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Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[mirror_ubuntu-zesty-kernel.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 DRV_NAME "vrf"
41 #define DRV_VERSION "1.0"
42
43 #define FIB_RULE_PREF 1000 /* default preference for FIB rules */
44 static bool add_fib_rules = true;
45
46 struct net_vrf {
47 struct rtable __rcu *rth;
48 struct rtable __rcu *rth_local;
49 struct rt6_info __rcu *rt6;
50 struct rt6_info __rcu *rt6_local;
51 u32 tb_id;
52 };
53
54 struct 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
64 static 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
74 static 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
80 static struct rtnl_link_stats64 *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 return stats;
106 }
107
108 /* Local traffic destined to local address. Reinsert the packet to rx
109 * path, similar to loopback handling.
110 */
111 static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
112 struct dst_entry *dst)
113 {
114 int len = skb->len;
115
116 skb_orphan(skb);
117
118 skb_dst_set(skb, dst);
119 skb_dst_force(skb);
120
121 /* set pkt_type to avoid skb hitting packet taps twice -
122 * once on Tx and again in Rx processing
123 */
124 skb->pkt_type = PACKET_LOOPBACK;
125
126 skb->protocol = eth_type_trans(skb, dev);
127
128 if (likely(netif_rx(skb) == NET_RX_SUCCESS))
129 vrf_rx_stats(dev, len);
130 else
131 this_cpu_inc(dev->dstats->rx_drps);
132
133 return NETDEV_TX_OK;
134 }
135
136 #if IS_ENABLED(CONFIG_IPV6)
137 static int vrf_ip6_local_out(struct net *net, struct sock *sk,
138 struct sk_buff *skb)
139 {
140 int err;
141
142 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net,
143 sk, skb, NULL, skb_dst(skb)->dev, dst_output);
144
145 if (likely(err == 1))
146 err = dst_output(net, sk, skb);
147
148 return err;
149 }
150
151 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
152 struct net_device *dev)
153 {
154 const struct ipv6hdr *iph = ipv6_hdr(skb);
155 struct net *net = dev_net(skb->dev);
156 struct flowi6 fl6 = {
157 /* needed to match OIF rule */
158 .flowi6_oif = dev->ifindex,
159 .flowi6_iif = LOOPBACK_IFINDEX,
160 .daddr = iph->daddr,
161 .saddr = iph->saddr,
162 .flowlabel = ip6_flowinfo(iph),
163 .flowi6_mark = skb->mark,
164 .flowi6_proto = iph->nexthdr,
165 .flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF,
166 };
167 int ret = NET_XMIT_DROP;
168 struct dst_entry *dst;
169 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
170
171 dst = ip6_route_output(net, NULL, &fl6);
172 if (dst == dst_null)
173 goto err;
174
175 skb_dst_drop(skb);
176
177 /* if dst.dev is loopback or the VRF device again this is locally
178 * originated traffic destined to a local address. Short circuit
179 * to Rx path using our local dst
180 */
181 if (dst->dev == net->loopback_dev || dst->dev == dev) {
182 struct net_vrf *vrf = netdev_priv(dev);
183 struct rt6_info *rt6_local;
184
185 /* release looked up dst and use cached local dst */
186 dst_release(dst);
187
188 rcu_read_lock();
189
190 rt6_local = rcu_dereference(vrf->rt6_local);
191 if (unlikely(!rt6_local)) {
192 rcu_read_unlock();
193 goto err;
194 }
195
196 /* Ordering issue: cached local dst is created on newlink
197 * before the IPv6 initialization. Using the local dst
198 * requires rt6i_idev to be set so make sure it is.
