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Merge remote-tracking branch 'amlogic/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 netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
141 struct net_device *dev)
142 {
143 const struct ipv6hdr *iph = ipv6_hdr(skb);
144 struct net *net = dev_net(skb->dev);
145 struct flowi6 fl6 = {
146 /* needed to match OIF rule */
147 .flowi6_oif = dev->ifindex,
148 .flowi6_iif = LOOPBACK_IFINDEX,
149 .daddr = iph->daddr,
150 .saddr = iph->saddr,
151 .flowlabel = ip6_flowinfo(iph),
152 .flowi6_mark = skb->mark,
153 .flowi6_proto = iph->nexthdr,
154 .flowi6_flags = FLOWI_FLAG_L3MDEV_SRC | FLOWI_FLAG_SKIP_NH_OIF,
155 };
156 int ret = NET_XMIT_DROP;
157 struct dst_entry *dst;
158 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
159
160 dst = ip6_route_output(net, NULL, &fl6);
161 if (dst == dst_null)
162 goto err;
163
164 skb_dst_drop(skb);
165
166 /* if dst.dev is loopback or the VRF device again this is locally
167 * originated traffic destined to a local address. Short circuit
168 * to Rx path using our local dst
169 */
170 if (dst->dev == net->loopback_dev || dst->dev == dev) {
171 struct net_vrf *vrf = netdev_priv(dev);
172 struct rt6_info *rt6_local;
173
174 /* release looked up dst and use cached local dst */
175 dst_release(dst);
176
177 rcu_read_lock();
178
179 rt6_local = rcu_dereference(vrf->rt6_local);
180 if (unlikely(!rt6_local)) {
181 rcu_read_unlock();
182 goto err;
183 }
184
185 /* Ordering issue: cached local dst is created on newlink
186 * before the IPv6 initialization. Using the local dst
187 * requires rt6i_idev to be set so make sure it is.
188 */
189 if (unlikely(!rt6_local->rt6i_idev)) {
190 rt6_local->rt6i_idev = in6_dev_get(dev);
191 if (!rt6_local->rt6i_idev) {
192 rcu_read_unlock();
193 goto err;
194 }
195 }
196
197 dst = &rt6_local->dst;
198 dst_hold(dst);
199
200 rcu_read_unlock();
201
202 return vrf_local_xmit(skb, dev, &rt6_local->dst);
203 }
204
205 skb_dst_set(skb, dst);
206
207 /* strip the ethernet header added for pass through VRF device */
208 __skb_pull(skb, skb_network_offset(skb));
209
210 ret = ip6_local_out(net, skb->sk, skb);
211 if (unlikely(net_xmit_eval(ret)))
212 dev->stats.tx_errors++;
213 else
214 ret = NET_XMIT_SUCCESS;
215
216 return ret;
217 err:
218 vrf_tx_error(dev, skb);
219 return NET_XMIT_DROP;
220 }
221 #else
222 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
223 struct net_device *dev)
224 {
225 vrf_tx_error(dev, skb);
226 return NET_XMIT_DROP;
227 }
228 #endif
229
230 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
231 struct net_device *vrf_dev)
232 {
233 struct iphdr *ip4h = ip_hdr(skb);
234 int ret = NET_XMIT_DROP;
235 struct flowi4 fl4 = {
236 /* needed to match OIF rule */
237 .flowi4_oif = vrf_dev->ifindex,
238 .flowi4_iif = LOOPBACK_IFINDEX,
239 .flowi4_tos = RT_TOS(ip4h->tos),
240 .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_L3MDEV_SRC |
241 FLOWI_FLAG_SKIP_NH_OIF,
242 .daddr = ip4h->daddr,
243 };
244 struct net *net = dev_net(vrf_dev);
245 struct rtable *rt;
246
247 rt = ip_route_output_flow(net, &fl4, NULL);
248 if (IS_ERR(rt))
249 goto err;
250
251 if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
252 ip_rt_put(rt);
253 goto err;
254 }
255
256 skb_dst_drop(skb);
257
258 /* if dst.dev is loopback or the VRF device again this is locally
259 * originated traffic destined to a local address. Short circuit
260 * to Rx path using our local dst
261 */
262 if (rt->dst.dev == net->loopback_dev || rt->dst.dev == vrf_dev) {
263 struct net_vrf *vrf = netdev_priv(vrf_dev);
264 struct rtable *rth_local;
265 struct dst_entry *dst = NULL;
266
267 ip_rt_put(rt);
268
269 rcu_read_lock();
270
271 rth_local = rcu_dereference(vrf->rth_local);
272 if (likely(rth_local)) {
273 dst = &rth_local->dst;
274 dst_hold(dst);
275 }
276
277 rcu_read_unlock();
278
279 if (unlikely(!dst))
280 goto err;
281
