Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * vrf.c: device driver to encapsulate a VRF space
4 *
5 * Copyright (c) 2015 Cumulus Networks. All rights reserved.
6 * Copyright (c) 2015 Shrijeet Mukherjee <shm@cumulusnetworks.com>
7 * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com>
8 *
9 * Based on dummy, team and ipvlan drivers
10 */
11
12#include <linux/ethtool.h>
13#include <linux/module.h>
14#include <linux/kernel.h>
15#include <linux/netdevice.h>
16#include <linux/etherdevice.h>
17#include <linux/ip.h>
18#include <linux/init.h>
19#include <linux/moduleparam.h>
20#include <linux/netfilter.h>
21#include <linux/rtnetlink.h>
22#include <net/rtnetlink.h>
23#include <linux/u64_stats_sync.h>
24#include <linux/hashtable.h>
25#include <linux/spinlock_types.h>
26
27#include <linux/inetdevice.h>
28#include <net/arp.h>
29#include <net/ip.h>
30#include <net/ip_fib.h>
31#include <net/ip6_fib.h>
32#include <net/ip6_route.h>
33#include <net/route.h>
34#include <net/addrconf.h>
35#include <net/l3mdev.h>
36#include <net/fib_rules.h>
37#include <net/sch_generic.h>
38#include <net/netns/generic.h>
39#include <net/netfilter/nf_conntrack.h>
40
41#define DRV_NAME "vrf"
42#define DRV_VERSION "1.1"
43
44#define FIB_RULE_PREF 1000 /* default preference for FIB rules */
45
46#define HT_MAP_BITS 4
47#define HASH_INITVAL ((u32)0xcafef00d)
48
49struct vrf_map {
50 DECLARE_HASHTABLE(ht, HT_MAP_BITS);
51 spinlock_t vmap_lock;
52
53 /* shared_tables:
54 * count how many distinct tables do not comply with the strict mode
55 * requirement.
56 * shared_tables value must be 0 in order to enable the strict mode.
57 *
58 * example of the evolution of shared_tables:
59 * | time
60 * add vrf0 --> table 100 shared_tables = 0 | t0
61 * add vrf1 --> table 101 shared_tables = 0 | t1
62 * add vrf2 --> table 100 shared_tables = 1 | t2
63 * add vrf3 --> table 100 shared_tables = 1 | t3
64 * add vrf4 --> table 101 shared_tables = 2 v t4
65 *
66 * shared_tables is a "step function" (or "staircase function")
67 * and it is increased by one when the second vrf is associated to a
68 * table.
69 *
70 * at t2, vrf0 and vrf2 are bound to table 100: shared_tables = 1.
71 *
72 * at t3, another dev (vrf3) is bound to the same table 100 but the
73 * value of shared_tables is still 1.
74 * This means that no matter how many new vrfs will register on the
75 * table 100, the shared_tables will not increase (considering only
76 * table 100).
77 *
78 * at t4, vrf4 is bound to table 101, and shared_tables = 2.
79 *
80 * Looking at the value of shared_tables we can immediately know if
81 * the strict_mode can or cannot be enforced. Indeed, strict_mode
82 * can be enforced iff shared_tables = 0.
83 *
84 * Conversely, shared_tables is decreased when a vrf is de-associated
85 * from a table with exactly two associated vrfs.
86 */
87 u32 shared_tables;
88
89 bool strict_mode;
90};
91
92struct vrf_map_elem {
93 struct hlist_node hnode;
94 struct list_head vrf_list; /* VRFs registered to this table */
95
96 u32 table_id;
97 int users;
98 int ifindex;
99};
100
101static unsigned int vrf_net_id;
102
103/* per netns vrf data */
104struct netns_vrf {
105 /* protected by rtnl lock */
106 bool add_fib_rules;
107
108 struct vrf_map vmap;
109 struct ctl_table_header *ctl_hdr;
110};
111
112struct net_vrf {
113 struct rtable __rcu *rth;
114 struct rt6_info __rcu *rt6;
115#if IS_ENABLED(CONFIG_IPV6)
116 struct fib6_table *fib6_table;
117#endif
118 u32 tb_id;
119
120 struct list_head me_list; /* entry in vrf_map_elem */
121 int ifindex;
122};
123
124static void vrf_rx_stats(struct net_device *dev, int len)
125{
126 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
127
128 u64_stats_update_begin(&dstats->syncp);
129 dstats->rx_packets++;
130 dstats->rx_bytes += len;
131 u64_stats_update_end(&dstats->syncp);
132}
133
134static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
135{
136 vrf_dev->stats.tx_errors++;
137 kfree_skb(skb);
138}
139
140static void vrf_get_stats64(struct net_device *dev,
141 struct rtnl_link_stats64 *stats)
142{
143 int i;
144
145 for_each_possible_cpu(i) {
146 const struct pcpu_dstats *dstats;
147 u64 tbytes, tpkts, tdrops, rbytes, rpkts;
148 unsigned int start;
149
150 dstats = per_cpu_ptr(dev->dstats, i);
151 do {
152 start = u64_stats_fetch_begin(&dstats->syncp);
153 tbytes = dstats->tx_bytes;
154 tpkts = dstats->tx_packets;
155 tdrops = dstats->tx_drops;
156 rbytes = dstats->rx_bytes;
157 rpkts = dstats->rx_packets;
158 } while (u64_stats_fetch_retry(&dstats->syncp, start));
159 stats->tx_bytes += tbytes;
160 stats->tx_packets += tpkts;
161 stats->tx_dropped += tdrops;
162 stats->rx_bytes += rbytes;
163 stats->rx_packets += rpkts;
164 }
165}
166
167static struct vrf_map *netns_vrf_map(struct net *net)
168{
169 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
170
171 return &nn_vrf->vmap;
172}
173
174static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev)
175{
176 return netns_vrf_map(dev_net(dev));
177}
178
179static int vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem *me)
180{
181 struct list_head *me_head = &me->vrf_list;
182 struct net_vrf *vrf;
183
184 if (list_empty(me_head))
185 return -ENODEV;
186
187 vrf = list_first_entry(me_head, struct net_vrf, me_list);
188
189 return vrf->ifindex;
190}
191
192static struct vrf_map_elem *vrf_map_elem_alloc(gfp_t flags)
193{
194 struct vrf_map_elem *me;
195
196 me = kmalloc(sizeof(*me), flags);
197 if (!me)
198 return NULL;
199
200 return me;
201}
202
203static void vrf_map_elem_free(struct vrf_map_elem *me)
204{
205 kfree(me);
206}
207
208static void vrf_map_elem_init(struct vrf_map_elem *me, int table_id,
209 int ifindex, int users)
210{
211 me->table_id = table_id;
212 me->ifindex = ifindex;
213 me->users = users;
214 INIT_LIST_HEAD(&me->vrf_list);
215}
216
217static struct vrf_map_elem *vrf_map_lookup_elem(struct vrf_map *vmap,
218 u32 table_id)
219{
220 struct vrf_map_elem *me;
221 u32 key;
222
223 key = jhash_1word(table_id, HASH_INITVAL);
224 hash_for_each_possible(vmap->ht, me, hnode, key) {
225 if (me->table_id == table_id)
226 return me;
227 }
228
229 return NULL;
230}
231
232static void vrf_map_add_elem(struct vrf_map *vmap, struct vrf_map_elem *me)
233{
234 u32 table_id = me->table_id;
235 u32 key;
236
237 key = jhash_1word(table_id, HASH_INITVAL);
238 hash_add(vmap->ht, &me->hnode, key);
239}
240
241static void vrf_map_del_elem(struct vrf_map_elem *me)
242{
243 hash_del(&me->hnode);
244}
245
246static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock)
247{
248 spin_lock(&vmap->vmap_lock);
249}
250
251static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock)
252{
253 spin_unlock(&vmap->vmap_lock);
254}
255
256/* called with rtnl lock held */
257static int
258vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack)
259{
260 struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
261 struct net_vrf *vrf = netdev_priv(dev);
262 struct vrf_map_elem *new_me, *me;
263 u32 table_id = vrf->tb_id;
264 bool free_new_me = false;
265 int users;
266 int res;
267
268 /* we pre-allocate elements used in the spin-locked section (so that we
269 * keep the spinlock as short as possible).
270 */
271 new_me = vrf_map_elem_alloc(GFP_KERNEL);
272 if (!new_me)
273 return -ENOMEM;
274
275 vrf_map_elem_init(new_me, table_id, dev->ifindex, 0);
276
277 vrf_map_lock(vmap);
278
279 me = vrf_map_lookup_elem(vmap, table_id);
280 if (!me) {
281 me = new_me;
282 vrf_map_add_elem(vmap, me);
283 goto link_vrf;
284 }
285
286 /* we already have an entry in the vrf_map, so it means there is (at
287 * least) a vrf registered on the specific table.
288 */
289 free_new_me = true;
290 if (vmap->strict_mode) {
291 /* vrfs cannot share the same table */
292 NL_SET_ERR_MSG(extack, "Table is used by another VRF");
293 res = -EBUSY;
294 goto unlock;
295 }
296
297link_vrf:
298 users = ++me->users;
299 if (users == 2)
300 ++vmap->shared_tables;
301
302 list_add(&vrf->me_list, &me->vrf_list);
303
304 res = 0;
305
306unlock:
307 vrf_map_unlock(vmap);
308
309 /* clean-up, if needed */
310 if (free_new_me)
311 vrf_map_elem_free(new_me);
312
313 return res;
314}
315
316/* called with rtnl lock held */
317static void vrf_map_unregister_dev(struct net_device *dev)
318{
319 struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
320 struct net_vrf *vrf = netdev_priv(dev);
321 u32 table_id = vrf->tb_id;
322 struct vrf_map_elem *me;
323 int users;
324
325 vrf_map_lock(vmap);
326
327 me = vrf_map_lookup_elem(vmap, table_id);
328 if (!me)
329 goto unlock;
330
331 list_del(&vrf->me_list);
332
333 users = --me->users;
334 if (users == 1) {
335 --vmap->shared_tables;
336 } else if (users == 0) {
337 vrf_map_del_elem(me);
338
339 /* no one will refer to this element anymore */
340 vrf_map_elem_free(me);
341 }
342
343unlock:
344 vrf_map_unlock(vmap);
345}
346
347/* return the vrf device index associated with the table_id */
348static int vrf_ifindex_lookup_by_table_id(struct net *net, u32 table_id)
349{
350 struct vrf_map *vmap = netns_vrf_map(net);
351 struct vrf_map_elem *me;
352 int ifindex;
353
354 vrf_map_lock(vmap);
355
356 if (!vmap->strict_mode) {
357 ifindex = -EPERM;
358 goto unlock;
359 }
360
361 me = vrf_map_lookup_elem(vmap, table_id);
362 if (!me) {
363 ifindex = -ENODEV;
364 goto unlock;
365 }
366
367 ifindex = vrf_map_elem_get_vrf_ifindex(me);
368
369unlock:
370 vrf_map_unlock(vmap);
371
372 return ifindex;
373}
374
375/* by default VRF devices do not have a qdisc and are expected
376 * to be created with only a single queue.
377 */
378static bool qdisc_tx_is_default(const struct net_device *dev)
379{
380 struct netdev_queue *txq;
381 struct Qdisc *qdisc;
382
383 if (dev->num_tx_queues > 1)
384 return false;
385
386 txq = netdev_get_tx_queue(dev, 0);
387 qdisc = rcu_access_pointer(txq->qdisc);
388
389 return !qdisc->enqueue;
390}
391
392/* Local traffic destined to local address. Reinsert the packet to rx
393 * path, similar to loopback handling.
