REROUTED));
381 }
382 
383 /* holding rtnl */
384 static void vrf_rtable_release(struct net_vrf *vrf)
385 {
386 	struct rtable *rth = rtnl_dereference(vrf->rth);
387 
388 	rcu_assign_pointer(vrf->rth, NULL);
389 
390 	if (rth)
391 		dst_release(&rth->dst);
392 }
393 
394 static int vrf_rtable_create(struct net_device *dev)
395 {
396 	struct net_vrf *vrf = netdev_priv(dev);
397 	struct rtable *rth;
398 
399 	if (!fib_new_table(dev_net(dev), vrf->tb_id))
400 		return -ENOMEM;
401 
402 	rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1, 0);
403 	if (!rth)
404 		return -ENOMEM;
405 
406 	rth->dst.output	= vrf_output;
407 	rth->rt_table_id = vrf->tb_id;
408 
409 	rcu_assign_pointer(vrf->rth, rth);
410 
411 	return 0;
412 }
413 
414 /**************************** device handling ********************/
415 
416 /* cycle interface to flush neighbor cache and move routes across tables */
417 static void cycle_netdev(struct net_device *dev)
418 {
419 	unsigned int flags = dev->flags;
420 	int ret;
421 
422 	if (!netif_running(dev))
423 		return;
424 
425 	ret = dev_change_flags(dev, flags & ~IFF_UP);
426 	if (ret >= 0)
427 		ret = dev_change_flags(dev, flags);
428 
429 	if (ret < 0) {
430 		netdev_err(dev,
431 			   "Failed to cycle device %s; route tables might be wrong!\n",
432 			   dev->name);
433 	}
434 }
435 
436 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
437 {
438 	int ret;
439 
440 	ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL);
441 	if (ret < 0)
442 		return ret;
443 
444 	port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
445 	cycle_netdev(port_dev);
446 
447 	return 0;
448 }
449 
450 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
451 {
452 	if (netif_is_l3_master(port_dev) || netif_is_l3_slave(port_dev))
453 		return -EINVAL;
454 
455 	return do_vrf_add_slave(dev, port_dev);
456 }
457 
458 /* inverse of do_vrf_add_slave */
459 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
460 {
461 	netdev_upper_dev_unlink(port_dev, dev);
462 	port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
463 
464 	cycle_netdev(port_dev);
465 
466 	return 0;
467 }
468 
469 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
470 {
471 	return do_vrf_del_slave(dev, port_dev);
472 }
473 
474 static void vrf_dev_uninit(struct net_device *dev)
475 {
476 	struct net_vrf *vrf = netdev_priv(dev);
477 	struct net_device *port_dev;
478 	struct list_head *iter;
479 
480 	vrf_rtable_release(vrf);
481 	vrf_rt6_release(vrf);
482 
483 	netdev_for_each_lower_dev(dev, port_dev, iter)
484 		vrf_del_slave(dev, port_dev);
485 
486 	free_percpu(dev->dstats);
487 	dev->dstats = NULL;
488 }
489 
490 static int vrf_dev_init(struct net_device *dev)
491 {
492 	struct net_vrf *vrf = netdev_priv(dev);
493 