282 return vrf_local_xmit(skb, vrf_dev, dst);
283 }
284
285 skb_dst_set(skb, &rt->dst);
286
287 /* strip the ethernet header added for pass through VRF device */
288 __skb_pull(skb, skb_network_offset(skb));
289
290 if (!ip4h->saddr) {
291 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
292 RT_SCOPE_LINK);
293 }
294
295 ret = ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
296 if (unlikely(net_xmit_eval(ret)))
297 vrf_dev->stats.tx_errors++;
298 else
299 ret = NET_XMIT_SUCCESS;
300
301 out:
302 return ret;
303 err:
304 vrf_tx_error(vrf_dev, skb);
305 goto out;
306 }
307
308 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
309 {
310 switch (skb->protocol) {
311 case htons(ETH_P_IP):
312 return vrf_process_v4_outbound(skb, dev);
313 case htons(ETH_P_IPV6):
314 return vrf_process_v6_outbound(skb, dev);
315 default:
316 vrf_tx_error(dev, skb);
317 return NET_XMIT_DROP;
318 }
319 }
320
321 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
322 {
323 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
324
325 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
326 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
327
328 u64_stats_update_begin(&dstats->syncp);
329 dstats->tx_pkts++;
330 dstats->tx_bytes += skb->len;
331 u64_stats_update_end(&dstats->syncp);
332 } else {
333 this_cpu_inc(dev->dstats->tx_drps);
334 }
335
336 return ret;
337 }
338
339 #if IS_ENABLED(CONFIG_IPV6)
340 /* modelled after ip6_finish_output2 */
341 static int vrf_finish_output6(struct net *net, struct sock *sk,
342 struct sk_buff *skb)
343 {
344 struct dst_entry *dst = skb_dst(skb);
345 struct net_device *dev = dst->dev;
346 struct neighbour *neigh;
347 struct in6_addr *nexthop;
348 int ret;
349
350 skb->protocol = htons(ETH_P_IPV6);
351 skb->dev = dev;
352
353 rcu_read_lock_bh();
354 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
355 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
356 if (unlikely(!neigh))
357 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
358 if (!IS_ERR(neigh)) {
359 ret = dst_neigh_output(dst, neigh, skb);
360 rcu_read_unlock_bh();
361 return ret;
362 }
363 rcu_read_unlock_bh();
364
365 IP6_INC_STATS(dev_net(dst->dev),
366 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
367 kfree_skb(skb);
368 return -EINVAL;
369 }
370
371 /* modelled after ip6_output */
372 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
373 {
374 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
375 net, sk, skb, NULL, skb_dst(skb)->dev,
376 vrf_finish_output6,
377 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
378 }
379
380 /* holding rtnl */
381 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
382 {
383 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
384 struct rt6_info *rt6_local = rtnl_dereference(vrf->rt6_local);
385 struct net *net = dev_net(dev);
386 struct dst_entry *dst;
387
388 RCU_INIT_POINTER(vrf->rt6, NULL);
389 RCU_INIT_POINTER(vrf->rt6_local, NULL);
390 synchronize_rcu();
391
392 /* move dev in dst's to loopback so this VRF device can be deleted
393 * - based on dst_ifdown
394 */
395 if (rt6) {
396 dst = &rt6->dst;
397 dev_put(dst->dev);
398 dst->dev = net->loopback_dev;
399 dev_hold(dst->dev);
400 dst_release(dst);
401 }
402
403 if (rt6_local) {
404 if (rt6_local->rt6i_idev)
405 in6_dev_put(rt6_local->rt6i_idev);
406
407 dst = &rt6_local->dst;
408 dev_put(dst->dev);
409 dst->dev = net->loopback_dev;
410 dev_hold(dst->dev);
411 dst_release(dst);
412 }
413 }
414
415 static int vrf_rt6_create(struct net_device *dev)
416 {
417 int flags = DST_HOST | DST_NOPOLICY | DST_NOXFRM | DST_NOCACHE;
418 struct net_vrf *vrf = netdev_priv(dev);
419 struct net *net = dev_net(dev);
420 struct fib6_table *rt6i_table;
421 struct rt6_info *rt6, *rt6_local;
422 int rc = -ENOMEM;
423
424 /* IPv6 can be CONFIG enabled and then disabled runtime */
425 if (!ipv6_mod_enabled())
426 return 0;
427
428 rt6i_table = fib6_new_table(net, vrf->tb_id);
