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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#include <net/fib_rules.h>
39#include <net/netns/generic.h>
40
41#define DRV_NAME "vrf"
42#define DRV_VERSION "1.0"
43
44#define FIB_RULE_PREF 1000 /* default preference for FIB rules */
45
46static unsigned int vrf_net_id;
47
48struct net_vrf {
49 struct rtable __rcu *rth;
50 struct rt6_info __rcu *rt6;
51 u32 tb_id;
52};
53
54struct pcpu_dstats {
55 u64 tx_pkts;
56 u64 tx_bytes;
57 u64 tx_drps;
58 u64 rx_pkts;
59 u64 rx_bytes;
60 u64 rx_drps;
61 struct u64_stats_sync syncp;
62};
63
64static void vrf_rx_stats(struct net_device *dev, int len)
65{
66 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
67
68 u64_stats_update_begin(&dstats->syncp);
69 dstats->rx_pkts++;
70 dstats->rx_bytes += len;
71 u64_stats_update_end(&dstats->syncp);
72}
73
74static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
75{
76 vrf_dev->stats.tx_errors++;
77 kfree_skb(skb);
78}
79
80static void vrf_get_stats64(struct net_device *dev,
81 struct rtnl_link_stats64 *stats)
82{
83 int i;
84
85 for_each_possible_cpu(i) {
86 const struct pcpu_dstats *dstats;
87 u64 tbytes, tpkts, tdrops, rbytes, rpkts;
88 unsigned int start;
89
90 dstats = per_cpu_ptr(dev->dstats, i);
91 do {
92 start = u64_stats_fetch_begin_irq(&dstats->syncp);
93 tbytes = dstats->tx_bytes;
94 tpkts = dstats->tx_pkts;
95 tdrops = dstats->tx_drps;
96 rbytes = dstats->rx_bytes;
97 rpkts = dstats->rx_pkts;
98 } while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
99 stats->tx_bytes += tbytes;
100 stats->tx_packets += tpkts;
101 stats->tx_dropped += tdrops;
102 stats->rx_bytes += rbytes;
103 stats->rx_packets += rpkts;
104 }
105}
106
107/* by default VRF devices do not have a qdisc and are expected
108 * to be created with only a single queue.
109 */
110static bool qdisc_tx_is_default(const struct net_device *dev)
111{
112 struct netdev_queue *txq;
113 struct Qdisc *qdisc;
114
115 if (dev->num_tx_queues > 1)
116 return false;
117
118 txq = netdev_get_tx_queue(dev, 0);
119 qdisc = rcu_access_pointer(txq->qdisc);
120
121 return !qdisc->enqueue;
122}
123
124/* Local traffic destined to local address. Reinsert the packet to rx
125 * path, similar to loopback handling.
126 */
127static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
128 struct dst_entry *dst)
129{
130 int len = skb->len;
131
132 skb_orphan(skb);
133
134 skb_dst_set(skb, dst);
135
136 /* set pkt_type to avoid skb hitting packet taps twice -
137 * once on Tx and again in Rx processing
138 */
139 skb->pkt_type = PACKET_LOOPBACK;
140
141 skb->protocol = eth_type_trans(skb, dev);
142
143 if (likely(netif_rx(skb) == NET_RX_SUCCESS))
144 vrf_rx_stats(dev, len);
145 else
146 this_cpu_inc(dev->dstats->rx_drps);
147
148 return NETDEV_TX_OK;
149}
150
151#if IS_ENABLED(CONFIG_IPV6)
152static int vrf_ip6_local_out(struct net *net, struct sock *sk,
153 struct sk_buff *skb)
154{
155 int err;
156
157 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net,
158 sk, skb, NULL, skb_dst(skb)->dev, dst_output);
159
160 if (likely(err == 1))
161 err = dst_output(net, sk, skb);
162
163 return err;
164}
165
166static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
167 struct net_device *dev)
168{
169 const struct ipv6hdr *iph = ipv6_hdr(skb);
170 struct net *net = dev_net(skb->dev);
171 struct flowi6 fl6 = {
172 /* needed to match OIF rule */
173 .flowi6_oif = dev->ifindex,
174 .flowi6_iif = LOOPBACK_IFINDEX,
175 .daddr = iph->daddr,
176 .saddr = iph->saddr,
177 .flowlabel = ip6_flowinfo(iph),
178 .flowi6_mark = skb->mark,
179 .flowi6_proto = iph->nexthdr,
180 .flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF,
181 };
182 int ret = NET_XMIT_DROP;
183 struct dst_entry *dst;
184 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
185
186 dst = ip6_route_output(net, NULL, &fl6);
187 if (dst == dst_null)
188 goto err;
189
190 skb_dst_drop(skb);
191
192 /* if dst.dev is loopback or the VRF device again this is locally
193 * originated traffic destined to a local address. Short circuit
194 * to Rx path
195 */
196 if (dst->dev == dev)
197 return vrf_local_xmit(skb, dev, dst);
198
199 skb_dst_set(skb, dst);
200
201 /* strip the ethernet header added for pass through VRF device */
202 __skb_pull(skb, skb_network_offset(skb));
203
204 ret = vrf_ip6_local_out(net, skb->sk, skb);
205 if (unlikely(net_xmit_eval(ret)))
206 dev->stats.tx_errors++;
207 else
208 ret = NET_XMIT_SUCCESS;
209
210 return ret;
211err:
212 vrf_tx_error(dev, skb);
213 return NET_XMIT_DROP;
214}
215#else
216static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
217 struct net_device *dev)
218{
219 vrf_tx_error(dev, skb);
220 return NET_XMIT_DROP;
221}
222#endif
223
224/* based on ip_local_out; can't use it b/c the dst is switched pointing to us */
225static int vrf_ip_local_out(struct net *net, struct sock *sk,
226 struct sk_buff *skb)
227{
228 int err;
229
230 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
231 skb, NULL, skb_dst(skb)->dev, dst_output);
232 if (likely(err == 1))
233 err = dst_output(net, sk, skb);
234
235 return err;
236}
237
238static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
239 struct net_device *vrf_dev)
240{
241 struct iphdr *ip4h = ip_hdr(skb);
242 int ret = NET_XMIT_DROP;
243 struct flowi4 fl4 = {
244 /* needed to match OIF rule */
245 .flowi4_oif = vrf_dev->ifindex,
246 .flowi4_iif = LOOPBACK_IFINDEX,
247 .flowi4_tos = RT_TOS(ip4h->tos),
248 .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF,
249 .flowi4_proto = ip4h->protocol,
250 .daddr = ip4h->daddr,
251 .saddr = ip4h->saddr,
252 };
253 struct net *net = dev_net(vrf_dev);
254 struct rtable *rt;
255
256 rt = ip_route_output_flow(net, &fl4, NULL);
257 if (IS_ERR(rt))
258 goto err;
259
260 skb_dst_drop(skb);
261
262 /* if dst.dev is loopback or the VRF device again this is locally
263 * originated traffic destined to a local address. Short circuit
264 * to Rx path
265 */
266 if (rt->dst.dev == vrf_dev)
267 return vrf_local_xmit(skb, vrf_dev, &rt->dst);
268
269 skb_dst_set(skb, &rt->dst);
270
271 /* strip the ethernet header added for pass through VRF device */
272 __skb_pull(skb, skb_network_offset(skb));
273
274 if (!ip4h->saddr) {
275 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
276 RT_SCOPE_LINK);
277 }
278
279 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
280 if (unlikely(net_xmit_eval(ret)))
281 vrf_dev->stats.tx_errors++;
282 else
283 ret = NET_XMIT_SUCCESS;
284
285out:
286 return ret;
287err:
288 vrf_tx_error(vrf_dev, skb);
289 goto out;
290}
291
292static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
293{
294 switch (skb->protocol) {
295 case htons(ETH_P_IP):
296 return vrf_process_v4_outbound(skb, dev);
297 case htons(ETH_P_IPV6):
298 return vrf_process_v6_outbound(skb, dev);
299 default:
300 vrf_tx_error(dev, skb);
301 return NET_XMIT_DROP;
302 }
303}
304
305static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
306{
307 int len = skb->len;
308 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
309
310 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
311 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
312
313 u64_stats_update_begin(&dstats->syncp);
314 dstats->tx_pkts++;
315 dstats->tx_bytes += len;
316 u64_stats_update_end(&dstats->syncp);
317 } else {
318 this_cpu_inc(dev->dstats->tx_drps);
319 }
320
321 return ret;
322}
323
324static int vrf_finish_direct(struct net *net, struct sock *sk,
325 struct sk_buff *skb)
326{
327 struct net_device *vrf_dev = skb->dev;
328
329 if (!list_empty(&vrf_dev->ptype_all) &&
330 likely(skb_headroom(skb) >= ETH_HLEN)) {
331 struct ethhdr *eth = skb_push(skb, ETH_HLEN);
332
333 ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
334 eth_zero_addr(eth->h_dest);
335 eth->h_proto = skb->protocol;
336
337 rcu_read_lock_bh();
338 dev_queue_xmit_nit(skb, vrf_dev);
339 rcu_read_unlock_bh();
340
341 skb_pull(skb, ETH_HLEN);
342 }
343
344 return 1;
345}
346
347#if IS_ENABLED(CONFIG_IPV6)
348/* modelled after ip6_finish_output2 */
349static int vrf_finish_output6(struct net *net, struct sock *sk,
350 struct sk_buff *skb)
351{
352 struct dst_entry *dst = skb_dst(skb);
353 struct net_device *dev = dst->dev;
354 struct neighbour *neigh;
355 struct in6_addr *nexthop;
356 int ret;
357
358 nf_reset(skb);
359
360 skb->protocol = htons(ETH_P_IPV6);
361 skb->dev = dev;
362
363 rcu_read_lock_bh();
364 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
365 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
366 if (unlikely(!neigh))
367 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
368 if (!IS_ERR(neigh)) {
369 sock_confirm_neigh(skb, neigh);
370 ret = neigh_output(neigh, skb);
371 rcu_read_unlock_bh();
372 return ret;
373 }
374 rcu_read_unlock_bh();
375
376 IP6_INC_STATS(dev_net(dst->dev),
377 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
378 kfree_skb(skb);
379 return -EINVAL;
380}
381
382/* modelled after ip6_output */
383static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
384{
385 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
386 net, sk, skb, NULL, skb_dst(skb)->dev,
387 vrf_finish_output6,
388 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
389}
390
391/* set dst on skb to send packet to us via dev_xmit path. Allows
392 * packet to go through device based features such as qdisc, netfilter
393 * hooks and packet sockets with skb->dev set to vrf device.
