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cgroup: move CONFIG_SOCK_CGROUP_DATA to init/Kconfig
[linux-2.6/btrfs-unstable.git] / drivers / net / vrf.c
blob23dfb0eac0981704f2770bc3abe9bb32a80e3fc9
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 .daddr = ip4h->daddr,
267 };
268 struct net *net = dev_net(vrf_dev);
269 struct rtable *rt;
270
271 rt = ip_route_output_flow(net, &fl4, NULL);
272 if (IS_ERR(rt))
273 goto err;
274
275 skb_dst_drop(skb);
276
277 /* if dst.dev is loopback or the VRF device again this is locally
278 * originated traffic destined to a local address. Short circuit
279 * to Rx path using our local dst
280 */
281 if (rt->dst.dev == net->loopback_dev || rt->dst.dev == vrf_dev) {
282 struct net_vrf *vrf = netdev_priv(vrf_dev);
283 struct rtable *rth_local;
284 struct dst_entry *dst = NULL;
285
286 ip_rt_put(rt);
287
288 rcu_read_lock();
289
290 rth_local = rcu_dereference(vrf->rth_local);
291 if (likely(rth_local)) {
292 dst = &rth_local->dst;
293 dst_hold(dst);
294 }
295
296 rcu_read_unlock();
297
298 if (unlikely(!dst))
299 goto err;
300
301 return vrf_local_xmit(skb, vrf_dev, dst);
302 }
303
304 skb_dst_set(skb, &rt->dst);
305
306 /* strip the ethernet header added for pass through VRF device */
307 __skb_pull(skb, skb_network_offset(skb));
308
309 if (!ip4h->saddr) {
310 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
311 RT_SCOPE_LINK);
312 }
313
314 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
315 if (unlikely(net_xmit_eval(ret)))
316 vrf_dev->stats.tx_errors++;
317 else
318 ret = NET_XMIT_SUCCESS;
319
320 out:
321 return ret;
322 err:
323 vrf_tx_error(vrf_dev, skb);
324 goto out;
325 }
326
327 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
328 {
329 switch (skb->protocol) {
330 case htons(ETH_P_IP):
331 return vrf_process_v4_outbound(skb, dev);
332 case htons(ETH_P_IPV6):
333 return vrf_process_v6_outbound(skb, dev);
334 default:
335 vrf_tx_error(dev, skb);
336 return NET_XMIT_DROP;
337 }
338 }
339
340 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
341 {
342 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
343
344 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
345 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
346
347 u64_stats_update_begin(&dstats->syncp);
348 dstats->tx_pkts++;
349 dstats->tx_bytes += skb->len;
350 u64_stats_update_end(&dstats->syncp);
351 } else {
352 this_cpu_inc(dev->dstats->tx_drps);
353 }
354
355 return ret;
356 }
357
358 #if IS_ENABLED(CONFIG_IPV6)
359 /* modelled after ip6_finish_output2 */
360 static int vrf_finish_output6(struct net *net, struct sock *sk,
361 struct sk_buff *skb)
362 {
363 struct dst_entry *dst = skb_dst(skb);
364 struct net_device *dev = dst->dev;
365 struct neighbour *neigh;
366 struct in6_addr *nexthop;
367 int ret;
368
369 nf_reset(skb);
370
371 skb->protocol = htons(ETH_P_IPV6);
372 skb->dev = dev;
373
374 rcu_read_lock_bh();
375 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
376 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
377 if (unlikely(!neigh))
378 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
379 if (!IS_ERR(neigh)) {
380 ret = dst_neigh_output(dst, neigh, skb);
381 rcu_read_unlock_bh();
382 return ret;
383 }
384 rcu_read_unlock_bh();
385
386 IP6_INC_STATS(dev_net(dst->dev),
387 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
388 kfree_skb(skb);
389 return -EINVAL;
390 }
391
392 /* modelled after ip6_output */
393 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
394 {
395 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
396 net, sk, skb, NULL, skb_dst(skb)->dev,
397 vrf_finish_output6,
398 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
399 }
400
401 /* set dst on skb to send packet to us via dev_xmit path. Allows
402 * packet to go through device based features such as qdisc, netfilter
403 * hooks and packet sockets with skb->dev set to vrf device.