394 */
395static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
396 struct dst_entry *dst)
397{
398 int len = skb->len;
399
400 skb_orphan(skb);
401
402 skb_dst_set(skb, dst);
403
404 /* set pkt_type to avoid skb hitting packet taps twice -
405 * once on Tx and again in Rx processing
406 */
407 skb->pkt_type = PACKET_LOOPBACK;
408
409 skb->protocol = eth_type_trans(skb, dev);
410
411 if (likely(__netif_rx(skb) == NET_RX_SUCCESS))
412 vrf_rx_stats(dev, len);
413 else
414 this_cpu_inc(dev->dstats->rx_drops);
415
416 return NETDEV_TX_OK;
417}
418
419static void vrf_nf_set_untracked(struct sk_buff *skb)
420{
421 if (skb_get_nfct(skb) == 0)
422 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
423}
424
425static void vrf_nf_reset_ct(struct sk_buff *skb)
426{
427 if (skb_get_nfct(skb) == IP_CT_UNTRACKED)
428 nf_reset_ct(skb);
429}
430
431#if IS_ENABLED(CONFIG_IPV6)
432static int vrf_ip6_local_out(struct net *net, struct sock *sk,
433 struct sk_buff *skb)
434{
435 int err;
436
437 vrf_nf_reset_ct(skb);
438
439 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net,
440 sk, skb, NULL, skb_dst(skb)->dev, dst_output);
441
442 if (likely(err == 1))
443 err = dst_output(net, sk, skb);
444
445 return err;
446}
447
448static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
449 struct net_device *dev)
450{
451 const struct ipv6hdr *iph;
452 struct net *net = dev_net(skb->dev);
453 struct flowi6 fl6;
454 int ret = NET_XMIT_DROP;
455 struct dst_entry *dst;
456 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
457
458 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
459 goto err;
460
461 iph = ipv6_hdr(skb);
462
463 memset(&fl6, 0, sizeof(fl6));
464 /* needed to match OIF rule */
465 fl6.flowi6_l3mdev = dev->ifindex;
466 fl6.flowi6_iif = LOOPBACK_IFINDEX;
467 fl6.daddr = iph->daddr;
468 fl6.saddr = iph->saddr;
469 fl6.flowlabel = ip6_flowinfo(iph);
470 fl6.flowi6_mark = skb->mark;
471 fl6.flowi6_proto = iph->nexthdr;
472
473 dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL);
474 if (IS_ERR(dst) || dst == dst_null)
475 goto err;
476
477 skb_dst_drop(skb);
478
479 /* if dst.dev is the VRF device again this is locally originated traffic
480 * destined to a local address. Short circuit to Rx path.
481 */
482 if (dst->dev == dev)
483 return vrf_local_xmit(skb, dev, dst);
484
485 skb_dst_set(skb, dst);
486
487 /* strip the ethernet header added for pass through VRF device */
488 __skb_pull(skb, skb_network_offset(skb));
489
490 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
491 ret = vrf_ip6_local_out(net, skb->sk, skb);
492 if (unlikely(net_xmit_eval(ret)))
493 dev->stats.tx_errors++;
494 else
495 ret = NET_XMIT_SUCCESS;
496
497 return ret;
498err:
499 vrf_tx_error(dev, skb);
500 return NET_XMIT_DROP;
501}
502#else
503static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
504 struct net_device *dev)
505{
506 vrf_tx_error(dev, skb);
507 return NET_XMIT_DROP;
508}
509#endif
510
511/* based on ip_local_out; can't use it b/c the dst is switched pointing to us */
512static int vrf_ip_local_out(struct net *net, struct sock *sk,
513 struct sk_buff *skb)
514{
515 int err;
516
517 vrf_nf_reset_ct(skb);
518
519 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
520 skb, NULL, skb_dst(skb)->dev, dst_output);
521 if (likely(err == 1))
522 err = dst_output(net, sk, skb);
523
524 return err;
525}
526
527static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
528 struct net_device *vrf_dev)
529{
530 struct iphdr *ip4h;
531 int ret = NET_XMIT_DROP;
532 struct flowi4 fl4;
533 struct net *net = dev_net(vrf_dev);
534 struct rtable *rt;
535
536 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
537 goto err;
538
539 ip4h = ip_hdr(skb);
540
541 memset(&fl4, 0, sizeof(fl4));
542 /* needed to match OIF rule */
543 fl4.flowi4_l3mdev = vrf_dev->ifindex;
544 fl4.flowi4_iif = LOOPBACK_IFINDEX;
545 fl4.flowi4_tos = RT_TOS(ip4h->tos);
546 fl4.flowi4_flags = FLOWI_FLAG_ANYSRC;
547 fl4.flowi4_proto = ip4h->protocol;
548 fl4.daddr = ip4h->daddr;
549 fl4.saddr = ip4h->saddr;
550
551 rt = ip_route_output_flow(net, &fl4, NULL);
552 if (IS_ERR(rt))
553 goto err;
554
555 skb_dst_drop(skb);
556
557 /* if dst.dev is the VRF device again this is locally originated traffic
558 * destined to a local address. Short circuit to Rx path.
559 */
560 if (rt->dst.dev == vrf_dev)
561 return vrf_local_xmit(skb, vrf_dev, &rt->dst);
562
563 skb_dst_set(skb, &rt->dst);
564
565 /* strip the ethernet header added for pass through VRF device */
566 __skb_pull(skb, skb_network_offset(skb));
567
568 if (!ip4h->saddr) {
569 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
570 RT_SCOPE_LINK);
571 }
572
573 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
574 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
575 if (unlikely(net_xmit_eval(ret)))
576 vrf_dev->stats.tx_errors++;
577 else
578 ret = NET_XMIT_SUCCESS;
579
580out:
581 return ret;
582err:
583 vrf_tx_error(vrf_dev, skb);
584 goto out;
585}
586
587static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
588{
589 switch (skb->protocol) {
590 case htons(ETH_P_IP):
591 return vrf_process_v4_outbound(skb, dev);
592 case htons(ETH_P_IPV6):
593 return vrf_process_v6_outbound(skb, dev);
594 default:
595 vrf_tx_error(dev, skb);
596 return NET_XMIT_DROP;
597 }
598}
599
600static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
601{
602 int len = skb->len;
603 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
604
605 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
606 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
607
608 u64_stats_update_begin(&dstats->syncp);
609 dstats->tx_packets++;
610 dstats->tx_bytes += len;
611 u64_stats_update_end(&dstats->syncp);
612 } else {
613 this_cpu_inc(dev->dstats->tx_drops);
614 }
615
616 return ret;
617}
618
619static void vrf_finish_direct(struct sk_buff *skb)
620{
621 struct net_device *vrf_dev = skb->dev;
622
623 if (!list_empty(&vrf_dev->ptype_all) &&
624 likely(skb_headroom(skb) >= ETH_HLEN)) {
625 struct ethhdr *eth = skb_push(skb, ETH_HLEN);
626
627 ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
628 eth_zero_addr(eth->h_dest);
629 eth->h_proto = skb->protocol;
630
631 dev_queue_xmit_nit(skb, vrf_dev);
632
633 skb_pull(skb, ETH_HLEN);
634 }
635
636 vrf_nf_reset_ct(skb);
637}
638
639#if IS_ENABLED(CONFIG_IPV6)
640/* modelled after ip6_finish_output2 */
641static int vrf_finish_output6(struct net *net, struct sock *sk,
642 struct sk_buff *skb)
643{
644 struct dst_entry *dst = skb_dst(skb);
645 struct net_device *dev = dst->dev;
646 const struct in6_addr *nexthop;
647 struct neighbour *neigh;
648 int ret;
649
650 vrf_nf_reset_ct(skb);
651
652 skb->protocol = htons(ETH_P_IPV6);
653 skb->dev = dev;
654
655 rcu_read_lock();
656 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
657 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
658 if (unlikely(!neigh))
659 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
660 if (!IS_ERR(neigh)) {
661 sock_confirm_neigh(skb, neigh);
662 ret = neigh_output(neigh, skb, false);
663 rcu_read_unlock();
664 return ret;
665 }
666 rcu_read_unlock();
667
668 IP6_INC_STATS(dev_net(dst->dev),
669 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
670 kfree_skb(skb);
671 return -EINVAL;
672}
673
674/* modelled after ip6_output */
675static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
676{
677 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
678 net, sk, skb, NULL, skb_dst(skb)->dev,
679 vrf_finish_output6,
680 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
681}
682
683/* set dst on skb to send packet to us via dev_xmit path. Allows
684 * packet to go through device based features such as qdisc, netfilter
685 * hooks and packet sockets with skb->dev set to vrf device.
686 */
687static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev,
688 struct sk_buff *skb)
689{
690 struct net_vrf *vrf = netdev_priv(vrf_dev);
691 struct dst_entry *dst = NULL;
692 struct rt6_info *rt6;
693
694 rcu_read_lock();
695
696 rt6 = rcu_dereference(vrf->rt6);
697 if (likely(rt6)) {
698 dst = &rt6->dst;
699 dst_hold(dst);
700 }
701
702 rcu_read_unlock();
703
704 if (unlikely(!dst)) {
705 vrf_tx_error(vrf_dev, skb);
706 return NULL;
707 }
708
709 skb_dst_drop(skb);
710 skb_dst_set(skb, dst);
711
712 return skb;
713}
714
715static int vrf_output6_direct_finish(struct net *net, struct sock *sk,
716 struct sk_buff *skb)
717{
718 vrf_finish_direct(skb);
719
720 return vrf_ip6_local_out(net, sk, skb);
721}
722
723static int vrf_output6_direct(struct net *net, struct sock *sk,
724 struct sk_buff *skb)
725{
726 int err = 1;
727
728 skb->protocol = htons(ETH_P_IPV6);
729
730 if (!(IPCB(skb)->flags & IPSKB_REROUTED))
731 err = nf_hook(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb,
732 NULL, skb->dev, vrf_output6_direct_finish);
733
734 if (likely(err == 1))
735 vrf_finish_direct(skb);
736
737 return err;
738}
739
740static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk,
741 struct sk_buff *skb)
742{
743 int err;
744
745 err = vrf_output6_direct(net, sk, skb);
746 if (likely(err == 1))
747 err = vrf_ip6_local_out(net, sk, skb);
748
749 return err;
750}
751
752static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
753 struct sock *sk,
754 struct sk_buff *skb)
755{
756 struct net *net = dev_net(vrf_dev);
757 int err;
758
759 skb->dev = vrf_dev;
760
761 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk,
762 skb, NULL, vrf_dev, vrf_ip6_out_direct_finish);
763
764 if (likely(err == 1))
765 err = vrf_output6_direct(net, sk, skb);
766
767 if (likely(err == 1))
768 return skb;
769
770 return NULL;
771}
772
773static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
774 struct sock *sk,
775 struct sk_buff *skb)
776{
777 /* don't divert link scope packets */
778 if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
779 return skb;
780
781 vrf_nf_set_untracked(skb);
782
783 if (qdisc_tx_is_default(vrf_dev) ||
784 IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
785 return vrf_ip6_out_direct(vrf_dev, sk, skb);
786
787 return vrf_ip6_out_redirect(vrf_dev, skb);
788}
789
790/* holding rtnl */
791static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
792{
793 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
794 struct net *net = dev_net(dev);
795 struct dst_entry *dst;
796
797 RCU_INIT_POINTER(vrf->rt6, NULL);
798 synchronize_rcu();
799
800 /* move dev in dst's to loopback so this VRF device can be deleted
801 * - based on dst_ifdown
802 */
803 if (rt6) {
804 dst = &rt6->dst;
805 netdev_ref_replace(dst->dev, net->loopback_dev,
806 &dst->dev_tracker, GFP_KERNEL);
807 dst->dev = net->loopback_dev;
808 dst_release(dst);
809 }
810}
811
812static int vrf_rt6_create(struct net_device *dev)
813{
814 int flags = DST_NOPOLICY | DST_NOXFRM;
815 struct net_vrf *vrf = netdev_priv(dev);
816 struct net *net = dev_net(dev);
817 struct rt6_info *rt6;
818 int rc = -ENOMEM;
819
820 /* IPv6 can be CONFIG enabled and then disabled runtime */
821 if (!ipv6_mod_enabled())
822 return 0;
823
824 vrf->fib6_table = fib6_new_table(net, vrf->tb_id);
825 if (!vrf->fib6_table)
826 goto out;
827
828 /* create a dst for routing packets out a VRF device */
829 rt6 = ip6_dst_alloc(net, dev, flags);
830 if (!rt6)
831 goto out;
832
833 rt6->dst.output = vrf_output6;
834
835 rcu_assign_pointer(vrf->rt6, rt6);
836
837 rc = 0;
838out:
839 return rc;
840}
841#else
842static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
843 struct sock *sk,
844 struct sk_buff *skb)
845{
846 return skb;
847}
848
849static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
850{
851}
852
853static int vrf_rt6_create(struct net_device *dev)
854{
855 return 0;
856}
857#endif
858
859/* modelled after ip_finish_output2 */
860static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
861{
862 struct dst_entry *dst = skb_dst(skb);
863 struct rtable *rt = (struct rtable *)dst;
864 struct net_device *dev = dst->dev;
865 unsigned int hh_len = LL_RESERVED_SPACE(dev);
866 struct neighbour *neigh;
867 bool is_v6gw = false;
868
869 vrf_nf_reset_ct(skb);
870
871 /* Be paranoid, rather than too clever. */
872 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
873 skb = skb_expand_head(skb, hh_len);
874 if (!skb) {
875 dev->stats.tx_errors++;
876 return -ENOMEM;
877 }
878 }
879
880 rcu_read_lock();
881
882 neigh = ip_neigh_for_gw(rt, skb, &is_v6gw);
883 if (!IS_ERR(neigh)) {
884 int ret;
885
886 sock_confirm_neigh(skb, neigh);
887 /* if crossing protocols, can not use the cached header */
888 ret = neigh_output(neigh, skb, is_v6gw);
889 rcu_read_unlock();
890 return ret;
891 }
892
893 rcu_read_unlock();
894 vrf_tx_error(skb->dev, skb);
895 return -EINVAL;
896}
897
898static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
899{
900 struct net_device *dev = skb_dst(skb)->dev;
901
902 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
903
904 skb->dev = dev;
905 skb->protocol = htons(ETH_P_IP);
906
907 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
908 net, sk, skb, NULL, dev,
909 vrf_finish_output,
910 !(IPCB(skb)->flags & IPSKB_REROUTED));
911}
912
913/* set dst on skb to send packet to us via dev_xmit path. Allows
914 * packet to go through device based features such as qdisc, netfilter
915 * hooks and packet sockets with skb->dev set to vrf device.