394 */
395static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev,
396 struct sk_buff *skb)
397{
398 struct net_vrf *vrf = netdev_priv(vrf_dev);
399 struct dst_entry *dst = NULL;
400 struct rt6_info *rt6;
401
402 rcu_read_lock();
403
404 rt6 = rcu_dereference(vrf->rt6);
405 if (likely(rt6)) {
406 dst = &rt6->dst;
407 dst_hold(dst);
408 }
409
410 rcu_read_unlock();
411
412 if (unlikely(!dst)) {
413 vrf_tx_error(vrf_dev, skb);
414 return NULL;
415 }
416
417 skb_dst_drop(skb);
418 skb_dst_set(skb, dst);
419
420 return skb;
421}
422
423static int vrf_output6_direct(struct net *net, struct sock *sk,
424 struct sk_buff *skb)
425{
426 skb->protocol = htons(ETH_P_IPV6);
427
428 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
429 net, sk, skb, NULL, skb->dev,
430 vrf_finish_direct,
431 !(IPCB(skb)->flags & IPSKB_REROUTED));
432}
433
434static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
435 struct sock *sk,
436 struct sk_buff *skb)
437{
438 struct net *net = dev_net(vrf_dev);
439 int err;
440
441 skb->dev = vrf_dev;
442
443 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk,
444 skb, NULL, vrf_dev, vrf_output6_direct);
445
446 if (likely(err == 1))
447 err = vrf_output6_direct(net, sk, skb);
448
449 /* reset skb device */
450 if (likely(err == 1))
451 nf_reset(skb);
452 else
453 skb = NULL;
454
455 return skb;
456}
457
458static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
459 struct sock *sk,
460 struct sk_buff *skb)
461{
462 /* don't divert link scope packets */
463 if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
464 return skb;
465
466 if (qdisc_tx_is_default(vrf_dev))
467 return vrf_ip6_out_direct(vrf_dev, sk, skb);
468
469 return vrf_ip6_out_redirect(vrf_dev, skb);
470}
471
472/* holding rtnl */
473static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
474{
475 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
476 struct net *net = dev_net(dev);
477 struct dst_entry *dst;
478
479 RCU_INIT_POINTER(vrf->rt6, NULL);
480 synchronize_rcu();
481
482 /* move dev in dst's to loopback so this VRF device can be deleted
483 * - based on dst_ifdown
484 */
485 if (rt6) {
486 dst = &rt6->dst;
487 dev_put(dst->dev);
488 dst->dev = net->loopback_dev;
489 dev_hold(dst->dev);
490 dst_release(dst);
491 }
492}
493
494static int vrf_rt6_create(struct net_device *dev)
495{
496 int flags = DST_HOST | DST_NOPOLICY | DST_NOXFRM;
497 struct net_vrf *vrf = netdev_priv(dev);
498 struct net *net = dev_net(dev);
499 struct fib6_table *rt6i_table;
500 struct rt6_info *rt6;
501 int rc = -ENOMEM;
502
503 /* IPv6 can be CONFIG enabled and then disabled runtime */
504 if (!ipv6_mod_enabled())
505 return 0;
506
507 rt6i_table = fib6_new_table(net, vrf->tb_id);
508 if (!rt6i_table)
509 goto out;
510
511 /* create a dst for routing packets out a VRF device */
512 rt6 = ip6_dst_alloc(net, dev, flags);
513 if (!rt6)
514 goto out;
515
516 rt6->rt6i_table = rt6i_table;
517 rt6->dst.output = vrf_output6;
518
519 rcu_assign_pointer(vrf->rt6, rt6);
520
521 rc = 0;
522out:
523 return rc;
524}
525#else
526static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
527 struct sock *sk,
528 struct sk_buff *skb)
529{
530 return skb;
531}
532
533static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
534{
535}
536
537static int vrf_rt6_create(struct net_device *dev)
538{
539 return 0;
540}
541#endif
542
543/* modelled after ip_finish_output2 */
544static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
545{
546 struct dst_entry *dst = skb_dst(skb);
547 struct rtable *rt = (struct rtable *)dst;
548 struct net_device *dev = dst->dev;
549 unsigned int hh_len = LL_RESERVED_SPACE(dev);
550 struct neighbour *neigh;
551 u32 nexthop;
552 int ret = -EINVAL;
553
554 nf_reset(skb);
555
556 /* Be paranoid, rather than too clever. */
557 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
558 struct sk_buff *skb2;
559
560 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
561 if (!skb2) {
562 ret = -ENOMEM;
563 goto err;
564 }
565 if (skb->sk)
566 skb_set_owner_w(skb2, skb->sk);
567
568 consume_skb(skb);
569 skb = skb2;
570 }
571
572 rcu_read_lock_bh();
573
574 nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr);
575 neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
576 if (unlikely(!neigh))
577 neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
578 if (!IS_ERR(neigh)) {
579 sock_confirm_neigh(skb, neigh);
580 ret = neigh_output(neigh, skb);
581 rcu_read_unlock_bh();
582 return ret;
583 }
584
585 rcu_read_unlock_bh();
586err:
587 vrf_tx_error(skb->dev, skb);
588 return ret;
589}
590
591static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
592{
593 struct net_device *dev = skb_dst(skb)->dev;
594
595 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
596
597 skb->dev = dev;
598 skb->protocol = htons(ETH_P_IP);
599
600 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
601 net, sk, skb, NULL, dev,
602 vrf_finish_output,
603 !(IPCB(skb)->flags & IPSKB_REROUTED));
604}
605
606/* set dst on skb to send packet to us via dev_xmit path. Allows
607 * packet to go through device based features such as qdisc, netfilter
608 * hooks and packet sockets with skb->dev set to vrf device.
609 */
610static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev,
611 struct sk_buff *skb)
612{
613 struct net_vrf *vrf = netdev_priv(vrf_dev);
614 struct dst_entry *dst = NULL;
615 struct rtable *rth;
616
617 rcu_read_lock();
618
619 rth = rcu_dereference(vrf->rth);
620 if (likely(rth)) {
621 dst = &rth->dst;
622 dst_hold(dst);
623 }
624
625 rcu_read_unlock();
626
627 if (unlikely(!dst)) {
628 vrf_tx_error(vrf_dev, skb);
629 return NULL;
630 }
631
632 skb_dst_drop(skb);
633 skb_dst_set(skb, dst);
634
635 return skb;
636}
637
638static int vrf_output_direct(struct net *net, struct sock *sk,
639 struct sk_buff *skb)
640{
641 skb->protocol = htons(ETH_P_IP);
642
643 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
644 net, sk, skb, NULL, skb->dev,
645 vrf_finish_direct,
646 !(IPCB(skb)->flags & IPSKB_REROUTED));
647}
648
649static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
650 struct sock *sk,
651 struct sk_buff *skb)
652{
653 struct net *net = dev_net(vrf_dev);
654 int err;
655
656 skb->dev = vrf_dev;
657
658 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
659 skb, NULL, vrf_dev, vrf_output_direct);
660
661 if (likely(err == 1))
662 err = vrf_output_direct(net, sk, skb);
663
664 /* reset skb device */
665 if (likely(err == 1))
666 nf_reset(skb);
667 else
668 skb = NULL;
669
670 return skb;
671}
672
673static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
674 struct sock *sk,
675 struct sk_buff *skb)
676{
677 /* don't divert multicast or local broadcast */
678 if (ipv4_is_multicast(ip_hdr(skb)->daddr) ||
679 ipv4_is_lbcast(ip_hdr(skb)->daddr))
680 return skb;
681
682 if (qdisc_tx_is_default(vrf_dev))
683 return vrf_ip_out_direct(vrf_dev, sk, skb);
684
685 return vrf_ip_out_redirect(vrf_dev, skb);
686}
687
688/* called with rcu lock held */
689static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
690 struct sock *sk,
691 struct sk_buff *skb,
692 u16 proto)
693{
694 switch (proto) {
695 case AF_INET:
696 return vrf_ip_out(vrf_dev, sk, skb);
697 case AF_INET6:
698 return vrf_ip6_out(vrf_dev, sk, skb);
699 }
700
701 return skb;
702}
703
704/* holding rtnl */
705static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
706{
707 struct rtable *rth = rtnl_dereference(vrf->rth);
708 struct net *net = dev_net(dev);
709 struct dst_entry *dst;
710
711 RCU_INIT_POINTER(vrf->rth, NULL);
712 synchronize_rcu();
713
714 /* move dev in dst's to loopback so this VRF device can be deleted
715 * - based on dst_ifdown
716 */
717 if (rth) {
718 dst = &rth->dst;
719 dev_put(dst->dev);
720 dst->dev = net->loopback_dev;
721 dev_hold(dst->dev);
722 dst_release(dst);
723 }
724}
725
726static int vrf_rtable_create(struct net_device *dev)
727{
728 struct net_vrf *vrf = netdev_priv(dev);
729 struct rtable *rth;
730
731 if (!fib_new_table(dev_net(dev), vrf->tb_id))
732 return -ENOMEM;
733
734 /* create a dst for routing packets out through a VRF device */
735 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1, 0);
736 if (!rth)
737 return -ENOMEM;
738
739 rth->dst.output = vrf_output;
740
741 rcu_assign_pointer(vrf->rth, rth);
742
743 return 0;
744}
745
746/**************************** device handling ********************/
747
748/* cycle interface to flush neighbor cache and move routes across tables */
749static void cycle_netdev(struct net_device *dev)
750{
751 unsigned int flags = dev->flags;
752 int ret;
753
754 if (!netif_running(dev))
755 return;
756
757 ret = dev_change_flags(dev, flags & ~IFF_UP);
758 if (ret >= 0)
759 ret = dev_change_flags(dev, flags);
760
761 if (ret < 0) {
762 netdev_err(dev,
763 "Failed to cycle device %s; route tables might be wrong!\n",
764 dev->name);
765 }
766}
767
768static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
769 struct netlink_ext_ack *extack)
770{
771 int ret;
772
773 /* do not allow loopback device to be enslaved to a VRF.
774 * The vrf device acts as the loopback for the vrf.
775 */
776 if (port_dev == dev_net(dev)->loopback_dev) {
777 NL_SET_ERR_MSG(extack,
778 "Can not enslave loopback device to a VRF");
779 return -EOPNOTSUPP;
780 }
781
782 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
783 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack);
784 if (ret < 0)
785 goto err;
786
787 cycle_netdev(port_dev);
788
789 return 0;
790
791err:
792 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
793 return ret;
794}
795
796static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
797 struct netlink_ext_ack *extack)
798{
799 if (netif_is_l3_master(port_dev)) {
800 NL_SET_ERR_MSG(extack,
801 "Can not enslave an L3 master device to a VRF");
802 return -EINVAL;
803 }
804
805 if (netif_is_l3_slave(port_dev))
806 return -EINVAL;
807
808 return do_vrf_add_slave(dev, port_dev, extack);
809}
810
811/* inverse of do_vrf_add_slave */
812static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
813{
814 netdev_upper_dev_unlink(port_dev, dev);
815 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
816
817 cycle_netdev(port_dev);
818
819 return 0;
820}
821
822static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
823{
824 return do_vrf_del_slave(dev, port_dev);
825}
826
827static void vrf_dev_uninit(struct net_device *dev)
828{
829 struct net_vrf *vrf = netdev_priv(dev);
830
831 vrf_rtable_release(dev, vrf);
832 vrf_rt6_release(dev, vrf);
833
834 free_percpu(dev->dstats);
835 dev->dstats = NULL;
836}
837
838static int vrf_dev_init(struct net_device *dev)
839{
840 struct net_vrf *vrf = netdev_priv(dev);
841
842 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
843 if (!dev->dstats)
844 goto out_nomem;
845
846 /* create the default dst which points back to us */
847 if (vrf_rtable_create(dev) != 0)
848 goto out_stats;
849
850 if (vrf_rt6_create(dev) != 0)
851 goto out_rth;
852
853 dev->flags = IFF_MASTER | IFF_NOARP;
854
855 /* MTU is irrelevant for VRF device; set to 64k similar to lo */
856 dev->mtu = 64 * 1024;
857
858 /* similarly, oper state is irrelevant; set to up to avoid confusion */
859 dev->operstate = IF_OPER_UP;
860 netdev_lockdep_set_classes(dev);
861 return 0;
862
863out_rth:
864 vrf_rtable_release(dev, vrf);
865out_stats:
866 free_percpu(dev->dstats);
867 dev->dstats = NULL;
868out_nomem:
869 return -ENOMEM;
870}
871
872static const struct net_device_ops vrf_netdev_ops = {
873 .ndo_init = vrf_dev_init,
874 .ndo_uninit = vrf_dev_uninit,
875 .ndo_start_xmit = vrf_xmit,
876 .ndo_get_stats64 = vrf_get_stats64,
877 .ndo_add_slave = vrf_add_slave,
878 .ndo_del_slave = vrf_del_slave,
879};
880
881static u32 vrf_fib_table(const struct net_device *dev)
882{
883 struct net_vrf *vrf = netdev_priv(dev);
884
885 return vrf->tb_id;
886}
887
888static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
889{
890 kfree_skb(skb);
891 return 0;
892}
893
894static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
895 struct sk_buff *skb,
896 struct net_device *dev)
897{
898 struct net *net = dev_net(dev);
899
900 if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1)
901 skb = NULL; /* kfree_skb(skb) handled by nf code */
902
903 return skb;
904}
905
906#if IS_ENABLED(CONFIG_IPV6)
907/* neighbor handling is done with actual device; do not want
908 * to flip skb->dev for those ndisc packets. This really fails
909 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
910 * a start.