429 if (!rt6i_table)
430 goto out;
431
432 /* create a dst for routing packets out a VRF device */
433 rt6 = ip6_dst_alloc(net, dev, flags);
434 if (!rt6)
435 goto out;
436
437 dst_hold(&rt6->dst);
438
439 rt6->rt6i_table = rt6i_table;
440 rt6->dst.output = vrf_output6;
441
442 /* create a dst for local routing - packets sent locally
443 * to local address via the VRF device as a loopback
444 */
445 rt6_local = ip6_dst_alloc(net, dev, flags);
446 if (!rt6_local) {
447 dst_release(&rt6->dst);
448 goto out;
449 }
450
451 dst_hold(&rt6_local->dst);
452
453 rt6_local->rt6i_idev = in6_dev_get(dev);
454 rt6_local->rt6i_flags = RTF_UP | RTF_NONEXTHOP | RTF_LOCAL;
455 rt6_local->rt6i_table = rt6i_table;
456 rt6_local->dst.input = ip6_input;
457
458 rcu_assign_pointer(vrf->rt6, rt6);
459 rcu_assign_pointer(vrf->rt6_local, rt6_local);
460
461 rc = 0;
462 out:
463 return rc;
464 }
465 #else
466 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
467 {
468 }
469
470 static int vrf_rt6_create(struct net_device *dev)
471 {
472 return 0;
473 }
474 #endif
475
476 /* modelled after ip_finish_output2 */
477 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
478 {
479 struct dst_entry *dst = skb_dst(skb);
480 struct rtable *rt = (struct rtable *)dst;
481 struct net_device *dev = dst->dev;
482 unsigned int hh_len = LL_RESERVED_SPACE(dev);
483 struct neighbour *neigh;
484 u32 nexthop;
485 int ret = -EINVAL;
486
487 /* Be paranoid, rather than too clever. */
488 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
489 struct sk_buff *skb2;
490
491 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
492 if (!skb2) {
493 ret = -ENOMEM;
494 goto err;
495 }
496 if (skb->sk)
497 skb_set_owner_w(skb2, skb->sk);
498
499 consume_skb(skb);
500 skb = skb2;
501 }
502
503 rcu_read_lock_bh();
504
505 nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr);
506 neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
507 if (unlikely(!neigh))
508 neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
509 if (!IS_ERR(neigh))
510 ret = dst_neigh_output(dst, neigh, skb);
511
512 rcu_read_unlock_bh();
513 err:
514 if (unlikely(ret < 0))
515 vrf_tx_error(skb->dev, skb);
516 return ret;
517 }
518
519 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
520 {
521 struct net_device *dev = skb_dst(skb)->dev;
522
523 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
524
525 skb->dev = dev;
526 skb->protocol = htons(ETH_P_IP);
527
528 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
529 net, sk, skb, NULL, dev,
530 vrf_finish_output,
531 !(IPCB(skb)->flags & IPSKB_REROUTED));
532 }
533
534 /* holding rtnl */
535 static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
536 {
537 struct rtable *rth = rtnl_dereference(vrf->rth);
538 struct rtable *rth_local = rtnl_dereference(vrf->rth_local);
539 struct net *net = dev_net(dev);
540 struct dst_entry *dst;
541
542 RCU_INIT_POINTER(vrf->rth, NULL);
543 RCU_INIT_POINTER(vrf->rth_local, NULL);
544 synchronize_rcu();
545
546 /* move dev in dst's to loopback so this VRF device can be deleted
547 * - based on dst_ifdown
548 */
549 if (rth) {
550 dst = &rth->dst;
551 dev_put(dst->dev);
552 dst->dev = net->loopback_dev;
553 dev_hold(dst->dev);
554 dst_release(dst);
555 }
556
557 if (rth_local) {
558 dst = &rth_local->dst;
559 dev_put(dst->dev);
560 dst->dev = net->loopback_dev;
561 dev_hold(dst->dev);
562 dst_release(dst);
563 }
564 }
565
566 static int vrf_rtable_create(struct net_device *dev)
567 {
568 struct net_vrf *vrf = netdev_priv(dev);
569 struct rtable *rth, *rth_local;
570
571 if (!fib_new_table(dev_net(dev), vrf->tb_id))
572 return -ENOMEM;
573
574 /* create a dst for routing packets out through a VRF device */
575 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1, 0);
576 if (!rth)
577 return -ENOMEM;
578
579 /* create a dst for local ingress routing - packets sent locally
580 * to local address via the VRF device as a loopback
