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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#include <net/inet_dscp.h>
41
42#define DRV_NAME "vrf"
43#define DRV_VERSION "1.1"
44
45#define FIB_RULE_PREF 1000 /* default preference for FIB rules */
46
47#define HT_MAP_BITS 4
48#define HASH_INITVAL ((u32)0xcafef00d)
49
50struct vrf_map {
51 DECLARE_HASHTABLE(ht, HT_MAP_BITS);
52 spinlock_t vmap_lock;
53
54 /* shared_tables:
55 * count how many distinct tables do not comply with the strict mode
56 * requirement.
57 * shared_tables value must be 0 in order to enable the strict mode.
58 *
59 * example of the evolution of shared_tables:
60 * | time
61 * add vrf0 --> table 100 shared_tables = 0 | t0
62 * add vrf1 --> table 101 shared_tables = 0 | t1
63 * add vrf2 --> table 100 shared_tables = 1 | t2
64 * add vrf3 --> table 100 shared_tables = 1 | t3
65 * add vrf4 --> table 101 shared_tables = 2 v t4
66 *
67 * shared_tables is a "step function" (or "staircase function")
68 * and it is increased by one when the second vrf is associated to a
69 * table.
70 *
71 * at t2, vrf0 and vrf2 are bound to table 100: shared_tables = 1.
72 *
73 * at t3, another dev (vrf3) is bound to the same table 100 but the
74 * value of shared_tables is still 1.
75 * This means that no matter how many new vrfs will register on the
76 * table 100, the shared_tables will not increase (considering only
77 * table 100).
78 *
79 * at t4, vrf4 is bound to table 101, and shared_tables = 2.
80 *
81 * Looking at the value of shared_tables we can immediately know if
82 * the strict_mode can or cannot be enforced. Indeed, strict_mode
83 * can be enforced iff shared_tables = 0.
84 *
85 * Conversely, shared_tables is decreased when a vrf is de-associated
86 * from a table with exactly two associated vrfs.
87 */
88 u32 shared_tables;
89
90 bool strict_mode;
91};
92
93struct vrf_map_elem {
94 struct hlist_node hnode;
95 struct list_head vrf_list; /* VRFs registered to this table */
96
97 u32 table_id;
98 int users;
99 int ifindex;
100};
101
102static unsigned int vrf_net_id;
103
104/* per netns vrf data */
105struct netns_vrf {
106 /* protected by rtnl lock */
107 bool add_fib_rules;
108
109 struct vrf_map vmap;
110 struct ctl_table_header *ctl_hdr;
111};
112
113struct net_vrf {
114 struct rtable __rcu *rth;
115 struct rt6_info __rcu *rt6;
116#if IS_ENABLED(CONFIG_IPV6)
117 struct fib6_table *fib6_table;
118#endif
119 u32 tb_id;
120
121 struct list_head me_list; /* entry in vrf_map_elem */
122 int ifindex;
123};
124
125static void vrf_rx_stats(struct net_device *dev, int len)
126{
127 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
128
129 u64_stats_update_begin(&dstats->syncp);
130 u64_stats_inc(&dstats->rx_packets);
131 u64_stats_add(&dstats->rx_bytes, len);
132 u64_stats_update_end(&dstats->syncp);
133}
134
135static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
136{
137 vrf_dev->stats.tx_errors++;
138 kfree_skb(skb);
139}
140
141static struct vrf_map *netns_vrf_map(struct net *net)
142{
143 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
144
145 return &nn_vrf->vmap;
146}
147
148static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev)
149{
150 return netns_vrf_map(dev_net(dev));
151}
152
153static int vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem *me)
154{
155 struct list_head *me_head = &me->vrf_list;
156 struct net_vrf *vrf;
157
158 if (list_empty(me_head))
159 return -ENODEV;
160
161 vrf = list_first_entry(me_head, struct net_vrf, me_list);
162
163 return vrf->ifindex;
164}
165
166static struct vrf_map_elem *vrf_map_elem_alloc(gfp_t flags)
167{
168 struct vrf_map_elem *me;
169
170 me = kmalloc(sizeof(*me), flags);
171 if (!me)
172 return NULL;
173
174 return me;
175}
176
177static void vrf_map_elem_free(struct vrf_map_elem *me)
178{
179 kfree(me);
180}
181
182static void vrf_map_elem_init(struct vrf_map_elem *me, int table_id,
