Loading...
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/ethtool.h>
13#include <linux/module.h>
14#include <linux/kernel.h>
15#include <linux/netdevice.h>
16#include <linux/etherdevice.h>
17#include <linux/ip.h>
18#include <linux/init.h>
19#include <linux/moduleparam.h>
20#include <linux/netfilter.h>
21#include <linux/rtnetlink.h>
22#include <net/rtnetlink.h>
23#include <linux/u64_stats_sync.h>
24#include <linux/hashtable.h>
25#include <linux/spinlock_types.h>
26
27#include <linux/inetdevice.h>
28#include <net/arp.h>
29#include <net/ip.h>
30#include <net/ip_fib.h>
31#include <net/ip6_fib.h>
32#include <net/ip6_route.h>
33#include <net/route.h>
34#include <net/addrconf.h>
35#include <net/l3mdev.h>
36#include <net/fib_rules.h>
37#include <net/sch_generic.h>
38#include <net/netns/generic.h>
39#include <net/netfilter/nf_conntrack.h>
40
41#define DRV_NAME "vrf"
42#define DRV_VERSION "1.1"
43
44#define FIB_RULE_PREF 1000 /* default preference for FIB rules */
45
46#define HT_MAP_BITS 4
47#define HASH_INITVAL ((u32)0xcafef00d)
48
49struct vrf_map {
50 DECLARE_HASHTABLE(ht, HT_MAP_BITS);
51 spinlock_t vmap_lock;
52
53 /* shared_tables:
54 * count how many distinct tables do not comply with the strict mode
55 * requirement.
56 * shared_tables value must be 0 in order to enable the strict mode.
57 *
58 * example of the evolution of shared_tables:
59 * | time
60 * add vrf0 --> table 100 shared_tables = 0 | t0
61 * add vrf1 --> table 101 shared_tables = 0 | t1
62 * add vrf2 --> table 100 shared_tables = 1 | t2
63 * add vrf3 --> table 100 shared_tables = 1 | t3
64 * add vrf4 --> table 101 shared_tables = 2 v t4
65 *
66 * shared_tables is a "step function" (or "staircase function")
67 * and it is increased by one when the second vrf is associated to a
68 * table.
69 *
70 * at t2, vrf0 and vrf2 are bound to table 100: shared_tables = 1.
71 *
72 * at t3, another dev (vrf3) is bound to the same table 100 but the
73 * value of shared_tables is still 1.
74 * This means that no matter how many new vrfs will register on the
75 * table 100, the shared_tables will not increase (considering only
76 * table 100).
77 *
78 * at t4, vrf4 is bound to table 101, and shared_tables = 2.
79 *
80 * Looking at the value of shared_tables we can immediately know if
81 * the strict_mode can or cannot be enforced. Indeed, strict_mode
82 * can be enforced iff shared_tables = 0.
83 *
84 * Conversely, shared_tables is decreased when a vrf is de-associated
85 * from a table with exactly two associated vrfs.
86 */
87 u32 shared_tables;
88
89 bool strict_mode;
90};
91
92struct vrf_map_elem {
93 struct hlist_node hnode;
94 struct list_head vrf_list; /* VRFs registered to this table */
95
96 u32 table_id;
97 int users;
98 int ifindex;
99};
100
101static unsigned int vrf_net_id;
102
103/* per netns vrf data */
104struct netns_vrf {
105 /* protected by rtnl lock */
106 bool add_fib_rules;
107
108 struct vrf_map vmap;
109 struct ctl_table_header *ctl_hdr;
110};
111
112struct net_vrf {
113 struct rtable __rcu *rth;
114 struct rt6_info __rcu *rt6;
115#if IS_ENABLED(CONFIG_IPV6)
116 struct fib6_table *fib6_table;
117#endif
118 u32 tb_id;
119
120 struct list_head me_list; /* entry in vrf_map_elem */
121 int ifindex;
122};
123
124struct pcpu_dstats {
125 u64 tx_pkts;
126 u64 tx_bytes;
127 u64 tx_drps;
128 u64 rx_pkts;
129 u64 rx_bytes;
130 u64 rx_drps;
131 struct u64_stats_sync syncp;
132};
133
134static void vrf_rx_stats(struct net_device *dev, int len)
135{
136 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
137
138 u64_stats_update_begin(&dstats->syncp);
139 dstats->rx_pkts++;
140 dstats->rx_bytes += len;
141 u64_stats_update_end(&dstats->syncp);
142}
143
144static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
145{
146 vrf_dev->stats.tx_errors++;
147 kfree_skb(skb);
148}
149
150static void vrf_get_stats64(struct net_device *dev,
151 struct rtnl_link_stats64 *stats)
152{
153 int i;
154
155 for_each_possible_cpu(i) {
156 const struct pcpu_dstats *dstats;
157 u64 tbytes, tpkts, tdrops, rbytes, rpkts;
158 unsigned int start;
159
160 dstats = per_cpu_ptr(dev->dstats, i);
161 do {
162 start = u64_stats_fetch_begin(&dstats->syncp);
163 tbytes = dstats->tx_bytes;
164 tpkts = dstats->tx_pkts;
165 tdrops = dstats->tx_drps;
166 rbytes = dstats->rx_bytes;
167 rpkts = dstats->rx_pkts;
168 } while (u64_stats_fetch_retry(&dstats->syncp, start));
169 stats->tx_bytes += tbytes;
170 stats->tx_packets += tpkts;
171 stats->tx_dropped += tdrops;
172 stats->rx_bytes += rbytes;
173 stats->rx_packets += rpkts;
174 }
175}
176
177static struct vrf_map *netns_vrf_map(struct net *net)
178{
179 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
180
181 return &nn_vrf->vmap;
182}
183
184static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev)
185{
186 return netns_vrf_map(dev_net(dev));
187}
188
189static int vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem *me)
190{
191 struct list_head *me_head = &me->vrf_list;
192 struct net_vrf *vrf;
193
194 if (list_empty(me_head))
195 return -ENODEV;
196
197 vrf = list_first_entry(me_head, struct net_vrf, me_list);
198
199 return vrf->ifindex;
200}
201
202static struct vrf_map_elem *vrf_map_elem_alloc(gfp_t flags)
203{
204 struct vrf_map_elem *me;
205
206 me = kmalloc(sizeof(*me), flags);
207 if (!me)
208 return NULL;
209
210 return me;
211}
212
213static void vrf_map_elem_free(struct vrf_map_elem *me)
214{
215 kfree(me);
216}
217
218static void vrf_map_elem_init(struct vrf_map_elem *me, int table_id,
219 int ifindex, int users)
220{
221 me->table_id = table_id;
222 me->ifindex = ifindex;
223 me->users = users;
224 INIT_LIST_HEAD(&me->vrf_list);
225}
226
227static struct vrf_map_elem *vrf_map_lookup_elem(struct vrf_map *vmap,
228 u32 table_id)
229{
230 struct vrf_map_elem *me;
231 u32 key;
232
233 key = jhash_1word(table_id, HASH_INITVAL);
234 hash_for_each_possible(vmap->ht, me, hnode, key) {
235 if (me->table_id == table_id)
236 return me;
237 }
238
239 return NULL;
240}
241
242static void vrf_map_add_elem(struct vrf_map *vmap, struct vrf_map_elem *me)
243{
244 u32 table_id = me->table_id;
245 u32 key;
246
247 key = jhash_1word(table_id, HASH_INITVAL);
248 hash_add(vmap->ht, &me->hnode, key);
249}
250
251static void vrf_map_del_elem(struct vrf_map_elem *me)
252{
253 hash_del(&me->hnode);
254}
255
256static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock)
257{
258 spin_lock(&vmap->vmap_lock);
259}
260
261static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock)
262{
263 spin_unlock(&vmap->vmap_lock);
264}
265
266/* called with rtnl lock held */
267static int
268vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack)
269{
270 struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
271 struct net_vrf *vrf = netdev_priv(dev);
272 struct vrf_map_elem *new_me, *me;
273 u32 table_id = vrf->tb_id;
274 bool free_new_me = false;
275 int users;
276 int res;
277
278 /* we pre-allocate elements used in the spin-locked section (so that we
279 * keep the spinlock as short as possible).