199 */
200 if (unlikely(!rt6_local->rt6i_idev)) {
201 rt6_local->rt6i_idev = in6_dev_get(dev);
202 if (!rt6_local->rt6i_idev) {
203 rcu_read_unlock();
204 goto err;
205 }
206 }
207
208 dst = &rt6_local->dst;
209 dst_hold(dst);
210
211 rcu_read_unlock();
212
213 return vrf_local_xmit(skb, dev, &rt6_local->dst);
214 }
215
216 skb_dst_set(skb, dst);
217
218 /* strip the ethernet header added for pass through VRF device */
219 __skb_pull(skb, skb_network_offset(skb));
220
221 ret = vrf_ip6_local_out(net, skb->sk, skb);
222 if (unlikely(net_xmit_eval(ret)))
223 dev->stats.tx_errors++;
224 else
225 ret = NET_XMIT_SUCCESS;
226
227 return ret;
228 err:
229 vrf_tx_error(dev, skb);
230 return NET_XMIT_DROP;
231 }
232 #else
233 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
234 struct net_device *dev)
235 {
236 vrf_tx_error(dev, skb);
237 return NET_XMIT_DROP;
238 }
239 #endif
240
241 /* based on ip_local_out; can't use it b/c the dst is switched pointing to us */
242 static int vrf_ip_local_out(struct net *net, struct sock *sk,
243 struct sk_buff *skb)
244 {
245 int err;
246
247 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
248 skb, NULL, skb_dst(skb)->dev, dst_output);
249 if (likely(err == 1))
250 err = dst_output(net, sk, skb);
251
252 return err;
253 }
254
255 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
256 struct net_device *vrf_dev)
257 {
258 struct iphdr *ip4h = ip_hdr(skb);
259 int ret = NET_XMIT_DROP;
260 struct flowi4 fl4 = {
261 /* needed to match OIF rule */
262 .flowi4_oif = vrf_dev->ifindex,
263 .flowi4_iif = LOOPBACK_IFINDEX,
264 .flowi4_tos = RT_TOS(ip4h->tos),
265 .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF,
266 .flowi4_proto = ip4h->protocol,
267 .daddr = ip4h->daddr,
268 .saddr = ip4h->saddr,
269 };
270 struct net *net = dev_net(vrf_dev);
271 struct rtable *rt;
272
273 rt = ip_route_output_flow(net, &fl4, NULL);
274 if (IS_ERR(rt))
275 goto err;
276
277 skb_dst_drop(skb);
278
279 /* if dst.dev is loopback or the VRF device again this is locally
280 * originated traffic destined to a local address. Short circuit
281 * to Rx path using our local dst
282 */
283 if (rt->dst.dev == net->loopback_dev || rt->dst.dev == vrf_dev) {
284 struct net_vrf *vrf = netdev_priv(vrf_dev);
285 struct rtable *rth_local;
286 struct dst_entry *dst = NULL;
287
288 ip_rt_put(rt);
289
290 rcu_read_lock();
291
292 rth_local = rcu_dereference(vrf->rth_local);
293 if (likely(rth_local)) {
294 dst = &rth_local->dst;
295 dst_hold(dst);
296 }
297
298 rcu_read_unlock();
299
300 if (unlikely(!dst))
301 goto err;
302
303 return vrf_local_xmit(skb, vrf_dev, dst);
304 }
305
306 skb_dst_set(skb, &rt->dst);
307
308 /* strip the ethernet header added for pass through VRF device */
309 __skb_pull(skb, skb_network_offset(skb));
310
311 if (!ip4h->saddr) {
312 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
313 RT_SCOPE_LINK);
314 }
315
316 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
317 if (unlikely(net_xmit_eval(ret)))
318 vrf_dev->stats.tx_errors++;
319 else
320 ret = NET_XMIT_SUCCESS;
321
322 out:
323 return ret;
324 err:
325 vrf_tx_error(vrf_dev, skb);
326 goto out;
327 }
328
329 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
330 {
331 switch (skb->protocol) {
332 case htons(ETH_P_IP):
333 return vrf_process_v4_outbound(skb, dev);
334 case htons(ETH_P_IPV6):
335 return vrf_process_v6_outbound(skb, dev);
336 default:
337 vrf_tx_error(dev, skb);
338 return NET_XMIT_DROP;
339 }
340 }
341
342 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
343 {
344 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
345
346 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
347 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
348
349 u64_stats_update_begin(&dstats->syncp);
350 dstats->tx_pkts++;