581 */
582 rth_local = rt_dst_alloc(dev, RTCF_LOCAL, RTN_LOCAL, 1, 1, 0);
583 if (!rth_local) {
584 dst_release(&rth->dst);
585 return -ENOMEM;
586 }
587
588 rth->dst.output = vrf_output;
589 rth->rt_table_id = vrf->tb_id;
590
591 rth_local->rt_table_id = vrf->tb_id;
592
593 rcu_assign_pointer(vrf->rth, rth);
594 rcu_assign_pointer(vrf->rth_local, rth_local);
595
596 return 0;
597 }
598
599 /**************************** device handling ********************/
600
601 /* cycle interface to flush neighbor cache and move routes across tables */
602 static void cycle_netdev(struct net_device *dev)
603 {
604 unsigned int flags = dev->flags;
605 int ret;
606
607 if (!netif_running(dev))
608 return;
609
610 ret = dev_change_flags(dev, flags & ~IFF_UP);
611 if (ret >= 0)
612 ret = dev_change_flags(dev, flags);
613
614 if (ret < 0) {
615 netdev_err(dev,
616 "Failed to cycle device %s; route tables might be wrong!\n",
617 dev->name);
618 }
619 }
620
621 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
622 {
623 int ret;
624
625 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL);
626 if (ret < 0)
627 return ret;
628
629 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
630 cycle_netdev(port_dev);
631
632 return 0;
633 }
634
635 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
636 {
637 if (netif_is_l3_master(port_dev) || netif_is_l3_slave(port_dev))
638 return -EINVAL;
639
640 return do_vrf_add_slave(dev, port_dev);
641 }
642
643 /* inverse of do_vrf_add_slave */
644 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
645 {
646 netdev_upper_dev_unlink(port_dev, dev);
647 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
648
649 cycle_netdev(port_dev);
650
651 return 0;
652 }
653
654 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
655 {
656 return do_vrf_del_slave(dev, port_dev);
657 }
658
659 static void vrf_dev_uninit(struct net_device *dev)
660 {
661 struct net_vrf *vrf = netdev_priv(dev);
662 struct net_device *port_dev;
663 struct list_head *iter;
664
665 vrf_rtable_release(dev, vrf);
666 vrf_rt6_release(dev, vrf);
667
668 netdev_for_each_lower_dev(dev, port_dev, iter)
669 vrf_del_slave(dev, port_dev);
670
671 free_percpu(dev->dstats);
672 dev->dstats = NULL;
673 }
674
675 static int vrf_dev_init(struct net_device *dev)
676 {
677 struct net_vrf *vrf = netdev_priv(dev);
678
679 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
680 if (!dev->dstats)
681 goto out_nomem;
682
683 /* create the default dst which points back to us */
684 if (vrf_rtable_create(dev) != 0)
685 goto out_stats;
686
687 if (vrf_rt6_create(dev) != 0)
688 goto out_rth;
689
690 dev->flags = IFF_MASTER | IFF_NOARP;
691
692 /* MTU is irrelevant for VRF device; set to 64k similar to lo */
693 dev->mtu = 64 * 1024;
694
695 /* similarly, oper state is irrelevant; set to up to avoid confusion */
696 dev->operstate = IF_OPER_UP;
697 netdev_lockdep_set_classes(dev);
698 return 0;
699
700 out_rth:
701 vrf_rtable_release(dev, vrf);
702 out_stats:
703 free_percpu(dev->dstats);
704 dev->dstats = NULL;
705 out_nomem:
706 return -ENOMEM;
707 }
708
709 static const struct net_device_ops vrf_netdev_ops = {
710 .ndo_init = vrf_dev_init,
711 .ndo_uninit = vrf_dev_uninit,
712 .ndo_start_xmit = vrf_xmit,
713 .ndo_get_stats64 = vrf_get_stats64,
714 .ndo_add_slave = vrf_add_slave,
715 .ndo_del_slave = vrf_del_slave,
716 };
717
718 static u32 vrf_fib_table(const struct net_device *dev)
719 {
720 struct net_vrf *vrf = netdev_priv(dev);
721
722 return vrf->tb_id;
723 }
724
725 static struct rtable *vrf_get_rtable(const struct net_device *dev,
726 const struct flowi4 *fl4)
727 {
728 struct rtable *rth = NULL;
729
730 if (!(fl4->flowi4_flags & FLOWI_FLAG_L3MDEV_SRC)) {
731 struct net_vrf *vrf = netdev_priv(dev);
732
733 rcu_read_lock();
734
735 rth = rcu_dereference(vrf->rth);
736 if (likely(rth))
737 dst_hold(&rth->dst);
738
739 rcu_read_unlock();
740 }
741