916 */
917static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev,
918 struct sk_buff *skb)
919{
920 struct net_vrf *vrf = netdev_priv(vrf_dev);
921 struct dst_entry *dst = NULL;
922 struct rtable *rth;
923
924 rcu_read_lock();
925
926 rth = rcu_dereference(vrf->rth);
927 if (likely(rth)) {
928 dst = &rth->dst;
929 dst_hold(dst);
930 }
931
932 rcu_read_unlock();
933
934 if (unlikely(!dst)) {
935 vrf_tx_error(vrf_dev, skb);
936 return NULL;
937 }
938
939 skb_dst_drop(skb);
940 skb_dst_set(skb, dst);
941
942 return skb;
943}
944
945static int vrf_output_direct_finish(struct net *net, struct sock *sk,
946 struct sk_buff *skb)
947{
948 vrf_finish_direct(skb);
949
950 return vrf_ip_local_out(net, sk, skb);
951}
952
953static int vrf_output_direct(struct net *net, struct sock *sk,
954 struct sk_buff *skb)
955{
956 int err = 1;
957
958 skb->protocol = htons(ETH_P_IP);
959
960 if (!(IPCB(skb)->flags & IPSKB_REROUTED))
961 err = nf_hook(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb,
962 NULL, skb->dev, vrf_output_direct_finish);
963
964 if (likely(err == 1))
965 vrf_finish_direct(skb);
966
967 return err;
968}
969
970static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk,
971 struct sk_buff *skb)
972{
973 int err;
974
975 err = vrf_output_direct(net, sk, skb);
976 if (likely(err == 1))
977 err = vrf_ip_local_out(net, sk, skb);
978
979 return err;
980}
981
982static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
983 struct sock *sk,
984 struct sk_buff *skb)
985{
986 struct net *net = dev_net(vrf_dev);
987 int err;
988
989 skb->dev = vrf_dev;
990
991 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
992 skb, NULL, vrf_dev, vrf_ip_out_direct_finish);
993
994 if (likely(err == 1))
995 err = vrf_output_direct(net, sk, skb);
996
997 if (likely(err == 1))
998 return skb;
999
1000 return NULL;
1001}
1002
1003static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
1004 struct sock *sk,
1005 struct sk_buff *skb)
1006{
1007 /* don't divert multicast or local broadcast */
1008 if (ipv4_is_multicast(ip_hdr(skb)->daddr) ||
1009 ipv4_is_lbcast(ip_hdr(skb)->daddr))
1010 return skb;
1011
1012 vrf_nf_set_untracked(skb);
1013
1014 if (qdisc_tx_is_default(vrf_dev) ||
1015 IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
1016 return vrf_ip_out_direct(vrf_dev, sk, skb);
1017
1018 return vrf_ip_out_redirect(vrf_dev, skb);
1019}
1020
1021/* called with rcu lock held */
1022static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
1023 struct sock *sk,
1024 struct sk_buff *skb,
1025 u16 proto)
1026{
1027 switch (proto) {
1028 case AF_INET:
1029 return vrf_ip_out(vrf_dev, sk, skb);
1030 case AF_INET6:
1031 return vrf_ip6_out(vrf_dev, sk, skb);
1032 }
1033
1034 return skb;
1035}
1036
1037/* holding rtnl */
1038static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
1039{
1040 struct rtable *rth = rtnl_dereference(vrf->rth);
1041 struct net *net = dev_net(dev);
1042 struct dst_entry *dst;
1043
1044 RCU_INIT_POINTER(vrf->rth, NULL);
1045 synchronize_rcu();
1046
1047 /* move dev in dst's to loopback so this VRF device can be deleted
1048 * - based on dst_ifdown
1049 */
1050 if (rth) {
1051 dst = &rth->dst;
1052 netdev_ref_replace(dst->dev, net->loopback_dev,
1053 &dst->dev_tracker, GFP_KERNEL);
1054 dst->dev = net->loopback_dev;
1055 dst_release(dst);
1056 }
1057}
1058
1059static int vrf_rtable_create(struct net_device *dev)
1060{
1061 struct net_vrf *vrf = netdev_priv(dev);
1062 struct rtable *rth;
1063
1064 if (!fib_new_table(dev_net(dev), vrf->tb_id))
1065 return -ENOMEM;
1066
1067 /* create a dst for routing packets out through a VRF device */
1068 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1);
1069 if (!rth)
1070 return -ENOMEM;
1071
1072 rth->dst.output = vrf_output;
1073
1074 rcu_assign_pointer(vrf->rth, rth);
1075
1076 return 0;
1077}
1078
1079/**************************** device handling ********************/
1080
1081/* cycle interface to flush neighbor cache and move routes across tables */
1082static void cycle_netdev(struct net_device *dev,
1083 struct netlink_ext_ack *extack)
1084{
1085 unsigned int flags = dev->flags;
1086 int ret;
1087
1088 if (!netif_running(dev))
1089 return;
1090
1091 ret = dev_change_flags(dev, flags & ~IFF_UP, extack);
1092 if (ret >= 0)
1093 ret = dev_change_flags(dev, flags, extack);
1094
1095 if (ret < 0) {
1096 netdev_err(dev,
1097 "Failed to cycle device %s; route tables might be wrong!\n",
1098 dev->name);
1099 }
1100}
1101
1102static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1103 struct netlink_ext_ack *extack)
1104{
1105 int ret;
1106
1107 /* do not allow loopback device to be enslaved to a VRF.
1108 * The vrf device acts as the loopback for the vrf.
1109 */
1110 if (port_dev == dev_net(dev)->loopback_dev) {
1111 NL_SET_ERR_MSG(extack,
1112 "Can not enslave loopback device to a VRF");
1113 return -EOPNOTSUPP;
1114 }
1115
1116 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
1117 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack);
1118 if (ret < 0)
1119 goto err;
1120
1121 cycle_netdev(port_dev, extack);
1122
1123 return 0;
1124
1125err:
1126 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1127 return ret;
1128}
1129
1130static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1131 struct netlink_ext_ack *extack)
1132{
1133 if (netif_is_l3_master(port_dev)) {
1134 NL_SET_ERR_MSG(extack,
1135 "Can not enslave an L3 master device to a VRF");
1136 return -EINVAL;
1137 }
1138
1139 if (netif_is_l3_slave(port_dev))
1140 return -EINVAL;
1141
1142 return do_vrf_add_slave(dev, port_dev, extack);
1143}
1144
1145/* inverse of do_vrf_add_slave */
1146static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1147{
1148 netdev_upper_dev_unlink(port_dev, dev);
1149 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1150
1151 cycle_netdev(port_dev, NULL);
1152
1153 return 0;
1154}
1155
1156static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1157{
1158 return do_vrf_del_slave(dev, port_dev);
1159}
1160
1161static void vrf_dev_uninit(struct net_device *dev)
1162{
1163 struct net_vrf *vrf = netdev_priv(dev);
1164
1165 vrf_rtable_release(dev, vrf);
1166 vrf_rt6_release(dev, vrf);
1167}
1168
1169static int vrf_dev_init(struct net_device *dev)
1170{
1171 struct net_vrf *vrf = netdev_priv(dev);
1172
1173 /* create the default dst which points back to us */
1174 if (vrf_rtable_create(dev) != 0)
1175 goto out_nomem;
1176
1177 if (vrf_rt6_create(dev) != 0)
1178 goto out_rth;
1179
1180 dev->flags = IFF_MASTER | IFF_NOARP;
1181
1182 /* similarly, oper state is irrelevant; set to up to avoid confusion */
1183 dev->operstate = IF_OPER_UP;
1184 netdev_lockdep_set_classes(dev);
1185 return 0;
1186
1187out_rth:
1188 vrf_rtable_release(dev, vrf);
1189out_nomem:
1190 return -ENOMEM;
1191}
1192
1193static const struct net_device_ops vrf_netdev_ops = {
1194 .ndo_init = vrf_dev_init,
1195 .ndo_uninit = vrf_dev_uninit,
1196 .ndo_start_xmit = vrf_xmit,
1197 .ndo_set_mac_address = eth_mac_addr,
1198 .ndo_get_stats64 = vrf_get_stats64,
1199 .ndo_add_slave = vrf_add_slave,
1200 .ndo_del_slave = vrf_del_slave,
1201};
1202
1203static u32 vrf_fib_table(const struct net_device *dev)
1204{
1205 struct net_vrf *vrf = netdev_priv(dev);
1206
1207 return vrf->tb_id;
1208}
1209
1210static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
1211{
1212 kfree_skb(skb);
1213 return 0;
1214}
1215
1216static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
1217 struct sk_buff *skb,
1218 struct net_device *dev)
1219{
1220 struct net *net = dev_net(dev);
1221
1222 if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1)
1223 skb = NULL; /* kfree_skb(skb) handled by nf code */
1224
1225 return skb;
1226}
1227
1228static int vrf_prepare_mac_header(struct sk_buff *skb,
1229 struct net_device *vrf_dev, u16 proto)
1230{
1231 struct ethhdr *eth;
1232 int err;
1233
1234 /* in general, we do not know if there is enough space in the head of
1235 * the packet for hosting the mac header.
1236 */
1237 err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev));
1238 if (unlikely(err))
1239 /* no space in the skb head */
1240 return -ENOBUFS;
1241
1242 __skb_push(skb, ETH_HLEN);
1243 eth = (struct ethhdr *)skb->data;
1244
1245 skb_reset_mac_header(skb);
1246 skb_reset_mac_len(skb);
1247
1248 /* we set the ethernet destination and the source addresses to the
1249 * address of the VRF device.
1250 */
1251 ether_addr_copy(eth->h_dest, vrf_dev->dev_addr);
1252 ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
1253 eth->h_proto = htons(proto);
1254
1255 /* the destination address of the Ethernet frame corresponds to the
1256 * address set on the VRF interface; therefore, the packet is intended
1257 * to be processed locally.
1258 */
1259 skb->protocol = eth->h_proto;
1260 skb->pkt_type = PACKET_HOST;
1261
1262 skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
1263
1264 skb_pull_inline(skb, ETH_HLEN);
1265
1266 return 0;
1267}
1268
1269/* prepare and add the mac header to the packet if it was not set previously.
1270 * In this way, packet sniffers such as tcpdump can parse the packet correctly.
1271 * If the mac header was already set, the original mac header is left
1272 * untouched and the function returns immediately.
1273 */
1274static int vrf_add_mac_header_if_unset(struct sk_buff *skb,
1275 struct net_device *vrf_dev,
1276 u16 proto, struct net_device *orig_dev)
1277{
1278 if (skb_mac_header_was_set(skb) && dev_has_header(orig_dev))
1279 return 0;
1280
1281 return vrf_prepare_mac_header(skb, vrf_dev, proto);
1282}
1283
1284#if IS_ENABLED(CONFIG_IPV6)
1285/* neighbor handling is done with actual device; do not want
1286 * to flip skb->dev for those ndisc packets. This really fails
1287 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
1288 * a start.