351 dstats->tx_bytes += skb->len;
352 u64_stats_update_end(&dstats->syncp);
353 } else {
354 this_cpu_inc(dev->dstats->tx_drps);
355 }
356
357 return ret;
358 }
359
360 #if IS_ENABLED(CONFIG_IPV6)
361 /* modelled after ip6_finish_output2 */
362 static int vrf_finish_output6(struct net *net, struct sock *sk,
363 struct sk_buff *skb)
364 {
365 struct dst_entry *dst = skb_dst(skb);
366 struct net_device *dev = dst->dev;
367 struct neighbour *neigh;
368 struct in6_addr *nexthop;
369 int ret;
370
371 nf_reset(skb);
372
373 skb->protocol = htons(ETH_P_IPV6);
374 skb->dev = dev;
375
376 rcu_read_lock_bh();
377 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
378 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
379 if (unlikely(!neigh))
380 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
381 if (!IS_ERR(neigh)) {
382 ret = dst_neigh_output(dst, neigh, skb);
383 rcu_read_unlock_bh();
384 return ret;
385 }
386 rcu_read_unlock_bh();
387
388 IP6_INC_STATS(dev_net(dst->dev),
389 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
390 kfree_skb(skb);
391 return -EINVAL;
392 }
393
394 /* modelled after ip6_output */
395 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
396 {
397 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
398 net, sk, skb, NULL, skb_dst(skb)->dev,
399 vrf_finish_output6,
400 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
401 }
402
403 /* set dst on skb to send packet to us via dev_xmit path. Allows
404 * packet to go through device based features such as qdisc, netfilter
405 * hooks and packet sockets with skb->dev set to vrf device.
406 */
407 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
408 struct sock *sk,
409 struct sk_buff *skb)
410 {
411 struct net_vrf *vrf = netdev_priv(vrf_dev);
412 struct dst_entry *dst = NULL;
413 struct rt6_info *rt6;
414
415 /* don't divert link scope packets */
416 if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
417 return skb;
418
419 rcu_read_lock();
420
421 rt6 = rcu_dereference(vrf->rt6);
422 if (likely(rt6)) {
423 dst = &rt6->dst;
424 dst_hold(dst);
425 }
426
427 rcu_read_unlock();
428
429 if (unlikely(!dst)) {
430 vrf_tx_error(vrf_dev, skb);
431 return NULL;
432 }
433
434 skb_dst_drop(skb);
435 skb_dst_set(skb, dst);
436
437 return skb;
438 }
439
440 /* holding rtnl */
441 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
442 {
443 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
444 struct rt6_info *rt6_local = rtnl_dereference(vrf->rt6_local);
445 struct net *net = dev_net(dev);
446 struct dst_entry *dst;
447
448 RCU_INIT_POINTER(vrf->rt6, NULL);
449 RCU_INIT_POINTER(vrf->rt6_local, NULL);
450 synchronize_rcu();
451
452 /* move dev in dst's to loopback so this VRF device can be deleted
453 * - based on dst_ifdown
454 */
455 if (rt6) {
456 dst = &rt6->dst;
457 dev_put(dst->dev);
458 dst->dev = net->loopback_dev;
459 dev_hold(dst->dev);
460 dst_release(dst);
461 }
462
463 if (rt6_local) {
464 if (rt6_local->rt6i_idev)
465 in6_dev_put(rt6_local->rt6i_idev);
466
467 dst = &rt6_local->dst;
468 dev_put(dst->dev);
469 dst->dev = net->loopback_dev;
470 dev_hold(dst->dev);
471 dst_release(dst);
472 }
473 }
474
475 static int vrf_rt6_create(struct net_device *dev)
476 {
477 int flags = DST_HOST | DST_NOPOLICY | DST_NOXFRM | DST_NOCACHE;
478 struct net_vrf *vrf = netdev_priv(dev);
479 struct net *net = dev_net(dev);
480 struct fib6_table *rt6i_table;
481 struct rt6_info *rt6, *rt6_local;
482 int rc = -ENOMEM;
483
484 /* IPv6 can be CONFIG enabled and then disabled runtime */
485 if (!ipv6_mod_enabled())
486 return 0;
487
488 rt6i_table = fib6_new_table(net, vrf->tb_id);
489 if (!rt6i_table)
490 goto out;
491
492 /* create a dst for routing packets out a VRF device */
493 rt6 = ip6_dst_alloc(net, dev, flags);
494 if (!rt6)
495 goto out;