911 */
912static bool ipv6_ndisc_frame(const struct sk_buff *skb)
913{
914 const struct ipv6hdr *iph = ipv6_hdr(skb);
915 bool rc = false;
916
917 if (iph->nexthdr == NEXTHDR_ICMP) {
918 const struct icmp6hdr *icmph;
919 struct icmp6hdr _icmph;
920
921 icmph = skb_header_pointer(skb, sizeof(*iph),
922 sizeof(_icmph), &_icmph);
923 if (!icmph)
924 goto out;
925
926 switch (icmph->icmp6_type) {
927 case NDISC_ROUTER_SOLICITATION:
928 case NDISC_ROUTER_ADVERTISEMENT:
929 case NDISC_NEIGHBOUR_SOLICITATION:
930 case NDISC_NEIGHBOUR_ADVERTISEMENT:
931 case NDISC_REDIRECT:
932 rc = true;
933 break;
934 }
935 }
936
937out:
938 return rc;
939}
940
941static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
942 const struct net_device *dev,
943 struct flowi6 *fl6,
944 int ifindex,
945 const struct sk_buff *skb,
946 int flags)
947{
948 struct net_vrf *vrf = netdev_priv(dev);
949 struct fib6_table *table = NULL;
950 struct rt6_info *rt6;
951
952 rcu_read_lock();
953
954 /* fib6_table does not have a refcnt and can not be freed */
955 rt6 = rcu_dereference(vrf->rt6);
956 if (likely(rt6))
957 table = rt6->rt6i_table;
958
959 rcu_read_unlock();
960
961 if (!table)
962 return NULL;
963
964 return ip6_pol_route(net, table, ifindex, fl6, skb, flags);
965}
966
967static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
968 int ifindex)
969{
970 const struct ipv6hdr *iph = ipv6_hdr(skb);
971 struct flowi6 fl6 = {
972 .flowi6_iif = ifindex,
973 .flowi6_mark = skb->mark,
974 .flowi6_proto = iph->nexthdr,
975 .daddr = iph->daddr,
976 .saddr = iph->saddr,
977 .flowlabel = ip6_flowinfo(iph),
978 };
979 struct net *net = dev_net(vrf_dev);
980 struct rt6_info *rt6;
981
982 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb,
983 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
984 if (unlikely(!rt6))
985 return;
986
987 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
988 return;
989
990 skb_dst_set(skb, &rt6->dst);
991}
992
993static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
994 struct sk_buff *skb)
995{
996 int orig_iif = skb->skb_iif;
997 bool need_strict;
998
999 /* loopback traffic; do not push through packet taps again.
1000 * Reset pkt_type for upper layers to process skb
1001 */
1002 if (skb->pkt_type == PACKET_LOOPBACK) {
1003 skb->dev = vrf_dev;
1004 skb->skb_iif = vrf_dev->ifindex;
1005 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1006 skb->pkt_type = PACKET_HOST;
1007 goto out;
1008 }
1009
1010 /* if packet is NDISC or addressed to multicast or link-local
1011 * then keep the ingress interface
1012 */
1013 need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
1014 if (!ipv6_ndisc_frame(skb) && !need_strict) {
1015 vrf_rx_stats(vrf_dev, skb->len);
1016 skb->dev = vrf_dev;
1017 skb->skb_iif = vrf_dev->ifindex;
1018
1019 if (!list_empty(&vrf_dev->ptype_all)) {
1020 skb_push(skb, skb->mac_len);
1021 dev_queue_xmit_nit(skb, vrf_dev);
1022 skb_pull(skb, skb->mac_len);
1023 }
1024
1025 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1026 }
1027
1028 if (need_strict)
1029 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1030
1031 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
1032out:
1033 return skb;
1034}
1035
1036#else
1037static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1038 struct sk_buff *skb)
1039{
1040 return skb;
1041}
1042#endif
1043
1044static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
1045 struct sk_buff *skb)
1046{
1047 skb->dev = vrf_dev;
1048 skb->skb_iif = vrf_dev->ifindex;
1049 IPCB(skb)->flags |= IPSKB_L3SLAVE;
1050
1051 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
1052 goto out;
1053
1054 /* loopback traffic; do not push through packet taps again.
1055 * Reset pkt_type for upper layers to process skb
1056 */
1057 if (skb->pkt_type == PACKET_LOOPBACK) {
1058 skb->pkt_type = PACKET_HOST;
1059 goto out;
1060 }
1061
1062 vrf_rx_stats(vrf_dev, skb->len);
1063
1064 if (!list_empty(&vrf_dev->ptype_all)) {
1065 skb_push(skb, skb->mac_len);
1066 dev_queue_xmit_nit(skb, vrf_dev);
1067 skb_pull(skb, skb->mac_len);
1068 }
1069
1070 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
1071out:
1072 return skb;
1073}
1074
1075/* called with rcu lock held */
1076static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1077 struct sk_buff *skb,
1078 u16 proto)
1079{
1080 switch (proto) {
1081 case AF_INET:
1082 return vrf_ip_rcv(vrf_dev, skb);
1083 case AF_INET6:
1084 return vrf_ip6_rcv(vrf_dev, skb);
1085 }
1086
1087 return skb;
1088}
1089
1090#if IS_ENABLED(CONFIG_IPV6)
1091/* send to link-local or multicast address via interface enslaved to
1092 * VRF device. Force lookup to VRF table without changing flow struct
1093 */
1094static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1095 struct flowi6 *fl6)
1096{
1097 struct net *net = dev_net(dev);
1098 int flags = RT6_LOOKUP_F_IFACE;
1099 struct dst_entry *dst = NULL;
1100 struct rt6_info *rt;
1101
1102 /* VRF device does not have a link-local address and
1103 * sending packets to link-local or mcast addresses over
1104 * a VRF device does not make sense
1105 */
1106 if (fl6->flowi6_oif == dev->ifindex) {
1107 dst = &net->ipv6.ip6_null_entry->dst;
1108 dst_hold(dst);
1109 return dst;
1110 }
1111
1112 if (!ipv6_addr_any(&fl6->saddr))
1113 flags |= RT6_LOOKUP_F_HAS_SADDR;
1114
1115 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags);
1116 if (rt)
1117 dst = &rt->dst;
1118
1119 return dst;
1120}
1121#endif
1122
1123static const struct l3mdev_ops vrf_l3mdev_ops = {
1124 .l3mdev_fib_table = vrf_fib_table,
1125 .l3mdev_l3_rcv = vrf_l3_rcv,
1126 .l3mdev_l3_out = vrf_l3_out,
1127#if IS_ENABLED(CONFIG_IPV6)
1128 .l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1129#endif
1130};
1131
1132static void vrf_get_drvinfo(struct net_device *dev,
1133 struct ethtool_drvinfo *info)
1134{
1135 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
1136 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
1137}
1138
1139static const struct ethtool_ops vrf_ethtool_ops = {
1140 .get_drvinfo = vrf_get_drvinfo,
1141};
1142
1143static inline size_t vrf_fib_rule_nl_size(void)
1144{
1145 size_t sz;
1146
1147 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1148 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */
1149 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */
1150 sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */
1151
1152 return sz;
1153}
1154
1155static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1156{
1157 struct fib_rule_hdr *frh;
1158 struct nlmsghdr *nlh;
1159 struct sk_buff *skb;
1160 int err;
1161
1162 if (family == AF_INET6 && !ipv6_mod_enabled())
1163 return 0;
1164
1165 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
1166 if (!skb)
1167 return -ENOMEM;
1168
1169 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
1170 if (!nlh)
1171 goto nla_put_failure;
1172
1173 /* rule only needs to appear once */
1174 nlh->nlmsg_flags |= NLM_F_EXCL;
1175
1176 frh = nlmsg_data(nlh);
1177 memset(frh, 0, sizeof(*frh));
1178 frh->family = family;
1179 frh->action = FR_ACT_TO_TBL;
1180
1181 if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL))
1182 goto nla_put_failure;
1183
1184 if (nla_put_u8(skb, FRA_L3MDEV, 1))
1185 goto nla_put_failure;
1186
1187 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
1188 goto nla_put_failure;
1189
1190 nlmsg_end(skb, nlh);
1191
1192 /* fib_nl_{new,del}rule handling looks for net from skb->sk */
1193 skb->sk = dev_net(dev)->rtnl;
1194 if (add_it) {
1195 err = fib_nl_newrule(skb, nlh, NULL);
1196 if (err == -EEXIST)
1197 err = 0;
1198 } else {
1199 err = fib_nl_delrule(skb, nlh, NULL);
1200 if (err == -ENOENT)
1201 err = 0;
1202 }
1203 nlmsg_free(skb);
1204
1205 return err;
1206
1207nla_put_failure:
1208 nlmsg_free(skb);
1209
1210 return -EMSGSIZE;
1211}
1212
1213static int vrf_add_fib_rules(const struct net_device *dev)
1214{
1215 int err;
1216
1217 err = vrf_fib_rule(dev, AF_INET, true);
1218 if (err < 0)
1219 goto out_err;
1220
1221 err = vrf_fib_rule(dev, AF_INET6, true);
1222 if (err < 0)
1223 goto ipv6_err;
1224
1225#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1226 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true);
1227 if (err < 0)
1228 goto ipmr_err;
1229#endif
1230
1231 return 0;
1232
1233#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1234ipmr_err:
1235 vrf_fib_rule(dev, AF_INET6, false);
1236#endif
1237
1238ipv6_err:
1239 vrf_fib_rule(dev, AF_INET, false);
1240
1241out_err:
1242 netdev_err(dev, "Failed to add FIB rules.\n");
1243 return err;
1244}
1245
1246static void vrf_setup(struct net_device *dev)
1247{
1248 ether_setup(dev);
1249
1250 /* Initialize the device structure. */
1251 dev->netdev_ops = &vrf_netdev_ops;
1252 dev->l3mdev_ops = &vrf_l3mdev_ops;
1253 dev->ethtool_ops = &vrf_ethtool_ops;
1254 dev->needs_free_netdev = true;
1255
1256 /* Fill in device structure with ethernet-generic values. */
1257 eth_hw_addr_random(dev);
1258
1259 /* don't acquire vrf device's netif_tx_lock when transmitting */
1260 dev->features |= NETIF_F_LLTX;
1261
1262 /* don't allow vrf devices to change network namespaces. */
1263 dev->features |= NETIF_F_NETNS_LOCAL;
1264
1265 /* does not make sense for a VLAN to be added to a vrf device */
1266 dev->features |= NETIF_F_VLAN_CHALLENGED;
1267
1268 /* enable offload features */
1269 dev->features |= NETIF_F_GSO_SOFTWARE;
1270 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM;
1271 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1272
1273 dev->hw_features = dev->features;
1274 dev->hw_enc_features = dev->features;
1275
1276 /* default to no qdisc; user can add if desired */
1277 dev->priv_flags |= IFF_NO_QUEUE;
1278}
1279
1280static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],
1281 struct netlink_ext_ack *extack)
1282{
1283 if (tb[IFLA_ADDRESS]) {
1284 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
1285 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1286 return -EINVAL;
1287 }
1288 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
1289 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1290 return -EADDRNOTAVAIL;
1291 }
1292 }
1293 return 0;
1294}
1295
1296static void vrf_dellink(struct net_device *dev, struct list_head *head)
1297{
1298 struct net_device *port_dev;
1299 struct list_head *iter;
1300
1301 netdev_for_each_lower_dev(dev, port_dev, iter)
1302 vrf_del_slave(dev, port_dev);
1303
1304 unregister_netdevice_queue(dev, head);
1305}
1306
1307static int vrf_newlink(struct net *src_net, struct net_device *dev,
1308 struct nlattr *tb[], struct nlattr *data[],
1309 struct netlink_ext_ack *extack)
1310{
1311 struct net_vrf *vrf = netdev_priv(dev);
1312 bool *add_fib_rules;
1313 struct net *net;
1314 int err;
1315
1316 if (!data || !data[IFLA_VRF_TABLE]) {
1317 NL_SET_ERR_MSG(extack, "VRF table id is missing");
1318 return -EINVAL;
1319 }
1320