1289 */
1290static bool ipv6_ndisc_frame(const struct sk_buff *skb)
1291{
1292 const struct ipv6hdr *iph = ipv6_hdr(skb);
1293 bool rc = false;
1294
1295 if (iph->nexthdr == NEXTHDR_ICMP) {
1296 const struct icmp6hdr *icmph;
1297 struct icmp6hdr _icmph;
1298
1299 icmph = skb_header_pointer(skb, sizeof(*iph),
1300 sizeof(_icmph), &_icmph);
1301 if (!icmph)
1302 goto out;
1303
1304 switch (icmph->icmp6_type) {
1305 case NDISC_ROUTER_SOLICITATION:
1306 case NDISC_ROUTER_ADVERTISEMENT:
1307 case NDISC_NEIGHBOUR_SOLICITATION:
1308 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1309 case NDISC_REDIRECT:
1310 rc = true;
1311 break;
1312 }
1313 }
1314
1315out:
1316 return rc;
1317}
1318
1319static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
1320 const struct net_device *dev,
1321 struct flowi6 *fl6,
1322 int ifindex,
1323 const struct sk_buff *skb,
1324 int flags)
1325{
1326 struct net_vrf *vrf = netdev_priv(dev);
1327
1328 return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags);
1329}
1330
1331static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
1332 int ifindex)
1333{
1334 const struct ipv6hdr *iph = ipv6_hdr(skb);
1335 struct flowi6 fl6 = {
1336 .flowi6_iif = ifindex,
1337 .flowi6_mark = skb->mark,
1338 .flowi6_proto = iph->nexthdr,
1339 .daddr = iph->daddr,
1340 .saddr = iph->saddr,
1341 .flowlabel = ip6_flowinfo(iph),
1342 };
1343 struct net *net = dev_net(vrf_dev);
1344 struct rt6_info *rt6;
1345
1346 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb,
1347 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
1348 if (unlikely(!rt6))
1349 return;
1350
1351 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
1352 return;
1353
1354 skb_dst_set(skb, &rt6->dst);
1355}
1356
1357static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1358 struct sk_buff *skb)
1359{
1360 int orig_iif = skb->skb_iif;
1361 bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
1362 bool is_ndisc = ipv6_ndisc_frame(skb);
1363
1364 /* loopback, multicast & non-ND link-local traffic; do not push through
1365 * packet taps again. Reset pkt_type for upper layers to process skb.
1366 * For non-loopback strict packets, determine the dst using the original
1367 * ifindex.
1368 */
1369 if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) {
1370 skb->dev = vrf_dev;
1371 skb->skb_iif = vrf_dev->ifindex;
1372 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1373
1374 if (skb->pkt_type == PACKET_LOOPBACK)
1375 skb->pkt_type = PACKET_HOST;
1376 else
1377 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1378
1379 goto out;
1380 }
1381
1382 /* if packet is NDISC then keep the ingress interface */
1383 if (!is_ndisc) {
1384 struct net_device *orig_dev = skb->dev;
1385
1386 vrf_rx_stats(vrf_dev, skb->len);
1387 skb->dev = vrf_dev;
1388 skb->skb_iif = vrf_dev->ifindex;
1389
1390 if (!list_empty(&vrf_dev->ptype_all)) {
1391 int err;
1392
1393 err = vrf_add_mac_header_if_unset(skb, vrf_dev,
1394 ETH_P_IPV6,
1395 orig_dev);
1396 if (likely(!err)) {
1397 skb_push(skb, skb->mac_len);
1398 dev_queue_xmit_nit(skb, vrf_dev);
1399 skb_pull(skb, skb->mac_len);
1400 }
1401 }
1402
1403 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1404 }
1405
1406 if (need_strict)
1407 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1408
1409 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
1410out:
1411 return skb;
1412}
1413
1414#else
1415static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1416 struct sk_buff *skb)
1417{
1418 return skb;
1419}
1420#endif
1421
1422static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
1423 struct sk_buff *skb)
1424{
1425 struct net_device *orig_dev = skb->dev;
1426
1427 skb->dev = vrf_dev;
1428 skb->skb_iif = vrf_dev->ifindex;
1429 IPCB(skb)->flags |= IPSKB_L3SLAVE;
1430
1431 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
1432 goto out;
1433
1434 /* loopback traffic; do not push through packet taps again.
1435 * Reset pkt_type for upper layers to process skb
1436 */
1437 if (skb->pkt_type == PACKET_LOOPBACK) {
1438 skb->pkt_type = PACKET_HOST;
1439 goto out;
1440 }
1441
1442 vrf_rx_stats(vrf_dev, skb->len);
1443
1444 if (!list_empty(&vrf_dev->ptype_all)) {
1445 int err;
1446
1447 err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP,
1448 orig_dev);
1449 if (likely(!err)) {
1450 skb_push(skb, skb->mac_len);
1451 dev_queue_xmit_nit(skb, vrf_dev);
1452 skb_pull(skb, skb->mac_len);
1453 }
1454 }
1455
1456 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
1457out:
1458 return skb;
1459}
1460
1461/* called with rcu lock held */
1462static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1463 struct sk_buff *skb,
1464 u16 proto)
1465{
1466 switch (proto) {
1467 case AF_INET:
1468 return vrf_ip_rcv(vrf_dev, skb);
1469 case AF_INET6:
1470 return vrf_ip6_rcv(vrf_dev, skb);
1471 }
1472
1473 return skb;
1474}
1475
1476#if IS_ENABLED(CONFIG_IPV6)
1477/* send to link-local or multicast address via interface enslaved to
1478 * VRF device. Force lookup to VRF table without changing flow struct
1479 * Note: Caller to this function must hold rcu_read_lock() and no refcnt
1480 * is taken on the dst by this function.
1481 */
1482static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1483 struct flowi6 *fl6)
1484{
1485 struct net *net = dev_net(dev);
1486 int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF;
1487 struct dst_entry *dst = NULL;
1488 struct rt6_info *rt;
1489
1490 /* VRF device does not have a link-local address and
1491 * sending packets to link-local or mcast addresses over
1492 * a VRF device does not make sense
1493 */
1494 if (fl6->flowi6_oif == dev->ifindex) {
1495 dst = &net->ipv6.ip6_null_entry->dst;
1496 return dst;
1497 }
1498
1499 if (!ipv6_addr_any(&fl6->saddr))
1500 flags |= RT6_LOOKUP_F_HAS_SADDR;
1501
1502 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags);
1503 if (rt)
1504 dst = &rt->dst;
1505
1506 return dst;
1507}
1508#endif
1509
1510static const struct l3mdev_ops vrf_l3mdev_ops = {
1511 .l3mdev_fib_table = vrf_fib_table,
1512 .l3mdev_l3_rcv = vrf_l3_rcv,
1513 .l3mdev_l3_out = vrf_l3_out,
1514#if IS_ENABLED(CONFIG_IPV6)
1515 .l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1516#endif
1517};
1518
1519static void vrf_get_drvinfo(struct net_device *dev,
1520 struct ethtool_drvinfo *info)
1521{
1522 strscpy(info->driver, DRV_NAME, sizeof(info->driver));
1523 strscpy(info->version, DRV_VERSION, sizeof(info->version));
1524}
1525
1526static const struct ethtool_ops vrf_ethtool_ops = {
1527 .get_drvinfo = vrf_get_drvinfo,
1528};
1529
1530static inline size_t vrf_fib_rule_nl_size(void)
1531{
1532 size_t sz;
1533
1534 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1535 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */
1536 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */
1537 sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */
1538
1539 return sz;
1540}
1541
1542static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1543{
1544 struct fib_rule_hdr *frh;
1545 struct nlmsghdr *nlh;
1546 struct sk_buff *skb;
1547 int err;
1548
1549 if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) &&
1550 !ipv6_mod_enabled())
1551 return 0;
1552
1553 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
1554 if (!skb)
1555 return -ENOMEM;
1556
1557 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
1558 if (!nlh)
1559 goto nla_put_failure;
1560
1561 /* rule only needs to appear once */
1562 nlh->nlmsg_flags |= NLM_F_EXCL;
1563
1564 frh = nlmsg_data(nlh);
1565 memset(frh, 0, sizeof(*frh));
1566 frh->family = family;
1567 frh->action = FR_ACT_TO_TBL;
1568
1569 if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL))
1570 goto nla_put_failure;
1571
1572 if (nla_put_u8(skb, FRA_L3MDEV, 1))
1573 goto nla_put_failure;
1574
1575 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
1576 goto nla_put_failure;
1577
1578 nlmsg_end(skb, nlh);
1579
1580 /* fib_nl_{new,del}rule handling looks for net from skb->sk */
1581 skb->sk = dev_net(dev)->rtnl;
1582 if (add_it) {
1583 err = fib_nl_newrule(skb, nlh, NULL);
1584 if (err == -EEXIST)
1585 err = 0;
1586 } else {
1587 err = fib_nl_delrule(skb, nlh, NULL);
1588 if (err == -ENOENT)
1589 err = 0;
1590 }
1591 nlmsg_free(skb);
1592
1593 return err;
1594
1595nla_put_failure:
1596 nlmsg_free(skb);
1597
1598 return -EMSGSIZE;
1599}
1600
1601static int vrf_add_fib_rules(const struct net_device *dev)
1602{
1603 int err;
1604
1605 err = vrf_fib_rule(dev, AF_INET, true);
1606 if (err < 0)
1607 goto out_err;
1608
1609 err = vrf_fib_rule(dev, AF_INET6, true);
1610 if (err < 0)
1611 goto ipv6_err;
1612
1613#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1614 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true);
1615 if (err < 0)
1616 goto ipmr_err;
1617#endif
1618
1619#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1620 err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, true);
1621 if (err < 0)
1622 goto ip6mr_err;
1623#endif
1624
1625 return 0;
1626
1627#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1628ip6mr_err:
1629 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, false);
1630#endif
1631
1632#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1633ipmr_err:
1634 vrf_fib_rule(dev, AF_INET6, false);
1635#endif
1636
1637ipv6_err:
1638 vrf_fib_rule(dev, AF_INET, false);
1639
1640out_err:
1641 netdev_err(dev, "Failed to add FIB rules.\n");
1642 return err;
1643}
1644
1645static void vrf_setup(struct net_device *dev)
1646{
1647 ether_setup(dev);
1648
1649 /* Initialize the device structure. */
1650 dev->netdev_ops = &vrf_netdev_ops;
1651 dev->l3mdev_ops = &vrf_l3mdev_ops;
1652 dev->ethtool_ops = &vrf_ethtool_ops;
1653 dev->needs_free_netdev = true;
1654
1655 /* Fill in device structure with ethernet-generic values. */
1656 eth_hw_addr_random(dev);
1657
1658 /* don't acquire vrf device's netif_tx_lock when transmitting */
1659 dev->features |= NETIF_F_LLTX;
1660
1661 /* don't allow vrf devices to change network namespaces. */
1662 dev->features |= NETIF_F_NETNS_LOCAL;
1663
1664 /* does not make sense for a VLAN to be added to a vrf device */
1665 dev->features |= NETIF_F_VLAN_CHALLENGED;
1666
1667 /* enable offload features */
1668 dev->features |= NETIF_F_GSO_SOFTWARE;
1669 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC;
1670 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1671
1672 dev->hw_features = dev->features;
1673 dev->hw_enc_features = dev->features;
1674
1675 /* default to no qdisc; user can add if desired */
1676 dev->priv_flags |= IFF_NO_QUEUE;
1677 dev->priv_flags |= IFF_NO_RX_HANDLER;
1678 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1679
1680 /* VRF devices do not care about MTU, but if the MTU is set
1681 * too low then the ipv4 and ipv6 protocols are disabled
1682 * which breaks networking.
1683 */
1684 dev->min_mtu = IPV6_MIN_MTU;
1685 dev->max_mtu = IP6_MAX_MTU;
1686 dev->mtu = dev->max_mtu;
1687
1688 dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS;
1689}
1690
1691static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],
1692 struct netlink_ext_ack *extack)
1693{
1694 if (tb[IFLA_ADDRESS]) {
1695 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
1696 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1697 return -EINVAL;
1698 }
1699 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
1700 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1701 return -EADDRNOTAVAIL;
1702 }
1703 }
1704 return 0;
1705}
1706
1707static void vrf_dellink(struct net_device *dev, struct list_head *head)
1708{
1709 struct net_device *port_dev;
1710 struct list_head *iter;
1711
1712 netdev_for_each_lower_dev(dev, port_dev, iter)
1713 vrf_del_slave(dev, port_dev);
1714
1715 vrf_map_unregister_dev(dev);
1716
1717 unregister_netdevice_queue(dev, head);
1718}
1719
1720static int vrf_newlink(struct net *src_net, struct net_device *dev,
1721 struct nlattr *tb[], struct nlattr *data[],
1722 struct netlink_ext_ack *extack)
1723{
1724 struct net_vrf *vrf = netdev_priv(dev);
1725 struct netns_vrf *nn_vrf;
1726 bool *add_fib_rules;
1727 struct net *net;
1728 int err;
1729
1730 if (!data || !data[IFLA_VRF_TABLE]) {
1731 NL_SET_ERR_MSG(extack, "VRF table id is missing");
1732 return -EINVAL;
1733 }
1734
1735 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
1736 if (vrf->tb_id == RT_TABLE_UNSPEC) {
1737 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE],
1738 "Invalid VRF table id");
1739 return -EINVAL;
1740 }
1741
1742 dev->priv_flags |= IFF_L3MDEV_MASTER;
1743
1744 err = register_netdevice(dev);
1745 if (err)
1746 goto out;
1747
1748 /* mapping between table_id and vrf;
1749 * note: such binding could not be done in the dev init function
1750 * because dev->ifindex id is not available yet.