496
497 dst_hold(&rt6->dst);
498
499 rt6->rt6i_table = rt6i_table;
500 rt6->dst.output = vrf_output6;
501
502 /* create a dst for local routing - packets sent locally
503 * to local address via the VRF device as a loopback
504 */
505 rt6_local = ip6_dst_alloc(net, dev, flags);
506 if (!rt6_local) {
507 dst_release(&rt6->dst);
508 goto out;
509 }
510
511 dst_hold(&rt6_local->dst);
512
513 rt6_local->rt6i_idev = in6_dev_get(dev);
514 rt6_local->rt6i_flags = RTF_UP | RTF_NONEXTHOP | RTF_LOCAL;
515 rt6_local->rt6i_table = rt6i_table;
516 rt6_local->dst.input = ip6_input;
517
518 rcu_assign_pointer(vrf->rt6, rt6);
519 rcu_assign_pointer(vrf->rt6_local, rt6_local);
520
521 rc = 0;
522 out:
523 return rc;
524 }
525 #else
526 static 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
533 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
534 {
535 }
536
537 static int vrf_rt6_create(struct net_device *dev)
538 {
539 return 0;
540 }
541 #endif
542
543 /* modelled after ip_finish_output2 */
544 static 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 ret = dst_neigh_output(dst, neigh, skb);
580
581 rcu_read_unlock_bh();
582 err:
583 if (unlikely(ret < 0))
584 vrf_tx_error(skb->dev, skb);
585 return ret;
586 }
587
588 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
589 {
590 struct net_device *dev = skb_dst(skb)->dev;
591
592 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
593
594 skb->dev = dev;
595 skb->protocol = htons(ETH_P_IP);
596
597 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
598 net, sk, skb, NULL, dev,
599 vrf_finish_output,
600 !(IPCB(skb)->flags & IPSKB_REROUTED));
601 }
602
603 /* set dst on skb to send packet to us via dev_xmit path. Allows
604 * packet to go through device based features such as qdisc, netfilter
605 * hooks and packet sockets with skb->dev set to vrf device.
606 */
607 static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
608 struct sock *sk,
609 struct sk_buff *skb)
610 {
611 struct net_vrf *vrf = netdev_priv(vrf_dev);
612 struct dst_entry *dst = NULL;
613 struct rtable *rth;
614
615 /* don't divert multicast */
616 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
617 return skb;
618
619 rcu_read_lock();
620
621 rth = rcu_dereference(vrf->rth);
622 if (likely(rth)) {
623 dst = &rth->dst;
624 dst_hold(dst);
625 }
626
627 rcu_read_unlock();
628
629 if (unlikely(!dst)) {
630 vrf_tx_error(vrf_dev, skb);
631 return NULL;
632 }
633
634 skb_dst_drop(skb);
635 skb_dst_set(skb, dst);
636
637 return skb;
638 }
639
640 /* called with rcu lock held */
641 static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
642 struct sock *sk,
643 struct sk_buff *skb,
644 u16 proto)
645 {
646 switch (proto) {
647 case AF_INET:
648 return vrf_ip_out(vrf_dev, sk, skb);
649 case AF_INET6:
650 return vrf_ip6_out(vrf_dev, sk, skb);
651 }
652
653 return skb;
654 }
655
656 /* holding rtnl */
657 static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
658 {
659 struct rtable *rth = rtnl_dereference(vrf->rth);
660 struct rtable *rth_local = rtnl_dereference(vrf->rth_local);
661 struct net *net = dev_net(dev);
662 struct dst_entry *dst;
663
664 RCU_INIT_POINTER(vrf->rth, NULL);
665 RCU_INIT_POINTER(vrf->rth_local, NULL);
666 synchronize_rcu();
667
668 /* move dev in dst's to loopback so this VRF device can be deleted
669 * - based on dst_ifdown
670 */
671 if (rth) {
672 dst = &rth->dst;
673 dev_put(dst->dev);
674 dst->dev = net->loopback_dev;
675 dev_hold(dst->dev);
676 dst_release(dst);
677 }
678
679 if (rth_local) {
680 dst = &rth_local->dst;
681 dev_put(dst->dev);
682 dst->dev = net->loopback_dev;
683 dev_hold(dst->dev);
684 dst_release(dst);
685 }
686 }
687
688 static int vrf_rtable_create(struct net_device *dev)
689 {
690 struct net_vrf *vrf = netdev_priv(dev);
691 struct rtable *rth, *rth_local;