494 	dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
495 	if (!dev->dstats)
496 		goto out_nomem;
497 
498 	/* create the default dst which points back to us */
499 	if (vrf_rtable_create(dev) != 0)
500 		goto out_stats;
501 
502 	if (vrf_rt6_create(dev) != 0)
503 		goto out_rth;
504 
505 	dev->flags = IFF_MASTER | IFF_NOARP;
506 
507 	return 0;
508 
509 out_rth:
510 	vrf_rtable_release(vrf);
511 out_stats:
512 	free_percpu(dev->dstats);
513 	dev->dstats = NULL;
514 out_nomem:
515 	return -ENOMEM;
516 }
517 
518 static const struct net_device_ops vrf_netdev_ops = {
519 	.ndo_init		= vrf_dev_init,
520 	.ndo_uninit		= vrf_dev_uninit,
521 	.ndo_start_xmit		= vrf_xmit,
522 	.ndo_get_stats64	= vrf_get_stats64,
523 	.ndo_add_slave		= vrf_add_slave,
524 	.ndo_del_slave		= vrf_del_slave,
525 };
526 
527 static u32 vrf_fib_table(const struct net_device *dev)
528 {
529 	struct net_vrf *vrf = netdev_priv(dev);
530 
531 	return vrf->tb_id;
532 }
533 
534 static struct rtable *vrf_get_rtable(const struct net_device *dev,
535 				     const struct flowi4 *fl4)
536 {
537 	struct rtable *rth = NULL;
538 
539 	if (!(fl4->flowi4_flags & FLOWI_FLAG_L3MDEV_SRC)) {
540 		struct net_vrf *vrf = netdev_priv(dev);
541 
542 		rcu_read_lock();
543 
544 		rth = rcu_dereference(vrf->rth);
545 		if (likely(rth))
546 			dst_hold(&rth->dst);
547 
548 		rcu_read_unlock();
549 	}
550 
551 	return rth;
552 }
553 
554 /* called under rcu_read_lock */
555 static int vrf_get_saddr(struct net_device *dev, struct flowi4 *fl4)
556 {
557 	struct fib_result res = { .tclassid = 0 };
558 	struct net *net = dev_net(dev);
559 	u32 orig_tos = fl4->flowi4_tos;
560 	u8 flags = fl4->flowi4_flags;
561 	u8 scope = fl4->flowi4_scope;
562 	u8 tos = RT_FL_TOS(fl4);
563 	int rc;
564 
565 	if (unlikely(!fl4->daddr))
566 		return 0;
567 
568 	fl4->flowi4_flags |= FLOWI_FLAG_SKIP_NH_OIF;
569 	fl4->flowi4_iif = LOOPBACK_IFINDEX;
570 	/* make sure oif is set to VRF device for lookup */
571 	fl4->flowi4_oif = dev->ifindex;
572 	fl4->flowi4_tos = tos & IPTOS_RT_MASK;
573 	fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
574 			     RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
575 
576 	rc = fib_lookup(net, fl4, &res, 0);
577 	if (!rc) {
578 		if (res.type == RTN_LOCAL)
579 			fl4->saddr = res.fi->fib_prefsrc ? : fl4->daddr;
580 		else
581 			fib_select_path(net, &res, fl4, -1);
582 	}
583 
584 	fl4->flowi4_flags = flags;
585 	fl4->flowi4_tos = orig_tos;
586 	fl4->flowi4_scope = scope;
587 
588 	return rc;
589 }
590 
591 #if IS_ENABLED(CONFIG_IPV6)
592 /* neighbor handling is done with actual device; do not want
593  * to flip skb->dev for those ndisc packets. This really fails
594  * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
595  * a start.
