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Merge remote-tracking branch 'percpu/for-next'
[deliverable/linux.git] / drivers / net / vrf.c
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
40 #define RT_FL_TOS(oldflp4) \
41 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
42
43 #define DRV_NAME "vrf"
44 #define DRV_VERSION "1.0"
45
46 #define FIB_RULE_PREF 1000 /* default preference for FIB rules */
47 static bool add_fib_rules = true;
48
49 struct net_vrf {
50 struct rtable __rcu *rth;
51 struct rtable __rcu *rth_local;
52 struct rt6_info __rcu *rt6;
53 struct rt6_info __rcu *rt6_local;
54 u32 tb_id;
55 };
56
57 struct pcpu_dstats {
58 u64 tx_pkts;
59 u64 tx_bytes;
60 u64 tx_drps;
61 u64 rx_pkts;
62 u64 rx_bytes;
63 u64 rx_drps;
64 struct u64_stats_sync syncp;
65 };
66
67 static void vrf_rx_stats(struct net_device *dev, int len)
68 {
69 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
70
71 u64_stats_update_begin(&dstats->syncp);
72 dstats->rx_pkts++;
73 dstats->rx_bytes += len;
74 u64_stats_update_end(&dstats->syncp);
75 }
76
77 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
78 {
79 vrf_dev->stats.tx_errors++;
80 kfree_skb(skb);
81 }
82
83 static struct rtnl_link_stats64 *vrf_get_stats64(struct net_device *dev,
84 struct rtnl_link_stats64 *stats)
85 {
86 int i;
87
88 for_each_possible_cpu(i) {
89 const struct pcpu_dstats *dstats;
90 u64 tbytes, tpkts, tdrops, rbytes, rpkts;
91 unsigned int start;
92
93 dstats = per_cpu_ptr(dev->dstats, i);
94 do {
95 start = u64_stats_fetch_begin_irq(&dstats->syncp);
96 tbytes = dstats->tx_bytes;
97 tpkts = dstats->tx_pkts;
98 tdrops = dstats->tx_drps;
99 rbytes = dstats->rx_bytes;
100 rpkts = dstats->rx_pkts;
101 } while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
102 stats->tx_bytes += tbytes;
103 stats->tx_packets += tpkts;
104 stats->tx_dropped += tdrops;
105 stats->rx_bytes += rbytes;
106 stats->rx_packets += rpkts;
107 }
108 return stats;
109 }
110
111 /* Local traffic destined to local address. Reinsert the packet to rx
112 * path, similar to loopback handling.
113 */
114 static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
115 struct dst_entry *dst)
116 {
117 int len = skb->len;
118
119 skb_orphan(skb);
120
121 skb_dst_set(skb, dst);
122 skb_dst_force(skb);
123
124 /* set pkt_type to avoid skb hitting packet taps twice -
125 * once on Tx and again in Rx processing
126 */
127 skb->pkt_type = PACKET_LOOPBACK;
128
129 skb->protocol = eth_type_trans(skb, dev);
130
131 if (likely(netif_rx(skb) == NET_RX_SUCCESS))
132 vrf_rx_stats(dev, len);
133 else
134 this_cpu_inc(dev->dstats->rx_drps);
135
136 return NETDEV_TX_OK;
137 }
138
139 #if IS_ENABLED(CONFIG_IPV6)
140 static int vrf_ip6_local_out(struct net *net, struct sock *sk,
141 struct sk_buff *skb)
142 {
143 int err;
144
145 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net,
146 sk, skb, NULL, skb_dst(skb)->dev, dst_output);
147
148 if (likely(err == 1))
149 err = dst_output(net, sk, skb);
150
151 return err;
152 }
153
154 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
155 struct net_device *dev)
156 {
157 const struct ipv6hdr *iph = ipv6_hdr(skb);
158 struct net *net = dev_net(skb->dev);
159 struct flowi6 fl6 = {
160 /* needed to match OIF rule */
161 .flowi6_oif = dev->ifindex,
162 .flowi6_iif = LOOPBACK_IFINDEX,
163 .daddr = iph->daddr,
164 .saddr = iph->saddr,
165 .flowlabel = ip6_flowinfo(iph),
166 .flowi6_mark = skb->mark,
167 .flowi6_proto = iph->nexthdr,
168 .flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF,
169 };
170 int ret = NET_XMIT_DROP;
171 struct dst_entry *dst;
172 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
173
174 dst = ip6_route_output(net, NULL, &fl6);
175 if (dst == dst_null)
176 goto err;
177
178 skb_dst_drop(skb);
179
180 /* if dst.dev is loopback or the VRF device again this is locally
181 * originated traffic destined to a local address. Short circuit
182 * to Rx path using our local dst
183 */
184 if (dst->dev == net->loopback_dev || dst->dev == dev) {
185 struct net_vrf *vrf = netdev_priv(dev);
186 struct rt6_info *rt6_local;
187
188 /* release looked up dst and use cached local dst */
189 dst_release(dst);
190
191 rcu_read_lock();
192
193 rt6_local = rcu_dereference(vrf->rt6_local);
194 if (unlikely(!rt6_local)) {
195 rcu_read_unlock();
196 goto err;
197 }
198
199 /* Ordering issue: cached local dst is created on newlink
200 * before the IPv6 initialization. Using the local dst
201 * requires rt6i_idev to be set so make sure it is.