183 int ifindex, int users)
184{
185 me->table_id = table_id;
186 me->ifindex = ifindex;
187 me->users = users;
188 INIT_LIST_HEAD(&me->vrf_list);
189}
190
191static struct vrf_map_elem *vrf_map_lookup_elem(struct vrf_map *vmap,
192 u32 table_id)
193{
194 struct vrf_map_elem *me;
195 u32 key;
196
197 key = jhash_1word(table_id, HASH_INITVAL);
198 hash_for_each_possible(vmap->ht, me, hnode, key) {
199 if (me->table_id == table_id)
200 return me;
201 }
202
203 return NULL;
204}
205
206static void vrf_map_add_elem(struct vrf_map *vmap, struct vrf_map_elem *me)
207{
208 u32 table_id = me->table_id;
209 u32 key;
210
211 key = jhash_1word(table_id, HASH_INITVAL);
212 hash_add(vmap->ht, &me->hnode, key);
213}
214
215static void vrf_map_del_elem(struct vrf_map_elem *me)
216{
217 hash_del(&me->hnode);
218}
219
220static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock)
221{
222 spin_lock(&vmap->vmap_lock);
223}
224
225static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock)
226{
227 spin_unlock(&vmap->vmap_lock);
228}
229
230/* called with rtnl lock held */
231static int
232vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack)
233{
234 struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
235 struct net_vrf *vrf = netdev_priv(dev);
236 struct vrf_map_elem *new_me, *me;
237 u32 table_id = vrf->tb_id;
238 bool free_new_me = false;
239 int users;
240 int res;
241
242 /* we pre-allocate elements used in the spin-locked section (so that we
243 * keep the spinlock as short as possible).
244 */
245 new_me = vrf_map_elem_alloc(GFP_KERNEL);
246 if (!new_me)
247 return -ENOMEM;
248
249 vrf_map_elem_init(new_me, table_id, dev->ifindex, 0);
250
251 vrf_map_lock(vmap);
252
253 me = vrf_map_lookup_elem(vmap, table_id);
254 if (!me) {
255 me = new_me;
256 vrf_map_add_elem(vmap, me);
257 goto link_vrf;
258 }
259
260 /* we already have an entry in the vrf_map, so it means there is (at
261 * least) a vrf registered on the specific table.
262 */
263 free_new_me = true;
264 if (vmap->strict_mode) {
265 /* vrfs cannot share the same table */
266 NL_SET_ERR_MSG(extack, "Table is used by another VRF");
267 res = -EBUSY;
268 goto unlock;
269 }
270
271link_vrf:
272 users = ++me->users;
273 if (users == 2)
274 ++vmap->shared_tables;
275
276 list_add(&vrf->me_list, &me->vrf_list);
277
278 res = 0;
279
280unlock:
281 vrf_map_unlock(vmap);
282
283 /* clean-up, if needed */
284 if (free_new_me)
285 vrf_map_elem_free(new_me);
286
287 return res;
288}
289
290/* called with rtnl lock held */
291static void vrf_map_unregister_dev(struct net_device *dev)
292{
293 struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
294 struct net_vrf *vrf = netdev_priv(dev);
295 u32 table_id = vrf->tb_id;
296 struct vrf_map_elem *me;
297 int users;
298
299 vrf_map_lock(vmap);
300
301 me = vrf_map_lookup_elem(vmap, table_id);
302 if (!me)
303 goto unlock;
304
305 list_del(&vrf->me_list);
306
307 users = --me->users;
308 if (users == 1) {
309 --vmap->shared_tables;
310 } else if (users == 0) {
311 vrf_map_del_elem(me);
312
313 /* no one will refer to this element anymore */
314 vrf_map_elem_free(me);
315 }
316
317unlock:
318 vrf_map_unlock(vmap);
319}
320
321/* return the vrf device index associated with the table_id */
322static int vrf_ifindex_lookup_by_table_id(struct net *net, u32 table_id)
323{
324 struct vrf_map *vmap = netns_vrf_map(net);
325 struct vrf_map_elem *me;
326 int ifindex;
327
328 vrf_map_lock(vmap);
329
330 if (!vmap->strict_mode) {
331 ifindex = -EPERM;
332 goto unlock;
333 }
334
335 me = vrf_map_lookup_elem(vmap, table_id);
336 if (!me) {
337 ifindex = -ENODEV;
338 goto unlock;
339 }
340
341 ifindex = vrf_map_elem_get_vrf_ifindex(me);
342
343unlock:
344 vrf_map_unlock(vmap);
345
346 return ifindex;
347}
348
349/* by default VRF devices do not have a qdisc and are expected
350 * to be created with only a single queue.