596  */
597 static bool ipv6_ndisc_frame(const struct sk_buff *skb)
598 {
599 	const struct ipv6hdr *iph = ipv6_hdr(skb);
600 	bool rc = false;
601 
602 	if (iph->nexthdr == NEXTHDR_ICMP) {
603 		const struct icmp6hdr *icmph;
604 		struct icmp6hdr _icmph;
605 
606 		icmph = skb_header_pointer(skb, sizeof(*iph),
607 					   sizeof(_icmph), &_icmph);
608 		if (!icmph)
609 			goto out;
610 
611 		switch (icmph->icmp6_type) {
612 		case NDISC_ROUTER_SOLICITATION:
613 		case NDISC_ROUTER_ADVERTISEMENT:
614 		case NDISC_NEIGHBOUR_SOLICITATION:
615 		case NDISC_NEIGHBOUR_ADVERTISEMENT:
616 		case NDISC_REDIRECT:
617 			rc = true;
618 			break;
619 		}
620 	}
621 
622 out:
623 	return rc;
624 }
625 
626 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
627 				   struct sk_buff *skb)
628 {
629 	/* if packet is NDISC keep the ingress interface */
630 	if (!ipv6_ndisc_frame(skb)) {
631 		skb->dev = vrf_dev;
632 		skb->skb_iif = vrf_dev->ifindex;
633 
634 		skb_push(skb, skb->mac_len);
635 		dev_queue_xmit_nit(skb, vrf_dev);
636 		skb_pull(skb, skb->mac_len);
637 
638 		IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
639 	}
640 
641 	return skb;
642 }
643 
644 #else
645 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
646 				   struct sk_buff *skb)
647 {
648 	return skb;
649 }
650 #endif
651 
652 static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
653 				  struct sk_buff *skb)
654 {
655 	skb->dev = vrf_dev;
656 	skb->skb_iif = vrf_dev->ifindex;
657 
658 	skb_push(skb, skb->mac_len);
659 	dev_queue_xmit_nit(skb, vrf_dev);
660 	skb_pull(skb, skb->mac_len);
661 
662 	return skb;
663 }
664 
665 /* called with rcu lock held */
666 static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
667 				  struct sk_buff *skb,
668 				  u16 proto)
669 {
670 	switch (proto) {
671 	case AF_INET:
672 		return vrf_ip_rcv(vrf_dev, skb);
673 	case AF_INET6:
674 		return vrf_ip6_rcv(vrf_dev, skb);
675 	}
676 
677 	return skb;
678 }
679 
680 #if IS_ENABLED(CONFIG_IPV6)
681 static struct dst_entry *vrf_get_rt6_dst(const struct net_device *dev,
682 					 const struct flowi6 *fl6)
683 {
684 	struct dst_entry *dst = NULL;
685 
686 	if (!(fl6->flowi6_flags & FLOWI_FLAG_L3MDEV_SRC)) {
687 		struct net_vrf *vrf = netdev_priv(dev);
688 		struct rt6_info *rt;
689 
690 		rcu_read_lock();
691 
692 		rt = rcu_dereference(vrf->rt6);
693 		if (likely(rt)) {
694 			dst = &rt->dst;
695 			dst_hold(dst);
696 		}
697 
698 		rcu_read_unlock();
699 	}
700 
701 	return dst;
702 }
703 #endif
704 
705 static const struct l3mdev_ops vrf_l3mdev_ops = {
706 	.l3mdev_fib_table	= vrf_fib_table,
707 	.l3mdev_get_rtable	= vrf_get_rtable,
708 	.l3mdev_get_saddr	= vrf_get_saddr,
709 	.l3mdev_l3_rcv		= vrf_l3_rcv,
710 #if IS_ENABLED(CONFIG_IPV6)
711 	.l3mdev_get_rt6_dst	= vrf_get_rt6_dst,
712 #endif
713 };
714 
715 static void vrf_get_drvinfo(struct net_device *dev,
716 			    struct ethtool_drvinfo *info)
717 {
718 	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
719 	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
720 }
721 
722 static const struct ethtool_ops vrf_ethtool_ops = {
723 	.get_drvinfo	= vrf_get_drvinfo,
724 };
725 
726 static void vrf_setup(struct net_device *dev)
727 {
728 	ether_setup(dev);
729 
730 	/* Initialize the device structure. */
731 	dev->netdev_ops = &vrf_netdev_ops;
732 	dev->l3mdev_ops = &vrf_l3mdev_ops;
733 	dev->ethtool_ops = &vrf_ethtool_ops;
734 	dev->destructor = free_netdev;
735 
736 	/* Fill in device structure with ethernet-generic values. */
737 	eth_hw_addr_random(dev);
738 
739 	/* don't acquire vrf device's netif_tx_lock when transmitting */
740 	dev->features |= NETIF_F_LLTX;
741 