404 */
405 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
406 struct sock *sk,
407 struct sk_buff *skb)
408 {
409 struct net_vrf *vrf = netdev_priv(vrf_dev);
410 struct dst_entry *dst = NULL;
411 struct rt6_info *rt6;
412
413 /* don't divert link scope packets */
414 if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
415 return skb;
416
417 rcu_read_lock();
418
419 rt6 = rcu_dereference(vrf->rt6);
420 if (likely(rt6)) {
421 dst = &rt6->dst;
422 dst_hold(dst);
423 }
424
425 rcu_read_unlock();
426
427 if (unlikely(!dst)) {
428 vrf_tx_error(vrf_dev, skb);
429 return NULL;
430 }
431
432 skb_dst_drop(skb);
433 skb_dst_set(skb, dst);
434
435 return skb;
436 }
437
438 /* holding rtnl */
439 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
440 {
441 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
442 struct rt6_info *rt6_local = rtnl_dereference(vrf->rt6_local);
443 struct net *net = dev_net(dev);
444 struct dst_entry *dst;
445
446 RCU_INIT_POINTER(vrf->rt6, NULL);
447 RCU_INIT_POINTER(vrf->rt6_local, NULL);
448 synchronize_rcu();
449
450 /* move dev in dst's to loopback so this VRF device can be deleted
451 * - based on dst_ifdown
452 */
453 if (rt6) {
454 dst = &rt6->dst;
455 dev_put(dst->dev);
456 dst->dev = net->loopback_dev;
457 dev_hold(dst->dev);
458 dst_release(dst);
459 }
460
461 if (rt6_local) {
462 if (rt6_local->rt6i_idev)
463 in6_dev_put(rt6_local->rt6i_idev);
464
465 dst = &rt6_local->dst;
466 dev_put(dst->dev);
467 dst->dev = net->loopback_dev;
468 dev_hold(dst->dev);
469 dst_release(dst);
470 }
471 }
472
473 static int vrf_rt6_create(struct net_device *dev)
474 {
475 int flags = DST_HOST | DST_NOPOLICY | DST_NOXFRM | DST_NOCACHE;
476 struct net_vrf *vrf = netdev_priv(dev);
477 struct net *net = dev_net(dev);
478 struct fib6_table *rt6i_table;
479 struct rt6_info *rt6, *rt6_local;
480 int rc = -ENOMEM;
481
482 /* IPv6 can be CONFIG enabled and then disabled runtime */
483 if (!ipv6_mod_enabled())
484 return 0;
485
486 rt6i_table = fib6_new_table(net, vrf->tb_id);
487 if (!rt6i_table)
488 goto out;
489
490 /* create a dst for routing packets out a VRF device */
491 rt6 = ip6_dst_alloc(net, dev, flags);
492 if (!rt6)
493 goto out;
494
495 dst_hold(&rt6->dst);
496
497 rt6->rt6i_table = rt6i_table;
498 rt6->dst.output = vrf_output6;
499
500 /* create a dst for local routing - packets sent locally
501 * to local address via the VRF device as a loopback
502 */
503 rt6_local = ip6_dst_alloc(net, dev, flags);
504 if (!rt6_local) {
505 dst_release(&rt6->dst);
506 goto out;
507 }
508
509 dst_hold(&rt6_local->dst);
510
511 rt6_local->rt6i_idev = in6_dev_get(dev);
512 rt6_local->rt6i_flags = RTF_UP | RTF_NONEXTHOP | RTF_LOCAL;
513 rt6_local->rt6i_table = rt6i_table;
514 rt6_local->dst.input = ip6_input;
515
516 rcu_assign_pointer(vrf->rt6, rt6);
517 rcu_assign_pointer(vrf->rt6_local, rt6_local);
518
519 rc = 0;
520 out:
521 return rc;
522 }
523 #else
524 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
525 struct sock *sk,
526 struct sk_buff *skb)
527 {
528 return skb;
529 }
530
531 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
532 {
533 }
534
535 static int vrf_rt6_create(struct net_device *dev)
536 {
537 return 0;
538 }
539 #endif
540
541 /* modelled after ip_finish_output2 */
542 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
543 {
544 struct dst_entry *dst = skb_dst(skb);
545 struct rtable *rt = (struct rtable *)dst;
546 struct net_device *dev = dst->dev;
547 unsigned int hh_len = LL_RESERVED_SPACE(dev);
548 struct neighbour *neigh;
549 u32 nexthop;
550 int ret = -EINVAL;
551
552 nf_reset(skb);
553
554 /* Be paranoid, rather than too clever. */
555 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
556 struct sk_buff *skb2;
557
558 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
559 if (!skb2) {
560 ret = -ENOMEM;
561 goto err;
562 }
563 if (skb->sk)
564 skb_set_owner_w(skb2, skb->sk);
565
566 consume_skb(skb);
567 skb = skb2;
568 }
569