202 */
203 if (unlikely(!rt6_local->rt6i_idev)) {
204 rt6_local->rt6i_idev = in6_dev_get(dev);
205 if (!rt6_local->rt6i_idev) {
206 rcu_read_unlock();
207 goto err;
208 }
209 }
210
211 dst = &rt6_local->dst;
212 dst_hold(dst);
213
214 rcu_read_unlock();
215
216 return vrf_local_xmit(skb, dev, &rt6_local->dst);
217 }
218
219 skb_dst_set(skb, dst);
220
221 /* strip the ethernet header added for pass through VRF device */
222 __skb_pull(skb, skb_network_offset(skb));
223
224 ret = vrf_ip6_local_out(net, skb->sk, skb);
225 if (unlikely(net_xmit_eval(ret)))
226 dev->stats.tx_errors++;
227 else
228 ret = NET_XMIT_SUCCESS;
229
230 return ret;
231 err:
232 vrf_tx_error(dev, skb);
233 return NET_XMIT_DROP;
234 }
235 #else
236 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
237 struct net_device *dev)
238 {
239 vrf_tx_error(dev, skb);
240 return NET_XMIT_DROP;
241 }
242 #endif
243
244 /* based on ip_local_out; can't use it b/c the dst is switched pointing to us */
245 static int vrf_ip_local_out(struct net *net, struct sock *sk,
246 struct sk_buff *skb)
247 {
248 int err;
249
250 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
251 skb, NULL, skb_dst(skb)->dev, dst_output);
252 if (likely(err == 1))
253 err = dst_output(net, sk, skb);
254
255 return err;
256 }
257
258 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
259 struct net_device *vrf_dev)
260 {
261 struct iphdr *ip4h = ip_hdr(skb);
262 int ret = NET_XMIT_DROP;
263 struct flowi4 fl4 = {
264 /* needed to match OIF rule */
265 .flowi4_oif = vrf_dev->ifindex,
266 .flowi4_iif = LOOPBACK_IFINDEX,
267 .flowi4_tos = RT_TOS(ip4h->tos),
268 .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF,
269 .daddr = ip4h->daddr,
270 };
271 struct net *net = dev_net(vrf_dev);
272 struct rtable *rt;
273
274 rt = ip_route_output_flow(net, &fl4, NULL);
275 if (IS_ERR(rt))
276 goto err;
277
278 if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
279 ip_rt_put(rt);
280 goto err;
281 }
282
283 skb_dst_drop(skb);
284
285 /* if dst.dev is loopback or the VRF device again this is locally
286 * originated traffic destined to a local address. Short circuit
287 * to Rx path using our local dst
288 */
289 if (rt->dst.dev == net->loopback_dev || rt->dst.dev == vrf_dev) {
290 struct net_vrf *vrf = netdev_priv(vrf_dev);
291 struct rtable *rth_local;
292 struct dst_entry *dst = NULL;
293
294 ip_rt_put(rt);
295
296 rcu_read_lock();
297
298 rth_local = rcu_dereference(vrf->rth_local);
299 if (likely(rth_local)) {
300 dst = &rth_local->dst;
301 dst_hold(dst);
302 }
303
304 rcu_read_unlock();
305
306 if (unlikely(!dst))
307 goto err;
308
309 return vrf_local_xmit(skb, vrf_dev, dst);
310 }
311
312 skb_dst_set(skb, &rt->dst);
313
314 /* strip the ethernet header added for pass through VRF device */
315 __skb_pull(skb, skb_network_offset(skb));
316
317 if (!ip4h->saddr) {
318 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
319 RT_SCOPE_LINK);
320 }
321
322 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
323 if (unlikely(net_xmit_eval(ret)))
324 vrf_dev->stats.tx_errors++;
325 else
326 ret = NET_XMIT_SUCCESS;
327
328 out:
329 return ret;
330 err:
331 vrf_tx_error(vrf_dev, skb);
332 goto out;
333 }
334
335 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
336 {
337 switch (skb->protocol) {
338 case htons(ETH_P_IP):
339 return vrf_process_v4_outbound(skb, dev);
340 case htons(ETH_P_IPV6):
341 return vrf_process_v6_outbound(skb, dev);
342 default:
343 vrf_tx_error(dev, skb);
344 return NET_XMIT_DROP;
345 }
346 }
347
348 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
349 {
350 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
351
352 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
353 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
354
355 u64_stats_update_begin(&dstats->syncp);
356 dstats->tx_pkts++;
357 dstats->tx_bytes += skb->len;
358 u64_stats_update_end(&dstats->syncp);
359 } else {
360 this_cpu_inc(dev->dstats->tx_drps);
361 }
362
363 return ret;
364 }
365
366 #if IS_ENABLED(CONFIG_IPV6)
367 /* modelled after ip6_finish_output2 */