1751 */
1752 vrf->ifindex = dev->ifindex;
1753
1754 err = vrf_map_register_dev(dev, extack);
1755 if (err) {
1756 unregister_netdevice(dev);
1757 goto out;
1758 }
1759
1760 net = dev_net(dev);
1761 nn_vrf = net_generic(net, vrf_net_id);
1762
1763 add_fib_rules = &nn_vrf->add_fib_rules;
1764 if (*add_fib_rules) {
1765 err = vrf_add_fib_rules(dev);
1766 if (err) {
1767 vrf_map_unregister_dev(dev);
1768 unregister_netdevice(dev);
1769 goto out;
1770 }
1771 *add_fib_rules = false;
1772 }
1773
1774out:
1775 return err;
1776}
1777
1778static size_t vrf_nl_getsize(const struct net_device *dev)
1779{
1780 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
1781}
1782
1783static int vrf_fillinfo(struct sk_buff *skb,
1784 const struct net_device *dev)
1785{
1786 struct net_vrf *vrf = netdev_priv(dev);
1787
1788 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
1789}
1790
1791static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1792 const struct net_device *slave_dev)
1793{
1794 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1795}
1796
1797static int vrf_fill_slave_info(struct sk_buff *skb,
1798 const struct net_device *vrf_dev,
1799 const struct net_device *slave_dev)
1800{
1801 struct net_vrf *vrf = netdev_priv(vrf_dev);
1802
1803 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
1804 return -EMSGSIZE;
1805
1806 return 0;
1807}
1808
1809static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1810 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1811};
1812
1813static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1814 .kind = DRV_NAME,
1815 .priv_size = sizeof(struct net_vrf),
1816
1817 .get_size = vrf_nl_getsize,
1818 .policy = vrf_nl_policy,
1819 .validate = vrf_validate,
1820 .fill_info = vrf_fillinfo,
1821
1822 .get_slave_size = vrf_get_slave_size,
1823 .fill_slave_info = vrf_fill_slave_info,
1824
1825 .newlink = vrf_newlink,
1826 .dellink = vrf_dellink,
1827 .setup = vrf_setup,
1828 .maxtype = IFLA_VRF_MAX,
1829};
1830
1831static int vrf_device_event(struct notifier_block *unused,
1832 unsigned long event, void *ptr)
1833{
1834 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1835
1836 /* only care about unregister events to drop slave references */
1837 if (event == NETDEV_UNREGISTER) {
1838 struct net_device *vrf_dev;
1839
1840 if (!netif_is_l3_slave(dev))
1841 goto out;
1842
1843 vrf_dev = netdev_master_upper_dev_get(dev);
1844 vrf_del_slave(vrf_dev, dev);
1845 }
1846out:
1847 return NOTIFY_DONE;
1848}
1849
1850static struct notifier_block vrf_notifier_block __read_mostly = {
1851 .notifier_call = vrf_device_event,
1852};
1853
1854static int vrf_map_init(struct vrf_map *vmap)
1855{
1856 spin_lock_init(&vmap->vmap_lock);
1857 hash_init(vmap->ht);
1858
1859 vmap->strict_mode = false;
1860
1861 return 0;
1862}
1863
1864#ifdef CONFIG_SYSCTL
1865static bool vrf_strict_mode(struct vrf_map *vmap)
1866{
1867 bool strict_mode;
1868
1869 vrf_map_lock(vmap);
1870 strict_mode = vmap->strict_mode;
1871 vrf_map_unlock(vmap);
1872
1873 return strict_mode;
1874}
1875
1876static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode)
1877{
1878 bool *cur_mode;
1879 int res = 0;
1880
1881 vrf_map_lock(vmap);
1882
1883 cur_mode = &vmap->strict_mode;
1884 if (*cur_mode == new_mode)
1885 goto unlock;
1886
1887 if (*cur_mode) {
1888 /* disable strict mode */
1889 *cur_mode = false;
1890 } else {
1891 if (vmap->shared_tables) {
1892 /* we cannot allow strict_mode because there are some
1893 * vrfs that share one or more tables.
1894 */
1895 res = -EBUSY;
1896 goto unlock;
1897 }
1898
1899 /* no tables are shared among vrfs, so we can go back
1900 * to 1:1 association between a vrf with its table.
1901 */
1902 *cur_mode = true;
1903 }
1904
1905unlock:
1906 vrf_map_unlock(vmap);
1907
1908 return res;
1909}
1910
1911static int vrf_shared_table_handler(struct ctl_table *table, int write,
1912 void *buffer, size_t *lenp, loff_t *ppos)
1913{
1914 struct net *net = (struct net *)table->extra1;
1915 struct vrf_map *vmap = netns_vrf_map(net);
1916 int proc_strict_mode = 0;
1917 struct ctl_table tmp = {
1918 .procname = table->procname,
1919 .data = &proc_strict_mode,
1920 .maxlen = sizeof(int),
1921 .mode = table->mode,
1922 .extra1 = SYSCTL_ZERO,
1923 .extra2 = SYSCTL_ONE,
1924 };
1925 int ret;
1926
1927 if (!write)
1928 proc_strict_mode = vrf_strict_mode(vmap);
1929
1930 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
1931
1932 if (write && ret == 0)
1933 ret = vrf_strict_mode_change(vmap, (bool)proc_strict_mode);
1934
1935 return ret;
1936}
1937
1938static const struct ctl_table vrf_table[] = {
1939 {
1940 .procname = "strict_mode",
1941 .data = NULL,
1942 .maxlen = sizeof(int),
1943 .mode = 0644,
1944 .proc_handler = vrf_shared_table_handler,
1945 /* set by the vrf_netns_init */
1946 .extra1 = NULL,
1947 },
1948};
1949
1950static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1951{
1952 struct ctl_table *table;
1953
1954 table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL);
1955 if (!table)
1956 return -ENOMEM;
1957
1958 /* init the extra1 parameter with the reference to current netns */
1959 table[0].extra1 = net;
1960
1961 nn_vrf->ctl_hdr = register_net_sysctl_sz(net, "net/vrf", table,
1962 ARRAY_SIZE(vrf_table));
1963 if (!nn_vrf->ctl_hdr) {
1964 kfree(table);
1965 return -ENOMEM;
1966 }
1967
1968 return 0;
1969}
1970
1971static void vrf_netns_exit_sysctl(struct net *net)
1972{
1973 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
1974 struct ctl_table *table;
1975
1976 table = nn_vrf->ctl_hdr->ctl_table_arg;
1977 unregister_net_sysctl_table(nn_vrf->ctl_hdr);
1978 kfree(table);
1979}
1980#else
1981static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1982{
1983 return 0;
1984}
1985
1986static void vrf_netns_exit_sysctl(struct net *net)
1987{
1988}
1989#endif
1990
1991/* Initialize per network namespace state */
1992static int __net_init vrf_netns_init(struct net *net)
1993{
1994 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
1995
1996 nn_vrf->add_fib_rules = true;
1997 vrf_map_init(&nn_vrf->vmap);
1998
1999 return vrf_netns_init_sysctl(net, nn_vrf);
2000}
2001
2002static void __net_exit vrf_netns_exit(struct net *net)
2003{
2004 vrf_netns_exit_sysctl(net);
2005}
2006
2007static struct pernet_operations vrf_net_ops __net_initdata = {
2008 .init = vrf_netns_init,
2009 .exit = vrf_netns_exit,
2010 .id = &vrf_net_id,
2011 .size = sizeof(struct netns_vrf),
2012};
2013
2014static int __init vrf_init_module(void)
2015{
2016 int rc;
2017
2018 register_netdevice_notifier(&vrf_notifier_block);
2019
2020 rc = register_pernet_subsys(&vrf_net_ops);
2021 if (rc < 0)
2022 goto error;
2023
2024 rc = l3mdev_table_lookup_register(L3MDEV_TYPE_VRF,
2025 vrf_ifindex_lookup_by_table_id);
2026 if (rc < 0)
2027 goto unreg_pernet;
2028
2029 rc = rtnl_link_register(&vrf_link_ops);
2030 if (rc < 0)
2031 goto table_lookup_unreg;
2032
2033 return 0;
2034
2035table_lookup_unreg:
2036 l3mdev_table_lookup_unregister(L3MDEV_TYPE_VRF,
2037 vrf_ifindex_lookup_by_table_id);
2038
2039unreg_pernet:
2040 unregister_pernet_subsys(&vrf_net_ops);
2041
2042error:
2043 unregister_netdevice_notifier(&vrf_notifier_block);
2044 return rc;
2045}
2046
2047module_init(vrf_init_module);
2048MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
2049MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
2050MODULE_LICENSE("GPL");
2051MODULE_ALIAS_RTNL_LINK(DRV_NAME);
2052MODULE_VERSION(DRV_VERSION);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * vrf.c: device driver to encapsulate a VRF space
4 *
5 * Copyright (c) 2015 Cumulus Networks. All rights reserved.
6 * Copyright (c) 2015 Shrijeet Mukherjee <shm@cumulusnetworks.com>
7 * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com>
8 *
9 * Based on dummy, team and ipvlan drivers
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/netdevice.h>
15#include <linux/etherdevice.h>
16#include <linux/ip.h>
17#include <linux/init.h>
18#include <linux/moduleparam.h>
19#include <linux/netfilter.h>
20#include <linux/rtnetlink.h>
21#include <net/rtnetlink.h>
22#include <linux/u64_stats_sync.h>
23#include <linux/hashtable.h>
24
25#include <linux/inetdevice.h>
26#include <net/arp.h>
27#include <net/ip.h>
28#include <net/ip_fib.h>
29#include <net/ip6_fib.h>
30#include <net/ip6_route.h>
31#include <net/route.h>
32#include <net/addrconf.h>
33#include <net/l3mdev.h>
34#include <net/fib_rules.h>
35#include <net/netns/generic.h>
36
37#define DRV_NAME "vrf"
38#define DRV_VERSION "1.0"
39
40#define FIB_RULE_PREF 1000 /* default preference for FIB rules */
41
42static unsigned int vrf_net_id;
43
44struct net_vrf {
45 struct rtable __rcu *rth;
46 struct rt6_info __rcu *rt6;
47#if IS_ENABLED(CONFIG_IPV6)
48 struct fib6_table *fib6_table;
49#endif
50 u32 tb_id;
51};
52
53struct pcpu_dstats {
54 u64 tx_pkts;
55 u64 tx_bytes;
56 u64 tx_drps;
57 u64 rx_pkts;
58 u64 rx_bytes;
59 u64 rx_drps;
60 struct u64_stats_sync syncp;
61};
62
63static void vrf_rx_stats(struct net_device *dev, int len)
64{
65 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
66
67 u64_stats_update_begin(&dstats->syncp);
68 dstats->rx_pkts++;
69 dstats->rx_bytes += len;
70 u64_stats_update_end(&dstats->syncp);
71}
72
73static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
74{
75 vrf_dev->stats.tx_errors++;
76 kfree_skb(skb);
77}
78
79static void vrf_get_stats64(struct net_device *dev,
80 struct rtnl_link_stats64 *stats)
81{
82 int i;
83
84 for_each_possible_cpu(i) {
85 const struct pcpu_dstats *dstats;
86 u64 tbytes, tpkts, tdrops, rbytes, rpkts;
87 unsigned int start;
88
89 dstats = per_cpu_ptr(dev->dstats, i);
90 do {
91 start = u64_stats_fetch_begin_irq(&dstats->syncp);
92 tbytes = dstats->tx_bytes;
93 tpkts = dstats->tx_pkts;
94 tdrops = dstats->tx_drps;
95 rbytes = dstats->rx_bytes;
96 rpkts = dstats->rx_pkts;
97 } while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
98 stats->tx_bytes += tbytes;
99 stats->tx_packets += tpkts;
100 stats->tx_dropped += tdrops;
101 stats->rx_bytes += rbytes;
102 stats->rx_packets += rpkts;
103 }
104}
105
106/* by default VRF devices do not have a qdisc and are expected
107 * to be created with only a single queue.