570 rcu_read_lock_bh();
571
572 nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr);
573 neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
574 if (unlikely(!neigh))
575 neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
576 if (!IS_ERR(neigh))
577 ret = dst_neigh_output(dst, neigh, skb);
578
579 rcu_read_unlock_bh();
580 err:
581 if (unlikely(ret < 0))
582 vrf_tx_error(skb->dev, skb);
583 return ret;
584 }
585
586 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
587 {
588 struct net_device *dev = skb_dst(skb)->dev;
589
590 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
591
592 skb->dev = dev;
593 skb->protocol = htons(ETH_P_IP);
594
595 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
596 net, sk, skb, NULL, dev,
597 vrf_finish_output,
598 !(IPCB(skb)->flags & IPSKB_REROUTED));
599 }
600
601 /* set dst on skb to send packet to us via dev_xmit path. Allows
602 * packet to go through device based features such as qdisc, netfilter
603 * hooks and packet sockets with skb->dev set to vrf device.
604 */
605 static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
606 struct sock *sk,
607 struct sk_buff *skb)
608 {
609 struct net_vrf *vrf = netdev_priv(vrf_dev);
610 struct dst_entry *dst = NULL;
611 struct rtable *rth;
612
613 /* don't divert multicast */
614 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
615 return skb;
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 if (NF_HOOK(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) < 0)
857 skb = NULL; /* kfree_skb(skb) handled by nf code */
858
859 return skb;
860 }
861
862 #if IS_ENABLED(CONFIG_IPV6)
863 /* neighbor handling is done with actual device; do not want
864 * to flip skb->dev for those ndisc packets. This really fails
865 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
866 * a start.
867 */
868 static bool ipv6_ndisc_frame(const struct sk_buff *skb)
869 {
870 const struct ipv6hdr *iph = ipv6_hdr(skb);
871 bool rc = false;
872
873 if (iph->nexthdr == NEXTHDR_ICMP) {
874 const struct icmp6hdr *icmph;
875 struct icmp6hdr _icmph;
876
877 icmph = skb_header_pointer(skb, sizeof(*iph),
878 sizeof(_icmph), &_icmph);
879 if (!icmph)
880 goto out;
881
882 switch (icmph->icmp6_type) {
883 case NDISC_ROUTER_SOLICITATION:
884 case NDISC_ROUTER_ADVERTISEMENT:
885 case NDISC_NEIGHBOUR_SOLICITATION:
886 case NDISC_NEIGHBOUR_ADVERTISEMENT:
887 case NDISC_REDIRECT:
888 rc = true;
889 break;
890 }
891 }
892
893 out:
894 return rc;
895 }
896
897 static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
898 const struct net_device *dev,
899 struct flowi6 *fl6,
900 int ifindex,
901 int flags)
902 {
903 struct net_vrf *vrf = netdev_priv(dev);
904 struct fib6_table *table = NULL;
905 struct rt6_info *rt6;
906
907 rcu_read_lock();
908
909 /* fib6_table does not have a refcnt and can not be freed */
910 rt6 = rcu_dereference(vrf->rt6);
911 if (likely(rt6))
912 table = rt6->rt6i_table;
913
914 rcu_read_unlock();
915
916 if (!table)
917 return NULL;
918
919 return ip6_pol_route(net, table, ifindex, fl6, flags);
920 }
921
922 static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
923 int ifindex)
924 {
925 const struct ipv6hdr *iph = ipv6_hdr(skb);
926 struct flowi6 fl6 = {
927 .daddr = iph->daddr,
928 .saddr = iph->saddr,
929 .flowlabel = ip6_flowinfo(iph),
930 .flowi6_mark = skb->mark,
931 .flowi6_proto = iph->nexthdr,
932 .flowi6_iif = ifindex,
933 };
934 struct net *net = dev_net(vrf_dev);
935 struct rt6_info *rt6;
936
937 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex,
938 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
939 if (unlikely(!rt6))
940 return;
941
942 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
943 return;
944
945 skb_dst_set(skb, &rt6->dst);
946 }
947
948 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
949 struct sk_buff *skb)
950 {
951 int orig_iif = skb->skb_iif;
952 bool need_strict;
953
954 /* loopback traffic; do not push through packet taps again.