1321 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
1322 if (vrf->tb_id == RT_TABLE_UNSPEC) {
1323 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE],
1324 "Invalid VRF table id");
1325 return -EINVAL;
1326 }
1327
1328 dev->priv_flags |= IFF_L3MDEV_MASTER;
1329
1330 err = register_netdevice(dev);
1331 if (err)
1332 goto out;
1333
1334 net = dev_net(dev);
1335 add_fib_rules = net_generic(net, vrf_net_id);
1336 if (*add_fib_rules) {
1337 err = vrf_add_fib_rules(dev);
1338 if (err) {
1339 unregister_netdevice(dev);
1340 goto out;
1341 }
1342 *add_fib_rules = false;
1343 }
1344
1345out:
1346 return err;
1347}
1348
1349static size_t vrf_nl_getsize(const struct net_device *dev)
1350{
1351 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
1352}
1353
1354static int vrf_fillinfo(struct sk_buff *skb,
1355 const struct net_device *dev)
1356{
1357 struct net_vrf *vrf = netdev_priv(dev);
1358
1359 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
1360}
1361
1362static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1363 const struct net_device *slave_dev)
1364{
1365 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1366}
1367
1368static int vrf_fill_slave_info(struct sk_buff *skb,
1369 const struct net_device *vrf_dev,
1370 const struct net_device *slave_dev)
1371{
1372 struct net_vrf *vrf = netdev_priv(vrf_dev);
1373
1374 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
1375 return -EMSGSIZE;
1376
1377 return 0;
1378}
1379
1380static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1381 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1382};
1383
1384static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1385 .kind = DRV_NAME,
1386 .priv_size = sizeof(struct net_vrf),
1387
1388 .get_size = vrf_nl_getsize,
1389 .policy = vrf_nl_policy,
1390 .validate = vrf_validate,
1391 .fill_info = vrf_fillinfo,
1392
1393 .get_slave_size = vrf_get_slave_size,
1394 .fill_slave_info = vrf_fill_slave_info,
1395
1396 .newlink = vrf_newlink,
1397 .dellink = vrf_dellink,
1398 .setup = vrf_setup,
1399 .maxtype = IFLA_VRF_MAX,
1400};
1401
1402static int vrf_device_event(struct notifier_block *unused,
1403 unsigned long event, void *ptr)
1404{
1405 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1406
1407 /* only care about unregister events to drop slave references */
1408 if (event == NETDEV_UNREGISTER) {
1409 struct net_device *vrf_dev;
1410
1411 if (!netif_is_l3_slave(dev))
1412 goto out;
1413
1414 vrf_dev = netdev_master_upper_dev_get(dev);
1415 vrf_del_slave(vrf_dev, dev);
1416 }
1417out:
1418 return NOTIFY_DONE;
1419}
1420
1421static struct notifier_block vrf_notifier_block __read_mostly = {
1422 .notifier_call = vrf_device_event,
1423};
1424
1425/* Initialize per network namespace state */
1426static int __net_init vrf_netns_init(struct net *net)
1427{
1428 bool *add_fib_rules = net_generic(net, vrf_net_id);
1429
1430 *add_fib_rules = true;
1431
1432 return 0;
1433}
1434
1435static struct pernet_operations vrf_net_ops __net_initdata = {
1436 .init = vrf_netns_init,
1437 .id = &vrf_net_id,
1438 .size = sizeof(bool),
1439};
1440
1441static int __init vrf_init_module(void)
1442{
1443 int rc;
1444
1445 register_netdevice_notifier(&vrf_notifier_block);
1446
1447 rc = register_pernet_subsys(&vrf_net_ops);
1448 if (rc < 0)
1449 goto error;
1450
1451 rc = rtnl_link_register(&vrf_link_ops);
1452 if (rc < 0) {
1453 unregister_pernet_subsys(&vrf_net_ops);
1454 goto error;
1455 }
1456
1457 return 0;
1458
1459error:
1460 unregister_netdevice_notifier(&vrf_notifier_block);
1461 return rc;
1462}
1463
1464module_init(vrf_init_module);
1465MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
1466MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
1467MODULE_LICENSE("GPL");
1468MODULE_ALIAS_RTNL_LINK(DRV_NAME);
1469MODULE_VERSION(DRV_VERSION);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * vrf.c: device driver to encapsulate a VRF space
4 *
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 drivers
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/netdevice.h>
15#include <linux/etherdevice.h>
16#include <linux/ip.h>
17#include <linux/init.h>
18#include <linux/moduleparam.h>
19#include <linux/netfilter.h>
20#include <linux/rtnetlink.h>
21#include <net/rtnetlink.h>
22#include <linux/u64_stats_sync.h>
23#include <linux/hashtable.h>
24#include <linux/spinlock_types.h>
25
26#include <linux/inetdevice.h>
27#include <net/arp.h>
28#include <net/ip.h>
29#include <net/ip_fib.h>
30#include <net/ip6_fib.h>
31#include <net/ip6_route.h>
32#include <net/route.h>
33#include <net/addrconf.h>
34#include <net/l3mdev.h>
35#include <net/fib_rules.h>
36#include <net/netns/generic.h>
37
38#define DRV_NAME "vrf"
39#define DRV_VERSION "1.1"
40
41#define FIB_RULE_PREF 1000 /* default preference for FIB rules */
42
43#define HT_MAP_BITS 4
44#define HASH_INITVAL ((u32)0xcafef00d)
45
46struct vrf_map {
47 DECLARE_HASHTABLE(ht, HT_MAP_BITS);
48 spinlock_t vmap_lock;
49
50 /* shared_tables:
51 * count how many distinct tables do not comply with the strict mode
52 * requirement.
53 * shared_tables value must be 0 in order to enable the strict mode.
54 *
55 * example of the evolution of shared_tables:
56 * | time
57 * add vrf0 --> table 100 shared_tables = 0 | t0
58 * add vrf1 --> table 101 shared_tables = 0 | t1
59 * add vrf2 --> table 100 shared_tables = 1 | t2
60 * add vrf3 --> table 100 shared_tables = 1 | t3
61 * add vrf4 --> table 101 shared_tables = 2 v t4
62 *
63 * shared_tables is a "step function" (or "staircase function")
64 * and it is increased by one when the second vrf is associated to a
65 * table.
66 *
67 * at t2, vrf0 and vrf2 are bound to table 100: shared_tables = 1.
68 *
69 * at t3, another dev (vrf3) is bound to the same table 100 but the
70 * value of shared_tables is still 1.
71 * This means that no matter how many new vrfs will register on the
72 * table 100, the shared_tables will not increase (considering only
73 * table 100).
74 *
75 * at t4, vrf4 is bound to table 101, and shared_tables = 2.
76 *
77 * Looking at the value of shared_tables we can immediately know if
78 * the strict_mode can or cannot be enforced. Indeed, strict_mode
79 * can be enforced iff shared_tables = 0.
80 *
81 * Conversely, shared_tables is decreased when a vrf is de-associated
82 * from a table with exactly two associated vrfs.
83 */
84 u32 shared_tables;
85
86 bool strict_mode;
87};
88
89struct vrf_map_elem {
90 struct hlist_node hnode;
91 struct list_head vrf_list; /* VRFs registered to this table */
92
93 u32 table_id;
94 int users;
95 int ifindex;
96};
97
98static unsigned int vrf_net_id;
99
100/* per netns vrf data */
101struct netns_vrf {
102 /* protected by rtnl lock */
103 bool add_fib_rules;
104
105 struct vrf_map vmap;
106 struct ctl_table_header *ctl_hdr;
107};
108
109struct net_vrf {
110 struct rtable __rcu *rth;
111 struct rt6_info __rcu *rt6;
112#if IS_ENABLED(CONFIG_IPV6)
113 struct fib6_table *fib6_table;
114#endif
115 u32 tb_id;
116
117 struct list_head me_list; /* entry in vrf_map_elem */
118 int ifindex;
119};
120
121struct pcpu_dstats {
122 u64 tx_pkts;
123 u64 tx_bytes;
124 u64 tx_drps;
125 u64 rx_pkts;
126 u64 rx_bytes;
127 u64 rx_drps;
128 struct u64_stats_sync syncp;
129};
130
131static void vrf_rx_stats(struct net_device *dev, int len)
132{
133 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
134
135 u64_stats_update_begin(&dstats->syncp);
136 dstats->rx_pkts++;
137 dstats->rx_bytes += len;
138 u64_stats_update_end(&dstats->syncp);
139}
140
141static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
142{
143 vrf_dev->stats.tx_errors++;
144 kfree_skb(skb);
145}
146
147static void vrf_get_stats64(struct net_device *dev,
148 struct rtnl_link_stats64 *stats)
149{
150 int i;
151
152 for_each_possible_cpu(i) {
153 const struct pcpu_dstats *dstats;
154 u64 tbytes, tpkts, tdrops, rbytes, rpkts;
155 unsigned int start;
156
157 dstats = per_cpu_ptr(dev->dstats, i);
158 do {
159 start = u64_stats_fetch_begin_irq(&dstats->syncp);
160 tbytes = dstats->tx_bytes;
161 tpkts = dstats->tx_pkts;
162 tdrops = dstats->tx_drps;
163 rbytes = dstats->rx_bytes;
164 rpkts = dstats->rx_pkts;
165 } while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
166 stats->tx_bytes += tbytes;
167 stats->tx_packets += tpkts;
168 stats->tx_dropped += tdrops;
169 stats->rx_bytes += rbytes;
170 stats->rx_packets += rpkts;
171 }
172}
173
174static struct vrf_map *netns_vrf_map(struct net *net)
175{
176 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
177
178 return &nn_vrf->vmap;
179}
180
181static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev)
182{
183 return netns_vrf_map(dev_net(dev));
184}
185
186static int vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem *me)
187{
188 struct list_head *me_head = &me->vrf_list;
189 struct net_vrf *vrf;
190
191 if (list_empty(me_head))
192 return -ENODEV;
193
194 vrf = list_first_entry(me_head, struct net_vrf, me_list);
195
196 return vrf->ifindex;
197}
198
199static struct vrf_map_elem *vrf_map_elem_alloc(gfp_t flags)
200{
201 struct vrf_map_elem *me;
202
203 me = kmalloc(sizeof(*me), flags);
204 if (!me)
205 return NULL;
206
207 return me;
208}
209
210static void vrf_map_elem_free(struct vrf_map_elem *me)
211{
212 kfree(me);
213}
214
215static void vrf_map_elem_init(struct vrf_map_elem *me, int table_id,
216 int ifindex, int users)
217{
218 me->table_id = table_id;
219 me->ifindex = ifindex;
220 me->users = users;
221 INIT_LIST_HEAD(&me->vrf_list);
222}
223
224static struct vrf_map_elem *vrf_map_lookup_elem(struct vrf_map *vmap,
225 u32 table_id)
226{
227 struct vrf_map_elem *me;
228 u32 key;
229
230 key = jhash_1word(table_id, HASH_INITVAL);
231 hash_for_each_possible(vmap->ht, me, hnode, key) {
232 if (me->table_id == table_id)
233 return me;
234 }
235
236 return NULL;
237}
238
239static void vrf_map_add_elem(struct vrf_map *vmap, struct vrf_map_elem *me)
240{
241 u32 table_id = me->table_id;
242 u32 key;
243
244 key = jhash_1word(table_id, HASH_INITVAL);
245 hash_add(vmap->ht, &me->hnode, key);
246}
247
248static void vrf_map_del_elem(struct vrf_map_elem *me)
249{
250 hash_del(&me->hnode);
251}
252
253static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock)
254{
255 spin_lock(&vmap->vmap_lock);
256}
257
258static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock)
259{
260 spin_unlock(&vmap->vmap_lock);
261}
262
263/* called with rtnl lock held */
264static int
265vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack)
266{
267 struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
268 struct net_vrf *vrf = netdev_priv(dev);
269 struct vrf_map_elem *new_me, *me;
270 u32 table_id = vrf->tb_id;
271 bool free_new_me = false;
272 int users;
273 int res;
274
275 /* we pre-allocate elements used in the spin-locked section (so that we
276 * keep the spinlock as short as possibile).