280 */
281 new_me = vrf_map_elem_alloc(GFP_KERNEL);
282 if (!new_me)
283 return -ENOMEM;
284
285 vrf_map_elem_init(new_me, table_id, dev->ifindex, 0);
286
287 vrf_map_lock(vmap);
288
289 me = vrf_map_lookup_elem(vmap, table_id);
290 if (!me) {
291 me = new_me;
292 vrf_map_add_elem(vmap, me);
293 goto link_vrf;
294 }
295
296 /* we already have an entry in the vrf_map, so it means there is (at
297 * least) a vrf registered on the specific table.
298 */
299 free_new_me = true;
300 if (vmap->strict_mode) {
301 /* vrfs cannot share the same table */
302 NL_SET_ERR_MSG(extack, "Table is used by another VRF");
303 res = -EBUSY;
304 goto unlock;
305 }
306
307link_vrf:
308 users = ++me->users;
309 if (users == 2)
310 ++vmap->shared_tables;
311
312 list_add(&vrf->me_list, &me->vrf_list);
313
314 res = 0;
315
316unlock:
317 vrf_map_unlock(vmap);
318
319 /* clean-up, if needed */
320 if (free_new_me)
321 vrf_map_elem_free(new_me);
322
323 return res;
324}
325
326/* called with rtnl lock held */
327static void vrf_map_unregister_dev(struct net_device *dev)
328{
329 struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
330 struct net_vrf *vrf = netdev_priv(dev);
331 u32 table_id = vrf->tb_id;
332 struct vrf_map_elem *me;
333 int users;
334
335 vrf_map_lock(vmap);
336
337 me = vrf_map_lookup_elem(vmap, table_id);
338 if (!me)
339 goto unlock;
340
341 list_del(&vrf->me_list);
342
343 users = --me->users;
344 if (users == 1) {
345 --vmap->shared_tables;
346 } else if (users == 0) {
347 vrf_map_del_elem(me);
348
349 /* no one will refer to this element anymore */
350 vrf_map_elem_free(me);
351 }
352
353unlock:
354 vrf_map_unlock(vmap);
355}
356
357/* return the vrf device index associated with the table_id */
358static int vrf_ifindex_lookup_by_table_id(struct net *net, u32 table_id)
359{
360 struct vrf_map *vmap = netns_vrf_map(net);
361 struct vrf_map_elem *me;
362 int ifindex;
363
364 vrf_map_lock(vmap);
365
366 if (!vmap->strict_mode) {
367 ifindex = -EPERM;
368 goto unlock;
369 }
370
371 me = vrf_map_lookup_elem(vmap, table_id);
372 if (!me) {
373 ifindex = -ENODEV;
374 goto unlock;
375 }
376
377 ifindex = vrf_map_elem_get_vrf_ifindex(me);
378
379unlock:
380 vrf_map_unlock(vmap);
381
382 return ifindex;
383}
384
385/* by default VRF devices do not have a qdisc and are expected
386 * to be created with only a single queue.
387 */
388static bool qdisc_tx_is_default(const struct net_device *dev)
389{
390 struct netdev_queue *txq;
391 struct Qdisc *qdisc;
392
393 if (dev->num_tx_queues > 1)
394 return false;
395
396 txq = netdev_get_tx_queue(dev, 0);
397 qdisc = rcu_access_pointer(txq->qdisc);
398
399 return !qdisc->enqueue;
400}
401
402/* Local traffic destined to local address. Reinsert the packet to rx
403 * path, similar to loopback handling.
404 */
405static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
406 struct dst_entry *dst)
407{
408 int len = skb->len;
409
410 skb_orphan(skb);
411
412 skb_dst_set(skb, dst);
413
414 /* set pkt_type to avoid skb hitting packet taps twice -
415 * once on Tx and again in Rx processing
416 */
417 skb->pkt_type = PACKET_LOOPBACK;
418
419 skb->protocol = eth_type_trans(skb, dev);
420
421 if (likely(__netif_rx(skb) == NET_RX_SUCCESS))
422 vrf_rx_stats(dev, len);
423 else
424 this_cpu_inc(dev->dstats->rx_drps);
425
426 return NETDEV_TX_OK;
427}
428
429static void vrf_nf_set_untracked(struct sk_buff *skb)
430{
431 if (skb_get_nfct(skb) == 0)
432 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
433}
434
435static void vrf_nf_reset_ct(struct sk_buff *skb)
436{
437 if (skb_get_nfct(skb) == IP_CT_UNTRACKED)
438 nf_reset_ct(skb);
439}
440
441#if IS_ENABLED(CONFIG_IPV6)
442static int vrf_ip6_local_out(struct net *net, struct sock *sk,
443 struct sk_buff *skb)
444{
445 int err;
446
447 vrf_nf_reset_ct(skb);
448
449 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net,
450 sk, skb, NULL, skb_dst(skb)->dev, dst_output);
451
452 if (likely(err == 1))
453 err = dst_output(net, sk, skb);
454
455 return err;
456}
457
458static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
459 struct net_device *dev)
460{
461 const struct ipv6hdr *iph;
462 struct net *net = dev_net(skb->dev);
463 struct flowi6 fl6;
464 int ret = NET_XMIT_DROP;
465 struct dst_entry *dst;
466 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
467
468 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
469 goto err;
470
471 iph = ipv6_hdr(skb);
472
473 memset(&fl6, 0, sizeof(fl6));
474 /* needed to match OIF rule */
475 fl6.flowi6_l3mdev = dev->ifindex;
476 fl6.flowi6_iif = LOOPBACK_IFINDEX;
477 fl6.daddr = iph->daddr;
478 fl6.saddr = iph->saddr;
479 fl6.flowlabel = ip6_flowinfo(iph);
480 fl6.flowi6_mark = skb->mark;
481 fl6.flowi6_proto = iph->nexthdr;
482
483 dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL);
484 if (IS_ERR(dst) || dst == dst_null)
485 goto err;
486
487 skb_dst_drop(skb);
488
489 /* if dst.dev is the VRF device again this is locally originated traffic
490 * destined to a local address. Short circuit to Rx path.