108 */
109static bool qdisc_tx_is_default(const struct net_device *dev)
110{
111 struct netdev_queue *txq;
112 struct Qdisc *qdisc;
113
114 if (dev->num_tx_queues > 1)
115 return false;
116
117 txq = netdev_get_tx_queue(dev, 0);
118 qdisc = rcu_access_pointer(txq->qdisc);
119
120 return !qdisc->enqueue;
121}
122
123/* Local traffic destined to local address. Reinsert the packet to rx
124 * path, similar to loopback handling.
125 */
126static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
127 struct dst_entry *dst)
128{
129 int len = skb->len;
130
131 skb_orphan(skb);
132
133 skb_dst_set(skb, dst);
134
135 /* set pkt_type to avoid skb hitting packet taps twice -
136 * once on Tx and again in Rx processing
137 */
138 skb->pkt_type = PACKET_LOOPBACK;
139
140 skb->protocol = eth_type_trans(skb, dev);
141
142 if (likely(netif_rx(skb) == NET_RX_SUCCESS))
143 vrf_rx_stats(dev, len);
144 else
145 this_cpu_inc(dev->dstats->rx_drps);
146
147 return NETDEV_TX_OK;
148}
149
150#if IS_ENABLED(CONFIG_IPV6)
151static int vrf_ip6_local_out(struct net *net, struct sock *sk,
152 struct sk_buff *skb)
153{
154 int err;
155
156 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net,
157 sk, skb, NULL, skb_dst(skb)->dev, dst_output);
158
159 if (likely(err == 1))
160 err = dst_output(net, sk, skb);
161
162 return err;
163}
164
165static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
166 struct net_device *dev)
167{
168 const struct ipv6hdr *iph;
169 struct net *net = dev_net(skb->dev);
170 struct flowi6 fl6;
171 int ret = NET_XMIT_DROP;
172 struct dst_entry *dst;
173 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
174
175 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
176 goto err;
177
178 iph = ipv6_hdr(skb);
179
180 memset(&fl6, 0, sizeof(fl6));
181 /* needed to match OIF rule */
182 fl6.flowi6_oif = dev->ifindex;
183 fl6.flowi6_iif = LOOPBACK_IFINDEX;
184 fl6.daddr = iph->daddr;
185 fl6.saddr = iph->saddr;
186 fl6.flowlabel = ip6_flowinfo(iph);
187 fl6.flowi6_mark = skb->mark;
188 fl6.flowi6_proto = iph->nexthdr;
189 fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF;
190
191 dst = ip6_route_output(net, NULL, &fl6);
192 if (dst == dst_null)
193 goto err;
194
195 skb_dst_drop(skb);
196
197 /* if dst.dev is loopback or the VRF device again this is locally
198 * originated traffic destined to a local address. Short circuit
199 * to Rx path
200 */
201 if (dst->dev == dev)
202 return vrf_local_xmit(skb, dev, dst);
203
204 skb_dst_set(skb, dst);
205
206 /* strip the ethernet header added for pass through VRF device */
207 __skb_pull(skb, skb_network_offset(skb));
208
209 ret = vrf_ip6_local_out(net, skb->sk, skb);
210 if (unlikely(net_xmit_eval(ret)))
211 dev->stats.tx_errors++;
212 else
213 ret = NET_XMIT_SUCCESS;
214
215 return ret;
216err:
217 vrf_tx_error(dev, skb);
218 return NET_XMIT_DROP;
219}
220#else
221static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
222 struct net_device *dev)
223{
224 vrf_tx_error(dev, skb);
225 return NET_XMIT_DROP;
226}
227#endif
228
229/* based on ip_local_out; can't use it b/c the dst is switched pointing to us */
230static int vrf_ip_local_out(struct net *net, struct sock *sk,
231 struct sk_buff *skb)
232{
233 int err;
234
235 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
236 skb, NULL, skb_dst(skb)->dev, dst_output);
237 if (likely(err == 1))
238 err = dst_output(net, sk, skb);
239
240 return err;
241}
242
243static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
244 struct net_device *vrf_dev)
245{
246 struct iphdr *ip4h;
247 int ret = NET_XMIT_DROP;
248 struct flowi4 fl4;
249 struct net *net = dev_net(vrf_dev);
250 struct rtable *rt;
251
252 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
253 goto err;
254
255 ip4h = ip_hdr(skb);
256
257 memset(&fl4, 0, sizeof(fl4));
258 /* needed to match OIF rule */
259 fl4.flowi4_oif = vrf_dev->ifindex;
260 fl4.flowi4_iif = LOOPBACK_IFINDEX;
261 fl4.flowi4_tos = RT_TOS(ip4h->tos);
262 fl4.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF;
263 fl4.flowi4_proto = ip4h->protocol;
264 fl4.daddr = ip4h->daddr;
265 fl4.saddr = ip4h->saddr;
266
267 rt = ip_route_output_flow(net, &fl4, NULL);
268 if (IS_ERR(rt))
269 goto err;
270
271 skb_dst_drop(skb);
272
273 /* if dst.dev is loopback or the VRF device again this is locally
274 * originated traffic destined to a local address. Short circuit
275 * to Rx path
276 */
277 if (rt->dst.dev == vrf_dev)
278 return vrf_local_xmit(skb, vrf_dev, &rt->dst);
279
280 skb_dst_set(skb, &rt->dst);
281
282 /* strip the ethernet header added for pass through VRF device */
283 __skb_pull(skb, skb_network_offset(skb));
284
285 if (!ip4h->saddr) {
286 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
287 RT_SCOPE_LINK);
288 }
289
290 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
291 if (unlikely(net_xmit_eval(ret)))
292 vrf_dev->stats.tx_errors++;
293 else
294 ret = NET_XMIT_SUCCESS;
295
296out:
297 return ret;
298err:
299 vrf_tx_error(vrf_dev, skb);
300 goto out;
301}
302
303static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
304{
305 switch (skb->protocol) {
306 case htons(ETH_P_IP):
307 return vrf_process_v4_outbound(skb, dev);
308 case htons(ETH_P_IPV6):
309 return vrf_process_v6_outbound(skb, dev);
310 default:
311 vrf_tx_error(dev, skb);
312 return NET_XMIT_DROP;
313 }
314}
315
316static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
317{
318 int len = skb->len;
319 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
320
321 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
322 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
323
324 u64_stats_update_begin(&dstats->syncp);
325 dstats->tx_pkts++;
326 dstats->tx_bytes += len;
327 u64_stats_update_end(&dstats->syncp);
328 } else {
329 this_cpu_inc(dev->dstats->tx_drps);
330 }
331
332 return ret;
333}
334
335static int vrf_finish_direct(struct net *net, struct sock *sk,
336 struct sk_buff *skb)
337{
338 struct net_device *vrf_dev = skb->dev;
339
340 if (!list_empty(&vrf_dev->ptype_all) &&
341 likely(skb_headroom(skb) >= ETH_HLEN)) {
342 struct ethhdr *eth = skb_push(skb, ETH_HLEN);
343
344 ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
345 eth_zero_addr(eth->h_dest);
346 eth->h_proto = skb->protocol;
347
348 rcu_read_lock_bh();
349 dev_queue_xmit_nit(skb, vrf_dev);
350 rcu_read_unlock_bh();
351
352 skb_pull(skb, ETH_HLEN);
353 }
354
355 return 1;
356}
357
358#if IS_ENABLED(CONFIG_IPV6)
359/* modelled after ip6_finish_output2 */
360static 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 const struct in6_addr *nexthop;
366 struct neighbour *neigh;
367 int ret;
368
369 nf_reset_ct(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 sock_confirm_neigh(skb, neigh);
381 ret = neigh_output(neigh, skb, false);
382 rcu_read_unlock_bh();
383 return ret;
384 }
385 rcu_read_unlock_bh();
386
387 IP6_INC_STATS(dev_net(dst->dev),
388 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
389 kfree_skb(skb);
390 return -EINVAL;
391}
392
393/* modelled after ip6_output */
394static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
395{
396 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
397 net, sk, skb, NULL, skb_dst(skb)->dev,
398 vrf_finish_output6,
399 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
400}
401
402/* set dst on skb to send packet to us via dev_xmit path. Allows
403 * packet to go through device based features such as qdisc, netfilter
404 * hooks and packet sockets with skb->dev set to vrf device.
405 */
406static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev,
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 rcu_read_lock();
414
415 rt6 = rcu_dereference(vrf->rt6);
416 if (likely(rt6)) {
417 dst = &rt6->dst;
418 dst_hold(dst);
419 }
420
421 rcu_read_unlock();
422
423 if (unlikely(!dst)) {
424 vrf_tx_error(vrf_dev, skb);
425 return NULL;
426 }
427
428 skb_dst_drop(skb);
429 skb_dst_set(skb, dst);
430
431 return skb;
432}
433
434static int vrf_output6_direct(struct net *net, struct sock *sk,
435 struct sk_buff *skb)
436{
437 skb->protocol = htons(ETH_P_IPV6);
438
439 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
440 net, sk, skb, NULL, skb->dev,
441 vrf_finish_direct,
442 !(IPCB(skb)->flags & IPSKB_REROUTED));
443}
444
445static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
446 struct sock *sk,
447 struct sk_buff *skb)
448{
449 struct net *net = dev_net(vrf_dev);
450 int err;
451
452 skb->dev = vrf_dev;
453
454 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk,
455 skb, NULL, vrf_dev, vrf_output6_direct);
456
457 if (likely(err == 1))
458 err = vrf_output6_direct(net, sk, skb);
459
460 /* reset skb device */
461 if (likely(err == 1))
462 nf_reset_ct(skb);
463 else
464 skb = NULL;
465
466 return skb;
467}
468
469static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
470 struct sock *sk,
471 struct sk_buff *skb)
472{
473 /* don't divert link scope packets */
474 if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
475 return skb;
476
477 if (qdisc_tx_is_default(vrf_dev))
478 return vrf_ip6_out_direct(vrf_dev, sk, skb);
479
480 return vrf_ip6_out_redirect(vrf_dev, skb);
481}
482
483/* holding rtnl */
484static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
485{
486 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
487 struct net *net = dev_net(dev);
488 struct dst_entry *dst;
489
490 RCU_INIT_POINTER(vrf->rt6, NULL);
491 synchronize_rcu();
492
493 /* move dev in dst's to loopback so this VRF device can be deleted
494 * - based on dst_ifdown
495 */
496 if (rt6) {
497 dst = &rt6->dst;
498 dev_put(dst->dev);
499 dst->dev = net->loopback_dev;
500 dev_hold(dst->dev);
501 dst_release(dst);
502 }
503}
504
505static int vrf_rt6_create(struct net_device *dev)
506{
507 int flags = DST_HOST | DST_NOPOLICY | DST_NOXFRM;
508 struct net_vrf *vrf = netdev_priv(dev);
509 struct net *net = dev_net(dev);
510 struct rt6_info *rt6;
511 int rc = -ENOMEM;
512
513 /* IPv6 can be CONFIG enabled and then disabled runtime */
514 if (!ipv6_mod_enabled())
515 return 0;
516
517 vrf->fib6_table = fib6_new_table(net, vrf->tb_id);
518 if (!vrf->fib6_table)
519 goto out;
520
521 /* create a dst for routing packets out a VRF device */
522 rt6 = ip6_dst_alloc(net, dev, flags);
523 if (!rt6)
524 goto out;
525
526 rt6->dst.output = vrf_output6;
527
528 rcu_assign_pointer(vrf->rt6, rt6);
529
530 rc = 0;
531out:
532 return rc;
533}
534#else
535static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
536 struct sock *sk,
537 struct sk_buff *skb)
538{
539 return skb;
540}
541
542static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
543{
544}
545
546static int vrf_rt6_create(struct net_device *dev)
547{
548 return 0;
549}
550#endif
551
552/* modelled after ip_finish_output2 */
553static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
554{
555 struct dst_entry *dst = skb_dst(skb);
556 struct rtable *rt = (struct rtable *)dst;
557 struct net_device *dev = dst->dev;
558 unsigned int hh_len = LL_RESERVED_SPACE(dev);
559 struct neighbour *neigh;
560 bool is_v6gw = false;
561 int ret = -EINVAL;
562
563 nf_reset_ct(skb);
564
565 /* Be paranoid, rather than too clever. */
566 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
567 struct sk_buff *skb2;
568
569 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
570 if (!skb2) {
571 ret = -ENOMEM;
572 goto err;
573 }
574 if (skb->sk)
575 skb_set_owner_w(skb2, skb->sk);
576
577 consume_skb(skb);
578 skb = skb2;
579 }
580
581 rcu_read_lock_bh();
582
583 neigh = ip_neigh_for_gw(rt, skb, &is_v6gw);
584 if (!IS_ERR(neigh)) {
585 sock_confirm_neigh(skb, neigh);
586 /* if crossing protocols, can not use the cached header */
587 ret = neigh_output(neigh, skb, is_v6gw);
588 rcu_read_unlock_bh();
589 return ret;
590 }
591
592 rcu_read_unlock_bh();
593err:
594 vrf_tx_error(skb->dev, skb);
595 return ret;
596}
597
598static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
599{
600 struct net_device *dev = skb_dst(skb)->dev;
601
602 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
603
604 skb->dev = dev;
605 skb->protocol = htons(ETH_P_IP);
606
607 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
608 net, sk, skb, NULL, dev,
609 vrf_finish_output,
610 !(IPCB(skb)->flags & IPSKB_REROUTED));
611}
612
613/* set dst on skb to send packet to us via dev_xmit path. Allows
614 * packet to go through device based features such as qdisc, netfilter
615 * hooks and packet sockets with skb->dev set to vrf device.