742 return rth;
743 }
744
745 /* called under rcu_read_lock */
746 static int vrf_get_saddr(struct net_device *dev, struct flowi4 *fl4)
747 {
748 struct fib_result res = { .tclassid = 0 };
749 struct net *net = dev_net(dev);
750 u32 orig_tos = fl4->flowi4_tos;
751 u8 flags = fl4->flowi4_flags;
752 u8 scope = fl4->flowi4_scope;
753 u8 tos = RT_FL_TOS(fl4);
754 int rc;
755
756 if (unlikely(!fl4->daddr))
757 return 0;
758
759 fl4->flowi4_flags |= FLOWI_FLAG_SKIP_NH_OIF;
760 fl4->flowi4_iif = LOOPBACK_IFINDEX;
761 /* make sure oif is set to VRF device for lookup */
762 fl4->flowi4_oif = dev->ifindex;
763 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
764 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
765 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
766
767 rc = fib_lookup(net, fl4, &res, 0);
768 if (!rc) {
769 if (res.type == RTN_LOCAL)
770 fl4->saddr = res.fi->fib_prefsrc ? : fl4->daddr;
771 else
772 fib_select_path(net, &res, fl4, -1);
773 }
774
775 fl4->flowi4_flags = flags;
776 fl4->flowi4_tos = orig_tos;
777 fl4->flowi4_scope = scope;
778
779 return rc;
780 }
781
782 static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
783 {
784 return 0;
785 }
786
787 static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
788 struct sk_buff *skb,
789 struct net_device *dev)
790 {
791 struct net *net = dev_net(dev);
792
793 nf_reset(skb);
794
795 if (NF_HOOK(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) < 0)
796 skb = NULL; /* kfree_skb(skb) handled by nf code */
797
798 return skb;
799 }
800
801 #if IS_ENABLED(CONFIG_IPV6)
802 /* neighbor handling is done with actual device; do not want
803 * to flip skb->dev for those ndisc packets. This really fails
804 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
805 * a start.
806 */
807 static bool ipv6_ndisc_frame(const struct sk_buff *skb)
808 {
809 const struct ipv6hdr *iph = ipv6_hdr(skb);
810 bool rc = false;
811
812 if (iph->nexthdr == NEXTHDR_ICMP) {
813 const struct icmp6hdr *icmph;
814 struct icmp6hdr _icmph;
815
816 icmph = skb_header_pointer(skb, sizeof(*iph),
817 sizeof(_icmph), &_icmph);
818 if (!icmph)
819 goto out;
820
821 switch (icmph->icmp6_type) {
822 case NDISC_ROUTER_SOLICITATION:
823 case NDISC_ROUTER_ADVERTISEMENT:
824 case NDISC_NEIGHBOUR_SOLICITATION:
825 case NDISC_NEIGHBOUR_ADVERTISEMENT:
826 case NDISC_REDIRECT:
827 rc = true;
828 break;
829 }
830 }
831
832 out:
833 return rc;
834 }
835
836 static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
837 const struct net_device *dev,
838 struct flowi6 *fl6,
839 int ifindex,
840 int flags)
841 {
842 struct net_vrf *vrf = netdev_priv(dev);
843 struct fib6_table *table = NULL;
844 struct rt6_info *rt6;
845
846 rcu_read_lock();
847
848 /* fib6_table does not have a refcnt and can not be freed */
849 rt6 = rcu_dereference(vrf->rt6);
850 if (likely(rt6))
851 table = rt6->rt6i_table;
852
853 rcu_read_unlock();
854
855 if (!table)
856 return NULL;
857
858 return ip6_pol_route(net, table, ifindex, fl6, flags);
859 }
860
861 static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
862 int ifindex)
863 {
864 const struct ipv6hdr *iph = ipv6_hdr(skb);
865 struct flowi6 fl6 = {
866 .daddr = iph->daddr,
867 .saddr = iph->saddr,
868 .flowlabel = ip6_flowinfo(iph),
869 .flowi6_mark = skb->mark,
870 .flowi6_proto = iph->nexthdr,
871 .flowi6_iif = ifindex,
872 };
873 struct net *net = dev_net(vrf_dev);
874 struct rt6_info *rt6;
875
876 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex,
877 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
878 if (unlikely(!rt6))
879 return;
880
881 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
882 return;
883
884 skb_dst_set(skb, &rt6->dst);
885 }
886
887 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
888 struct sk_buff *skb)
889 {
890 int orig_iif = skb->skb_iif;
891 bool need_strict;
892
893 /* loopback traffic; do not push through packet taps again.