955 * Reset pkt_type for upper layers to process skb
956 */
957 if (skb->pkt_type == PACKET_LOOPBACK) {
958 skb->dev = vrf_dev;
959 skb->skb_iif = vrf_dev->ifindex;
960 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
961 skb->pkt_type = PACKET_HOST;
962 goto out;
963 }
964
965 /* if packet is NDISC or addressed to multicast or link-local
966 * then keep the ingress interface
967 */
968 need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
969 if (!ipv6_ndisc_frame(skb) && !need_strict) {
970 vrf_rx_stats(vrf_dev, skb->len);
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 IPCB(skb)->flags |= IPSKB_L3SLAVE;
1003
1004 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
1005 goto out;
1006
1007 /* loopback traffic; do not push through packet taps again.
1008 * Reset pkt_type for upper layers to process skb
1009 */
1010 if (skb->pkt_type == PACKET_LOOPBACK) {
1011 skb->pkt_type = PACKET_HOST;
1012 goto out;
1013 }
1014
1015 vrf_rx_stats(vrf_dev, skb->len);
1016
1017 skb_push(skb, skb->mac_len);
1018 dev_queue_xmit_nit(skb, vrf_dev);
1019 skb_pull(skb, skb->mac_len);
1020
1021 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
1022 out:
1023 return skb;
1024 }
1025
1026 /* called with rcu lock held */
1027 static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1028 struct sk_buff *skb,
1029 u16 proto)
1030 {
1031 switch (proto) {
1032 case AF_INET:
1033 return vrf_ip_rcv(vrf_dev, skb);
1034 case AF_INET6:
1035 return vrf_ip6_rcv(vrf_dev, skb);
1036 }
1037
1038 return skb;
1039 }
1040
1041 #if IS_ENABLED(CONFIG_IPV6)
1042 /* send to link-local or multicast address via interface enslaved to
1043 * VRF device. Force lookup to VRF table without changing flow struct
1044 */
1045 static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1046 struct flowi6 *fl6)
1047 {
1048 struct net *net = dev_net(dev);
1049 int flags = RT6_LOOKUP_F_IFACE;
1050 struct dst_entry *dst = NULL;
1051 struct rt6_info *rt;
1052
1053 /* VRF device does not have a link-local address and
1054 * sending packets to link-local or mcast addresses over
1055 * a VRF device does not make sense
1056 */
1057 if (fl6->flowi6_oif == dev->ifindex) {
1058 dst = &net->ipv6.ip6_null_entry->dst;
1059 dst_hold(dst);
1060 return dst;
1061 }
1062
1063 if (!ipv6_addr_any(&fl6->saddr))
1064 flags |= RT6_LOOKUP_F_HAS_SADDR;
1065
1066 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, flags);
1067 if (rt)
1068 dst = &rt->dst;
1069
1070 return dst;
1071 }
1072 #endif
1073
1074 static const struct l3mdev_ops vrf_l3mdev_ops = {
1075 .l3mdev_fib_table = vrf_fib_table,
1076 .l3mdev_l3_rcv = vrf_l3_rcv,
1077 .l3mdev_l3_out = vrf_l3_out,
1078 #if IS_ENABLED(CONFIG_IPV6)
1079 .l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1080 #endif
1081 };
1082
1083 static void vrf_get_drvinfo(struct net_device *dev,
1084 struct ethtool_drvinfo *info)
1085 {
1086 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
1087 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
1088 }
1089
1090 static const struct ethtool_ops vrf_ethtool_ops = {
1091 .get_drvinfo = vrf_get_drvinfo,
1092 };
1093
1094 static inline size_t vrf_fib_rule_nl_size(void)
1095 {
1096 size_t sz;
1097
1098 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1099 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */
1100 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */
1101
1102 return sz;
1103 }
1104
1105 static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1106 {