277 */
278 new_me = vrf_map_elem_alloc(GFP_KERNEL);
279 if (!new_me)
280 return -ENOMEM;
281
282 vrf_map_elem_init(new_me, table_id, dev->ifindex, 0);
283
284 vrf_map_lock(vmap);
285
286 me = vrf_map_lookup_elem(vmap, table_id);
287 if (!me) {
288 me = new_me;
289 vrf_map_add_elem(vmap, me);
290 goto link_vrf;
291 }
292
293 /* we already have an entry in the vrf_map, so it means there is (at
294 * least) a vrf registered on the specific table.
295 */
296 free_new_me = true;
297 if (vmap->strict_mode) {
298 /* vrfs cannot share the same table */
299 NL_SET_ERR_MSG(extack, "Table is used by another VRF");
300 res = -EBUSY;
301 goto unlock;
302 }
303
304link_vrf:
305 users = ++me->users;
306 if (users == 2)
307 ++vmap->shared_tables;
308
309 list_add(&vrf->me_list, &me->vrf_list);
310
311 res = 0;
312
313unlock:
314 vrf_map_unlock(vmap);
315
316 /* clean-up, if needed */
317 if (free_new_me)
318 vrf_map_elem_free(new_me);
319
320 return res;
321}
322
323/* called with rtnl lock held */
324static void vrf_map_unregister_dev(struct net_device *dev)
325{
326 struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
327 struct net_vrf *vrf = netdev_priv(dev);
328 u32 table_id = vrf->tb_id;
329 struct vrf_map_elem *me;
330 int users;
331
332 vrf_map_lock(vmap);
333
334 me = vrf_map_lookup_elem(vmap, table_id);
335 if (!me)
336 goto unlock;
337
338 list_del(&vrf->me_list);
339
340 users = --me->users;
341 if (users == 1) {
342 --vmap->shared_tables;
343 } else if (users == 0) {
344 vrf_map_del_elem(me);
345
346 /* no one will refer to this element anymore */
347 vrf_map_elem_free(me);
348 }
349
350unlock:
351 vrf_map_unlock(vmap);
352}
353
354/* return the vrf device index associated with the table_id */
355static int vrf_ifindex_lookup_by_table_id(struct net *net, u32 table_id)
356{
357 struct vrf_map *vmap = netns_vrf_map(net);
358 struct vrf_map_elem *me;
359 int ifindex;
360
361 vrf_map_lock(vmap);
362
363 if (!vmap->strict_mode) {
364 ifindex = -EPERM;
365 goto unlock;
366 }
367
368 me = vrf_map_lookup_elem(vmap, table_id);
369 if (!me) {
370 ifindex = -ENODEV;
371 goto unlock;
372 }
373
374 ifindex = vrf_map_elem_get_vrf_ifindex(me);
375
376unlock:
377 vrf_map_unlock(vmap);
378
379 return ifindex;
380}
381
382/* by default VRF devices do not have a qdisc and are expected
383 * to be created with only a single queue.
384 */
385static bool qdisc_tx_is_default(const struct net_device *dev)
386{
387 struct netdev_queue *txq;
388 struct Qdisc *qdisc;
389
390 if (dev->num_tx_queues > 1)
391 return false;
392
393 txq = netdev_get_tx_queue(dev, 0);
394 qdisc = rcu_access_pointer(txq->qdisc);
395
396 return !qdisc->enqueue;
397}
398
399/* Local traffic destined to local address. Reinsert the packet to rx
400 * path, similar to loopback handling.
401 */
402static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
403 struct dst_entry *dst)
404{
405 int len = skb->len;
406
407 skb_orphan(skb);
408
409 skb_dst_set(skb, dst);
410
411 /* set pkt_type to avoid skb hitting packet taps twice -
412 * once on Tx and again in Rx processing
413 */
414 skb->pkt_type = PACKET_LOOPBACK;
415
416 skb->protocol = eth_type_trans(skb, dev);
417
418 if (likely(netif_rx(skb) == NET_RX_SUCCESS))
419 vrf_rx_stats(dev, len);
420 else
421 this_cpu_inc(dev->dstats->rx_drps);
422
423 return NETDEV_TX_OK;
424}
425
426#if IS_ENABLED(CONFIG_IPV6)
427static int vrf_ip6_local_out(struct net *net, struct sock *sk,
428 struct sk_buff *skb)
429{
430 int err;
431
432 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net,
433 sk, skb, NULL, skb_dst(skb)->dev, dst_output);
434
435 if (likely(err == 1))
436 err = dst_output(net, sk, skb);
437
438 return err;
439}
440
441static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
442 struct net_device *dev)
443{
444 const struct ipv6hdr *iph;
445 struct net *net = dev_net(skb->dev);
446 struct flowi6 fl6;
447 int ret = NET_XMIT_DROP;
448 struct dst_entry *dst;
449 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
450
451 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
452 goto err;
453
454 iph = ipv6_hdr(skb);
455
456 memset(&fl6, 0, sizeof(fl6));
457 /* needed to match OIF rule */
458 fl6.flowi6_oif = dev->ifindex;
459 fl6.flowi6_iif = LOOPBACK_IFINDEX;
460 fl6.daddr = iph->daddr;
461 fl6.saddr = iph->saddr;
462 fl6.flowlabel = ip6_flowinfo(iph);
463 fl6.flowi6_mark = skb->mark;
464 fl6.flowi6_proto = iph->nexthdr;
465 fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF;
466
467 dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL);
468 if (IS_ERR(dst) || dst == dst_null)
469 goto err;
470
471 skb_dst_drop(skb);
472
473 /* if dst.dev is loopback or the VRF device again this is locally
474 * originated traffic destined to a local address. Short circuit
475 * to Rx path
476 */
477 if (dst->dev == dev)
478 return vrf_local_xmit(skb, dev, dst);
479
480 skb_dst_set(skb, dst);
481
482 /* strip the ethernet header added for pass through VRF device */
483 __skb_pull(skb, skb_network_offset(skb));
484
485 ret = vrf_ip6_local_out(net, skb->sk, skb);
486 if (unlikely(net_xmit_eval(ret)))
487 dev->stats.tx_errors++;
488 else
489 ret = NET_XMIT_SUCCESS;
490
491 return ret;
492err:
493 vrf_tx_error(dev, skb);
494 return NET_XMIT_DROP;
495}
496#else
497static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
498 struct net_device *dev)
499{
500 vrf_tx_error(dev, skb);
501 return NET_XMIT_DROP;
502}
503#endif
504
505/* based on ip_local_out; can't use it b/c the dst is switched pointing to us */
506static int vrf_ip_local_out(struct net *net, struct sock *sk,
507 struct sk_buff *skb)
508{
509 int err;
510
511 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
512 skb, NULL, skb_dst(skb)->dev, dst_output);
513 if (likely(err == 1))
514 err = dst_output(net, sk, skb);
515
516 return err;
517}
518
519static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
520 struct net_device *vrf_dev)
521{
522 struct iphdr *ip4h;
523 int ret = NET_XMIT_DROP;
524 struct flowi4 fl4;
525 struct net *net = dev_net(vrf_dev);
526 struct rtable *rt;
527
528 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
529 goto err;
530
531 ip4h = ip_hdr(skb);
532
533 memset(&fl4, 0, sizeof(fl4));
534 /* needed to match OIF rule */
535 fl4.flowi4_oif = vrf_dev->ifindex;
536 fl4.flowi4_iif = LOOPBACK_IFINDEX;
537 fl4.flowi4_tos = RT_TOS(ip4h->tos);
538 fl4.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF;
539 fl4.flowi4_proto = ip4h->protocol;
540 fl4.daddr = ip4h->daddr;
541 fl4.saddr = ip4h->saddr;
542
543 rt = ip_route_output_flow(net, &fl4, NULL);
544 if (IS_ERR(rt))
545 goto err;
546
547 skb_dst_drop(skb);
548
549 /* if dst.dev is loopback or the VRF device again this is locally
550 * originated traffic destined to a local address. Short circuit
551 * to Rx path
552 */
553 if (rt->dst.dev == vrf_dev)
554 return vrf_local_xmit(skb, vrf_dev, &rt->dst);
555
556 skb_dst_set(skb, &rt->dst);
557
558 /* strip the ethernet header added for pass through VRF device */
559 __skb_pull(skb, skb_network_offset(skb));
560
561 if (!ip4h->saddr) {
562 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
563 RT_SCOPE_LINK);
564 }
565
566 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
567 if (unlikely(net_xmit_eval(ret)))
568 vrf_dev->stats.tx_errors++;
569 else
570 ret = NET_XMIT_SUCCESS;
571
572out:
573 return ret;
574err:
575 vrf_tx_error(vrf_dev, skb);
576 goto out;
577}
578
579static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
580{
581 switch (skb->protocol) {
582 case htons(ETH_P_IP):
583 return vrf_process_v4_outbound(skb, dev);
584 case htons(ETH_P_IPV6):
585 return vrf_process_v6_outbound(skb, dev);
586 default:
587 vrf_tx_error(dev, skb);
588 return NET_XMIT_DROP;
589 }
590}
591
592static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
593{
594 int len = skb->len;
595 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
596
597 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
598 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
599
600 u64_stats_update_begin(&dstats->syncp);
601 dstats->tx_pkts++;
602 dstats->tx_bytes += len;
603 u64_stats_update_end(&dstats->syncp);
604 } else {
605 this_cpu_inc(dev->dstats->tx_drps);
606 }
607
608 return ret;
609}
610
611static int vrf_finish_direct(struct net *net, struct sock *sk,
612 struct sk_buff *skb)
613{
614 struct net_device *vrf_dev = skb->dev;
615
616 if (!list_empty(&vrf_dev->ptype_all) &&
617 likely(skb_headroom(skb) >= ETH_HLEN)) {
618 struct ethhdr *eth = skb_push(skb, ETH_HLEN);
619
620 ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
621 eth_zero_addr(eth->h_dest);
622 eth->h_proto = skb->protocol;
623
624 rcu_read_lock_bh();
625 dev_queue_xmit_nit(skb, vrf_dev);
626 rcu_read_unlock_bh();
627
628 skb_pull(skb, ETH_HLEN);
629 }
630
631 return 1;
632}
633
634#if IS_ENABLED(CONFIG_IPV6)
635/* modelled after ip6_finish_output2 */
636static int vrf_finish_output6(struct net *net, struct sock *sk,
637 struct sk_buff *skb)
638{
639 struct dst_entry *dst = skb_dst(skb);
640 struct net_device *dev = dst->dev;
641 const struct in6_addr *nexthop;
642 struct neighbour *neigh;
643 int ret;
644
645 nf_reset_ct(skb);
646
647 skb->protocol = htons(ETH_P_IPV6);
648 skb->dev = dev;
649
650 rcu_read_lock_bh();
651 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
652 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
653 if (unlikely(!neigh))
654 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
655 if (!IS_ERR(neigh)) {
656 sock_confirm_neigh(skb, neigh);
657 ret = neigh_output(neigh, skb, false);
658 rcu_read_unlock_bh();
659 return ret;
660 }
661 rcu_read_unlock_bh();
662
663 IP6_INC_STATS(dev_net(dst->dev),
664 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
665 kfree_skb(skb);
666 return -EINVAL;
667}
668
669/* modelled after ip6_output */
670static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
671{
672 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
673 net, sk, skb, NULL, skb_dst(skb)->dev,
674 vrf_finish_output6,
675 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
676}
677
678/* set dst on skb to send packet to us via dev_xmit path. Allows
679 * packet to go through device based features such as qdisc, netfilter
680 * hooks and packet sockets with skb->dev set to vrf device.