742 	/* don't allow vrf devices to change network namespaces. */
743 	dev->features |= NETIF_F_NETNS_LOCAL;
744 }
745 
746 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[])
747 {
748 	if (tb[IFLA_ADDRESS]) {
749 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
750 			return -EINVAL;
751 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
752 			return -EADDRNOTAVAIL;
753 	}
754 	return 0;
755 }
756 
757 static void vrf_dellink(struct net_device *dev, struct list_head *head)
758 {
759 	unregister_netdevice_queue(dev, head);
760 }
761 
762 static int vrf_newlink(struct net *src_net, struct net_device *dev,
763 		       struct nlattr *tb[], struct nlattr *data[])
764 {
765 	struct net_vrf *vrf = netdev_priv(dev);
766 
767 	if (!data || !data[IFLA_VRF_TABLE])
768 		return -EINVAL;
769 
770 	vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
771 
772 	dev->priv_flags |= IFF_L3MDEV_MASTER;
773 
774 	return register_netdevice(dev);
775 }
776 
777 static size_t vrf_nl_getsize(const struct net_device *dev)
778 {
779 	return nla_total_size(sizeof(u32));  /* IFLA_VRF_TABLE */
780 }
781 
782 static int vrf_fillinfo(struct sk_buff *skb,
783 			const struct net_device *dev)
784 {
785 	struct net_vrf *vrf = netdev_priv(dev);
786 
787 	return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
788 }
789 
790 static size_t vrf_get_slave_size(const struct net_device *bond_dev,
791 				 const struct net_device *slave_dev)
792 {
793 	return nla_total_size(sizeof(u32));  /* IFLA_VRF_PORT_TABLE */
794 }
795 
796 static int vrf_fill_slave_info(struct sk_buff *skb,
797 			       const struct net_device *vrf_dev,
798 			       const struct net_device *slave_dev)
799 {
800 	struct net_vrf *vrf = netdev_priv(vrf_dev);
801 
802 	if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
803 		return -EMSGSIZE;
804 
805 	return 0;
806 }
807 
808 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
809 	[IFLA_VRF_TABLE] = { .type = NLA_U32 },
810 };
811 
812 static struct rtnl_link_ops vrf_link_ops __read_mostly = {
813 	.kind		= DRV_NAME,
814 	.priv_size	= sizeof(struct net_vrf),
815 
816 	.get_size	= vrf_nl_getsize,
817 	.policy		= vrf_nl_policy,
818 	.validate	= vrf_validate,
819 	.fill_info	= vrf_fillinfo,
820 
821 	.get_slave_size  = vrf_get_slave_size,
822 	.fill_slave_info = vrf_fill_slave_info,
823 
824 	.newlink	= vrf_newlink,
825 	.dellink	= vrf_dellink,
826 	.setup		= vrf_setup,
827 	.maxtype	= IFLA_VRF_MAX,
828 };
829 
830 static int vrf_device_event(struct notifier_block *unused,
831 			    unsigned long event, void *ptr)
832 {
833 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
834 
835 	/* only care about unregister events to drop slave references */
836 	if (event == NETDEV_UNREGISTER) {
837 		struct net_device *vrf_dev;
838 
839 		if (!netif_is_l3_slave(dev))
840 			goto out;
841 
842 		vrf_dev = netdev_master_upper_dev_get(dev);
843 		vrf_del_slave(vrf_dev, dev);
844 	}
845 out:
846 	return NOTIFY_DONE;
847 }
848 
849 static struct notifier_block vrf_notifier_block __read_mostly = {
850 	.notifier_call = vrf_device_event,
851 };
852 
853 static int __init vrf_init_module(void)
854 {
855 	int rc;
856 
857 	register_netdevice_notifier(&vrf_notifier_block);
858 
859 	rc = rtnl_link_register(&vrf_link_ops);
860 	if (rc < 0)
861 		goto error;
862 
863 	return 0;
864 
865 error:
866 	unregister_netdevice_notifier(&vrf_notifier_block);
867 	return rc;
868 }
869 
870 module_init(vrf_init_module);
871 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
872 MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
873 MODULE_LICENSE("GPL");
874 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
875 MODULE_VERSION(DRV_VERSION);
876