351 */
352static bool qdisc_tx_is_default(const struct net_device *dev)
353{
354 struct netdev_queue *txq;
355 struct Qdisc *qdisc;
356
357 if (dev->num_tx_queues > 1)
358 return false;
359
360 txq = netdev_get_tx_queue(dev, 0);
361 qdisc = rcu_access_pointer(txq->qdisc);
362
363 return !qdisc->enqueue;
364}
365
366/* Local traffic destined to local address. Reinsert the packet to rx
367 * path, similar to loopback handling.
368 */
369static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
370 struct dst_entry *dst)
371{
372 int len = skb->len;
373
374 skb_orphan(skb);
375
376 skb_dst_set(skb, dst);
377
378 /* set pkt_type to avoid skb hitting packet taps twice -
379 * once on Tx and again in Rx processing
380 */
381 skb->pkt_type = PACKET_LOOPBACK;
382
383 skb->protocol = eth_type_trans(skb, dev);
384
385 if (likely(__netif_rx(skb) == NET_RX_SUCCESS)) {
386 vrf_rx_stats(dev, len);
387 } else {
388 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
389
390 u64_stats_update_begin(&dstats->syncp);
391 u64_stats_inc(&dstats->rx_drops);
392 u64_stats_update_end(&dstats->syncp);
393 }
394
395 return NETDEV_TX_OK;
396}
397
398static void vrf_nf_set_untracked(struct sk_buff *skb)
399{
400 if (skb_get_nfct(skb) == 0)
401 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
402}
403
404static void vrf_nf_reset_ct(struct sk_buff *skb)
405{
406 if (skb_get_nfct(skb) == IP_CT_UNTRACKED)
407 nf_reset_ct(skb);
408}
409
410#if IS_ENABLED(CONFIG_IPV6)
411static int vrf_ip6_local_out(struct net *net, struct sock *sk,
412 struct sk_buff *skb)
413{
414 int err;
415
416 vrf_nf_reset_ct(skb);
417
418 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net,
419 sk, skb, NULL, skb_dst(skb)->dev, dst_output);
420
421 if (likely(err == 1))
422 err = dst_output(net, sk, skb);
423
424 return err;
425}
426
427static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
428 struct net_device *dev)
429{
430 const struct ipv6hdr *iph;
431 struct net *net = dev_net(skb->dev);
432 struct flowi6 fl6;
433 int ret = NET_XMIT_DROP;
434 struct dst_entry *dst;
435 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
436
437 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
438 goto err;
439
440 iph = ipv6_hdr(skb);
441
442 memset(&fl6, 0, sizeof(fl6));
443 /* needed to match OIF rule */
444 fl6.flowi6_l3mdev = dev->ifindex;
445 fl6.flowi6_iif = LOOPBACK_IFINDEX;
446 fl6.daddr = iph->daddr;
447 fl6.saddr = iph->saddr;
448 fl6.flowlabel = ip6_flowinfo(iph);
449 fl6.flowi6_mark = skb->mark;
450 fl6.flowi6_proto = iph->nexthdr;
451
452 dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL);
453 if (IS_ERR(dst) || dst == dst_null)
454 goto err;
455
456 skb_dst_drop(skb);
457
458 /* if dst.dev is the VRF device again this is locally originated traffic
459 * destined to a local address. Short circuit to Rx path.