368 static int vrf_finish_output6(struct net *net, struct sock *sk,
369 struct sk_buff *skb)
370 {
371 struct dst_entry *dst = skb_dst(skb);
372 struct net_device *dev = dst->dev;
373 struct neighbour *neigh;
374 struct in6_addr *nexthop;
375 int ret;
376
377 skb->protocol = htons(ETH_P_IPV6);
378 skb->dev = dev;
379
380 rcu_read_lock_bh();
381 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
382 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
383 if (unlikely(!neigh))
384 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
385 if (!IS_ERR(neigh)) {
386 ret = dst_neigh_output(dst, neigh, skb);
387 rcu_read_unlock_bh();
388 return ret;
389 }
390 rcu_read_unlock_bh();
391
392 IP6_INC_STATS(dev_net(dst->dev),
393 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
394 kfree_skb(skb);
395 return -EINVAL;
396 }
397
398 /* modelled after ip6_output */
399 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
400 {
401 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
402 net, sk, skb, NULL, skb_dst(skb)->dev,
403 vrf_finish_output6,
404 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
405 }
406
407 /* set dst on skb to send packet to us via dev_xmit path. Allows
408 * packet to go through device based features such as qdisc, netfilter
409 * hooks and packet sockets with skb->dev set to vrf device.
410 */
411 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
412 struct sock *sk,
413 struct sk_buff *skb)
414 {
415 struct net_vrf *vrf = netdev_priv(vrf_dev);
416 struct dst_entry *dst = NULL;
417 struct rt6_info *rt6;
418
419 /* don't divert link scope packets */
420 if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
421 return skb;
422
423 rcu_read_lock();
424
425 rt6 = rcu_dereference(vrf->rt6);
426 if (likely(rt6)) {
427 dst = &rt6->dst;
428 dst_hold(dst);
429 }
430
431 rcu_read_unlock();
432
433 if (unlikely(!dst)) {
434 vrf_tx_error(vrf_dev, skb);
435 return NULL;
436 }
437
438 skb_dst_drop(skb);
439 skb_dst_set(skb, dst);
440
441 return skb;
442 }
443
444 /* holding rtnl */
445 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
446 {
447 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
448 struct rt6_info *rt6_local = rtnl_dereference(vrf->rt6_local);
449 struct net *net = dev_net(dev);
450 struct dst_entry *dst;
451
452 RCU_INIT_POINTER(vrf->rt6, NULL);
453 RCU_INIT_POINTER(vrf->rt6_local, NULL);
454 synchronize_rcu();
455
456 /* move dev in dst's to loopback so this VRF device can be deleted
457 * - based on dst_ifdown
458 */
459 if (rt6) {
460 dst = &rt6->dst;
461 dev_put(dst->dev);
462 dst->dev = net->loopback_dev;
463 dev_hold(dst->dev);
464 dst_release(dst);
465 }
466
467 if (rt6_local) {
468 if (rt6_local->rt6i_idev)
469 in6_dev_put(rt6_local->rt6i_idev);
470
471 dst = &rt6_local->dst;
472 dev_put(dst->dev);
473 dst->dev = net->loopback_dev;
474 dev_hold(dst->dev);
475 dst_release(dst);
476 }
477 }
478
479 static int vrf_rt6_create(struct net_device *dev)
480 {
481 int flags = DST_HOST | DST_NOPOLICY | DST_NOXFRM | DST_NOCACHE;
482 struct net_vrf *vrf = netdev_priv(dev);
483 struct net *net = dev_net(dev);
484 struct fib6_table *rt6i_table;
485 struct rt6_info *rt6, *rt6_local;
486 int rc = -ENOMEM;
487
488 /* IPv6 can be CONFIG enabled and then disabled runtime */
489 if (!ipv6_mod_enabled())
490 return 0;
491
492 rt6i_table = fib6_new_table(net, vrf->tb_id);
493 if (!rt6i_table)
494 goto out;
495
496 /* create a dst for routing packets out a VRF device */
497 rt6 = ip6_dst_alloc(net, dev, flags);
498 if (!rt6)
499 goto out;
500
501 dst_hold(&rt6->dst);
502
503 rt6->rt6i_table = rt6i_table;
504 rt6->dst.output = vrf_output6;
505
506 /* create a dst for local routing - packets sent locally
507 * to local address via the VRF device as a loopback
508 */
509 rt6_local = ip6_dst_alloc(net, dev, flags);
510 if (!rt6_local) {
511 dst_release(&rt6->dst);
512 goto out;
513 }
514
515 dst_hold(&rt6_local->dst);
516
517 rt6_local->rt6i_idev = in6_dev_get(dev);
518 rt6_local->rt6i_flags = RTF_UP | RTF_NONEXTHOP | RTF_LOCAL;
519 rt6_local->rt6i_table = rt6i_table;
520 rt6_local->dst.input = ip6_input;
521