1107 struct fib_rule_hdr *frh;
1108 struct nlmsghdr *nlh;
1109 struct sk_buff *skb;
1110 int err;
1111
1112 if (family == AF_INET6 && !ipv6_mod_enabled())
1113 return 0;
1114
1115 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
1116 if (!skb)
1117 return -ENOMEM;
1118
1119 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
1120 if (!nlh)
1121 goto nla_put_failure;
1122
1123 /* rule only needs to appear once */
1124 nlh->nlmsg_flags &= NLM_F_EXCL;
1125
1126 frh = nlmsg_data(nlh);
1127 memset(frh, 0, sizeof(*frh));
1128 frh->family = family;
1129 frh->action = FR_ACT_TO_TBL;
1130
1131 if (nla_put_u32(skb, FRA_L3MDEV, 1))
1132 goto nla_put_failure;
1133
1134 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
1135 goto nla_put_failure;
1136
1137 nlmsg_end(skb, nlh);
1138
1139 /* fib_nl_{new,del}rule handling looks for net from skb->sk */
1140 skb->sk = dev_net(dev)->rtnl;
1141 if (add_it) {
1142 err = fib_nl_newrule(skb, nlh);
1143 if (err == -EEXIST)
1144 err = 0;
1145 } else {
1146 err = fib_nl_delrule(skb, nlh);
1147 if (err == -ENOENT)
1148 err = 0;
1149 }
1150 nlmsg_free(skb);
1151
1152 return err;
1153
1154 nla_put_failure:
1155 nlmsg_free(skb);
1156
1157 return -EMSGSIZE;
1158 }
1159
1160 static int vrf_add_fib_rules(const struct net_device *dev)
1161 {
1162 int err;
1163
1164 err = vrf_fib_rule(dev, AF_INET, true);
1165 if (err < 0)
1166 goto out_err;
1167
1168 err = vrf_fib_rule(dev, AF_INET6, true);
1169 if (err < 0)
1170 goto ipv6_err;
1171
1172 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1173 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true);
1174 if (err < 0)
1175 goto ipmr_err;
1176 #endif
1177
1178 return 0;
1179
1180 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1181 ipmr_err:
1182 vrf_fib_rule(dev, AF_INET6, false);
1183 #endif
1184
1185 ipv6_err:
1186 vrf_fib_rule(dev, AF_INET, false);
1187
1188 out_err:
1189 netdev_err(dev, "Failed to add FIB rules.\n");
1190 return err;
1191 }
1192
1193 static void vrf_setup(struct net_device *dev)
1194 {
1195 ether_setup(dev);
1196
1197 /* Initialize the device structure. */
1198 dev->netdev_ops = &vrf_netdev_ops;
1199 dev->l3mdev_ops = &vrf_l3mdev_ops;
1200 dev->ethtool_ops = &vrf_ethtool_ops;
1201 dev->destructor = free_netdev;
1202
1203 /* Fill in device structure with ethernet-generic values. */
1204 eth_hw_addr_random(dev);
1205
1206 /* don't acquire vrf device's netif_tx_lock when transmitting */
1207 dev->features |= NETIF_F_LLTX;
1208
1209 /* don't allow vrf devices to change network namespaces. */
1210 dev->features |= NETIF_F_NETNS_LOCAL;
1211
1212 /* does not make sense for a VLAN to be added to a vrf device */
1213 dev->features |= NETIF_F_VLAN_CHALLENGED;
1214
1215 /* enable offload features */
1216 dev->features |= NETIF_F_GSO_SOFTWARE;
1217 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM;
1218 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1219
1220 dev->hw_features = dev->features;
1221 dev->hw_enc_features = dev->features;
1222
1223 /* default to no qdisc; user can add if desired */
1224 dev->priv_flags |= IFF_NO_QUEUE;
1225 }
1226
1227 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[])
1228 {
1229 if (tb[IFLA_ADDRESS]) {
1230 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1231 return -EINVAL;
1232 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1233 return -EADDRNOTAVAIL;
1234 }
1235 return 0;
1236 }
1237
1238 static void vrf_dellink(struct net_device *dev, struct list_head *head)