460 */
461 if (dst->dev == dev)
462 return vrf_local_xmit(skb, dev, dst);
463
464 skb_dst_set(skb, dst);
465
466 /* strip the ethernet header added for pass through VRF device */
467 __skb_pull(skb, skb_network_offset(skb));
468
469 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
470 ret = vrf_ip6_local_out(net, skb->sk, skb);
471 if (unlikely(net_xmit_eval(ret)))
472 dev->stats.tx_errors++;
473 else
474 ret = NET_XMIT_SUCCESS;
475
476 return ret;
477err:
478 vrf_tx_error(dev, skb);
479 return NET_XMIT_DROP;
480}
481#else
482static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
483 struct net_device *dev)
484{
485 vrf_tx_error(dev, skb);
486 return NET_XMIT_DROP;
487}
488#endif
489
490/* based on ip_local_out; can't use it b/c the dst is switched pointing to us */
491static int vrf_ip_local_out(struct net *net, struct sock *sk,
492 struct sk_buff *skb)
493{
494 int err;
495
496 vrf_nf_reset_ct(skb);
497
498 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
499 skb, NULL, skb_dst(skb)->dev, dst_output);
500 if (likely(err == 1))
501 err = dst_output(net, sk, skb);
502
503 return err;
504}
505
506static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
507 struct net_device *vrf_dev)
508{
509 struct iphdr *ip4h;
510 int ret = NET_XMIT_DROP;
511 struct flowi4 fl4;
512 struct net *net = dev_net(vrf_dev);
513 struct rtable *rt;
514
515 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
516 goto err;
517
518 ip4h = ip_hdr(skb);
519
520 memset(&fl4, 0, sizeof(fl4));
521 /* needed to match OIF rule */
522 fl4.flowi4_l3mdev = vrf_dev->ifindex;
523 fl4.flowi4_iif = LOOPBACK_IFINDEX;
524 fl4.flowi4_tos = inet_dscp_to_dsfield(ip4h_dscp(ip4h));
525 fl4.flowi4_flags = FLOWI_FLAG_ANYSRC;
526 fl4.flowi4_proto = ip4h->protocol;
527 fl4.daddr = ip4h->daddr;
528 fl4.saddr = ip4h->saddr;
529
530 rt = ip_route_output_flow(net, &fl4, NULL);
531 if (IS_ERR(rt))
532 goto err;
533
534 skb_dst_drop(skb);
535
536 /* if dst.dev is the VRF device again this is locally originated traffic
537 * destined to a local address. Short circuit to Rx path.
538 */
539 if (rt->dst.dev == vrf_dev)
540 return vrf_local_xmit(skb, vrf_dev, &rt->dst);
541
542 skb_dst_set(skb, &rt->dst);
543
544 /* strip the ethernet header added for pass through VRF device */
545 __skb_pull(skb, skb_network_offset(skb));
546
547 if (!ip4h->saddr) {
548 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
549 RT_SCOPE_LINK);
550 }
551
552 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
553 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
554 if (unlikely(net_xmit_eval(ret)))
555 vrf_dev->stats.tx_errors++;
556 else
557 ret = NET_XMIT_SUCCESS;
558
559out:
560 return ret;
561err:
562 vrf_tx_error(vrf_dev, skb);
563 goto out;
564}
565
566static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
567{
568 switch (skb->protocol) {
569 case htons(ETH_P_IP):
570 return vrf_process_v4_outbound(skb, dev);
571 case htons(ETH_P_IPV6):
572 return vrf_process_v6_outbound(skb, dev);
573 default:
574 vrf_tx_error(dev, skb);
575 return NET_XMIT_DROP;
576 }
577}
578
579static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
580{
581 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
582
583 int len = skb->len;
584 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
585
586 u64_stats_update_begin(&dstats->syncp);
587 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
588
589 u64_stats_inc(&dstats->tx_packets);
590 u64_stats_add(&dstats->tx_bytes, len);
591 } else {
592 u64_stats_inc(&dstats->tx_drops);
593 }
594 u64_stats_update_end(&dstats->syncp);
595
596 return ret;
597}
598
599static void vrf_finish_direct(struct sk_buff *skb)
600{
601 struct net_device *vrf_dev = skb->dev;
602