692
693 if (!fib_new_table(dev_net(dev), vrf->tb_id))
694 return -ENOMEM;
695
696 /* create a dst for routing packets out through a VRF device */
697 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1, 0);
698 if (!rth)
699 return -ENOMEM;
700
701 /* create a dst for local ingress routing - packets sent locally
702 * to local address via the VRF device as a loopback
703 */
704 rth_local = rt_dst_alloc(dev, RTCF_LOCAL, RTN_LOCAL, 1, 1, 0);
705 if (!rth_local) {
706 dst_release(&rth->dst);
707 return -ENOMEM;
708 }
709
710 rth->dst.output = vrf_output;
711 rth->rt_table_id = vrf->tb_id;
712
713 rth_local->rt_table_id = vrf->tb_id;
714
715 rcu_assign_pointer(vrf->rth, rth);
716 rcu_assign_pointer(vrf->rth_local, rth_local);
717
718 return 0;
719 }
720
721 /**************************** device handling ********************/
722
723 /* cycle interface to flush neighbor cache and move routes across tables */
724 static void cycle_netdev(struct net_device *dev)
725 {
726 unsigned int flags = dev->flags;
727 int ret;
728
729 if (!netif_running(dev))
730 return;
731
732 ret = dev_change_flags(dev, flags & ~IFF_UP);
733 if (ret >= 0)
734 ret = dev_change_flags(dev, flags);
735
736 if (ret < 0) {
737 netdev_err(dev,
738 "Failed to cycle device %s; route tables might be wrong!\n",
739 dev->name);
740 }
741 }
742
743 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
744 {
745 int ret;
746
747 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL);
748 if (ret < 0)
749 return ret;
750
751 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
752 cycle_netdev(port_dev);
753
754 return 0;
755 }
756
757 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
758 {
759 if (netif_is_l3_master(port_dev) || netif_is_l3_slave(port_dev))
760 return -EINVAL;
761
762 return do_vrf_add_slave(dev, port_dev);
763 }
764
765 /* inverse of do_vrf_add_slave */
766 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
767 {
768 netdev_upper_dev_unlink(port_dev, dev);
769 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
770
771 cycle_netdev(port_dev);
772
773 return 0;
774 }
775
776 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
777 {
778 return do_vrf_del_slave(dev, port_dev);
779 }
780
781 static void vrf_dev_uninit(struct net_device *dev)
782 {
783 struct net_vrf *vrf = netdev_priv(dev);
784 struct net_device *port_dev;
785 struct list_head *iter;
786
787 vrf_rtable_release(dev, vrf);
788 vrf_rt6_release(dev, vrf);
789
790 netdev_for_each_lower_dev(dev, port_dev, iter)
791 vrf_del_slave(dev, port_dev);
792
793 free_percpu(dev->dstats);
794 dev->dstats = NULL;
795 }
796
797 static int vrf_dev_init(struct net_device *dev)
798 {
799 struct net_vrf *vrf = netdev_priv(dev);
800
801 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
802 if (!dev->dstats)
803 goto out_nomem;
804
805 /* create the default dst which points back to us */
806 if (vrf_rtable_create(dev) != 0)
807 goto out_stats;
808
809 if (vrf_rt6_create(dev) != 0)
810 goto out_rth;
811
812 dev->flags = IFF_MASTER | IFF_NOARP;
813
814 /* MTU is irrelevant for VRF device; set to 64k similar to lo */
815 dev->mtu = 64 * 1024;
816
817 /* similarly, oper state is irrelevant; set to up to avoid confusion */
818 dev->operstate = IF_OPER_UP;
819 netdev_lockdep_set_classes(dev);
820 return 0;
821
822 out_rth:
823 vrf_rtable_release(dev, vrf);
824 out_stats:
825 free_percpu(dev->dstats);
826 dev->dstats = NULL;
827 out_nomem:
828 return -ENOMEM;
829 }
830
831 static const struct net_device_ops vrf_netdev_ops = {
832 .ndo_init = vrf_dev_init,
833 .ndo_uninit = vrf_dev_uninit,
834 .ndo_start_xmit = vrf_xmit,
835 .ndo_get_stats64 = vrf_get_stats64,
836 .ndo_add_slave = vrf_add_slave,
837 .ndo_del_slave = vrf_del_slave,
838 };
839
840 static u32 vrf_fib_table(const struct net_device *dev)