491 */
492 if (dst->dev == dev)
493 return vrf_local_xmit(skb, dev, dst);
494
495 skb_dst_set(skb, dst);
496
497 /* strip the ethernet header added for pass through VRF device */
498 __skb_pull(skb, skb_network_offset(skb));
499
500 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
501 ret = vrf_ip6_local_out(net, skb->sk, skb);
502 if (unlikely(net_xmit_eval(ret)))
503 dev->stats.tx_errors++;
504 else
505 ret = NET_XMIT_SUCCESS;
506
507 return ret;
508err:
509 vrf_tx_error(dev, skb);
510 return NET_XMIT_DROP;
511}
512#else
513static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
514 struct net_device *dev)
515{
516 vrf_tx_error(dev, skb);
517 return NET_XMIT_DROP;
518}
519#endif
520
521/* based on ip_local_out; can't use it b/c the dst is switched pointing to us */
522static int vrf_ip_local_out(struct net *net, struct sock *sk,
523 struct sk_buff *skb)
524{
525 int err;
526
527 vrf_nf_reset_ct(skb);
528
529 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
530 skb, NULL, skb_dst(skb)->dev, dst_output);
531 if (likely(err == 1))
532 err = dst_output(net, sk, skb);
533
534 return err;
535}
536
537static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
538 struct net_device *vrf_dev)
539{
540 struct iphdr *ip4h;
541 int ret = NET_XMIT_DROP;
542 struct flowi4 fl4;
543 struct net *net = dev_net(vrf_dev);
544 struct rtable *rt;
545
546 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
547 goto err;
548
549 ip4h = ip_hdr(skb);
550
551 memset(&fl4, 0, sizeof(fl4));
552 /* needed to match OIF rule */
553 fl4.flowi4_l3mdev = vrf_dev->ifindex;
554 fl4.flowi4_iif = LOOPBACK_IFINDEX;
555 fl4.flowi4_tos = RT_TOS(ip4h->tos);
556 fl4.flowi4_flags = FLOWI_FLAG_ANYSRC;
557 fl4.flowi4_proto = ip4h->protocol;
558 fl4.daddr = ip4h->daddr;
559 fl4.saddr = ip4h->saddr;
560
561 rt = ip_route_output_flow(net, &fl4, NULL);
562 if (IS_ERR(rt))
563 goto err;
564
565 skb_dst_drop(skb);
566
567 /* if dst.dev is the VRF device again this is locally originated traffic
568 * destined to a local address. Short circuit to Rx path.
569 */
570 if (rt->dst.dev == vrf_dev)
571 return vrf_local_xmit(skb, vrf_dev, &rt->dst);
572
573 skb_dst_set(skb, &rt->dst);
574
575 /* strip the ethernet header added for pass through VRF device */
576 __skb_pull(skb, skb_network_offset(skb));
577
578 if (!ip4h->saddr) {
579 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
580 RT_SCOPE_LINK);
581 }
582
583 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
584 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
585 if (unlikely(net_xmit_eval(ret)))
586 vrf_dev->stats.tx_errors++;
587 else
588 ret = NET_XMIT_SUCCESS;
589
590out:
591 return ret;
592err:
593 vrf_tx_error(vrf_dev, skb);
594 goto out;
595}
596
597static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
598{
599 switch (skb->protocol) {
600 case htons(ETH_P_IP):
601 return vrf_process_v4_outbound(skb, dev);
602 case htons(ETH_P_IPV6):
603 return vrf_process_v6_outbound(skb, dev);
604 default:
605 vrf_tx_error(dev, skb);
606 return NET_XMIT_DROP;
607 }
608}
609
610static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
611{
612 int len = skb->len;
613 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
614
615 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
616 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
617
618 u64_stats_update_begin(&dstats->syncp);
619 dstats->tx_pkts++;
620 dstats->tx_bytes += len;
621 u64_stats_update_end(&dstats->syncp);
622 } else {
623 this_cpu_inc(dev->dstats->tx_drps);
624 }
625
626 return ret;
627}
628
629static void vrf_finish_direct(struct sk_buff *skb)
630{
631 struct net_device *vrf_dev = skb->dev;
632
633 if (!list_empty(&vrf_dev->ptype_all) &&
634 likely(skb_headroom(skb) >= ETH_HLEN)) {
635 struct ethhdr *eth = skb_push(skb, ETH_HLEN);
636
637 ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
638 eth_zero_addr(eth->h_dest);
639 eth->h_proto = skb->protocol;
640
641 rcu_read_lock_bh();
642 dev_queue_xmit_nit(skb, vrf_dev);
643 rcu_read_unlock_bh();
644
645 skb_pull(skb, ETH_HLEN);
646 }
647
648 vrf_nf_reset_ct(skb);
649}
650
651#if IS_ENABLED(CONFIG_IPV6)
652/* modelled after ip6_finish_output2 */
653static int vrf_finish_output6(struct net *net, struct sock *sk,
654 struct sk_buff *skb)
655{
656 struct dst_entry *dst = skb_dst(skb);
657 struct net_device *dev = dst->dev;
658 const struct in6_addr *nexthop;
659 struct neighbour *neigh;
660 int ret;
661
662 vrf_nf_reset_ct(skb);
663
664 skb->protocol = htons(ETH_P_IPV6);
665 skb->dev = dev;
666
667 rcu_read_lock_bh();
668 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
669 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
670 if (unlikely(!neigh))
671 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
672 if (!IS_ERR(neigh)) {
673 sock_confirm_neigh(skb, neigh);
674 ret = neigh_output(neigh, skb, false);
675 rcu_read_unlock_bh();
676 return ret;
677 }
678 rcu_read_unlock_bh();
679
680 IP6_INC_STATS(dev_net(dst->dev),
681 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
682 kfree_skb(skb);
683 return -EINVAL;
684}
685
686/* modelled after ip6_output */
687static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
688{
689 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
690 net, sk, skb, NULL, skb_dst(skb)->dev,
691 vrf_finish_output6,
692 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
693}
694
695/* set dst on skb to send packet to us via dev_xmit path. Allows
696 * packet to go through device based features such as qdisc, netfilter
697 * hooks and packet sockets with skb->dev set to vrf device.
698 */
699static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev,
700 struct sk_buff *skb)
701{
702 struct net_vrf *vrf = netdev_priv(vrf_dev);
703 struct dst_entry *dst = NULL;
704 struct rt6_info *rt6;
705
706 rcu_read_lock();
707
708 rt6 = rcu_dereference(vrf->rt6);
709 if (likely(rt6)) {
710 dst = &rt6->dst;
711 dst_hold(dst);
712 }
713
714 rcu_read_unlock();
715
716 if (unlikely(!dst)) {
717 vrf_tx_error(vrf_dev, skb);
718 return NULL;
719 }
720
721 skb_dst_drop(skb);
722 skb_dst_set(skb, dst);
723
724 return skb;
725}
726
727static int vrf_output6_direct_finish(struct net *net, struct sock *sk,
728 struct sk_buff *skb)
729{
730 vrf_finish_direct(skb);
731
732 return vrf_ip6_local_out(net, sk, skb);
733}
734
735static int vrf_output6_direct(struct net *net, struct sock *sk,
736 struct sk_buff *skb)
737{
738 int err = 1;
739
740 skb->protocol = htons(ETH_P_IPV6);
741
742 if (!(IPCB(skb)->flags & IPSKB_REROUTED))
743 err = nf_hook(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb,
744 NULL, skb->dev, vrf_output6_direct_finish);
745
746 if (likely(err == 1))
747 vrf_finish_direct(skb);
748
749 return err;
750}
751
752static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk,
753 struct sk_buff *skb)
754{
755 int err;
756
757 err = vrf_output6_direct(net, sk, skb);
758 if (likely(err == 1))
759 err = vrf_ip6_local_out(net, sk, skb);
760
761 return err;
762}
763
764static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
765 struct sock *sk,
766 struct sk_buff *skb)
767{
768 struct net *net = dev_net(vrf_dev);
769 int err;
770
771 skb->dev = vrf_dev;
772
773 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk,
774 skb, NULL, vrf_dev, vrf_ip6_out_direct_finish);
775
776 if (likely(err == 1))
777 err = vrf_output6_direct(net, sk, skb);
778
779 if (likely(err == 1))
780 return skb;
781
782 return NULL;
783}
784
785static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
786 struct sock *sk,
787 struct sk_buff *skb)
788{
789 /* don't divert link scope packets */
790 if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
791 return skb;
792
793 vrf_nf_set_untracked(skb);
794
795 if (qdisc_tx_is_default(vrf_dev) ||
796 IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
797 return vrf_ip6_out_direct(vrf_dev, sk, skb);
798
799 return vrf_ip6_out_redirect(vrf_dev, skb);