603 if (!list_empty(&vrf_dev->ptype_all) &&
604 likely(skb_headroom(skb) >= ETH_HLEN)) {
605 struct ethhdr *eth = skb_push(skb, ETH_HLEN);
606
607 ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
608 eth_zero_addr(eth->h_dest);
609 eth->h_proto = skb->protocol;
610
611 rcu_read_lock_bh();
612 dev_queue_xmit_nit(skb, vrf_dev);
613 rcu_read_unlock_bh();
614
615 skb_pull(skb, ETH_HLEN);
616 }
617
618 vrf_nf_reset_ct(skb);
619}
620
621#if IS_ENABLED(CONFIG_IPV6)
622/* modelled after ip6_finish_output2 */
623static int vrf_finish_output6(struct net *net, struct sock *sk,
624 struct sk_buff *skb)
625{
626 struct dst_entry *dst = skb_dst(skb);
627 struct net_device *dev = dst->dev;
628 const struct in6_addr *nexthop;
629 struct neighbour *neigh;
630 int ret;
631
632 vrf_nf_reset_ct(skb);
633
634 skb->protocol = htons(ETH_P_IPV6);
635 skb->dev = dev;
636
637 rcu_read_lock();
638 nexthop = rt6_nexthop(dst_rt6_info(dst), &ipv6_hdr(skb)->daddr);
639 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
640 if (unlikely(!neigh))
641 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
642 if (!IS_ERR(neigh)) {
643 sock_confirm_neigh(skb, neigh);
644 ret = neigh_output(neigh, skb, false);
645 rcu_read_unlock();
646 return ret;
647 }
648 rcu_read_unlock();
649
650 IP6_INC_STATS(dev_net(dst->dev),
651 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
652 kfree_skb(skb);
653 return -EINVAL;
654}
655
656/* modelled after ip6_output */
657static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
658{
659 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
660 net, sk, skb, NULL, skb_dst(skb)->dev,
661 vrf_finish_output6,
662 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
663}
664
665/* set dst on skb to send packet to us via dev_xmit path. Allows
666 * packet to go through device based features such as qdisc, netfilter
667 * hooks and packet sockets with skb->dev set to vrf device.
668 */
669static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev,
670 struct sk_buff *skb)
671{
672 struct net_vrf *vrf = netdev_priv(vrf_dev);
673 struct dst_entry *dst = NULL;
674 struct rt6_info *rt6;
675
676 rcu_read_lock();
677
678 rt6 = rcu_dereference(vrf->rt6);
679 if (likely(rt6)) {
680 dst = &rt6->dst;
681 dst_hold(dst);
682 }
683
684 rcu_read_unlock();
685
686 if (unlikely(!dst)) {
687 vrf_tx_error(vrf_dev, skb);
688 return NULL;
689 }
690
691 skb_dst_drop(skb);
692 skb_dst_set(skb, dst);
693
694 return skb;
695}
696
697static int vrf_output6_direct_finish(struct net *net, struct sock *sk,
698 struct sk_buff *skb)
699{
700 vrf_finish_direct(skb);
701
702 return vrf_ip6_local_out(net, sk, skb);
703}
704
705static int vrf_output6_direct(struct net *net, struct sock *sk,
706 struct sk_buff *skb)
707{
708 int err = 1;
709
710 skb->protocol = htons(ETH_P_IPV6);
711
712 if (!(IPCB(skb)->flags & IPSKB_REROUTED))
713 err = nf_hook(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb,
714 NULL, skb->dev, vrf_output6_direct_finish);
715
716 if (likely(err == 1))
717 vrf_finish_direct(skb);
718
719 return err;
720}
721
722static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk,
723 struct sk_buff *skb)
724{
725 int err;
726
727 err = vrf_output6_direct(net, sk, skb);
728 if (likely(err == 1))
729 err = vrf_ip6_local_out(net, sk, skb);
730
731 return err;
732}
733
734static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
735 struct sock *sk,
736 struct sk_buff *skb)
737{
738 struct net *net = dev_net(vrf_dev);
739 int err;
740
741 skb->dev = vrf_dev;
742
743 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk,
744 skb, NULL, vrf_dev, vrf_ip6_out_direct_finish);
745
746 if (likely(err == 1))
747 err = vrf_output6_direct(net, sk, skb);
748
749 if (likely(err == 1))