681 */
682static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev,
683 struct sk_buff *skb)
684{
685 struct net_vrf *vrf = netdev_priv(vrf_dev);
686 struct dst_entry *dst = NULL;
687 struct rt6_info *rt6;
688
689 rcu_read_lock();
690
691 rt6 = rcu_dereference(vrf->rt6);
692 if (likely(rt6)) {
693 dst = &rt6->dst;
694 dst_hold(dst);
695 }
696
697 rcu_read_unlock();
698
699 if (unlikely(!dst)) {
700 vrf_tx_error(vrf_dev, skb);
701 return NULL;
702 }
703
704 skb_dst_drop(skb);
705 skb_dst_set(skb, dst);
706
707 return skb;
708}
709
710static int vrf_output6_direct(struct net *net, struct sock *sk,
711 struct sk_buff *skb)
712{
713 skb->protocol = htons(ETH_P_IPV6);
714
715 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
716 net, sk, skb, NULL, skb->dev,
717 vrf_finish_direct,
718 !(IPCB(skb)->flags & IPSKB_REROUTED));
719}
720
721static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
722 struct sock *sk,
723 struct sk_buff *skb)
724{
725 struct net *net = dev_net(vrf_dev);
726 int err;
727
728 skb->dev = vrf_dev;
729
730 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk,
731 skb, NULL, vrf_dev, vrf_output6_direct);
732
733 if (likely(err == 1))
734 err = vrf_output6_direct(net, sk, skb);
735
736 /* reset skb device */
737 if (likely(err == 1))
738 nf_reset_ct(skb);
739 else
740 skb = NULL;
741
742 return skb;
743}
744
745static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
746 struct sock *sk,
747 struct sk_buff *skb)
748{
749 /* don't divert link scope packets */
750 if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
751 return skb;
752
753 if (qdisc_tx_is_default(vrf_dev) ||
754 IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
755 return vrf_ip6_out_direct(vrf_dev, sk, skb);
756
757 return vrf_ip6_out_redirect(vrf_dev, skb);
758}
759
760/* holding rtnl */
761static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
762{
763 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
764 struct net *net = dev_net(dev);
765 struct dst_entry *dst;
766
767 RCU_INIT_POINTER(vrf->rt6, NULL);
768 synchronize_rcu();
769
770 /* move dev in dst's to loopback so this VRF device can be deleted
771 * - based on dst_ifdown
772 */
773 if (rt6) {
774 dst = &rt6->dst;
775 dev_put(dst->dev);
776 dst->dev = net->loopback_dev;
777 dev_hold(dst->dev);
778 dst_release(dst);
779 }
780}
781
782static int vrf_rt6_create(struct net_device *dev)
783{
784 int flags = DST_NOPOLICY | DST_NOXFRM;
785 struct net_vrf *vrf = netdev_priv(dev);
786 struct net *net = dev_net(dev);
787 struct rt6_info *rt6;
788 int rc = -ENOMEM;
789
790 /* IPv6 can be CONFIG enabled and then disabled runtime */
791 if (!ipv6_mod_enabled())
792 return 0;
793
794 vrf->fib6_table = fib6_new_table(net, vrf->tb_id);
795 if (!vrf->fib6_table)
796 goto out;
797
798 /* create a dst for routing packets out a VRF device */
799 rt6 = ip6_dst_alloc(net, dev, flags);
800 if (!rt6)
801 goto out;
802
803 rt6->dst.output = vrf_output6;
804
805 rcu_assign_pointer(vrf->rt6, rt6);
806
807 rc = 0;
808out:
809 return rc;
810}
811#else
812static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
813 struct sock *sk,
814 struct sk_buff *skb)
815{
816 return skb;
817}
818
819static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
820{
821}
822
823static int vrf_rt6_create(struct net_device *dev)
824{
825 return 0;
826}
827#endif
828
829/* modelled after ip_finish_output2 */
830static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
831{
832 struct dst_entry *dst = skb_dst(skb);
833 struct rtable *rt = (struct rtable *)dst;
834 struct net_device *dev = dst->dev;
835 unsigned int hh_len = LL_RESERVED_SPACE(dev);
836 struct neighbour *neigh;
837 bool is_v6gw = false;
838 int ret = -EINVAL;
839
840 nf_reset_ct(skb);
841
842 /* Be paranoid, rather than too clever. */
843 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
844 struct sk_buff *skb2;
845
846 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
847 if (!skb2) {
848 ret = -ENOMEM;
849 goto err;
850 }
851 if (skb->sk)
852 skb_set_owner_w(skb2, skb->sk);
853
854 consume_skb(skb);
855 skb = skb2;
856 }
857
858 rcu_read_lock_bh();
859
860 neigh = ip_neigh_for_gw(rt, skb, &is_v6gw);
861 if (!IS_ERR(neigh)) {
862 sock_confirm_neigh(skb, neigh);
863 /* if crossing protocols, can not use the cached header */
864 ret = neigh_output(neigh, skb, is_v6gw);
865 rcu_read_unlock_bh();
866 return ret;
867 }
868
869 rcu_read_unlock_bh();
870err:
871 vrf_tx_error(skb->dev, skb);
872 return ret;
873}
874
875static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
876{
877 struct net_device *dev = skb_dst(skb)->dev;
878
879 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
880
881 skb->dev = dev;
882 skb->protocol = htons(ETH_P_IP);
883
884 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
885 net, sk, skb, NULL, dev,
886 vrf_finish_output,
887 !(IPCB(skb)->flags & IPSKB_REROUTED));
888}
889
890/* set dst on skb to send packet to us via dev_xmit path. Allows
891 * packet to go through device based features such as qdisc, netfilter
892 * hooks and packet sockets with skb->dev set to vrf device.
893 */
894static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev,
895 struct sk_buff *skb)
896{
897 struct net_vrf *vrf = netdev_priv(vrf_dev);
898 struct dst_entry *dst = NULL;
899 struct rtable *rth;
900
901 rcu_read_lock();
902
903 rth = rcu_dereference(vrf->rth);
904 if (likely(rth)) {
905 dst = &rth->dst;
906 dst_hold(dst);
907 }
908
909 rcu_read_unlock();
910
911 if (unlikely(!dst)) {
912 vrf_tx_error(vrf_dev, skb);
913 return NULL;
914 }
915
916 skb_dst_drop(skb);
917 skb_dst_set(skb, dst);
918
919 return skb;
920}
921
922static int vrf_output_direct(struct net *net, struct sock *sk,
923 struct sk_buff *skb)
924{
925 skb->protocol = htons(ETH_P_IP);
926
927 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
928 net, sk, skb, NULL, skb->dev,
929 vrf_finish_direct,
930 !(IPCB(skb)->flags & IPSKB_REROUTED));
931}
932
933static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
934 struct sock *sk,
935 struct sk_buff *skb)
936{
937 struct net *net = dev_net(vrf_dev);
938 int err;
939
940 skb->dev = vrf_dev;
941
942 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
943 skb, NULL, vrf_dev, vrf_output_direct);
944
945 if (likely(err == 1))
946 err = vrf_output_direct(net, sk, skb);
947
948 /* reset skb device */
949 if (likely(err == 1))
950 nf_reset_ct(skb);
951 else
952 skb = NULL;
953
954 return skb;
955}
956
957static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
958 struct sock *sk,
959 struct sk_buff *skb)
960{
961 /* don't divert multicast or local broadcast */
962 if (ipv4_is_multicast(ip_hdr(skb)->daddr) ||
963 ipv4_is_lbcast(ip_hdr(skb)->daddr))
964 return skb;
965
966 if (qdisc_tx_is_default(vrf_dev) ||
967 IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
968 return vrf_ip_out_direct(vrf_dev, sk, skb);
969
970 return vrf_ip_out_redirect(vrf_dev, skb);
971}
972
973/* called with rcu lock held */
974static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
975 struct sock *sk,
976 struct sk_buff *skb,
977 u16 proto)
978{
979 switch (proto) {
980 case AF_INET:
981 return vrf_ip_out(vrf_dev, sk, skb);
982 case AF_INET6:
983 return vrf_ip6_out(vrf_dev, sk, skb);
984 }
985
986 return skb;
987}
988
989/* holding rtnl */
990static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
991{
992 struct rtable *rth = rtnl_dereference(vrf->rth);
993 struct net *net = dev_net(dev);
994 struct dst_entry *dst;
995
996 RCU_INIT_POINTER(vrf->rth, NULL);
997 synchronize_rcu();
998
999 /* move dev in dst's to loopback so this VRF device can be deleted
1000 * - based on dst_ifdown
1001 */
1002 if (rth) {
1003 dst = &rth->dst;
1004 dev_put(dst->dev);
1005 dst->dev = net->loopback_dev;
1006 dev_hold(dst->dev);
1007 dst_release(dst);
1008 }
1009}
1010
1011static int vrf_rtable_create(struct net_device *dev)
1012{
1013 struct net_vrf *vrf = netdev_priv(dev);
1014 struct rtable *rth;
1015
1016 if (!fib_new_table(dev_net(dev), vrf->tb_id))
1017 return -ENOMEM;
1018
1019 /* create a dst for routing packets out through a VRF device */
1020 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1);
1021 if (!rth)
1022 return -ENOMEM;
1023
1024 rth->dst.output = vrf_output;
1025
1026 rcu_assign_pointer(vrf->rth, rth);
1027
1028 return 0;
1029}
1030
1031/**************************** device handling ********************/
1032
1033/* cycle interface to flush neighbor cache and move routes across tables */
1034static void cycle_netdev(struct net_device *dev,
1035 struct netlink_ext_ack *extack)
1036{
1037 unsigned int flags = dev->flags;
1038 int ret;
1039
1040 if (!netif_running(dev))
1041 return;
1042
1043 ret = dev_change_flags(dev, flags & ~IFF_UP, extack);
1044 if (ret >= 0)
1045 ret = dev_change_flags(dev, flags, extack);
1046
1047 if (ret < 0) {
1048 netdev_err(dev,
1049 "Failed to cycle device %s; route tables might be wrong!\n",
1050 dev->name);
1051 }
1052}
1053
1054static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1055 struct netlink_ext_ack *extack)
1056{
1057 int ret;
1058
1059 /* do not allow loopback device to be enslaved to a VRF.
1060 * The vrf device acts as the loopback for the vrf.