522 rcu_assign_pointer(vrf->rt6, rt6);
523 rcu_assign_pointer(vrf->rt6_local, rt6_local);
524
525 rc = 0;
526 out:
527 return rc;
528 }
529 #else
530 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
531 struct sock *sk,
532 struct sk_buff *skb)
533 {
534 return skb;
535 }
536
537 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
538 {
539 }
540
541 static int vrf_rt6_create(struct net_device *dev)
542 {
543 return 0;
544 }
545 #endif
546
547 /* modelled after ip_finish_output2 */
548 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
549 {
550 struct dst_entry *dst = skb_dst(skb);
551 struct rtable *rt = (struct rtable *)dst;
552 struct net_device *dev = dst->dev;
553 unsigned int hh_len = LL_RESERVED_SPACE(dev);
554 struct neighbour *neigh;
555 u32 nexthop;
556 int ret = -EINVAL;
557
558 /* Be paranoid, rather than too clever. */
559 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
560 struct sk_buff *skb2;
561
562 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
563 if (!skb2) {
564 ret = -ENOMEM;
565 goto err;
566 }
567 if (skb->sk)
568 skb_set_owner_w(skb2, skb->sk);
569
570 consume_skb(skb);
571 skb = skb2;
572 }
573
574 rcu_read_lock_bh();
575
576 nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr);
577 neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
578 if (unlikely(!neigh))
579 neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
580 if (!IS_ERR(neigh))
581 ret = dst_neigh_output(dst, neigh, skb);
582
583 rcu_read_unlock_bh();
584 err:
585 if (unlikely(ret < 0))
586 vrf_tx_error(skb->dev, skb);
587 return ret;
588 }
589
590 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
591 {
592 struct net_device *dev = skb_dst(skb)->dev;
593
594 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
595
596 skb->dev = dev;
597 skb->protocol = htons(ETH_P_IP);
598
599 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
600 net, sk, skb, NULL, dev,
601 vrf_finish_output,
602 !(IPCB(skb)->flags & IPSKB_REROUTED));
603 }
604
605 /* set dst on skb to send packet to us via dev_xmit path. Allows
606 * packet to go through device based features such as qdisc, netfilter
607 * hooks and packet sockets with skb->dev set to vrf device.
608 */
609 static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
610 struct sock *sk,
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
638 /* called with rcu lock held */
639 static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
640 struct sock *sk,
641 struct sk_buff *skb,
642 u16 proto)
643 {
644 switch (proto) {
645 case AF_INET:
646 return vrf_ip_out(vrf_dev, sk, skb);
647 case AF_INET6:
648 return vrf_ip6_out(vrf_dev, sk, skb);
649 }
650
651 return skb;
652 }
653
654 /* holding rtnl */
655 static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
656 {
657 struct rtable *rth = rtnl_dereference(vrf->rth);
658 struct rtable *rth_local = rtnl_dereference(vrf->rth_local);
659 struct net *net = dev_net(dev);
660 struct dst_entry *dst;
661
662 RCU_INIT_POINTER(vrf->rth, NULL);
663 RCU_INIT_POINTER(vrf->rth_local, NULL);
664 synchronize_rcu();
665
666 /* move dev in dst's to loopback so this VRF device can be deleted
667 * - based on dst_ifdown
668 */
669 if (rth) {
670 dst = &rth->dst;
671 dev_put(dst->dev);
672 dst->dev = net->loopback_dev;
673 dev_hold(dst->dev);
674 dst_release(dst);
675 }
676
677 if (rth_local) {
678 dst = &rth_local->dst;
679 dev_put(dst->dev);
680 dst->dev = net->loopback_dev;
681 dev_hold(dst->dev);
682 dst_release(dst);
683 }
684 }
685
686 static int vrf_rtable_create(struct net_device *dev)
687 {
688 struct net_vrf *vrf = netdev_priv(dev);
689 struct rtable *rth, *rth_local;
690
691 if (!fib_new_table(dev_net(dev), vrf->tb_id))
692 return -ENOMEM;
693
694 /* create a dst for routing packets out through a VRF device */
695 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1, 0);
696 if (!rth)
697 return -ENOMEM;
698
699 /* create a dst for local ingress routing - packets sent locally
700 * to local address via the VRF device as a loopback
701 */
702 rth_local = rt_dst_alloc(dev, RTCF_LOCAL, RTN_LOCAL, 1, 1, 0);
703 if (!rth_local) {