750 return skb;
751
752 return NULL;
753}
754
755static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
756 struct sock *sk,
757 struct sk_buff *skb)
758{
759 /* don't divert link scope packets */
760 if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
761 return skb;
762
763 vrf_nf_set_untracked(skb);
764
765 if (qdisc_tx_is_default(vrf_dev) ||
766 IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
767 return vrf_ip6_out_direct(vrf_dev, sk, skb);
768
769 return vrf_ip6_out_redirect(vrf_dev, skb);
770}
771
772/* holding rtnl */
773static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
774{
775 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
776 struct net *net = dev_net(dev);
777 struct dst_entry *dst;
778
779 RCU_INIT_POINTER(vrf->rt6, NULL);
780 synchronize_rcu();
781
782 /* move dev in dst's to loopback so this VRF device can be deleted
783 * - based on dst_ifdown
784 */
785 if (rt6) {
786 dst = &rt6->dst;
787 netdev_ref_replace(dst->dev, net->loopback_dev,
788 &dst->dev_tracker, GFP_KERNEL);
789 dst->dev = net->loopback_dev;
790 dst_release(dst);
791 }
792}
793
794static int vrf_rt6_create(struct net_device *dev)
795{
796 int flags = DST_NOPOLICY | DST_NOXFRM;
797 struct net_vrf *vrf = netdev_priv(dev);
798 struct net *net = dev_net(dev);
799 struct rt6_info *rt6;
800 int rc = -ENOMEM;
801
802 /* IPv6 can be CONFIG enabled and then disabled runtime */
803 if (!ipv6_mod_enabled())
804 return 0;
805
806 vrf->fib6_table = fib6_new_table(net, vrf->tb_id);
807 if (!vrf->fib6_table)
808 goto out;
809
810 /* create a dst for routing packets out a VRF device */
811 rt6 = ip6_dst_alloc(net, dev, flags);
812 if (!rt6)
813 goto out;
814
815 rt6->dst.output = vrf_output6;
816
817 rcu_assign_pointer(vrf->rt6, rt6);
818
819 rc = 0;
820out:
821 return rc;
822}
823#else
824static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
825 struct sock *sk,
826 struct sk_buff *skb)
827{
828 return skb;
829}
830
831static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
832{
833}
834
835static int vrf_rt6_create(struct net_device *dev)
836{
837 return 0;
838}
839#endif
840
841/* modelled after ip_finish_output2 */
842static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
843{
844 struct dst_entry *dst = skb_dst(skb);
845 struct rtable *rt = dst_rtable(dst);
846 struct net_device *dev = dst->dev;
847 unsigned int hh_len = LL_RESERVED_SPACE(dev);
848 struct neighbour *neigh;
849 bool is_v6gw = false;
850
851 vrf_nf_reset_ct(skb);
852
853 /* Be paranoid, rather than too clever. */
854 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
855 skb = skb_expand_head(skb, hh_len);
856 if (!skb) {
857 dev->stats.tx_errors++;
858 return -ENOMEM;
859 }
860 }
861
862 rcu_read_lock();
863
864 neigh = ip_neigh_for_gw(rt, skb, &is_v6gw);
865 if (!IS_ERR(neigh)) {
866 int ret;
867
868 sock_confirm_neigh(skb, neigh);
869 /* if crossing protocols, can not use the cached header */
870 ret = neigh_output(neigh, skb, is_v6gw);
871 rcu_read_unlock();
872 return ret;
873 }
874
875 rcu_read_unlock();
876 vrf_tx_error(skb->dev, skb);
877 return -EINVAL;
878}
879
880static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
881{
882 struct net_device *dev = skb_dst(skb)->dev;
883
884 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
885
886 skb->dev = dev;
887 skb->protocol = htons(ETH_P_IP);
888
889 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
890 net, sk, skb, NULL, dev,
891 vrf_finish_output,
892 !(IPCB(skb)->flags & IPSKB_REROUTED));
893}
894
895/* set dst on skb to send packet to us via dev_xmit path. Allows
896 * packet to go through device based features such as qdisc, netfilter
897 * hooks and packet sockets with skb->dev set to vrf device.