616 */
617static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev,
618 struct sk_buff *skb)
619{
620 struct net_vrf *vrf = netdev_priv(vrf_dev);
621 struct dst_entry *dst = NULL;
622 struct rtable *rth;
623
624 rcu_read_lock();
625
626 rth = rcu_dereference(vrf->rth);
627 if (likely(rth)) {
628 dst = &rth->dst;
629 dst_hold(dst);
630 }
631
632 rcu_read_unlock();
633
634 if (unlikely(!dst)) {
635 vrf_tx_error(vrf_dev, skb);
636 return NULL;
637 }
638
639 skb_dst_drop(skb);
640 skb_dst_set(skb, dst);
641
642 return skb;
643}
644
645static int vrf_output_direct(struct net *net, struct sock *sk,
646 struct sk_buff *skb)
647{
648 skb->protocol = htons(ETH_P_IP);
649
650 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
651 net, sk, skb, NULL, skb->dev,
652 vrf_finish_direct,
653 !(IPCB(skb)->flags & IPSKB_REROUTED));
654}
655
656static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
657 struct sock *sk,
658 struct sk_buff *skb)
659{
660 struct net *net = dev_net(vrf_dev);
661 int err;
662
663 skb->dev = vrf_dev;
664
665 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
666 skb, NULL, vrf_dev, vrf_output_direct);
667
668 if (likely(err == 1))
669 err = vrf_output_direct(net, sk, skb);
670
671 /* reset skb device */
672 if (likely(err == 1))
673 nf_reset_ct(skb);
674 else
675 skb = NULL;
676
677 return skb;
678}
679
680static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
681 struct sock *sk,
682 struct sk_buff *skb)
683{
684 /* don't divert multicast or local broadcast */
685 if (ipv4_is_multicast(ip_hdr(skb)->daddr) ||
686 ipv4_is_lbcast(ip_hdr(skb)->daddr))
687 return skb;
688
689 if (qdisc_tx_is_default(vrf_dev))
690 return vrf_ip_out_direct(vrf_dev, sk, skb);
691
692 return vrf_ip_out_redirect(vrf_dev, skb);
693}
694
695/* called with rcu lock held */
696static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
697 struct sock *sk,
698 struct sk_buff *skb,
699 u16 proto)
700{
701 switch (proto) {
702 case AF_INET:
703 return vrf_ip_out(vrf_dev, sk, skb);
704 case AF_INET6:
705 return vrf_ip6_out(vrf_dev, sk, skb);
706 }
707
708 return skb;
709}
710
711/* holding rtnl */
712static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
713{
714 struct rtable *rth = rtnl_dereference(vrf->rth);
715 struct net *net = dev_net(dev);
716 struct dst_entry *dst;
717
718 RCU_INIT_POINTER(vrf->rth, NULL);
719 synchronize_rcu();
720
721 /* move dev in dst's to loopback so this VRF device can be deleted
722 * - based on dst_ifdown
723 */
724 if (rth) {
725 dst = &rth->dst;
726 dev_put(dst->dev);
727 dst->dev = net->loopback_dev;
728 dev_hold(dst->dev);
729 dst_release(dst);
730 }
731}
732
733static int vrf_rtable_create(struct net_device *dev)
734{
735 struct net_vrf *vrf = netdev_priv(dev);
736 struct rtable *rth;
737
738 if (!fib_new_table(dev_net(dev), vrf->tb_id))
739 return -ENOMEM;
740
741 /* create a dst for routing packets out through a VRF device */
742 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1, 0);
743 if (!rth)
744 return -ENOMEM;
745
746 rth->dst.output = vrf_output;
747
748 rcu_assign_pointer(vrf->rth, rth);
749
750 return 0;
751}
752
753/**************************** device handling ********************/
754
755/* cycle interface to flush neighbor cache and move routes across tables */
756static void cycle_netdev(struct net_device *dev,
757 struct netlink_ext_ack *extack)
758{
759 unsigned int flags = dev->flags;
760 int ret;
761
762 if (!netif_running(dev))
763 return;
764
765 ret = dev_change_flags(dev, flags & ~IFF_UP, extack);
766 if (ret >= 0)
767 ret = dev_change_flags(dev, flags, extack);
768
769 if (ret < 0) {
770 netdev_err(dev,
771 "Failed to cycle device %s; route tables might be wrong!\n",
772 dev->name);
773 }
774}
775
776static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
777 struct netlink_ext_ack *extack)
778{
779 int ret;
780
781 /* do not allow loopback device to be enslaved to a VRF.
782 * The vrf device acts as the loopback for the vrf.
783 */
784 if (port_dev == dev_net(dev)->loopback_dev) {
785 NL_SET_ERR_MSG(extack,
786 "Can not enslave loopback device to a VRF");
787 return -EOPNOTSUPP;
788 }
789
790 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
791 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack);
792 if (ret < 0)
793 goto err;
794
795 cycle_netdev(port_dev, extack);
796
797 return 0;
798
799err:
800 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
801 return ret;
802}
803
804static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
805 struct netlink_ext_ack *extack)
806{
807 if (netif_is_l3_master(port_dev)) {
808 NL_SET_ERR_MSG(extack,
809 "Can not enslave an L3 master device to a VRF");
810 return -EINVAL;
811 }
812
813 if (netif_is_l3_slave(port_dev))
814 return -EINVAL;
815
816 return do_vrf_add_slave(dev, port_dev, extack);
817}
818
819/* inverse of do_vrf_add_slave */
820static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
821{
822 netdev_upper_dev_unlink(port_dev, dev);
823 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
824
825 cycle_netdev(port_dev, NULL);
826
827 return 0;
828}
829
830static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
831{
832 return do_vrf_del_slave(dev, port_dev);
833}
834
835static void vrf_dev_uninit(struct net_device *dev)
836{
837 struct net_vrf *vrf = netdev_priv(dev);
838
839 vrf_rtable_release(dev, vrf);
840 vrf_rt6_release(dev, vrf);
841
842 free_percpu(dev->dstats);
843 dev->dstats = NULL;
844}
845
846static int vrf_dev_init(struct net_device *dev)
847{
848 struct net_vrf *vrf = netdev_priv(dev);
849
850 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
851 if (!dev->dstats)
852 goto out_nomem;
853
854 /* create the default dst which points back to us */
855 if (vrf_rtable_create(dev) != 0)
856 goto out_stats;
857
858 if (vrf_rt6_create(dev) != 0)
859 goto out_rth;
860
861 dev->flags = IFF_MASTER | IFF_NOARP;
862
863 /* MTU is irrelevant for VRF device; set to 64k similar to lo */
864 dev->mtu = 64 * 1024;
865
866 /* similarly, oper state is irrelevant; set to up to avoid confusion */
867 dev->operstate = IF_OPER_UP;
868 return 0;
869
870out_rth:
871 vrf_rtable_release(dev, vrf);
872out_stats:
873 free_percpu(dev->dstats);
874 dev->dstats = NULL;
875out_nomem:
876 return -ENOMEM;
877}
878
879static const struct net_device_ops vrf_netdev_ops = {
880 .ndo_init = vrf_dev_init,
881 .ndo_uninit = vrf_dev_uninit,
882 .ndo_start_xmit = vrf_xmit,
883 .ndo_set_mac_address = eth_mac_addr,
884 .ndo_get_stats64 = vrf_get_stats64,
885 .ndo_add_slave = vrf_add_slave,
886 .ndo_del_slave = vrf_del_slave,
887};
888
889static u32 vrf_fib_table(const struct net_device *dev)
890{
891 struct net_vrf *vrf = netdev_priv(dev);
892
893 return vrf->tb_id;
894}
895
896static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
897{
898 kfree_skb(skb);
899 return 0;
900}
901
902static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
903 struct sk_buff *skb,
904 struct net_device *dev)
905{
906 struct net *net = dev_net(dev);
907
908 if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1)
909 skb = NULL; /* kfree_skb(skb) handled by nf code */
910
911 return skb;
912}
913
914#if IS_ENABLED(CONFIG_IPV6)
915/* neighbor handling is done with actual device; do not want
916 * to flip skb->dev for those ndisc packets. This really fails
917 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
918 * a start.
919 */
920static bool ipv6_ndisc_frame(const struct sk_buff *skb)
921{
922 const struct ipv6hdr *iph = ipv6_hdr(skb);
923 bool rc = false;
924
925 if (iph->nexthdr == NEXTHDR_ICMP) {
926 const struct icmp6hdr *icmph;
927 struct icmp6hdr _icmph;
928
929 icmph = skb_header_pointer(skb, sizeof(*iph),
930 sizeof(_icmph), &_icmph);
931 if (!icmph)
932 goto out;
933
934 switch (icmph->icmp6_type) {
935 case NDISC_ROUTER_SOLICITATION:
936 case NDISC_ROUTER_ADVERTISEMENT:
937 case NDISC_NEIGHBOUR_SOLICITATION:
938 case NDISC_NEIGHBOUR_ADVERTISEMENT:
939 case NDISC_REDIRECT:
940 rc = true;
941 break;
942 }
943 }
944
945out:
946 return rc;
947}
948
949static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
950 const struct net_device *dev,
951 struct flowi6 *fl6,
952 int ifindex,
953 const struct sk_buff *skb,
954 int flags)
955{
956 struct net_vrf *vrf = netdev_priv(dev);
957
958 return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags);
959}
960
961static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
962 int ifindex)
963{
964 const struct ipv6hdr *iph = ipv6_hdr(skb);
965 struct flowi6 fl6 = {
966 .flowi6_iif = ifindex,
967 .flowi6_mark = skb->mark,
968 .flowi6_proto = iph->nexthdr,
969 .daddr = iph->daddr,
970 .saddr = iph->saddr,
971 .flowlabel = ip6_flowinfo(iph),
972 };
973 struct net *net = dev_net(vrf_dev);
974 struct rt6_info *rt6;
975
976 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb,
977 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
978 if (unlikely(!rt6))
979 return;
980
981 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
982 return;
983
984 skb_dst_set(skb, &rt6->dst);
985}
986
987static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
988 struct sk_buff *skb)
989{
990 int orig_iif = skb->skb_iif;
991 bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
992 bool is_ndisc = ipv6_ndisc_frame(skb);
993
994 /* loopback, multicast & non-ND link-local traffic; do not push through
995 * packet taps again. Reset pkt_type for upper layers to process skb
996 */
997 if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) {
998 skb->dev = vrf_dev;
999 skb->skb_iif = vrf_dev->ifindex;
1000 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1001 if (skb->pkt_type == PACKET_LOOPBACK)
1002 skb->pkt_type = PACKET_HOST;
1003 goto out;
1004 }
1005
1006 /* if packet is NDISC then keep the ingress interface */
1007 if (!is_ndisc) {
1008 vrf_rx_stats(vrf_dev, skb->len);
1009 skb->dev = vrf_dev;
1010 skb->skb_iif = vrf_dev->ifindex;
1011
1012 if (!list_empty(&vrf_dev->ptype_all)) {
1013 skb_push(skb, skb->mac_len);
1014 dev_queue_xmit_nit(skb, vrf_dev);
1015 skb_pull(skb, skb->mac_len);
1016 }
1017
1018 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1019 }
1020
1021 if (need_strict)
1022 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1023
1024 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
1025out:
1026 return skb;
1027}
1028
1029#else
1030static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1031 struct sk_buff *skb)
1032{
1033 return skb;
1034}
1035#endif
1036
1037static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
1038 struct sk_buff *skb)
1039{
1040 skb->dev = vrf_dev;
1041 skb->skb_iif = vrf_dev->ifindex;
1042 IPCB(skb)->flags |= IPSKB_L3SLAVE;
1043
1044 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
1045 goto out;
1046
1047 /* loopback traffic; do not push through packet taps again.