841 {
842 struct net_vrf *vrf = netdev_priv(dev);
843
844 return vrf->tb_id;
845 }
846
847 static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
848 {
849 return 0;
850 }
851
852 static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
853 struct sk_buff *skb,
854 struct net_device *dev)
855 {
856 struct net *net = dev_net(dev);
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 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
963 skb->pkt_type = PACKET_HOST;
964 goto out;
965 }
966
967 /* if packet is NDISC or addressed to multicast or link-local
968 * then keep the ingress interface
969 */
970 need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
971 if (!ipv6_ndisc_frame(skb) && !need_strict) {
972 vrf_rx_stats(vrf_dev, skb->len);
973 skb->dev = vrf_dev;
974 skb->skb_iif = vrf_dev->ifindex;
975
976 skb_push(skb, skb->mac_len);
977 dev_queue_xmit_nit(skb, vrf_dev);
978 skb_pull(skb, skb->mac_len);
979
980 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
981 }
982
983 if (need_strict)
984 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
985
986 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
987 out:
988 return skb;
989 }
990
991 #else
992 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
993 struct sk_buff *skb)
994 {
995 return skb;
996 }
997 #endif
998
999 static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
1000 struct sk_buff *skb)
1001 {
1002 skb->dev = vrf_dev;
1003 skb->skb_iif = vrf_dev->ifindex;
1004 IPCB(skb)->flags |= IPSKB_L3SLAVE;
1005
1006 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
1007 goto out;
1008
1009 /* loopback traffic; do not push through packet taps again.
1010 * Reset pkt_type for upper layers to process skb
1011 */
1012 if (skb->pkt_type == PACKET_LOOPBACK) {
1013 skb->pkt_type = PACKET_HOST;
1014 goto out;
1015 }
1016
1017 vrf_rx_stats(vrf_dev, skb->len);
1018
1019 skb_push(skb, skb->mac_len);
1020 dev_queue_xmit_nit(skb, vrf_dev);
1021 skb_pull(skb, skb->mac_len);
1022
1023 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
1024 out:
1025 return skb;
1026 }
1027
1028 /* called with rcu lock held */
1029 static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1030 struct sk_buff *skb,
1031 u16 proto)
1032 {
1033 switch (proto) {
1034 case AF_INET:
1035 return vrf_ip_rcv(vrf_dev, skb);
1036 case AF_INET6:
1037 return vrf_ip6_rcv(vrf_dev, skb);
1038 }
1039
1040 return skb;
1041 }
1042
1043 #if IS_ENABLED(CONFIG_IPV6)
1044 /* send to link-local or multicast address via interface enslaved to
1045 * VRF device. Force lookup to VRF table without changing flow struct
1046 */
1047 static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1048 struct flowi6 *fl6)
1049 {
1050 struct net *net = dev_net(dev);
1051 int flags = RT6_LOOKUP_F_IFACE;
1052 struct dst_entry *dst = NULL;
1053 struct rt6_info *rt;
1054
1055 /* VRF device does not have a link-local address and
1056 * sending packets to link-local or mcast addresses over
1057 * a VRF device does not make sense
1058 */
1059 if (fl6->flowi6_oif == dev->ifindex) {
1060 dst = &net->ipv6.ip6_null_entry->dst;
1061 dst_hold(dst);
1062 return dst;
1063 }
1064
1065 if (!ipv6_addr_any(&fl6->saddr))
1066 flags |= RT6_LOOKUP_F_HAS_SADDR;
1067
1068 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, flags);
1069 if (rt)
1070 dst = &rt->dst;
1071
1072 return dst;
1073 }
1074 #endif
1075
1076 static const struct l3mdev_ops vrf_l3mdev_ops = {
1077 .l3mdev_fib_table = vrf_fib_table,
1078 .l3mdev_l3_rcv = vrf_l3_rcv,
1079 .l3mdev_l3_out = vrf_l3_out,
1080 #if IS_ENABLED(CONFIG_IPV6)
1081 .l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1082 #endif
1083 };
1084
1085 static void vrf_get_drvinfo(struct net_device *dev,
1086 struct ethtool_drvinfo *info)
1087 {