894 * Reset pkt_type for upper layers to process skb
895 */
896 if (skb->pkt_type == PACKET_LOOPBACK) {
897 skb->dev = vrf_dev;
898 skb->skb_iif = vrf_dev->ifindex;
899 skb->pkt_type = PACKET_HOST;
900 goto out;
901 }
902
903 /* if packet is NDISC or addressed to multicast or link-local
904 * then keep the ingress interface
905 */
906 need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
907 if (!ipv6_ndisc_frame(skb) && !need_strict) {
908 skb->dev = vrf_dev;
909 skb->skb_iif = vrf_dev->ifindex;
910
911 skb_push(skb, skb->mac_len);
912 dev_queue_xmit_nit(skb, vrf_dev);
913 skb_pull(skb, skb->mac_len);
914
915 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
916 }
917
918 if (need_strict)
919 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
920
921 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
922 out:
923 return skb;
924 }
925
926 #else
927 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
928 struct sk_buff *skb)
929 {
930 return skb;
931 }
932 #endif
933
934 static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
935 struct sk_buff *skb)
936 {
937 skb->dev = vrf_dev;
938 skb->skb_iif = vrf_dev->ifindex;
939
940 /* loopback traffic; do not push through packet taps again.
941 * Reset pkt_type for upper layers to process skb
942 */
943 if (skb->pkt_type == PACKET_LOOPBACK) {
944 skb->pkt_type = PACKET_HOST;
945 goto out;
946 }
947
948 skb_push(skb, skb->mac_len);
949 dev_queue_xmit_nit(skb, vrf_dev);
950 skb_pull(skb, skb->mac_len);
951
952 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
953 out:
954 return skb;
955 }
956
957 /* called with rcu lock held */
958 static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
959 struct sk_buff *skb,
960 u16 proto)
961 {
962 switch (proto) {
963 case AF_INET:
964 return vrf_ip_rcv(vrf_dev, skb);
965 case AF_INET6:
966 return vrf_ip6_rcv(vrf_dev, skb);
967 }
968
969 return skb;
970 }
971
972 #if IS_ENABLED(CONFIG_IPV6)
973 static struct dst_entry *vrf_get_rt6_dst(const struct net_device *dev,
974 struct flowi6 *fl6)
975 {
976 bool need_strict = rt6_need_strict(&fl6->daddr);
977 struct net_vrf *vrf = netdev_priv(dev);
978 struct net *net = dev_net(dev);
979 struct dst_entry *dst = NULL;
980 struct rt6_info *rt;
981
982 /* send to link-local or multicast address */
983 if (need_strict) {
984 int flags = RT6_LOOKUP_F_IFACE;
985
986 /* VRF device does not have a link-local address and
987 * sending packets to link-local or mcast addresses over
988 * a VRF device does not make sense
989 */
990 if (fl6->flowi6_oif == dev->ifindex) {
991 struct dst_entry *dst = &net->ipv6.ip6_null_entry->dst;
992
993 dst_hold(dst);
994 return dst;
995 }
996
997 if (!ipv6_addr_any(&fl6->saddr))
998 flags |= RT6_LOOKUP_F_HAS_SADDR;
999
1000 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, flags);
1001 if (rt)
1002 dst = &rt->dst;
1003
1004 } else if (!(fl6->flowi6_flags & FLOWI_FLAG_L3MDEV_SRC)) {
1005
1006 rcu_read_lock();
1007
1008 rt = rcu_dereference(vrf->rt6);
1009 if (likely(rt)) {
1010 dst = &rt->dst;
1011 dst_hold(dst);
1012 }
1013
1014 rcu_read_unlock();
1015 }
1016
1017 /* make sure oif is set to VRF device for lookup */
1018 if (!need_strict)
1019 fl6->flowi6_oif = dev->ifindex;
1020
1021 return dst;
1022 }
1023
1024 /* called under rcu_read_lock */
1025 static int vrf_get_saddr6(struct net_device *dev, const struct sock *sk,
1026 struct flowi6 *fl6)
1027 {
1028 struct net *net = dev_net(dev);
1029 struct dst_entry *dst;
1030 struct rt6_info *rt;
1031 int err;
1032
1033 if (rt6_need_strict(&fl6->daddr)) {
1034 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif,
1035 RT6_LOOKUP_F_IFACE);
1036 if (unlikely(!rt))
1037 return 0;
1038
1039 dst = &rt->dst;
1040 } else {
1041 __u8 flags = fl6->flowi6_flags;
1042
1043 fl6->flowi6_flags |= FLOWI_FLAG_L3MDEV_SRC;
1044 fl6->flowi6_flags |= FLOWI_FLAG_SKIP_NH_OIF;
1045
1046 dst = ip6_route_output(net, sk, fl6);
1047 rt = (struct rt6_info *)dst;
1048
1049 fl6->flowi6_flags = flags;
1050 }
1051