800}
801
802/* holding rtnl */
803static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
804{
805 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
806 struct net *net = dev_net(dev);
807 struct dst_entry *dst;
808
809 RCU_INIT_POINTER(vrf->rt6, NULL);
810 synchronize_rcu();
811
812 /* move dev in dst's to loopback so this VRF device can be deleted
813 * - based on dst_ifdown
814 */
815 if (rt6) {
816 dst = &rt6->dst;
817 netdev_ref_replace(dst->dev, net->loopback_dev,
818 &dst->dev_tracker, GFP_KERNEL);
819 dst->dev = net->loopback_dev;
820 dst_release(dst);
821 }
822}
823
824static int vrf_rt6_create(struct net_device *dev)
825{
826 int flags = DST_NOPOLICY | DST_NOXFRM;
827 struct net_vrf *vrf = netdev_priv(dev);
828 struct net *net = dev_net(dev);
829 struct rt6_info *rt6;
830 int rc = -ENOMEM;
831
832 /* IPv6 can be CONFIG enabled and then disabled runtime */
833 if (!ipv6_mod_enabled())
834 return 0;
835
836 vrf->fib6_table = fib6_new_table(net, vrf->tb_id);
837 if (!vrf->fib6_table)
838 goto out;
839
840 /* create a dst for routing packets out a VRF device */
841 rt6 = ip6_dst_alloc(net, dev, flags);
842 if (!rt6)
843 goto out;
844
845 rt6->dst.output = vrf_output6;
846
847 rcu_assign_pointer(vrf->rt6, rt6);
848
849 rc = 0;
850out:
851 return rc;
852}
853#else
854static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
855 struct sock *sk,
856 struct sk_buff *skb)
857{
858 return skb;
859}
860
861static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
862{
863}
864
865static int vrf_rt6_create(struct net_device *dev)
866{
867 return 0;
868}
869#endif
870
871/* modelled after ip_finish_output2 */
872static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
873{
874 struct dst_entry *dst = skb_dst(skb);
875 struct rtable *rt = (struct rtable *)dst;
876 struct net_device *dev = dst->dev;
877 unsigned int hh_len = LL_RESERVED_SPACE(dev);
878 struct neighbour *neigh;
879 bool is_v6gw = false;
880
881 vrf_nf_reset_ct(skb);
882
883 /* Be paranoid, rather than too clever. */
884 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
885 skb = skb_expand_head(skb, hh_len);
886 if (!skb) {
887 dev->stats.tx_errors++;
888 return -ENOMEM;
889 }
890 }
891
892 rcu_read_lock_bh();
893
894 neigh = ip_neigh_for_gw(rt, skb, &is_v6gw);
895 if (!IS_ERR(neigh)) {
896 int ret;
897
898 sock_confirm_neigh(skb, neigh);
899 /* if crossing protocols, can not use the cached header */
900 ret = neigh_output(neigh, skb, is_v6gw);
901 rcu_read_unlock_bh();
902 return ret;
903 }
904
905 rcu_read_unlock_bh();
906 vrf_tx_error(skb->dev, skb);
907 return -EINVAL;
908}
909
910static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
911{
912 struct net_device *dev = skb_dst(skb)->dev;
913
914 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
915
916 skb->dev = dev;
917 skb->protocol = htons(ETH_P_IP);
918
919 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
920 net, sk, skb, NULL, dev,
921 vrf_finish_output,
922 !(IPCB(skb)->flags & IPSKB_REROUTED));
923}
924
925/* set dst on skb to send packet to us via dev_xmit path. Allows
926 * packet to go through device based features such as qdisc, netfilter
927 * hooks and packet sockets with skb->dev set to vrf device.
928 */
929static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev,
930 struct sk_buff *skb)
931{
932 struct net_vrf *vrf = netdev_priv(vrf_dev);
933 struct dst_entry *dst = NULL;
934 struct rtable *rth;
935
936 rcu_read_lock();
937
938 rth = rcu_dereference(vrf->rth);
939 if (likely(rth)) {
940 dst = &rth->dst;
941 dst_hold(dst);
942 }
943
944 rcu_read_unlock();
945
946 if (unlikely(!dst)) {
947 vrf_tx_error(vrf_dev, skb);
948 return NULL;
949 }
950
951 skb_dst_drop(skb);
952 skb_dst_set(skb, dst);
953
954 return skb;
955}
956
957static int vrf_output_direct_finish(struct net *net, struct sock *sk,
958 struct sk_buff *skb)
959{
960 vrf_finish_direct(skb);
961
962 return vrf_ip_local_out(net, sk, skb);
963}
964
965static int vrf_output_direct(struct net *net, struct sock *sk,
966 struct sk_buff *skb)
967{
968 int err = 1;
969
970 skb->protocol = htons(ETH_P_IP);
971
972 if (!(IPCB(skb)->flags & IPSKB_REROUTED))
973 err = nf_hook(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb,
974 NULL, skb->dev, vrf_output_direct_finish);
975
976 if (likely(err == 1))
977 vrf_finish_direct(skb);
978
979 return err;
980}
981
982static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk,
983 struct sk_buff *skb)
984{
985 int err;
986
987 err = vrf_output_direct(net, sk, skb);
988 if (likely(err == 1))
989 err = vrf_ip_local_out(net, sk, skb);
990
991 return err;
992}
993
994static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
995 struct sock *sk,
996 struct sk_buff *skb)
997{
998 struct net *net = dev_net(vrf_dev);
999 int err;
1000
1001 skb->dev = vrf_dev;
1002
1003 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
1004 skb, NULL, vrf_dev, vrf_ip_out_direct_finish);
1005
1006 if (likely(err == 1))
1007 err = vrf_output_direct(net, sk, skb);
1008
1009 if (likely(err == 1))
1010 return skb;
1011
1012 return NULL;
1013}
1014
1015static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
1016 struct sock *sk,
1017 struct sk_buff *skb)
1018{
1019 /* don't divert multicast or local broadcast */
1020 if (ipv4_is_multicast(ip_hdr(skb)->daddr) ||
1021 ipv4_is_lbcast(ip_hdr(skb)->daddr))
1022 return skb;
1023
1024 vrf_nf_set_untracked(skb);
1025
1026 if (qdisc_tx_is_default(vrf_dev) ||
1027 IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
1028 return vrf_ip_out_direct(vrf_dev, sk, skb);
1029
1030 return vrf_ip_out_redirect(vrf_dev, skb);
1031}
1032
1033/* called with rcu lock held */
1034static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
1035 struct sock *sk,
1036 struct sk_buff *skb,
1037 u16 proto)
1038{
1039 switch (proto) {
1040 case AF_INET:
1041 return vrf_ip_out(vrf_dev, sk, skb);
1042 case AF_INET6:
1043 return vrf_ip6_out(vrf_dev, sk, skb);
1044 }
1045
1046 return skb;
1047}
1048
1049/* holding rtnl */
1050static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
1051{
1052 struct rtable *rth = rtnl_dereference(vrf->rth);
1053 struct net *net = dev_net(dev);
1054 struct dst_entry *dst;
1055
1056 RCU_INIT_POINTER(vrf->rth, NULL);
1057 synchronize_rcu();
1058
1059 /* move dev in dst's to loopback so this VRF device can be deleted
1060 * - based on dst_ifdown
1061 */
1062 if (rth) {
1063 dst = &rth->dst;
1064 netdev_ref_replace(dst->dev, net->loopback_dev,
1065 &dst->dev_tracker, GFP_KERNEL);
1066 dst->dev = net->loopback_dev;
1067 dst_release(dst);
1068 }
1069}
1070
1071static int vrf_rtable_create(struct net_device *dev)
1072{
1073 struct net_vrf *vrf = netdev_priv(dev);
1074 struct rtable *rth;
1075
1076 if (!fib_new_table(dev_net(dev), vrf->tb_id))
1077 return -ENOMEM;
1078
1079 /* create a dst for routing packets out through a VRF device */
1080 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1);
1081 if (!rth)
1082 return -ENOMEM;
1083
1084 rth->dst.output = vrf_output;
1085
1086 rcu_assign_pointer(vrf->rth, rth);
1087
1088 return 0;
1089}
1090
1091/**************************** device handling ********************/
1092
1093/* cycle interface to flush neighbor cache and move routes across tables */
1094static void cycle_netdev(struct net_device *dev,
1095 struct netlink_ext_ack *extack)
1096{
1097 unsigned int flags = dev->flags;
1098 int ret;
1099
1100 if (!netif_running(dev))
1101 return;
1102
1103 ret = dev_change_flags(dev, flags & ~IFF_UP, extack);
1104 if (ret >= 0)
1105 ret = dev_change_flags(dev, flags, extack);
1106
1107 if (ret < 0) {
1108 netdev_err(dev,
1109 "Failed to cycle device %s; route tables might be wrong!\n",
1110 dev->name);
1111 }
1112}
1113
1114static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1115 struct netlink_ext_ack *extack)
1116{
1117 int ret;
1118
1119 /* do not allow loopback device to be enslaved to a VRF.