1061 */
1062 if (port_dev == dev_net(dev)->loopback_dev) {
1063 NL_SET_ERR_MSG(extack,
1064 "Can not enslave loopback device to a VRF");
1065 return -EOPNOTSUPP;
1066 }
1067
1068 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
1069 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack);
1070 if (ret < 0)
1071 goto err;
1072
1073 cycle_netdev(port_dev, extack);
1074
1075 return 0;
1076
1077err:
1078 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1079 return ret;
1080}
1081
1082static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1083 struct netlink_ext_ack *extack)
1084{
1085 if (netif_is_l3_master(port_dev)) {
1086 NL_SET_ERR_MSG(extack,
1087 "Can not enslave an L3 master device to a VRF");
1088 return -EINVAL;
1089 }
1090
1091 if (netif_is_l3_slave(port_dev))
1092 return -EINVAL;
1093
1094 return do_vrf_add_slave(dev, port_dev, extack);
1095}
1096
1097/* inverse of do_vrf_add_slave */
1098static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1099{
1100 netdev_upper_dev_unlink(port_dev, dev);
1101 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1102
1103 cycle_netdev(port_dev, NULL);
1104
1105 return 0;
1106}
1107
1108static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1109{
1110 return do_vrf_del_slave(dev, port_dev);
1111}
1112
1113static void vrf_dev_uninit(struct net_device *dev)
1114{
1115 struct net_vrf *vrf = netdev_priv(dev);
1116
1117 vrf_rtable_release(dev, vrf);
1118 vrf_rt6_release(dev, vrf);
1119
1120 free_percpu(dev->dstats);
1121 dev->dstats = NULL;
1122}
1123
1124static int vrf_dev_init(struct net_device *dev)
1125{
1126 struct net_vrf *vrf = netdev_priv(dev);
1127
1128 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
1129 if (!dev->dstats)
1130 goto out_nomem;
1131
1132 /* create the default dst which points back to us */
1133 if (vrf_rtable_create(dev) != 0)
1134 goto out_stats;
1135
1136 if (vrf_rt6_create(dev) != 0)
1137 goto out_rth;
1138
1139 dev->flags = IFF_MASTER | IFF_NOARP;
1140
1141 /* MTU is irrelevant for VRF device; set to 64k similar to lo */
1142 dev->mtu = 64 * 1024;
1143
1144 /* similarly, oper state is irrelevant; set to up to avoid confusion */
1145 dev->operstate = IF_OPER_UP;
1146 netdev_lockdep_set_classes(dev);
1147 return 0;
1148
1149out_rth:
1150 vrf_rtable_release(dev, vrf);
1151out_stats:
1152 free_percpu(dev->dstats);
1153 dev->dstats = NULL;
1154out_nomem:
1155 return -ENOMEM;
1156}
1157
1158static const struct net_device_ops vrf_netdev_ops = {
1159 .ndo_init = vrf_dev_init,
1160 .ndo_uninit = vrf_dev_uninit,
1161 .ndo_start_xmit = vrf_xmit,
1162 .ndo_set_mac_address = eth_mac_addr,
1163 .ndo_get_stats64 = vrf_get_stats64,
1164 .ndo_add_slave = vrf_add_slave,
1165 .ndo_del_slave = vrf_del_slave,
1166};
1167
1168static u32 vrf_fib_table(const struct net_device *dev)
1169{
1170 struct net_vrf *vrf = netdev_priv(dev);
1171
1172 return vrf->tb_id;
1173}
1174
1175static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
1176{
1177 kfree_skb(skb);
1178 return 0;
1179}
1180
1181static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
1182 struct sk_buff *skb,
1183 struct net_device *dev)
1184{
1185 struct net *net = dev_net(dev);
1186
1187 if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1)
1188 skb = NULL; /* kfree_skb(skb) handled by nf code */
1189
1190 return skb;
1191}
1192
1193#if IS_ENABLED(CONFIG_IPV6)
1194/* neighbor handling is done with actual device; do not want
1195 * to flip skb->dev for those ndisc packets. This really fails
1196 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
1197 * a start.
1198 */
1199static bool ipv6_ndisc_frame(const struct sk_buff *skb)
1200{
1201 const struct ipv6hdr *iph = ipv6_hdr(skb);
1202 bool rc = false;
1203
1204 if (iph->nexthdr == NEXTHDR_ICMP) {
1205 const struct icmp6hdr *icmph;
1206 struct icmp6hdr _icmph;
1207
1208 icmph = skb_header_pointer(skb, sizeof(*iph),
1209 sizeof(_icmph), &_icmph);
1210 if (!icmph)
1211 goto out;
1212
1213 switch (icmph->icmp6_type) {
1214 case NDISC_ROUTER_SOLICITATION:
1215 case NDISC_ROUTER_ADVERTISEMENT:
1216 case NDISC_NEIGHBOUR_SOLICITATION:
1217 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1218 case NDISC_REDIRECT:
1219 rc = true;
1220 break;
1221 }
1222 }
1223
1224out:
1225 return rc;
1226}
1227
1228static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
1229 const struct net_device *dev,
1230 struct flowi6 *fl6,
1231 int ifindex,
1232 const struct sk_buff *skb,
1233 int flags)
1234{
1235 struct net_vrf *vrf = netdev_priv(dev);
1236
1237 return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags);
1238}
1239
1240static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
1241 int ifindex)
1242{
1243 const struct ipv6hdr *iph = ipv6_hdr(skb);
1244 struct flowi6 fl6 = {
1245 .flowi6_iif = ifindex,
1246 .flowi6_mark = skb->mark,
1247 .flowi6_proto = iph->nexthdr,
1248 .daddr = iph->daddr,
1249 .saddr = iph->saddr,
1250 .flowlabel = ip6_flowinfo(iph),
1251 };
1252 struct net *net = dev_net(vrf_dev);
1253 struct rt6_info *rt6;
1254
1255 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb,
1256 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
1257 if (unlikely(!rt6))
1258 return;
1259
1260 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
1261 return;
1262
1263 skb_dst_set(skb, &rt6->dst);
1264}
1265
1266static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1267 struct sk_buff *skb)
1268{
1269 int orig_iif = skb->skb_iif;
1270 bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
1271 bool is_ndisc = ipv6_ndisc_frame(skb);
1272
1273 /* loopback, multicast & non-ND link-local traffic; do not push through
1274 * packet taps again. Reset pkt_type for upper layers to process skb
1275 */
1276 if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) {
1277 skb->dev = vrf_dev;
1278 skb->skb_iif = vrf_dev->ifindex;
1279 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1280 if (skb->pkt_type == PACKET_LOOPBACK)
1281 skb->pkt_type = PACKET_HOST;
1282 goto out;
1283 }
1284
1285 /* if packet is NDISC then keep the ingress interface */
1286 if (!is_ndisc) {
1287 vrf_rx_stats(vrf_dev, skb->len);
1288 skb->dev = vrf_dev;
1289 skb->skb_iif = vrf_dev->ifindex;
1290
1291 if (!list_empty(&vrf_dev->ptype_all)) {
1292 skb_push(skb, skb->mac_len);
1293 dev_queue_xmit_nit(skb, vrf_dev);
1294 skb_pull(skb, skb->mac_len);
1295 }
1296
1297 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1298 }
1299
1300 if (need_strict)
1301 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1302
1303 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
1304out:
1305 return skb;
1306}
1307
1308#else
1309static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1310 struct sk_buff *skb)
1311{
1312 return skb;
1313}
1314#endif
1315
1316static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
1317 struct sk_buff *skb)
1318{
1319 skb->dev = vrf_dev;
1320 skb->skb_iif = vrf_dev->ifindex;
1321 IPCB(skb)->flags |= IPSKB_L3SLAVE;
1322
1323 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
1324 goto out;
1325
1326 /* loopback traffic; do not push through packet taps again.
1327 * Reset pkt_type for upper layers to process skb
1328 */
1329 if (skb->pkt_type == PACKET_LOOPBACK) {
1330 skb->pkt_type = PACKET_HOST;
1331 goto out;
1332 }
1333
1334 vrf_rx_stats(vrf_dev, skb->len);
1335
1336 if (!list_empty(&vrf_dev->ptype_all)) {
1337 skb_push(skb, skb->mac_len);
1338 dev_queue_xmit_nit(skb, vrf_dev);
1339 skb_pull(skb, skb->mac_len);
1340 }
1341
1342 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
1343out:
1344 return skb;
1345}
1346
1347/* called with rcu lock held */
1348static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1349 struct sk_buff *skb,
1350 u16 proto)
1351{
1352 switch (proto) {
1353 case AF_INET:
1354 return vrf_ip_rcv(vrf_dev, skb);
1355 case AF_INET6:
1356 return vrf_ip6_rcv(vrf_dev, skb);
1357 }
1358
1359 return skb;
1360}
1361
1362#if IS_ENABLED(CONFIG_IPV6)
1363/* send to link-local or multicast address via interface enslaved to
1364 * VRF device. Force lookup to VRF table without changing flow struct
1365 * Note: Caller to this function must hold rcu_read_lock() and no refcnt
1366 * is taken on the dst by this function.
1367 */
1368static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1369 struct flowi6 *fl6)
1370{
1371 struct net *net = dev_net(dev);
1372 int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF;
1373 struct dst_entry *dst = NULL;
1374 struct rt6_info *rt;
1375
1376 /* VRF device does not have a link-local address and
1377 * sending packets to link-local or mcast addresses over
1378 * a VRF device does not make sense
1379 */
1380 if (fl6->flowi6_oif == dev->ifindex) {
1381 dst = &net->ipv6.ip6_null_entry->dst;
1382 return dst;
1383 }
1384
1385 if (!ipv6_addr_any(&fl6->saddr))
1386 flags |= RT6_LOOKUP_F_HAS_SADDR;
1387
1388 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags);
1389 if (rt)
1390 dst = &rt->dst;
1391
1392 return dst;
1393}
1394#endif
1395
1396static const struct l3mdev_ops vrf_l3mdev_ops = {
1397 .l3mdev_fib_table = vrf_fib_table,
1398 .l3mdev_l3_rcv = vrf_l3_rcv,
1399 .l3mdev_l3_out = vrf_l3_out,
1400#if IS_ENABLED(CONFIG_IPV6)
1401 .l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1402#endif
1403};
1404
1405static void vrf_get_drvinfo(struct net_device *dev,
1406 struct ethtool_drvinfo *info)
1407{
1408 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
1409 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
1410}
1411
1412static const struct ethtool_ops vrf_ethtool_ops = {
1413 .get_drvinfo = vrf_get_drvinfo,
1414};
1415
1416static inline size_t vrf_fib_rule_nl_size(void)
1417{
1418 size_t sz;
1419
1420 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1421 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */
1422 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */
1423 sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */
1424
1425 return sz;
1426}
1427
1428static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1429{
1430 struct fib_rule_hdr *frh;
1431 struct nlmsghdr *nlh;
1432 struct sk_buff *skb;
1433 int err;
1434
1435 if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) &&
1436 !ipv6_mod_enabled())
1437 return 0;
1438
1439 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
1440 if (!skb)
1441 return -ENOMEM;
1442
1443 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
1444 if (!nlh)
1445 goto nla_put_failure;
1446
1447 /* rule only needs to appear once */
1448 nlh->nlmsg_flags |= NLM_F_EXCL;
1449
1450 frh = nlmsg_data(nlh);
1451 memset(frh, 0, sizeof(*frh));
1452 frh->family = family;
1453 frh->action = FR_ACT_TO_TBL;
1454
1455 if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL))
1456 goto nla_put_failure;
1457
1458 if (nla_put_u8(skb, FRA_L3MDEV, 1))
1459 goto nla_put_failure;
1460
1461 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
1462 goto nla_put_failure;
1463
1464 nlmsg_end(skb, nlh);
1465
1466 /* fib_nl_{new,del}rule handling looks for net from skb->sk */
1467 skb->sk = dev_net(dev)->rtnl;
1468 if (add_it) {
1469 err = fib_nl_newrule(skb, nlh, NULL);
1470 if (err == -EEXIST)
1471 err = 0;
1472 } else {
1473 err = fib_nl_delrule(skb, nlh, NULL);
1474 if (err == -ENOENT)
1475 err = 0;
1476 }
1477 nlmsg_free(skb);
1478
1479 return err;
1480
1481nla_put_failure:
1482 nlmsg_free(skb);
1483
1484 return -EMSGSIZE;
1485}
1486
1487static int vrf_add_fib_rules(const struct net_device *dev)
1488{
1489 int err;
1490
1491 err = vrf_fib_rule(dev, AF_INET, true);
1492 if (err < 0)
1493 goto out_err;
1494
1495 err = vrf_fib_rule(dev, AF_INET6, true);
1496 if (err < 0)
1497 goto ipv6_err;
1498
1499#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1500 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true);
1501 if (err < 0)
1502 goto ipmr_err;
1503#endif
1504
1505#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1506 err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, true);
1507 if (err < 0)
1508 goto ip6mr_err;
1509#endif
1510
1511 return 0;
1512
1513#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1514ip6mr_err:
1515 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, false);
1516#endif
1517
1518#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1519ipmr_err:
1520 vrf_fib_rule(dev, AF_INET6, false);
1521#endif
1522
1523ipv6_err:
1524 vrf_fib_rule(dev, AF_INET, false);
1525
1526out_err:
1527 netdev_err(dev, "Failed to add FIB rules.\n");
1528 return err;
1529}
1530
1531static void vrf_setup(struct net_device *dev)
1532{
1533 ether_setup(dev);
1534
1535 /* Initialize the device structure. */
1536 dev->netdev_ops = &vrf_netdev_ops;
1537 dev->l3mdev_ops = &vrf_l3mdev_ops;
1538 dev->ethtool_ops = &vrf_ethtool_ops;
1539 dev->needs_free_netdev = true;
1540
1541 /* Fill in device structure with ethernet-generic values. */
1542 eth_hw_addr_random(dev);
1543
1544 /* don't acquire vrf device's netif_tx_lock when transmitting */
1545 dev->features |= NETIF_F_LLTX;
1546
1547 /* don't allow vrf devices to change network namespaces. */
1548 dev->features |= NETIF_F_NETNS_LOCAL;
1549
1550 /* does not make sense for a VLAN to be added to a vrf device */
1551 dev->features |= NETIF_F_VLAN_CHALLENGED;
1552
1553 /* enable offload features */
1554 dev->features |= NETIF_F_GSO_SOFTWARE;
1555 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC;
1556 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1557
1558 dev->hw_features = dev->features;
1559 dev->hw_enc_features = dev->features;
1560
1561 /* default to no qdisc; user can add if desired */
1562 dev->priv_flags |= IFF_NO_QUEUE;
1563 dev->priv_flags |= IFF_NO_RX_HANDLER;
1564 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1565
1566 /* VRF devices do not care about MTU, but if the MTU is set
1567 * too low then the ipv4 and ipv6 protocols are disabled
1568 * which breaks networking.