704 dst_release(&rth->dst);
705 return -ENOMEM;
706 }
707
708 rth->dst.output = vrf_output;
709 rth->rt_table_id = vrf->tb_id;
710
711 rth_local->rt_table_id = vrf->tb_id;
712
713 rcu_assign_pointer(vrf->rth, rth);
714 rcu_assign_pointer(vrf->rth_local, rth_local);
715
716 return 0;
717 }
718
719 /**************************** device handling ********************/
720
721 /* cycle interface to flush neighbor cache and move routes across tables */
722 static void cycle_netdev(struct net_device *dev)
723 {
724 unsigned int flags = dev->flags;
725 int ret;
726
727 if (!netif_running(dev))
728 return;
729
730 ret = dev_change_flags(dev, flags & ~IFF_UP);
731 if (ret >= 0)
732 ret = dev_change_flags(dev, flags);
733
734 if (ret < 0) {
735 netdev_err(dev,
736 "Failed to cycle device %s; route tables might be wrong!\n",
737 dev->name);
738 }
739 }
740
741 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
742 {
743 int ret;
744
745 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL);
746 if (ret < 0)
747 return ret;
748
749 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
750 cycle_netdev(port_dev);
751
752 return 0;
753 }
754
755 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
756 {
757 if (netif_is_l3_master(port_dev) || netif_is_l3_slave(port_dev))
758 return -EINVAL;
759
760 return do_vrf_add_slave(dev, port_dev);
761 }
762
763 /* inverse of do_vrf_add_slave */
764 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
765 {
766 netdev_upper_dev_unlink(port_dev, dev);
767 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
768
769 cycle_netdev(port_dev);
770
771 return 0;
772 }
773
774 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
775 {
776 return do_vrf_del_slave(dev, port_dev);
777 }
778
779 static void vrf_dev_uninit(struct net_device *dev)
780 {
781 struct net_vrf *vrf = netdev_priv(dev);
782 struct net_device *port_dev;
783 struct list_head *iter;
784
785 vrf_rtable_release(dev, vrf);
786 vrf_rt6_release(dev, vrf);
787
788 netdev_for_each_lower_dev(dev, port_dev, iter)
789 vrf_del_slave(dev, port_dev);
790
791 free_percpu(dev->dstats);
792 dev->dstats = NULL;
793 }
794
795 static int vrf_dev_init(struct net_device *dev)
796 {
797 struct net_vrf *vrf = netdev_priv(dev);
798
799 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
800 if (!dev->dstats)
801 goto out_nomem;
802
803 /* create the default dst which points back to us */
804 if (vrf_rtable_create(dev) != 0)
805 goto out_stats;
806
807 if (vrf_rt6_create(dev) != 0)
808 goto out_rth;
809
810 dev->flags = IFF_MASTER | IFF_NOARP;
811
812 /* MTU is irrelevant for VRF device; set to 64k similar to lo */
813 dev->mtu = 64 * 1024;
814
815 /* similarly, oper state is irrelevant; set to up to avoid confusion */
816 dev->operstate = IF_OPER_UP;
817 netdev_lockdep_set_classes(dev);
818 return 0;
819
820 out_rth:
821 vrf_rtable_release(dev, vrf);
822 out_stats:
823 free_percpu(dev->dstats);
824 dev->dstats = NULL;
825 out_nomem:
826 return -ENOMEM;
827 }
828
829 static const struct net_device_ops vrf_netdev_ops = {
830 .ndo_init = vrf_dev_init,
831 .ndo_uninit = vrf_dev_uninit,
832 .ndo_start_xmit = vrf_xmit,
833 .ndo_get_stats64 = vrf_get_stats64,
834 .ndo_add_slave = vrf_add_slave,
835 .ndo_del_slave = vrf_del_slave,
836 };
837
838 static u32 vrf_fib_table(const struct net_device *dev)
839 {
840 struct net_vrf *vrf = netdev_priv(dev);
841
842 return vrf->tb_id;
843 }
844
845 static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
846 {
847 return 0;
848 }
849
850 static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
851 struct sk_buff *skb,
852 struct net_device *dev)
853 {
854 struct net *net = dev_net(dev);
855
856 nf_reset(skb);
857
858 if (NF_HOOK(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) < 0)
859 skb = NULL; /* kfree_skb(skb) handled by nf code */
860
861 return skb;
862 }
863
864 #if IS_ENABLED(CONFIG_IPV6)
865 /* neighbor handling is done with actual device; do not want
866 * to flip skb->dev for those ndisc packets. This really fails
867 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
868 * a start.