1120 * The vrf device acts as the loopback for the vrf.
1121 */
1122 if (port_dev == dev_net(dev)->loopback_dev) {
1123 NL_SET_ERR_MSG(extack,
1124 "Can not enslave loopback device to a VRF");
1125 return -EOPNOTSUPP;
1126 }
1127
1128 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
1129 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack);
1130 if (ret < 0)
1131 goto err;
1132
1133 cycle_netdev(port_dev, extack);
1134
1135 return 0;
1136
1137err:
1138 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1139 return ret;
1140}
1141
1142static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1143 struct netlink_ext_ack *extack)
1144{
1145 if (netif_is_l3_master(port_dev)) {
1146 NL_SET_ERR_MSG(extack,
1147 "Can not enslave an L3 master device to a VRF");
1148 return -EINVAL;
1149 }
1150
1151 if (netif_is_l3_slave(port_dev))
1152 return -EINVAL;
1153
1154 return do_vrf_add_slave(dev, port_dev, extack);
1155}
1156
1157/* inverse of do_vrf_add_slave */
1158static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1159{
1160 netdev_upper_dev_unlink(port_dev, dev);
1161 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1162
1163 cycle_netdev(port_dev, NULL);
1164
1165 return 0;
1166}
1167
1168static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1169{
1170 return do_vrf_del_slave(dev, port_dev);
1171}
1172
1173static void vrf_dev_uninit(struct net_device *dev)
1174{
1175 struct net_vrf *vrf = netdev_priv(dev);
1176
1177 vrf_rtable_release(dev, vrf);
1178 vrf_rt6_release(dev, vrf);
1179
1180 free_percpu(dev->dstats);
1181 dev->dstats = NULL;
1182}
1183
1184static int vrf_dev_init(struct net_device *dev)
1185{
1186 struct net_vrf *vrf = netdev_priv(dev);
1187
1188 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
1189 if (!dev->dstats)
1190 goto out_nomem;
1191
1192 /* create the default dst which points back to us */
1193 if (vrf_rtable_create(dev) != 0)
1194 goto out_stats;
1195
1196 if (vrf_rt6_create(dev) != 0)
1197 goto out_rth;
1198
1199 dev->flags = IFF_MASTER | IFF_NOARP;
1200
1201 /* similarly, oper state is irrelevant; set to up to avoid confusion */
1202 dev->operstate = IF_OPER_UP;
1203 netdev_lockdep_set_classes(dev);
1204 return 0;
1205
1206out_rth:
1207 vrf_rtable_release(dev, vrf);
1208out_stats:
1209 free_percpu(dev->dstats);
1210 dev->dstats = NULL;
1211out_nomem:
1212 return -ENOMEM;
1213}
1214
1215static const struct net_device_ops vrf_netdev_ops = {
1216 .ndo_init = vrf_dev_init,
1217 .ndo_uninit = vrf_dev_uninit,
1218 .ndo_start_xmit = vrf_xmit,
1219 .ndo_set_mac_address = eth_mac_addr,
1220 .ndo_get_stats64 = vrf_get_stats64,
1221 .ndo_add_slave = vrf_add_slave,
1222 .ndo_del_slave = vrf_del_slave,
1223};
1224
1225static u32 vrf_fib_table(const struct net_device *dev)
1226{
1227 struct net_vrf *vrf = netdev_priv(dev);
1228
1229 return vrf->tb_id;
1230}
1231
1232static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
1233{
1234 kfree_skb(skb);
1235 return 0;
1236}
1237
1238static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
1239 struct sk_buff *skb,
1240 struct net_device *dev)
1241{
1242 struct net *net = dev_net(dev);
1243
1244 if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1)
1245 skb = NULL; /* kfree_skb(skb) handled by nf code */
1246
1247 return skb;
1248}
1249
1250static int vrf_prepare_mac_header(struct sk_buff *skb,
1251 struct net_device *vrf_dev, u16 proto)
1252{
1253 struct ethhdr *eth;
1254 int err;
1255
1256 /* in general, we do not know if there is enough space in the head of
1257 * the packet for hosting the mac header.
1258 */
1259 err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev));
1260 if (unlikely(err))
1261 /* no space in the skb head */
1262 return -ENOBUFS;
1263
1264 __skb_push(skb, ETH_HLEN);
1265 eth = (struct ethhdr *)skb->data;
1266
1267 skb_reset_mac_header(skb);
1268 skb_reset_mac_len(skb);
1269
1270 /* we set the ethernet destination and the source addresses to the
1271 * address of the VRF device.
1272 */
1273 ether_addr_copy(eth->h_dest, vrf_dev->dev_addr);
1274 ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
1275 eth->h_proto = htons(proto);
1276
1277 /* the destination address of the Ethernet frame corresponds to the
1278 * address set on the VRF interface; therefore, the packet is intended
1279 * to be processed locally.
1280 */
1281 skb->protocol = eth->h_proto;
1282 skb->pkt_type = PACKET_HOST;
1283
1284 skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
1285
1286 skb_pull_inline(skb, ETH_HLEN);
1287
1288 return 0;
1289}
1290
1291/* prepare and add the mac header to the packet if it was not set previously.
1292 * In this way, packet sniffers such as tcpdump can parse the packet correctly.
1293 * If the mac header was already set, the original mac header is left
1294 * untouched and the function returns immediately.
1295 */
1296static int vrf_add_mac_header_if_unset(struct sk_buff *skb,
1297 struct net_device *vrf_dev,
1298 u16 proto, struct net_device *orig_dev)
1299{
1300 if (skb_mac_header_was_set(skb) && dev_has_header(orig_dev))
1301 return 0;
1302
1303 return vrf_prepare_mac_header(skb, vrf_dev, proto);
1304}
1305
1306#if IS_ENABLED(CONFIG_IPV6)
1307/* neighbor handling is done with actual device; do not want
1308 * to flip skb->dev for those ndisc packets. This really fails
1309 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
1310 * a start.