1088 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
1089 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
1090 }
1091
1092 static const struct ethtool_ops vrf_ethtool_ops = {
1093 .get_drvinfo = vrf_get_drvinfo,
1094 };
1095
1096 static inline size_t vrf_fib_rule_nl_size(void)
1097 {
1098 size_t sz;
1099
1100 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1101 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */
1102 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */
1103
1104 return sz;
1105 }
1106
1107 static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1108 {
1109 struct fib_rule_hdr *frh;
1110 struct nlmsghdr *nlh;
1111 struct sk_buff *skb;
1112 int err;
1113
1114 if (family == AF_INET6 && !ipv6_mod_enabled())
1115 return 0;
1116
1117 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
1118 if (!skb)
1119 return -ENOMEM;
1120
1121 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
1122 if (!nlh)
1123 goto nla_put_failure;
1124
1125 /* rule only needs to appear once */
1126 nlh->nlmsg_flags &= NLM_F_EXCL;
1127
1128 frh = nlmsg_data(nlh);
1129 memset(frh, 0, sizeof(*frh));
1130 frh->family = family;
1131 frh->action = FR_ACT_TO_TBL;
1132
1133 if (nla_put_u32(skb, FRA_L3MDEV, 1))
1134 goto nla_put_failure;
1135
1136 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
1137 goto nla_put_failure;
1138
1139 nlmsg_end(skb, nlh);
1140
1141 /* fib_nl_{new,del}rule handling looks for net from skb->sk */
1142 skb->sk = dev_net(dev)->rtnl;
1143 if (add_it) {
1144 err = fib_nl_newrule(skb, nlh);
1145 if (err == -EEXIST)
1146 err = 0;
1147 } else {
1148 err = fib_nl_delrule(skb, nlh);
1149 if (err == -ENOENT)
1150 err = 0;
1151 }
1152 nlmsg_free(skb);
1153
1154 return err;
1155
1156 nla_put_failure:
1157 nlmsg_free(skb);
1158
1159 return -EMSGSIZE;
1160 }
1161
1162 static int vrf_add_fib_rules(const struct net_device *dev)
1163 {
1164 int err;
1165
1166 err = vrf_fib_rule(dev, AF_INET, true);
1167 if (err < 0)
1168 goto out_err;
1169
1170 err = vrf_fib_rule(dev, AF_INET6, true);
1171 if (err < 0)
1172 goto ipv6_err;
1173
1174 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1175 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true);
1176 if (err < 0)
1177 goto ipmr_err;
1178 #endif
1179
1180 return 0;
1181
1182 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1183 ipmr_err:
1184 vrf_fib_rule(dev, AF_INET6, false);
1185 #endif
1186
1187 ipv6_err:
1188 vrf_fib_rule(dev, AF_INET, false);
1189
1190 out_err:
1191 netdev_err(dev, "Failed to add FIB rules.\n");
1192 return err;
1193 }
1194
1195 static void vrf_setup(struct net_device *dev)
1196 {
1197 ether_setup(dev);
1198
1199 /* Initialize the device structure. */
1200 dev->netdev_ops = &vrf_netdev_ops;
1201 dev->l3mdev_ops = &vrf_l3mdev_ops;
1202 dev->ethtool_ops = &vrf_ethtool_ops;
1203 dev->destructor = free_netdev;
1204
1205 /* Fill in device structure with ethernet-generic values. */
1206 eth_hw_addr_random(dev);
1207
1208 /* don't acquire vrf device's netif_tx_lock when transmitting */
1209 dev->features |= NETIF_F_LLTX;
1210
1211 /* don't allow vrf devices to change network namespaces. */
1212 dev->features |= NETIF_F_NETNS_LOCAL;
1213
1214 /* does not make sense for a VLAN to be added to a vrf device */
1215 dev->features |= NETIF_F_VLAN_CHALLENGED;
1216
1217 /* enable offload features */
1218 dev->features |= NETIF_F_GSO_SOFTWARE;
1219 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM;
1220 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1221
1222 dev->hw_features = dev->features;
1223 dev->hw_enc_features = dev->features;
1224
1225 /* default to no qdisc; user can add if desired */
1226 dev->priv_flags |= IFF_NO_QUEUE;
1227 }
1228
1229 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[])
1230 {
1231 if (tb[IFLA_ADDRESS]) {