869 */
870 static bool ipv6_ndisc_frame(const struct sk_buff *skb)
871 {
872 const struct ipv6hdr *iph = ipv6_hdr(skb);
873 bool rc = false;
874
875 if (iph->nexthdr == NEXTHDR_ICMP) {
876 const struct icmp6hdr *icmph;
877 struct icmp6hdr _icmph;
878
879 icmph = skb_header_pointer(skb, sizeof(*iph),
880 sizeof(_icmph), &_icmph);
881 if (!icmph)
882 goto out;
883
884 switch (icmph->icmp6_type) {
885 case NDISC_ROUTER_SOLICITATION:
886 case NDISC_ROUTER_ADVERTISEMENT:
887 case NDISC_NEIGHBOUR_SOLICITATION:
888 case NDISC_NEIGHBOUR_ADVERTISEMENT:
889 case NDISC_REDIRECT:
890 rc = true;
891 break;
892 }
893 }
894
895 out:
896 return rc;
897 }
898
899 static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
900 const struct net_device *dev,
901 struct flowi6 *fl6,
902 int ifindex,
903 int flags)
904 {
905 struct net_vrf *vrf = netdev_priv(dev);
906 struct fib6_table *table = NULL;
907 struct rt6_info *rt6;
908
909 rcu_read_lock();
910
911 /* fib6_table does not have a refcnt and can not be freed */
912 rt6 = rcu_dereference(vrf->rt6);
913 if (likely(rt6))
914 table = rt6->rt6i_table;
915
916 rcu_read_unlock();
917
918 if (!table)
919 return NULL;
920
921 return ip6_pol_route(net, table, ifindex, fl6, flags);
922 }
923
924 static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
925 int ifindex)
926 {
927 const struct ipv6hdr *iph = ipv6_hdr(skb);
928 struct flowi6 fl6 = {
929 .daddr = iph->daddr,
930 .saddr = iph->saddr,
931 .flowlabel = ip6_flowinfo(iph),
932 .flowi6_mark = skb->mark,
933 .flowi6_proto = iph->nexthdr,
934 .flowi6_iif = ifindex,
935 };
936 struct net *net = dev_net(vrf_dev);
937 struct rt6_info *rt6;
938
939 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex,
940 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
941 if (unlikely(!rt6))
942 return;
943
944 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
945 return;
946
947 skb_dst_set(skb, &rt6->dst);
948 }
949
950 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
951 struct sk_buff *skb)
952 {
953 int orig_iif = skb->skb_iif;
954 bool need_strict;
955
956 /* loopback traffic; do not push through packet taps again.
957 * Reset pkt_type for upper layers to process skb
958 */
959 if (skb->pkt_type == PACKET_LOOPBACK) {
960 skb->dev = vrf_dev;
961 skb->skb_iif = vrf_dev->ifindex;
962 skb->pkt_type = PACKET_HOST;
963 goto out;
964 }
965
966 /* if packet is NDISC or addressed to multicast or link-local
967 * then keep the ingress interface
968 */
969 need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
970 if (!ipv6_ndisc_frame(skb) && !need_strict) {
971 skb->dev = vrf_dev;
972 skb->skb_iif = vrf_dev->ifindex;
973
974 skb_push(skb, skb->mac_len);
975 dev_queue_xmit_nit(skb, vrf_dev);
976 skb_pull(skb, skb->mac_len);
977
978 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
979 }
980
981 if (need_strict)
982 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
983
984 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
985 out:
986 return skb;
987 }
988
989 #else
990 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
991 struct sk_buff *skb)
992 {
993 return skb;
994 }
995 #endif
996
997 static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
998 struct sk_buff *skb)
999 {
1000 skb->dev = vrf_dev;
1001 skb->skb_iif = vrf_dev->ifindex;
1002
1003 /* loopback traffic; do not push through packet taps again.