1569 */
1570 dev->min_mtu = IPV6_MIN_MTU;
1571 dev->max_mtu = ETH_MAX_MTU;
1572}
1573
1574static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],
1575 struct netlink_ext_ack *extack)
1576{
1577 if (tb[IFLA_ADDRESS]) {
1578 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
1579 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1580 return -EINVAL;
1581 }
1582 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
1583 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1584 return -EADDRNOTAVAIL;
1585 }
1586 }
1587 return 0;
1588}
1589
1590static void vrf_dellink(struct net_device *dev, struct list_head *head)
1591{
1592 struct net_device *port_dev;
1593 struct list_head *iter;
1594
1595 netdev_for_each_lower_dev(dev, port_dev, iter)
1596 vrf_del_slave(dev, port_dev);
1597
1598 vrf_map_unregister_dev(dev);
1599
1600 unregister_netdevice_queue(dev, head);
1601}
1602
1603static int vrf_newlink(struct net *src_net, struct net_device *dev,
1604 struct nlattr *tb[], struct nlattr *data[],
1605 struct netlink_ext_ack *extack)
1606{
1607 struct net_vrf *vrf = netdev_priv(dev);
1608 struct netns_vrf *nn_vrf;
1609 bool *add_fib_rules;
1610 struct net *net;
1611 int err;
1612
1613 if (!data || !data[IFLA_VRF_TABLE]) {
1614 NL_SET_ERR_MSG(extack, "VRF table id is missing");
1615 return -EINVAL;
1616 }
1617
1618 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
1619 if (vrf->tb_id == RT_TABLE_UNSPEC) {
1620 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE],
1621 "Invalid VRF table id");
1622 return -EINVAL;
1623 }
1624
1625 dev->priv_flags |= IFF_L3MDEV_MASTER;
1626
1627 err = register_netdevice(dev);
1628 if (err)
1629 goto out;
1630
1631 /* mapping between table_id and vrf;
1632 * note: such binding could not be done in the dev init function
1633 * because dev->ifindex id is not available yet.
1634 */
1635 vrf->ifindex = dev->ifindex;
1636
1637 err = vrf_map_register_dev(dev, extack);
1638 if (err) {
1639 unregister_netdevice(dev);
1640 goto out;
1641 }
1642
1643 net = dev_net(dev);
1644 nn_vrf = net_generic(net, vrf_net_id);
1645
1646 add_fib_rules = &nn_vrf->add_fib_rules;
1647 if (*add_fib_rules) {
1648 err = vrf_add_fib_rules(dev);
1649 if (err) {
1650 vrf_map_unregister_dev(dev);
1651 unregister_netdevice(dev);
1652 goto out;
1653 }
1654 *add_fib_rules = false;
1655 }
1656
1657out:
1658 return err;
1659}
1660
1661static size_t vrf_nl_getsize(const struct net_device *dev)
1662{
1663 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
1664}
1665
1666static int vrf_fillinfo(struct sk_buff *skb,
1667 const struct net_device *dev)
1668{
1669 struct net_vrf *vrf = netdev_priv(dev);
1670
1671 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
1672}
1673
1674static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1675 const struct net_device *slave_dev)
1676{
1677 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1678}
1679
1680static int vrf_fill_slave_info(struct sk_buff *skb,
1681 const struct net_device *vrf_dev,
1682 const struct net_device *slave_dev)
1683{
1684 struct net_vrf *vrf = netdev_priv(vrf_dev);
1685
1686 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
1687 return -EMSGSIZE;
1688
1689 return 0;
1690}
1691
1692static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1693 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1694};
1695
1696static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1697 .kind = DRV_NAME,
1698 .priv_size = sizeof(struct net_vrf),
1699
1700 .get_size = vrf_nl_getsize,
1701 .policy = vrf_nl_policy,
1702 .validate = vrf_validate,
1703 .fill_info = vrf_fillinfo,
1704
1705 .get_slave_size = vrf_get_slave_size,
1706 .fill_slave_info = vrf_fill_slave_info,
1707
1708 .newlink = vrf_newlink,
1709 .dellink = vrf_dellink,
1710 .setup = vrf_setup,
1711 .maxtype = IFLA_VRF_MAX,
1712};
1713
1714static int vrf_device_event(struct notifier_block *unused,
1715 unsigned long event, void *ptr)
1716{
1717 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1718
1719 /* only care about unregister events to drop slave references */
1720 if (event == NETDEV_UNREGISTER) {
1721 struct net_device *vrf_dev;
1722
1723 if (!netif_is_l3_slave(dev))
1724 goto out;
1725
1726 vrf_dev = netdev_master_upper_dev_get(dev);
1727 vrf_del_slave(vrf_dev, dev);
1728 }
1729out:
1730 return NOTIFY_DONE;
1731}
1732
1733static struct notifier_block vrf_notifier_block __read_mostly = {
1734 .notifier_call = vrf_device_event,
1735};
1736
1737static int vrf_map_init(struct vrf_map *vmap)
1738{
1739 spin_lock_init(&vmap->vmap_lock);
1740 hash_init(vmap->ht);
1741
1742 vmap->strict_mode = false;
1743
1744 return 0;
1745}
1746
1747#ifdef CONFIG_SYSCTL
1748static bool vrf_strict_mode(struct vrf_map *vmap)
1749{
1750 bool strict_mode;
1751
1752 vrf_map_lock(vmap);
1753 strict_mode = vmap->strict_mode;
1754 vrf_map_unlock(vmap);
1755
1756 return strict_mode;
1757}
1758
1759static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode)
1760{
1761 bool *cur_mode;
1762 int res = 0;
1763
1764 vrf_map_lock(vmap);
1765
1766 cur_mode = &vmap->strict_mode;
1767 if (*cur_mode == new_mode)
1768 goto unlock;
1769
1770 if (*cur_mode) {
1771 /* disable strict mode */
1772 *cur_mode = false;
1773 } else {
1774 if (vmap->shared_tables) {
1775 /* we cannot allow strict_mode because there are some
1776 * vrfs that share one or more tables.
1777 */
1778 res = -EBUSY;
1779 goto unlock;
1780 }
1781
1782 /* no tables are shared among vrfs, so we can go back
1783 * to 1:1 association between a vrf with its table.
1784 */
1785 *cur_mode = true;
1786 }
1787
1788unlock:
1789 vrf_map_unlock(vmap);
1790
1791 return res;
1792}
1793
1794static int vrf_shared_table_handler(struct ctl_table *table, int write,
1795 void *buffer, size_t *lenp, loff_t *ppos)
1796{
1797 struct net *net = (struct net *)table->extra1;
1798 struct vrf_map *vmap = netns_vrf_map(net);
1799 int proc_strict_mode = 0;
1800 struct ctl_table tmp = {
1801 .procname = table->procname,
1802 .data = &proc_strict_mode,
1803 .maxlen = sizeof(int),
1804 .mode = table->mode,
1805 .extra1 = SYSCTL_ZERO,
1806 .extra2 = SYSCTL_ONE,
1807 };
1808 int ret;
1809
1810 if (!write)
1811 proc_strict_mode = vrf_strict_mode(vmap);
1812
1813 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
1814
1815 if (write && ret == 0)
1816 ret = vrf_strict_mode_change(vmap, (bool)proc_strict_mode);
1817
1818 return ret;
1819}
1820
1821static const struct ctl_table vrf_table[] = {
1822 {
1823 .procname = "strict_mode",
1824 .data = NULL,
1825 .maxlen = sizeof(int),
1826 .mode = 0644,
1827 .proc_handler = vrf_shared_table_handler,
1828 /* set by the vrf_netns_init */
1829 .extra1 = NULL,
1830 },
1831 { },
1832};
1833
1834static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1835{
1836 struct ctl_table *table;
1837
1838 table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL);
1839 if (!table)
1840 return -ENOMEM;
1841
1842 /* init the extra1 parameter with the reference to current netns */
1843 table[0].extra1 = net;
1844
1845 nn_vrf->ctl_hdr = register_net_sysctl(net, "net/vrf", table);
1846 if (!nn_vrf->ctl_hdr) {
1847 kfree(table);
1848 return -ENOMEM;
1849 }
1850
1851 return 0;
1852}
1853
1854static void vrf_netns_exit_sysctl(struct net *net)
1855{
1856 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
1857 struct ctl_table *table;
1858
1859 table = nn_vrf->ctl_hdr->ctl_table_arg;
1860 unregister_net_sysctl_table(nn_vrf->ctl_hdr);
1861 kfree(table);
1862}
1863#else
1864static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1865{
1866 return 0;
1867}
1868
1869static void vrf_netns_exit_sysctl(struct net *net)
1870{
1871}
1872#endif
1873
1874/* Initialize per network namespace state */
1875static int __net_init vrf_netns_init(struct net *net)
1876{
1877 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
1878
1879 nn_vrf->add_fib_rules = true;
1880 vrf_map_init(&nn_vrf->vmap);
1881
1882 return vrf_netns_init_sysctl(net, nn_vrf);
1883}
1884
1885static void __net_exit vrf_netns_exit(struct net *net)
1886{
1887 vrf_netns_exit_sysctl(net);
1888}
1889
1890static struct pernet_operations vrf_net_ops __net_initdata = {
1891 .init = vrf_netns_init,
1892 .exit = vrf_netns_exit,
1893 .id = &vrf_net_id,
1894 .size = sizeof(struct netns_vrf),
1895};
1896
1897static int __init vrf_init_module(void)
1898{
1899 int rc;
1900
1901 register_netdevice_notifier(&vrf_notifier_block);
1902
1903 rc = register_pernet_subsys(&vrf_net_ops);
1904 if (rc < 0)
1905 goto error;
1906
1907 rc = l3mdev_table_lookup_register(L3MDEV_TYPE_VRF,
1908 vrf_ifindex_lookup_by_table_id);
1909 if (rc < 0)
1910 goto unreg_pernet;
1911
1912 rc = rtnl_link_register(&vrf_link_ops);
1913 if (rc < 0)
1914 goto table_lookup_unreg;
1915
1916 return 0;
1917
1918table_lookup_unreg:
1919 l3mdev_table_lookup_unregister(L3MDEV_TYPE_VRF,
1920 vrf_ifindex_lookup_by_table_id);
1921
1922unreg_pernet:
1923 unregister_pernet_subsys(&vrf_net_ops);
1924
1925error:
1926 unregister_netdevice_notifier(&vrf_notifier_block);
1927 return rc;
1928}
1929
1930module_init(vrf_init_module);
1931MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
1932MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
1933MODULE_LICENSE("GPL");
1934MODULE_ALIAS_RTNL_LINK(DRV_NAME);
1935MODULE_VERSION(DRV_VERSION);