1311 */
1312static bool ipv6_ndisc_frame(const struct sk_buff *skb)
1313{
1314 const struct ipv6hdr *iph = ipv6_hdr(skb);
1315 bool rc = false;
1316
1317 if (iph->nexthdr == NEXTHDR_ICMP) {
1318 const struct icmp6hdr *icmph;
1319 struct icmp6hdr _icmph;
1320
1321 icmph = skb_header_pointer(skb, sizeof(*iph),
1322 sizeof(_icmph), &_icmph);
1323 if (!icmph)
1324 goto out;
1325
1326 switch (icmph->icmp6_type) {
1327 case NDISC_ROUTER_SOLICITATION:
1328 case NDISC_ROUTER_ADVERTISEMENT:
1329 case NDISC_NEIGHBOUR_SOLICITATION:
1330 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1331 case NDISC_REDIRECT:
1332 rc = true;
1333 break;
1334 }
1335 }
1336
1337out:
1338 return rc;
1339}
1340
1341static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
1342 const struct net_device *dev,
1343 struct flowi6 *fl6,
1344 int ifindex,
1345 const struct sk_buff *skb,
1346 int flags)
1347{
1348 struct net_vrf *vrf = netdev_priv(dev);
1349
1350 return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags);
1351}
1352
1353static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
1354 int ifindex)
1355{
1356 const struct ipv6hdr *iph = ipv6_hdr(skb);
1357 struct flowi6 fl6 = {
1358 .flowi6_iif = ifindex,
1359 .flowi6_mark = skb->mark,
1360 .flowi6_proto = iph->nexthdr,
1361 .daddr = iph->daddr,
1362 .saddr = iph->saddr,
1363 .flowlabel = ip6_flowinfo(iph),
1364 };
1365 struct net *net = dev_net(vrf_dev);
1366 struct rt6_info *rt6;
1367
1368 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb,
1369 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
1370 if (unlikely(!rt6))
1371 return;
1372
1373 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
1374 return;
1375
1376 skb_dst_set(skb, &rt6->dst);
1377}
1378
1379static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1380 struct sk_buff *skb)
1381{
1382 int orig_iif = skb->skb_iif;
1383 bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
1384 bool is_ndisc = ipv6_ndisc_frame(skb);
1385
1386 /* loopback, multicast & non-ND link-local traffic; do not push through
1387 * packet taps again. Reset pkt_type for upper layers to process skb.
1388 * For non-loopback strict packets, determine the dst using the original
1389 * ifindex.
1390 */
1391 if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) {
1392 skb->dev = vrf_dev;
1393 skb->skb_iif = vrf_dev->ifindex;
1394 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1395
1396 if (skb->pkt_type == PACKET_LOOPBACK)
1397 skb->pkt_type = PACKET_HOST;
1398 else
1399 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1400
1401 goto out;
1402 }
1403
1404 /* if packet is NDISC then keep the ingress interface */
1405 if (!is_ndisc) {
1406 struct net_device *orig_dev = skb->dev;
1407
1408 vrf_rx_stats(vrf_dev, skb->len);
1409 skb->dev = vrf_dev;
1410 skb->skb_iif = vrf_dev->ifindex;
1411
1412 if (!list_empty(&vrf_dev->ptype_all)) {
1413 int err;
1414
1415 err = vrf_add_mac_header_if_unset(skb, vrf_dev,
1416 ETH_P_IPV6,
1417 orig_dev);
1418 if (likely(!err)) {
1419 skb_push(skb, skb->mac_len);
1420 dev_queue_xmit_nit(skb, vrf_dev);
1421 skb_pull(skb, skb->mac_len);
1422 }
1423 }
1424
1425 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1426 }
1427
1428 if (need_strict)
1429 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1430
1431 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
1432out:
1433 return skb;
1434}
1435
1436#else
1437static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1438 struct sk_buff *skb)
1439{
1440 return skb;
1441}
1442#endif
1443
1444static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
1445 struct sk_buff *skb)
1446{
1447 struct net_device *orig_dev = skb->dev;
1448
1449 skb->dev = vrf_dev;
1450 skb->skb_iif = vrf_dev->ifindex;
1451 IPCB(skb)->flags |= IPSKB_L3SLAVE;
1452
1453 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
1454 goto out;
1455
1456 /* loopback traffic; do not push through packet taps again.
1457 * Reset pkt_type for upper layers to process skb
1458 */
1459 if (skb->pkt_type == PACKET_LOOPBACK) {
1460 skb->pkt_type = PACKET_HOST;
1461 goto out;
1462 }
1463
1464 vrf_rx_stats(vrf_dev, skb->len);
1465
1466 if (!list_empty(&vrf_dev->ptype_all)) {
1467 int err;
1468
1469 err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP,
1470 orig_dev);
1471 if (likely(!err)) {
1472 skb_push(skb, skb->mac_len);
1473 dev_queue_xmit_nit(skb, vrf_dev);
1474 skb_pull(skb, skb->mac_len);
1475 }
1476 }
1477
1478 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
1479out:
1480 return skb;
1481}
1482
1483/* called with rcu lock held */
1484static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1485 struct sk_buff *skb,
1486 u16 proto)
1487{
1488 switch (proto) {
1489 case AF_INET:
1490 return vrf_ip_rcv(vrf_dev, skb);
1491 case AF_INET6:
1492 return vrf_ip6_rcv(vrf_dev, skb);
1493 }
1494
1495 return skb;
1496}
1497
1498#if IS_ENABLED(CONFIG_IPV6)
1499/* send to link-local or multicast address via interface enslaved to
1500 * VRF device. Force lookup to VRF table without changing flow struct
1501 * Note: Caller to this function must hold rcu_read_lock() and no refcnt
1502 * is taken on the dst by this function.