1239 {
1240 unregister_netdevice_queue(dev, head);
1241 }
1242
1243 static int vrf_newlink(struct net *src_net, struct net_device *dev,
1244 struct nlattr *tb[], struct nlattr *data[])
1245 {
1246 struct net_vrf *vrf = netdev_priv(dev);
1247 int err;
1248
1249 if (!data || !data[IFLA_VRF_TABLE])
1250 return -EINVAL;
1251
1252 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
1253
1254 dev->priv_flags |= IFF_L3MDEV_MASTER;
1255
1256 err = register_netdevice(dev);
1257 if (err)
1258 goto out;
1259
1260 if (add_fib_rules) {
1261 err = vrf_add_fib_rules(dev);
1262 if (err) {
1263 unregister_netdevice(dev);
1264 goto out;
1265 }
1266 add_fib_rules = false;
1267 }
1268
1269 out:
1270 return err;
1271 }
1272
1273 static size_t vrf_nl_getsize(const struct net_device *dev)
1274 {
1275 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
1276 }
1277
1278 static int vrf_fillinfo(struct sk_buff *skb,
1279 const struct net_device *dev)
1280 {
1281 struct net_vrf *vrf = netdev_priv(dev);
1282
1283 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
1284 }
1285
1286 static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1287 const struct net_device *slave_dev)
1288 {
1289 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1290 }
1291
1292 static int vrf_fill_slave_info(struct sk_buff *skb,
1293 const struct net_device *vrf_dev,
1294 const struct net_device *slave_dev)
1295 {
1296 struct net_vrf *vrf = netdev_priv(vrf_dev);
1297
1298 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
1299 return -EMSGSIZE;
1300
1301 return 0;
1302 }
1303
1304 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1305 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1306 };
1307
1308 static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1309 .kind = DRV_NAME,
1310 .priv_size = sizeof(struct net_vrf),
1311
1312 .get_size = vrf_nl_getsize,
1313 .policy = vrf_nl_policy,
1314 .validate = vrf_validate,
1315 .fill_info = vrf_fillinfo,
1316
1317 .get_slave_size = vrf_get_slave_size,
1318 .fill_slave_info = vrf_fill_slave_info,
1319
1320 .newlink = vrf_newlink,
1321 .dellink = vrf_dellink,
1322 .setup = vrf_setup,
1323 .maxtype = IFLA_VRF_MAX,
1324 };
1325
1326 static int vrf_device_event(struct notifier_block *unused,
1327 unsigned long event, void *ptr)
1328 {
1329 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1330
1331 /* only care about unregister events to drop slave references */
1332 if (event == NETDEV_UNREGISTER) {
1333 struct net_device *vrf_dev;
1334
1335 if (!netif_is_l3_slave(dev))
1336 goto out;
1337
1338 vrf_dev = netdev_master_upper_dev_get(dev);
1339 vrf_del_slave(vrf_dev, dev);
1340 }
1341 out:
1342 return NOTIFY_DONE;
1343 }
1344
1345 static struct notifier_block vrf_notifier_block __read_mostly = {
1346 .notifier_call = vrf_device_event,
1347 };
1348
1349 static int __init vrf_init_module(void)
1350 {
1351 int rc;
1352
1353 register_netdevice_notifier(&vrf_notifier_block);
1354
1355 rc = rtnl_link_register(&vrf_link_ops);
1356 if (rc < 0)
1357 goto error;
1358
1359 return 0;
1360
1361 error:
1362 unregister_netdevice_notifier(&vrf_notifier_block);
1363 return rc;
1364 }
1365
1366 module_init(vrf_init_module);
1367 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
1368 MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
1369 MODULE_LICENSE("GPL");
1370 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
1371 MODULE_VERSION(DRV_VERSION);
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