1052 err = dst->error;
1053 if (!err) {
1054 err = ip6_route_get_saddr(net, rt, &fl6->daddr,
1055 sk ? inet6_sk(sk)->srcprefs : 0,
1056 &fl6->saddr);
1057 }
1058
1059 dst_release(dst);
1060
1061 return err;
1062 }
1063 #endif
1064
1065 static const struct l3mdev_ops vrf_l3mdev_ops = {
1066 .l3mdev_fib_table = vrf_fib_table,
1067 .l3mdev_get_rtable = vrf_get_rtable,
1068 .l3mdev_get_saddr = vrf_get_saddr,
1069 .l3mdev_l3_rcv = vrf_l3_rcv,
1070 #if IS_ENABLED(CONFIG_IPV6)
1071 .l3mdev_get_rt6_dst = vrf_get_rt6_dst,
1072 .l3mdev_get_saddr6 = vrf_get_saddr6,
1073 #endif
1074 };
1075
1076 static void vrf_get_drvinfo(struct net_device *dev,
1077 struct ethtool_drvinfo *info)
1078 {
1079 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
1080 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
1081 }
1082
1083 static const struct ethtool_ops vrf_ethtool_ops = {
1084 .get_drvinfo = vrf_get_drvinfo,
1085 };
1086
1087 static inline size_t vrf_fib_rule_nl_size(void)
1088 {
1089 size_t sz;
1090
1091 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1092 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */
1093 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */
1094
1095 return sz;
1096 }
1097
1098 static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1099 {
1100 struct fib_rule_hdr *frh;
1101 struct nlmsghdr *nlh;
1102 struct sk_buff *skb;
1103 int err;
1104
1105 if (family == AF_INET6 && !ipv6_mod_enabled())
1106 return 0;
1107
1108 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
1109 if (!skb)
1110 return -ENOMEM;
1111
1112 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
1113 if (!nlh)
1114 goto nla_put_failure;
1115
1116 /* rule only needs to appear once */
1117 nlh->nlmsg_flags &= NLM_F_EXCL;
1118
1119 frh = nlmsg_data(nlh);
1120 memset(frh, 0, sizeof(*frh));
1121 frh->family = family;
1122 frh->action = FR_ACT_TO_TBL;
1123
1124 if (nla_put_u32(skb, FRA_L3MDEV, 1))
1125 goto nla_put_failure;
1126
1127 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
1128 goto nla_put_failure;
1129
1130 nlmsg_end(skb, nlh);
1131
1132 /* fib_nl_{new,del}rule handling looks for net from skb->sk */
1133 skb->sk = dev_net(dev)->rtnl;
1134 if (add_it) {
1135 err = fib_nl_newrule(skb, nlh);
1136 if (err == -EEXIST)
1137 err = 0;
1138 } else {
1139 err = fib_nl_delrule(skb, nlh);
1140 if (err == -ENOENT)
1141 err = 0;
1142 }
1143 nlmsg_free(skb);
1144
1145 return err;
1146
1147 nla_put_failure:
1148 nlmsg_free(skb);
1149
1150 return -EMSGSIZE;
1151 }
1152
1153 static int vrf_add_fib_rules(const struct net_device *dev)
1154 {
1155 int err;
1156
1157 err = vrf_fib_rule(dev, AF_INET, true);
1158 if (err < 0)
1159 goto out_err;
1160
1161 err = vrf_fib_rule(dev, AF_INET6, true);
1162 if (err < 0)
1163 goto ipv6_err;
1164
1165 return 0;
1166
1167 ipv6_err:
1168 vrf_fib_rule(dev, AF_INET, false);
1169
1170 out_err:
1171 netdev_err(dev, "Failed to add FIB rules.\n");
1172 return err;
1173 }
1174
1175 static void vrf_setup(struct net_device *dev)
1176 {
1177 ether_setup(dev);
1178
1179 /* Initialize the device structure. */
1180 dev->netdev_ops = &vrf_netdev_ops;
1181 dev->l3mdev_ops = &vrf_l3mdev_ops;
1182 dev->ethtool_ops = &vrf_ethtool_ops;
1183 dev->destructor = free_netdev;
1184
1185 /* Fill in device structure with ethernet-generic values. */
1186 eth_hw_addr_random(dev);
1187
1188 /* don't acquire vrf device's netif_tx_lock when transmitting */
1189 dev->features |= NETIF_F_LLTX;
1190
1191 /* don't allow vrf devices to change network namespaces. */
1192 dev->features |= NETIF_F_NETNS_LOCAL;
1193
1194 /* does not make sense for a VLAN to be added to a vrf device */
1195 dev->features |= NETIF_F_VLAN_CHALLENGED;
1196
1197 /* enable offload features */
1198 dev->features |= NETIF_F_GSO_SOFTWARE;
1199 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM;
1200 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1201
1202 dev->hw_features = dev->features;
1203 dev->hw_enc_features = dev->features;
1204