1048 * Reset pkt_type for upper layers to process skb
1049 */
1050 if (skb->pkt_type == PACKET_LOOPBACK) {
1051 skb->pkt_type = PACKET_HOST;
1052 goto out;
1053 }
1054
1055 vrf_rx_stats(vrf_dev, skb->len);
1056
1057 if (!list_empty(&vrf_dev->ptype_all)) {
1058 skb_push(skb, skb->mac_len);
1059 dev_queue_xmit_nit(skb, vrf_dev);
1060 skb_pull(skb, skb->mac_len);
1061 }
1062
1063 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
1064out:
1065 return skb;
1066}
1067
1068/* called with rcu lock held */
1069static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1070 struct sk_buff *skb,
1071 u16 proto)
1072{
1073 switch (proto) {
1074 case AF_INET:
1075 return vrf_ip_rcv(vrf_dev, skb);
1076 case AF_INET6:
1077 return vrf_ip6_rcv(vrf_dev, skb);
1078 }
1079
1080 return skb;
1081}
1082
1083#if IS_ENABLED(CONFIG_IPV6)
1084/* send to link-local or multicast address via interface enslaved to
1085 * VRF device. Force lookup to VRF table without changing flow struct
1086 * Note: Caller to this function must hold rcu_read_lock() and no refcnt
1087 * is taken on the dst by this function.
1088 */
1089static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1090 struct flowi6 *fl6)
1091{
1092 struct net *net = dev_net(dev);
1093 int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF;
1094 struct dst_entry *dst = NULL;
1095 struct rt6_info *rt;
1096
1097 /* VRF device does not have a link-local address and
1098 * sending packets to link-local or mcast addresses over
1099 * a VRF device does not make sense
1100 */
1101 if (fl6->flowi6_oif == dev->ifindex) {
1102 dst = &net->ipv6.ip6_null_entry->dst;
1103 return dst;
1104 }
1105
1106 if (!ipv6_addr_any(&fl6->saddr))
1107 flags |= RT6_LOOKUP_F_HAS_SADDR;
1108
1109 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags);
1110 if (rt)
1111 dst = &rt->dst;
1112
1113 return dst;
1114}
1115#endif
1116
1117static const struct l3mdev_ops vrf_l3mdev_ops = {
1118 .l3mdev_fib_table = vrf_fib_table,
1119 .l3mdev_l3_rcv = vrf_l3_rcv,
1120 .l3mdev_l3_out = vrf_l3_out,
1121#if IS_ENABLED(CONFIG_IPV6)
1122 .l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1123#endif
1124};
1125
1126static void vrf_get_drvinfo(struct net_device *dev,
1127 struct ethtool_drvinfo *info)
1128{
1129 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
1130 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
1131}
1132
1133static const struct ethtool_ops vrf_ethtool_ops = {
1134 .get_drvinfo = vrf_get_drvinfo,
1135};
1136
1137static inline size_t vrf_fib_rule_nl_size(void)
1138{
1139 size_t sz;
1140
1141 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1142 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */
1143 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */
1144 sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */
1145
1146 return sz;
1147}
1148
1149static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1150{
1151 struct fib_rule_hdr *frh;
1152 struct nlmsghdr *nlh;
1153 struct sk_buff *skb;
1154 int err;
1155
1156 if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) &&
1157 !ipv6_mod_enabled())
1158 return 0;
1159
1160 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
1161 if (!skb)
1162 return -ENOMEM;
1163
1164 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
1165 if (!nlh)
1166 goto nla_put_failure;
1167
1168 /* rule only needs to appear once */
1169 nlh->nlmsg_flags |= NLM_F_EXCL;
1170
1171 frh = nlmsg_data(nlh);
1172 memset(frh, 0, sizeof(*frh));
1173 frh->family = family;
1174 frh->action = FR_ACT_TO_TBL;
1175
1176 if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL))
1177 goto nla_put_failure;
1178
1179 if (nla_put_u8(skb, FRA_L3MDEV, 1))
1180 goto nla_put_failure;
1181
1182 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
1183 goto nla_put_failure;
1184
1185 nlmsg_end(skb, nlh);
1186
1187 /* fib_nl_{new,del}rule handling looks for net from skb->sk */
1188 skb->sk = dev_net(dev)->rtnl;
1189 if (add_it) {
1190 err = fib_nl_newrule(skb, nlh, NULL);
1191 if (err == -EEXIST)
1192 err = 0;
1193 } else {
1194 err = fib_nl_delrule(skb, nlh, NULL);
1195 if (err == -ENOENT)
1196 err = 0;
1197 }
1198 nlmsg_free(skb);
1199
1200 return err;
1201
1202nla_put_failure:
1203 nlmsg_free(skb);
1204
1205 return -EMSGSIZE;
1206}
1207
1208static int vrf_add_fib_rules(const struct net_device *dev)
1209{
1210 int err;
1211
1212 err = vrf_fib_rule(dev, AF_INET, true);
1213 if (err < 0)
1214 goto out_err;
1215
1216 err = vrf_fib_rule(dev, AF_INET6, true);
1217 if (err < 0)
1218 goto ipv6_err;
1219
1220#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1221 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true);
1222 if (err < 0)
1223 goto ipmr_err;
1224#endif
1225
1226#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1227 err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, true);
1228 if (err < 0)
1229 goto ip6mr_err;
1230#endif
1231
1232 return 0;
1233
1234#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1235ip6mr_err:
1236 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, false);
1237#endif
1238
1239#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1240ipmr_err:
1241 vrf_fib_rule(dev, AF_INET6, false);
1242#endif
1243
1244ipv6_err:
1245 vrf_fib_rule(dev, AF_INET, false);
1246
1247out_err:
1248 netdev_err(dev, "Failed to add FIB rules.\n");
1249 return err;
1250}
1251
1252static void vrf_setup(struct net_device *dev)
1253{
1254 ether_setup(dev);
1255
1256 /* Initialize the device structure. */
1257 dev->netdev_ops = &vrf_netdev_ops;
1258 dev->l3mdev_ops = &vrf_l3mdev_ops;
1259 dev->ethtool_ops = &vrf_ethtool_ops;
1260 dev->needs_free_netdev = true;
1261
1262 /* Fill in device structure with ethernet-generic values. */
1263 eth_hw_addr_random(dev);
1264
1265 /* don't acquire vrf device's netif_tx_lock when transmitting */
1266 dev->features |= NETIF_F_LLTX;
1267
1268 /* don't allow vrf devices to change network namespaces. */
1269 dev->features |= NETIF_F_NETNS_LOCAL;
1270
1271 /* does not make sense for a VLAN to be added to a vrf device */
1272 dev->features |= NETIF_F_VLAN_CHALLENGED;
1273
1274 /* enable offload features */
1275 dev->features |= NETIF_F_GSO_SOFTWARE;
1276 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC;
1277 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1278
1279 dev->hw_features = dev->features;
1280 dev->hw_enc_features = dev->features;
1281
1282 /* default to no qdisc; user can add if desired */
1283 dev->priv_flags |= IFF_NO_QUEUE;
1284 dev->priv_flags |= IFF_NO_RX_HANDLER;
1285 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1286
1287 /* VRF devices do not care about MTU, but if the MTU is set
1288 * too low then the ipv4 and ipv6 protocols are disabled
1289 * which breaks networking.
1290 */
1291 dev->min_mtu = IPV6_MIN_MTU;
1292 dev->max_mtu = ETH_MAX_MTU;
1293}
1294
1295static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],
1296 struct netlink_ext_ack *extack)
1297{
1298 if (tb[IFLA_ADDRESS]) {
1299 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
1300 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1301 return -EINVAL;
1302 }
1303 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
1304 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1305 return -EADDRNOTAVAIL;
1306 }
1307 }
1308 return 0;
1309}
1310
1311static void vrf_dellink(struct net_device *dev, struct list_head *head)
1312{
1313 struct net_device *port_dev;
1314 struct list_head *iter;
1315
1316 netdev_for_each_lower_dev(dev, port_dev, iter)
1317 vrf_del_slave(dev, port_dev);
1318
1319 unregister_netdevice_queue(dev, head);
1320}
1321
1322static int vrf_newlink(struct net *src_net, struct net_device *dev,
1323 struct nlattr *tb[], struct nlattr *data[],
1324 struct netlink_ext_ack *extack)
1325{
1326 struct net_vrf *vrf = netdev_priv(dev);
1327 bool *add_fib_rules;
1328 struct net *net;
1329 int err;
1330
1331 if (!data || !data[IFLA_VRF_TABLE]) {
1332 NL_SET_ERR_MSG(extack, "VRF table id is missing");
1333 return -EINVAL;
1334 }
1335
1336 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
1337 if (vrf->tb_id == RT_TABLE_UNSPEC) {
1338 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE],
1339 "Invalid VRF table id");
1340 return -EINVAL;
1341 }
1342
1343 dev->priv_flags |= IFF_L3MDEV_MASTER;
1344
1345 err = register_netdevice(dev);
1346 if (err)
1347 goto out;
1348
1349 net = dev_net(dev);
1350 add_fib_rules = net_generic(net, vrf_net_id);
1351 if (*add_fib_rules) {
1352 err = vrf_add_fib_rules(dev);
1353 if (err) {
1354 unregister_netdevice(dev);
1355 goto out;
1356 }
1357 *add_fib_rules = false;
1358 }
1359
1360out:
1361 return err;
1362}
1363
1364static size_t vrf_nl_getsize(const struct net_device *dev)
1365{
1366 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
1367}
1368
1369static int vrf_fillinfo(struct sk_buff *skb,
1370 const struct net_device *dev)
1371{
1372 struct net_vrf *vrf = netdev_priv(dev);
1373
1374 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
1375}
1376
1377static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1378 const struct net_device *slave_dev)
1379{
1380 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1381}
1382
1383static int vrf_fill_slave_info(struct sk_buff *skb,
1384 const struct net_device *vrf_dev,
1385 const struct net_device *slave_dev)
1386{
1387 struct net_vrf *vrf = netdev_priv(vrf_dev);
1388
1389 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
1390 return -EMSGSIZE;
1391
1392 return 0;
1393}
1394
1395static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1396 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1397};
1398
1399static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1400 .kind = DRV_NAME,
1401 .priv_size = sizeof(struct net_vrf),
1402
1403 .get_size = vrf_nl_getsize,
1404 .policy = vrf_nl_policy,
1405 .validate = vrf_validate,
1406 .fill_info = vrf_fillinfo,
1407
1408 .get_slave_size = vrf_get_slave_size,
1409 .fill_slave_info = vrf_fill_slave_info,
1410
1411 .newlink = vrf_newlink,
1412 .dellink = vrf_dellink,
1413 .setup = vrf_setup,
1414 .maxtype = IFLA_VRF_MAX,
1415};
1416
1417static int vrf_device_event(struct notifier_block *unused,
1418 unsigned long event, void *ptr)
1419{
1420 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1421
1422 /* only care about unregister events to drop slave references */
1423 if (event == NETDEV_UNREGISTER) {
1424 struct net_device *vrf_dev;
1425
1426 if (!netif_is_l3_slave(dev))
1427 goto out;
1428
1429 vrf_dev = netdev_master_upper_dev_get(dev);
1430 vrf_del_slave(vrf_dev, dev);
1431 }
1432out:
1433 return NOTIFY_DONE;
1434}
1435
1436static struct notifier_block vrf_notifier_block __read_mostly = {
1437 .notifier_call = vrf_device_event,
1438};
1439
1440/* Initialize per network namespace state */
1441static int __net_init vrf_netns_init(struct net *net)
1442{
1443 bool *add_fib_rules = net_generic(net, vrf_net_id);
1444
1445 *add_fib_rules = true;
1446
1447 return 0;
1448}
1449
1450static struct pernet_operations vrf_net_ops __net_initdata = {
1451 .init = vrf_netns_init,
1452 .id = &vrf_net_id,
1453 .size = sizeof(bool),
1454};
1455
1456static int __init vrf_init_module(void)
1457{
1458 int rc;
1459
1460 register_netdevice_notifier(&vrf_notifier_block);
1461
1462 rc = register_pernet_subsys(&vrf_net_ops);
1463 if (rc < 0)
1464 goto error;
1465
1466 rc = rtnl_link_register(&vrf_link_ops);
1467 if (rc < 0) {
1468 unregister_pernet_subsys(&vrf_net_ops);
1469 goto error;
1470 }
1471
1472 return 0;
1473
1474error:
1475 unregister_netdevice_notifier(&vrf_notifier_block);
1476 return rc;
1477}
1478
1479module_init(vrf_init_module);
1480MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
1481MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
1482MODULE_LICENSE("GPL");
1483MODULE_ALIAS_RTNL_LINK(DRV_NAME);
1484MODULE_VERSION(DRV_VERSION);