1232 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1233 return -EINVAL;
1234 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1235 return -EADDRNOTAVAIL;
1236 }
1237 return 0;
1238 }
1239
1240 static void vrf_dellink(struct net_device *dev, struct list_head *head)
1241 {
1242 unregister_netdevice_queue(dev, head);
1243 }
1244
1245 static int vrf_newlink(struct net *src_net, struct net_device *dev,
1246 struct nlattr *tb[], struct nlattr *data[])
1247 {
1248 struct net_vrf *vrf = netdev_priv(dev);
1249 int err;
1250
1251 if (!data || !data[IFLA_VRF_TABLE])
1252 return -EINVAL;
1253
1254 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
1255 if (vrf->tb_id == RT_TABLE_UNSPEC)
1256 return -EINVAL;
1257
1258 dev->priv_flags |= IFF_L3MDEV_MASTER;
1259
1260 err = register_netdevice(dev);
1261 if (err)
1262 goto out;
1263
1264 if (add_fib_rules) {
1265 err = vrf_add_fib_rules(dev);
1266 if (err) {
1267 unregister_netdevice(dev);
1268 goto out;
1269 }
1270 add_fib_rules = false;
1271 }
1272
1273 out:
1274 return err;
1275 }
1276
1277 static size_t vrf_nl_getsize(const struct net_device *dev)
1278 {
1279 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
1280 }
1281
1282 static int vrf_fillinfo(struct sk_buff *skb,
1283 const struct net_device *dev)
1284 {
1285 struct net_vrf *vrf = netdev_priv(dev);
1286
1287 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
1288 }
1289
1290 static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1291 const struct net_device *slave_dev)
1292 {
1293 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1294 }
1295
1296 static int vrf_fill_slave_info(struct sk_buff *skb,
1297 const struct net_device *vrf_dev,
1298 const struct net_device *slave_dev)
1299 {
1300 struct net_vrf *vrf = netdev_priv(vrf_dev);
1301
1302 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
1303 return -EMSGSIZE;
1304
1305 return 0;
1306 }
1307
1308 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1309 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1310 };
1311
1312 static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1313 .kind = DRV_NAME,
1314 .priv_size = sizeof(struct net_vrf),
1315
1316 .get_size = vrf_nl_getsize,
1317 .policy = vrf_nl_policy,
1318 .validate = vrf_validate,
1319 .fill_info = vrf_fillinfo,
1320
1321 .get_slave_size = vrf_get_slave_size,
1322 .fill_slave_info = vrf_fill_slave_info,
1323
1324 .newlink = vrf_newlink,
1325 .dellink = vrf_dellink,
1326 .setup = vrf_setup,
1327 .maxtype = IFLA_VRF_MAX,
1328 };
1329
1330 static int vrf_device_event(struct notifier_block *unused,
1331 unsigned long event, void *ptr)
1332 {
1333 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1334
1335 /* only care about unregister events to drop slave references */
1336 if (event == NETDEV_UNREGISTER) {
1337 struct net_device *vrf_dev;
1338
1339 if (!netif_is_l3_slave(dev))
1340 goto out;
1341
1342 vrf_dev = netdev_master_upper_dev_get(dev);
1343 vrf_del_slave(vrf_dev, dev);
1344 }
1345 out:
1346 return NOTIFY_DONE;
1347 }
1348
1349 static struct notifier_block vrf_notifier_block __read_mostly = {
1350 .notifier_call = vrf_device_event,
1351 };
1352
1353 static int __init vrf_init_module(void)
1354 {
1355 int rc;
1356
1357 register_netdevice_notifier(&vrf_notifier_block);
1358
1359 rc = rtnl_link_register(&vrf_link_ops);
1360 if (rc < 0)
1361 goto error;
1362
1363 return 0;
1364
1365 error:
1366 unregister_netdevice_notifier(&vrf_notifier_block);
1367 return rc;
1368 }
1369
1370 module_init(vrf_init_module);
1371 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
1372 MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
1373 MODULE_LICENSE("GPL");
1374 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
1375 MODULE_VERSION(DRV_VERSION);
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