1205 /* default to no qdisc; user can add if desired */
1206 dev->priv_flags |= IFF_NO_QUEUE;
1207 }
1208
1209 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[])
1210 {
1211 if (tb[IFLA_ADDRESS]) {
1212 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1213 return -EINVAL;
1214 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1215 return -EADDRNOTAVAIL;
1216 }
1217 return 0;
1218 }
1219
1220 static void vrf_dellink(struct net_device *dev, struct list_head *head)
1221 {
1222 unregister_netdevice_queue(dev, head);
1223 }
1224
1225 static int vrf_newlink(struct net *src_net, struct net_device *dev,
1226 struct nlattr *tb[], struct nlattr *data[])
1227 {
1228 struct net_vrf *vrf = netdev_priv(dev);
1229 int err;
1230
1231 if (!data || !data[IFLA_VRF_TABLE])
1232 return -EINVAL;
1233
1234 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
1235
1236 dev->priv_flags |= IFF_L3MDEV_MASTER;
1237
1238 err = register_netdevice(dev);
1239 if (err)
1240 goto out;
1241
1242 if (add_fib_rules) {
1243 err = vrf_add_fib_rules(dev);
1244 if (err) {
1245 unregister_netdevice(dev);
1246 goto out;
1247 }
1248 add_fib_rules = false;
1249 }
1250
1251 out:
1252 return err;
1253 }
1254
1255 static size_t vrf_nl_getsize(const struct net_device *dev)
1256 {
1257 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
1258 }
1259
1260 static int vrf_fillinfo(struct sk_buff *skb,
1261 const struct net_device *dev)
1262 {
1263 struct net_vrf *vrf = netdev_priv(dev);
1264
1265 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
1266 }
1267
1268 static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1269 const struct net_device *slave_dev)
1270 {
1271 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1272 }
1273
1274 static int vrf_fill_slave_info(struct sk_buff *skb,
1275 const struct net_device *vrf_dev,
1276 const struct net_device *slave_dev)
1277 {
1278 struct net_vrf *vrf = netdev_priv(vrf_dev);
1279
1280 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
1281 return -EMSGSIZE;
1282
1283 return 0;
1284 }
1285
1286 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1287 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1288 };
1289
1290 static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1291 .kind = DRV_NAME,
1292 .priv_size = sizeof(struct net_vrf),
1293
1294 .get_size = vrf_nl_getsize,
1295 .policy = vrf_nl_policy,
1296 .validate = vrf_validate,
1297 .fill_info = vrf_fillinfo,
1298
1299 .get_slave_size = vrf_get_slave_size,
1300 .fill_slave_info = vrf_fill_slave_info,
1301
1302 .newlink = vrf_newlink,
1303 .dellink = vrf_dellink,
1304 .setup = vrf_setup,
1305 .maxtype = IFLA_VRF_MAX,
1306 };
1307
1308 static int vrf_device_event(struct notifier_block *unused,
1309 unsigned long event, void *ptr)
1310 {
1311 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1312
1313 /* only care about unregister events to drop slave references */
1314 if (event == NETDEV_UNREGISTER) {
1315 struct net_device *vrf_dev;
1316
1317 if (!netif_is_l3_slave(dev))
1318 goto out;
1319
1320 vrf_dev = netdev_master_upper_dev_get(dev);
1321 vrf_del_slave(vrf_dev, dev);
1322 }
1323 out:
1324 return NOTIFY_DONE;
1325 }
1326
1327 static struct notifier_block vrf_notifier_block __read_mostly = {
1328 .notifier_call = vrf_device_event,
1329 };
1330
1331 static int __init vrf_init_module(void)
1332 {
1333 int rc;
1334
1335 register_netdevice_notifier(&vrf_notifier_block);
1336
1337 rc = rtnl_link_register(&vrf_link_ops);
1338 if (rc < 0)
1339 goto error;
1340
1341 return 0;
1342
1343 error:
1344 unregister_netdevice_notifier(&vrf_notifier_block);
1345 return rc;
1346 }
1347
1348 module_init(vrf_init_module);
1349 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
1350 MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
1351 MODULE_LICENSE("GPL");
1352 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
1353 MODULE_VERSION(DRV_VERSION);
Linux kernel - Deliverables
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