1503 */
1504static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1505 struct flowi6 *fl6)
1506{
1507 struct net *net = dev_net(dev);
1508 int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF;
1509 struct dst_entry *dst = NULL;
1510 struct rt6_info *rt;
1511
1512 /* VRF device does not have a link-local address and
1513 * sending packets to link-local or mcast addresses over
1514 * a VRF device does not make sense
1515 */
1516 if (fl6->flowi6_oif == dev->ifindex) {
1517 dst = &net->ipv6.ip6_null_entry->dst;
1518 return dst;
1519 }
1520
1521 if (!ipv6_addr_any(&fl6->saddr))
1522 flags |= RT6_LOOKUP_F_HAS_SADDR;
1523
1524 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags);
1525 if (rt)
1526 dst = &rt->dst;
1527
1528 return dst;
1529}
1530#endif
1531
1532static const struct l3mdev_ops vrf_l3mdev_ops = {
1533 .l3mdev_fib_table = vrf_fib_table,
1534 .l3mdev_l3_rcv = vrf_l3_rcv,
1535 .l3mdev_l3_out = vrf_l3_out,
1536#if IS_ENABLED(CONFIG_IPV6)
1537 .l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1538#endif
1539};
1540
1541static void vrf_get_drvinfo(struct net_device *dev,
1542 struct ethtool_drvinfo *info)
1543{
1544 strscpy(info->driver, DRV_NAME, sizeof(info->driver));
1545 strscpy(info->version, DRV_VERSION, sizeof(info->version));
1546}
1547
1548static const struct ethtool_ops vrf_ethtool_ops = {
1549 .get_drvinfo = vrf_get_drvinfo,
1550};
1551
1552static inline size_t vrf_fib_rule_nl_size(void)
1553{
1554 size_t sz;
1555
1556 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1557 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */
1558 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */
1559 sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */
1560
1561 return sz;
1562}
1563
1564static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1565{
1566 struct fib_rule_hdr *frh;
1567 struct nlmsghdr *nlh;
1568 struct sk_buff *skb;
1569 int err;
1570
1571 if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) &&
1572 !ipv6_mod_enabled())
1573 return 0;
1574
1575 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
1576 if (!skb)
1577 return -ENOMEM;
1578
1579 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
1580 if (!nlh)
1581 goto nla_put_failure;
1582
1583 /* rule only needs to appear once */
1584 nlh->nlmsg_flags |= NLM_F_EXCL;
1585
1586 frh = nlmsg_data(nlh);
1587 memset(frh, 0, sizeof(*frh));
1588 frh->family = family;
1589 frh->action = FR_ACT_TO_TBL;
1590
1591 if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL))
1592 goto nla_put_failure;
1593
1594 if (nla_put_u8(skb, FRA_L3MDEV, 1))
1595 goto nla_put_failure;
1596
1597 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
1598 goto nla_put_failure;
1599
1600 nlmsg_end(skb, nlh);
1601
1602 /* fib_nl_{new,del}rule handling looks for net from skb->sk */
1603 skb->sk = dev_net(dev)->rtnl;
1604 if (add_it) {
1605 err = fib_nl_newrule(skb, nlh, NULL);
1606 if (err == -EEXIST)
1607 err = 0;
1608 } else {
1609 err = fib_nl_delrule(skb, nlh, NULL);
1610 if (err == -ENOENT)
1611 err = 0;
1612 }
1613 nlmsg_free(skb);
1614
1615 return err;
1616
1617nla_put_failure:
1618 nlmsg_free(skb);
1619
1620 return -EMSGSIZE;
1621}
1622
1623static int vrf_add_fib_rules(const struct net_device *dev)
1624{
1625 int err;
1626
1627 err = vrf_fib_rule(dev, AF_INET, true);
1628 if (err < 0)
1629 goto out_err;
1630
1631 err = vrf_fib_rule(dev, AF_INET6, true);
1632 if (err < 0)
1633 goto ipv6_err;
1634
1635#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1636 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true);
1637 if (err < 0)
1638 goto ipmr_err;
1639#endif
1640
1641#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1642 err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, true);
1643 if (err < 0)
1644 goto ip6mr_err;
1645#endif
1646
1647 return 0;
1648
1649#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1650ip6mr_err:
1651 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, false);
1652#endif
1653
1654#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1655ipmr_err:
1656 vrf_fib_rule(dev, AF_INET6, false);
1657#endif
1658
1659ipv6_err:
1660 vrf_fib_rule(dev, AF_INET, false);
1661
1662out_err:
1663 netdev_err(dev, "Failed to add FIB rules.\n");
1664 return err;
1665}
1666
1667static void vrf_setup(struct net_device *dev)
1668{
1669 ether_setup(dev);
1670
1671 /* Initialize the device structure. */
1672 dev->netdev_ops = &vrf_netdev_ops;
1673 dev->l3mdev_ops = &vrf_l3mdev_ops;
1674 dev->ethtool_ops = &vrf_ethtool_ops;
1675 dev->needs_free_netdev = true;
1676
1677 /* Fill in device structure with ethernet-generic values. */
1678 eth_hw_addr_random(dev);
1679
1680 /* don't acquire vrf device's netif_tx_lock when transmitting */
1681 dev->features |= NETIF_F_LLTX;
1682
1683 /* don't allow vrf devices to change network namespaces. */
1684 dev->features |= NETIF_F_NETNS_LOCAL;
1685
1686 /* does not make sense for a VLAN to be added to a vrf device */
1687 dev->features |= NETIF_F_VLAN_CHALLENGED;
1688
1689 /* enable offload features */
1690 dev->features |= NETIF_F_GSO_SOFTWARE;
1691 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC;
1692 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1693
1694 dev->hw_features = dev->features;
1695 dev->hw_enc_features = dev->features;
1696
1697 /* default to no qdisc; user can add if desired */
1698 dev->priv_flags |= IFF_NO_QUEUE;
1699 dev->priv_flags |= IFF_NO_RX_HANDLER;
1700 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1701
1702 /* VRF devices do not care about MTU, but if the MTU is set
1703 * too low then the ipv4 and ipv6 protocols are disabled
1704 * which breaks networking.
1705 */
1706 dev->min_mtu = IPV6_MIN_MTU;
1707 dev->max_mtu = IP6_MAX_MTU;
1708 dev->mtu = dev->max_mtu;
1709}
1710
1711static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],
1712 struct netlink_ext_ack *extack)
1713{
1714 if (tb[IFLA_ADDRESS]) {
1715 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
1716 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1717 return -EINVAL;
1718 }
1719 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
1720 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1721 return -EADDRNOTAVAIL;
1722 }
1723 }
1724 return 0;
1725}
1726
1727static void vrf_dellink(struct net_device *dev, struct list_head *head)
1728{
1729 struct net_device *port_dev;
1730 struct list_head *iter;
1731
1732 netdev_for_each_lower_dev(dev, port_dev, iter)
1733 vrf_del_slave(dev, port_dev);
1734
1735 vrf_map_unregister_dev(dev);
1736
1737 unregister_netdevice_queue(dev, head);
1738}
1739
1740static int vrf_newlink(struct net *src_net, struct net_device *dev,
1741 struct nlattr *tb[], struct nlattr *data[],
1742 struct netlink_ext_ack *extack)
1743{
1744 struct net_vrf *vrf = netdev_priv(dev);
1745 struct netns_vrf *nn_vrf;
1746 bool *add_fib_rules;
1747 struct net *net;
1748 int err;
1749
1750 if (!data || !data[IFLA_VRF_TABLE]) {
1751 NL_SET_ERR_MSG(extack, "VRF table id is missing");
1752 return -EINVAL;
1753 }
1754
1755 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
1756 if (vrf->tb_id == RT_TABLE_UNSPEC) {
1757 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE],
1758 "Invalid VRF table id");
1759 return -EINVAL;
1760 }
1761
1762 dev->priv_flags |= IFF_L3MDEV_MASTER;
1763
1764 err = register_netdevice(dev);
1765 if (err)
1766 goto out;
1767
1768 /* mapping between table_id and vrf;
1769 * note: such binding could not be done in the dev init function
1770 * because dev->ifindex id is not available yet.