1004 * Reset pkt_type for upper layers to process skb
1005 */
1006 if (skb->pkt_type == PACKET_LOOPBACK) {
1007 skb->pkt_type = PACKET_HOST;
1008 goto out;
1009 }
1010
1011 skb_push(skb, skb->mac_len);
1012 dev_queue_xmit_nit(skb, vrf_dev);
1013 skb_pull(skb, skb->mac_len);
1014
1015 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
1016 out:
1017 return skb;
1018 }
1019
1020 /* called with rcu lock held */
1021 static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1022 struct sk_buff *skb,
1023 u16 proto)
1024 {
1025 switch (proto) {
1026 case AF_INET:
1027 return vrf_ip_rcv(vrf_dev, skb);
1028 case AF_INET6:
1029 return vrf_ip6_rcv(vrf_dev, skb);
1030 }
1031
1032 return skb;
1033 }
1034
1035 #if IS_ENABLED(CONFIG_IPV6)
1036 /* send to link-local or multicast address via interface enslaved to
1037 * VRF device. Force lookup to VRF table without changing flow struct
1038 */
1039 static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1040 struct flowi6 *fl6)
1041 {
1042 struct net *net = dev_net(dev);
1043 int flags = RT6_LOOKUP_F_IFACE;
1044 struct dst_entry *dst = NULL;
1045 struct rt6_info *rt;
1046
1047 /* VRF device does not have a link-local address and
1048 * sending packets to link-local or mcast addresses over
1049 * a VRF device does not make sense
1050 */
1051 if (fl6->flowi6_oif == dev->ifindex) {
1052 dst = &net->ipv6.ip6_null_entry->dst;
1053 dst_hold(dst);
1054 return dst;
1055 }
1056
1057 if (!ipv6_addr_any(&fl6->saddr))
1058 flags |= RT6_LOOKUP_F_HAS_SADDR;
1059
1060 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, flags);
1061 if (rt)
1062 dst = &rt->dst;
1063
1064 return dst;
1065 }
1066 #endif
1067
1068 static const struct l3mdev_ops vrf_l3mdev_ops = {
1069 .l3mdev_fib_table = vrf_fib_table,
1070 .l3mdev_l3_rcv = vrf_l3_rcv,
1071 .l3mdev_l3_out = vrf_l3_out,
1072 #if IS_ENABLED(CONFIG_IPV6)
1073 .l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1074 #endif
1075 };
1076
1077 static void vrf_get_drvinfo(struct net_device *dev,
1078 struct ethtool_drvinfo *info)
1079 {
1080 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
1081 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
1082 }
1083
1084 static const struct ethtool_ops vrf_ethtool_ops = {
1085 .get_drvinfo = vrf_get_drvinfo,
1086 };
1087
1088 static inline size_t vrf_fib_rule_nl_size(void)
1089 {
1090 size_t sz;
1091
1092 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1093 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */
1094 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */
1095
1096 return sz;
1097 }
1098
1099 static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1100 {
1101 struct fib_rule_hdr *frh;
1102 struct nlmsghdr *nlh;
1103 struct sk_buff *skb;
1104 int err;
1105
1106 if (family == AF_INET6 && !ipv6_mod_enabled())
1107 return 0;
1108
1109 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
1110 if (!skb)
1111 return -ENOMEM;
1112
1113 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
1114 if (!nlh)
1115 goto nla_put_failure;
1116
1117 /* rule only needs to appear once */
1118 nlh->nlmsg_flags &= NLM_F_EXCL;
1119
1120 frh = nlmsg_data(nlh);
1121 memset(frh, 0, sizeof(*frh));
1122 frh->family = family;
1123 frh->action = FR_ACT_TO_TBL;
1124
1125 if (nla_put_u32(skb, FRA_L3MDEV, 1))
1126 goto nla_put_failure;
1127
1128 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
1129 goto nla_put_failure;
1130
1131 nlmsg_end(skb, nlh);
1132
1133 /* fib_nl_{new,del}rule handling looks for net from skb->sk */
1134 skb->sk = dev_net(dev)->rtnl;
1135 if (add_it) {
1136 err = fib_nl_newrule(skb, nlh);
1137 if (err == -EEXIST)
1138 err = 0;
1139 } else {
1140 err = fib_nl_delrule(skb, nlh);
1141 if (err == -ENOENT)
1142 err = 0;
1143 }
1144 nlmsg_free(skb);
1145
1146 return err;
1147
1148 nla_put_failure:
1149 nlmsg_free(skb);
1150
1151 return -EMSGSIZE;
1152 }
1153
1154 static int vrf_add_fib_rules(const struct net_device *dev)
1155 {
1156 int err;
1157
1158 err = vrf_fib_rule(dev, AF_INET, true);
1159 if (err < 0)
1160 goto out_err;
1161
1162 err = vrf_fib_rule(dev, AF_INET6, true);
1163 if (err < 0)
1164 goto ipv6_err;
1165
1166 return 0;
1167
1168 ipv6_err:
1169 vrf_fib_rule(dev, AF_INET, false);
1170
1171 out_err:
1172 netdev_err(dev, "Failed to add FIB rules.\n");
1173 return err;
1174 }
1175
1176 static void vrf_setup(struct net_device *dev)
1177 {
1178 ether_setup(dev);
1179
1180 /* Initialize the device structure. */
1181 dev->netdev_ops = &vrf_netdev_ops;
1182 dev->l3mdev_ops = &vrf_l3mdev_ops;
1183 dev->ethtool_ops = &vrf_ethtool_ops;
1184 dev->destructor = free_netdev;
1185
1186 /* Fill in device structure with ethernet-generic values. */