1771 */
1772 vrf->ifindex = dev->ifindex;
1773
1774 err = vrf_map_register_dev(dev, extack);
1775 if (err) {
1776 unregister_netdevice(dev);
1777 goto out;
1778 }
1779
1780 net = dev_net(dev);
1781 nn_vrf = net_generic(net, vrf_net_id);
1782
1783 add_fib_rules = &nn_vrf->add_fib_rules;
1784 if (*add_fib_rules) {
1785 err = vrf_add_fib_rules(dev);
1786 if (err) {
1787 vrf_map_unregister_dev(dev);
1788 unregister_netdevice(dev);
1789 goto out;
1790 }
1791 *add_fib_rules = false;
1792 }
1793
1794out:
1795 return err;
1796}
1797
1798static size_t vrf_nl_getsize(const struct net_device *dev)
1799{
1800 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
1801}
1802
1803static int vrf_fillinfo(struct sk_buff *skb,
1804 const struct net_device *dev)
1805{
1806 struct net_vrf *vrf = netdev_priv(dev);
1807
1808 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
1809}
1810
1811static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1812 const struct net_device *slave_dev)
1813{
1814 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1815}
1816
1817static int vrf_fill_slave_info(struct sk_buff *skb,
1818 const struct net_device *vrf_dev,
1819 const struct net_device *slave_dev)
1820{
1821 struct net_vrf *vrf = netdev_priv(vrf_dev);
1822
1823 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
1824 return -EMSGSIZE;
1825
1826 return 0;
1827}
1828
1829static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1830 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1831};
1832
1833static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1834 .kind = DRV_NAME,
1835 .priv_size = sizeof(struct net_vrf),
1836
1837 .get_size = vrf_nl_getsize,
1838 .policy = vrf_nl_policy,
1839 .validate = vrf_validate,
1840 .fill_info = vrf_fillinfo,
1841
1842 .get_slave_size = vrf_get_slave_size,
1843 .fill_slave_info = vrf_fill_slave_info,
1844
1845 .newlink = vrf_newlink,
1846 .dellink = vrf_dellink,
1847 .setup = vrf_setup,
1848 .maxtype = IFLA_VRF_MAX,
1849};
1850
1851static int vrf_device_event(struct notifier_block *unused,
1852 unsigned long event, void *ptr)
1853{
1854 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1855
1856 /* only care about unregister events to drop slave references */
1857 if (event == NETDEV_UNREGISTER) {
1858 struct net_device *vrf_dev;
1859
1860 if (!netif_is_l3_slave(dev))
1861 goto out;
1862
1863 vrf_dev = netdev_master_upper_dev_get(dev);
1864 vrf_del_slave(vrf_dev, dev);
1865 }
1866out:
1867 return NOTIFY_DONE;
1868}
1869
1870static struct notifier_block vrf_notifier_block __read_mostly = {
1871 .notifier_call = vrf_device_event,
1872};
1873
1874static int vrf_map_init(struct vrf_map *vmap)
1875{
1876 spin_lock_init(&vmap->vmap_lock);
1877 hash_init(vmap->ht);
1878
1879 vmap->strict_mode = false;
1880
1881 return 0;
1882}
1883
1884#ifdef CONFIG_SYSCTL
1885static bool vrf_strict_mode(struct vrf_map *vmap)
1886{
1887 bool strict_mode;
1888
1889 vrf_map_lock(vmap);
1890 strict_mode = vmap->strict_mode;
1891 vrf_map_unlock(vmap);
1892
1893 return strict_mode;
1894}
1895
1896static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode)
1897{
1898 bool *cur_mode;
1899 int res = 0;
1900
1901 vrf_map_lock(vmap);
1902
1903 cur_mode = &vmap->strict_mode;
1904 if (*cur_mode == new_mode)
1905 goto unlock;
1906
1907 if (*cur_mode) {
1908 /* disable strict mode */
1909 *cur_mode = false;
1910 } else {
1911 if (vmap->shared_tables) {
1912 /* we cannot allow strict_mode because there are some
1913 * vrfs that share one or more tables.
1914 */
1915 res = -EBUSY;
1916 goto unlock;
1917 }
1918
1919 /* no tables are shared among vrfs, so we can go back
1920 * to 1:1 association between a vrf with its table.
1921 */
1922 *cur_mode = true;
1923 }
1924
1925unlock:
1926 vrf_map_unlock(vmap);
1927
1928 return res;
1929}
1930
1931static int vrf_shared_table_handler(struct ctl_table *table, int write,
1932 void *buffer, size_t *lenp, loff_t *ppos)
1933{
1934 struct net *net = (struct net *)table->extra1;
1935 struct vrf_map *vmap = netns_vrf_map(net);
1936 int proc_strict_mode = 0;
1937 struct ctl_table tmp = {
1938 .procname = table->procname,
1939 .data = &proc_strict_mode,
1940 .maxlen = sizeof(int),
1941 .mode = table->mode,
1942 .extra1 = SYSCTL_ZERO,
1943 .extra2 = SYSCTL_ONE,
1944 };
1945 int ret;
1946
1947 if (!write)
1948 proc_strict_mode = vrf_strict_mode(vmap);
1949
1950 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
1951
1952 if (write && ret == 0)
1953 ret = vrf_strict_mode_change(vmap, (bool)proc_strict_mode);
1954
1955 return ret;
1956}
1957
1958static const struct ctl_table vrf_table[] = {
1959 {
1960 .procname = "strict_mode",
1961 .data = NULL,
1962 .maxlen = sizeof(int),
1963 .mode = 0644,
1964 .proc_handler = vrf_shared_table_handler,
1965 /* set by the vrf_netns_init */
1966 .extra1 = NULL,
1967 },
1968 { },
1969};
1970
1971static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1972{
1973 struct ctl_table *table;
1974
1975 table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL);
1976 if (!table)
1977 return -ENOMEM;
1978
1979 /* init the extra1 parameter with the reference to current netns */
1980 table[0].extra1 = net;
1981
1982 nn_vrf->ctl_hdr = register_net_sysctl(net, "net/vrf", table);
1983 if (!nn_vrf->ctl_hdr) {
1984 kfree(table);
1985 return -ENOMEM;
1986 }
1987
1988 return 0;
1989}
1990
1991static void vrf_netns_exit_sysctl(struct net *net)
1992{
1993 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
1994 struct ctl_table *table;
1995
1996 table = nn_vrf->ctl_hdr->ctl_table_arg;
1997 unregister_net_sysctl_table(nn_vrf->ctl_hdr);
1998 kfree(table);
1999}
2000#else
2001static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
2002{
2003 return 0;
2004}
2005
2006static void vrf_netns_exit_sysctl(struct net *net)
2007{
2008}
2009#endif
2010
2011/* Initialize per network namespace state */
2012static int __net_init vrf_netns_init(struct net *net)
2013{
2014 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
2015
2016 nn_vrf->add_fib_rules = true;
2017 vrf_map_init(&nn_vrf->vmap);
2018
2019 return vrf_netns_init_sysctl(net, nn_vrf);
2020}
2021
2022static void __net_exit vrf_netns_exit(struct net *net)
2023{
2024 vrf_netns_exit_sysctl(net);
2025}
2026
2027static struct pernet_operations vrf_net_ops __net_initdata = {
2028 .init = vrf_netns_init,
2029 .exit = vrf_netns_exit,
2030 .id = &vrf_net_id,
2031 .size = sizeof(struct netns_vrf),
2032};
2033
2034static int __init vrf_init_module(void)
2035{
2036 int rc;
2037
2038 register_netdevice_notifier(&vrf_notifier_block);
2039
2040 rc = register_pernet_subsys(&vrf_net_ops);
2041 if (rc < 0)
2042 goto error;
2043
2044 rc = l3mdev_table_lookup_register(L3MDEV_TYPE_VRF,
2045 vrf_ifindex_lookup_by_table_id);
2046 if (rc < 0)
2047 goto unreg_pernet;
2048
2049 rc = rtnl_link_register(&vrf_link_ops);
2050 if (rc < 0)
2051 goto table_lookup_unreg;
2052
2053 return 0;
2054
2055table_lookup_unreg:
2056 l3mdev_table_lookup_unregister(L3MDEV_TYPE_VRF,
2057 vrf_ifindex_lookup_by_table_id);
2058
2059unreg_pernet:
2060 unregister_pernet_subsys(&vrf_net_ops);
2061
2062error:
2063 unregister_netdevice_notifier(&vrf_notifier_block);
2064 return rc;
2065}
2066
2067module_init(vrf_init_module);
2068MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
2069MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
2070MODULE_LICENSE("GPL");
2071MODULE_ALIAS_RTNL_LINK(DRV_NAME);
2072MODULE_VERSION(DRV_VERSION);