1187 eth_hw_addr_random(dev);
1188
1189 /* don't acquire vrf device's netif_tx_lock when transmitting */
1190 dev->features |= NETIF_F_LLTX;
1191
1192 /* don't allow vrf devices to change network namespaces. */
1193 dev->features |= NETIF_F_NETNS_LOCAL;
1194
1195 /* does not make sense for a VLAN to be added to a vrf device */
1196 dev->features |= NETIF_F_VLAN_CHALLENGED;
1197
1198 /* enable offload features */
1199 dev->features |= NETIF_F_GSO_SOFTWARE;
1200 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM;
1201 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1202
1203 dev->hw_features = dev->features;
1204 dev->hw_enc_features = dev->features;
1205
1206 /* default to no qdisc; user can add if desired */
1207 dev->priv_flags |= IFF_NO_QUEUE;
1208 }
1209
1210 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[])
1211 {
1212 if (tb[IFLA_ADDRESS]) {
1213 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1214 return -EINVAL;
1215 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1216 return -EADDRNOTAVAIL;
1217 }
1218 return 0;
1219 }
1220
1221 static void vrf_dellink(struct net_device *dev, struct list_head *head)
1222 {
1223 unregister_netdevice_queue(dev, head);
1224 }
1225
1226 static int vrf_newlink(struct net *src_net, struct net_device *dev,
1227 struct nlattr *tb[], struct nlattr *data[])
1228 {
1229 struct net_vrf *vrf = netdev_priv(dev);
1230 int err;
1231
1232 if (!data || !data[IFLA_VRF_TABLE])
1233 return -EINVAL;
1234
1235 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
1236
1237 dev->priv_flags |= IFF_L3MDEV_MASTER;
1238
1239 err = register_netdevice(dev);
1240 if (err)
1241 goto out;
1242
1243 if (add_fib_rules) {
1244 err = vrf_add_fib_rules(dev);
1245 if (err) {
1246 unregister_netdevice(dev);
1247 goto out;
1248 }
1249 add_fib_rules = false;
1250 }
1251
1252 out:
1253 return err;
1254 }
1255
1256 static size_t vrf_nl_getsize(const struct net_device *dev)
1257 {
1258 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
1259 }
1260
1261 static int vrf_fillinfo(struct sk_buff *skb,
1262 const struct net_device *dev)
1263 {
1264 struct net_vrf *vrf = netdev_priv(dev);
1265
1266 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
1267 }
1268
1269 static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1270 const struct net_device *slave_dev)
1271 {
1272 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1273 }
1274
1275 static int vrf_fill_slave_info(struct sk_buff *skb,
1276 const struct net_device *vrf_dev,
1277 const struct net_device *slave_dev)
1278 {
1279 struct net_vrf *vrf = netdev_priv(vrf_dev);
1280
1281 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
1282 return -EMSGSIZE;
1283
1284 return 0;
1285 }
1286
1287 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1288 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1289 };
1290
1291 static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1292 .kind = DRV_NAME,
1293 .priv_size = sizeof(struct net_vrf),
1294
1295 .get_size = vrf_nl_getsize,
1296 .policy = vrf_nl_policy,
1297 .validate = vrf_validate,
1298 .fill_info = vrf_fillinfo,
1299
1300 .get_slave_size = vrf_get_slave_size,
1301 .fill_slave_info = vrf_fill_slave_info,
1302
1303 .newlink = vrf_newlink,
1304 .dellink = vrf_dellink,
1305 .setup = vrf_setup,
1306 .maxtype = IFLA_VRF_MAX,
1307 };
1308
1309 static int vrf_device_event(struct notifier_block *unused,
1310 unsigned long event, void *ptr)
1311 {
1312 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1313
1314 /* only care about unregister events to drop slave references */
1315 if (event == NETDEV_UNREGISTER) {
1316 struct net_device *vrf_dev;
1317
1318 if (!netif_is_l3_slave(dev))
1319 goto out;
1320
1321 vrf_dev = netdev_master_upper_dev_get(dev);
1322 vrf_del_slave(vrf_dev, dev);
1323 }
1324 out:
1325 return NOTIFY_DONE;
1326 }
1327
1328 static struct notifier_block vrf_notifier_block __read_mostly = {
1329 .notifier_call = vrf_device_event,
1330 };
1331
1332 static int __init vrf_init_module(void)
1333 {
1334 int rc;
1335
1336 register_netdevice_notifier(&vrf_notifier_block);
1337
1338 rc = rtnl_link_register(&vrf_link_ops);
1339 if (rc < 0)
1340 goto error;
1341
1342 return 0;
1343
1344 error:
1345 unregister_netdevice_notifier(&vrf_notifier_block);
1346 return rc;
1347 }
1348
1349 module_init(vrf_init_module);
1350 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
1351 MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
1352 MODULE_LICENSE("GPL");
1353 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
1354 MODULE_VERSION(DRV_VERSION);
Linux kernel - Deliverables
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