898 */
899static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev,
900 struct sk_buff *skb)
901{
902 struct net_vrf *vrf = netdev_priv(vrf_dev);
903 struct dst_entry *dst = NULL;
904 struct rtable *rth;
905
906 rcu_read_lock();
907
908 rth = rcu_dereference(vrf->rth);
909 if (likely(rth)) {
910 dst = &rth->dst;
911 dst_hold(dst);
912 }
913
914 rcu_read_unlock();
915
916 if (unlikely(!dst)) {
917 vrf_tx_error(vrf_dev, skb);
918 return NULL;
919 }
920
921 skb_dst_drop(skb);
922 skb_dst_set(skb, dst);
923
924 return skb;
925}
926
927static int vrf_output_direct_finish(struct net *net, struct sock *sk,
928 struct sk_buff *skb)
929{
930 vrf_finish_direct(skb);
931
932 return vrf_ip_local_out(net, sk, skb);
933}
934
935static int vrf_output_direct(struct net *net, struct sock *sk,
936 struct sk_buff *skb)
937{
938 int err = 1;
939
940 skb->protocol = htons(ETH_P_IP);
941
942 if (!(IPCB(skb)->flags & IPSKB_REROUTED))
943 err = nf_hook(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb,
944 NULL, skb->dev, vrf_output_direct_finish);
945
946 if (likely(err == 1))
947 vrf_finish_direct(skb);
948
949 return err;
950}
951
952static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk,
953 struct sk_buff *skb)
954{
955 int err;
956
957 err = vrf_output_direct(net, sk, skb);
958 if (likely(err == 1))
959 err = vrf_ip_local_out(net, sk, skb);
960
961 return err;
962}
963
964static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
965 struct sock *sk,
966 struct sk_buff *skb)
967{
968 struct net *net = dev_net(vrf_dev);
969 int err;
970
971 skb->dev = vrf_dev;
972
973 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
974 skb, NULL, vrf_dev, vrf_ip_out_direct_finish);
975
976 if (likely(err == 1))
977 err = vrf_output_direct(net, sk, skb);
978
979 if (likely(err == 1))
980 return skb;
981
982 return NULL;
983}
984
985static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
986 struct sock *sk,
987 struct sk_buff *skb)
988{
989 /* don't divert multicast or local broadcast */
990 if (ipv4_is_multicast(ip_hdr(skb)->daddr) ||
991 ipv4_is_lbcast(ip_hdr(skb)->daddr))
992 return skb;
993
994 vrf_nf_set_untracked(skb);
995
996 if (qdisc_tx_is_default(vrf_dev) ||
997 IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
998 return vrf_ip_out_direct(vrf_dev, sk, skb);
999
1000 return vrf_ip_out_redirect(vrf_dev, skb);
1001}
1002
1003/* called with rcu lock held */
1004static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
1005 struct sock *sk,
1006 struct sk_buff *skb,
1007 u16 proto)
1008{
1009 switch (proto) {
1010 case AF_INET:
1011 return vrf_ip_out(vrf_dev, sk, skb);
1012 case AF_INET6:
1013 return vrf_ip6_out(vrf_dev, sk, skb);
1014 }
1015
1016 return skb;
1017}
1018
1019/* holding rtnl */
1020static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
1021{
1022 struct rtable *rth = rtnl_dereference(vrf->rth);
1023 struct net *net = dev_net(dev);
1024 struct dst_entry *dst;
1025
1026 RCU_INIT_POINTER(vrf->rth, NULL);
1027 synchronize_rcu();
1028
1029 /* move dev in dst's to loopback so this VRF device can be deleted
1030 * - based on dst_ifdown
1031 */
1032 if (rth) {
1033 dst = &rth->dst;
1034 netdev_ref_replace(dst->dev, net->loopback_dev,
1035 &dst->dev_tracker, GFP_KERNEL);
1036 dst->dev = net->loopback_dev;
1037 dst_release(dst);
1038 }
1039}
1040
1041static int vrf_rtable_create(struct net_device *dev)
1042{
1043 struct net_vrf *vrf = netdev_priv(dev);
1044 struct rtable *rth;
1045
1046 if (!fib_new_table(dev_net(dev), vrf->tb_id))
1047 return -ENOMEM;
1048
1049 /* create a dst for routing packets out through a VRF device */
1050 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1);
1051 if (!rth)
1052 return -ENOMEM;
1053
1054 rth->dst.output = vrf_output;
1055
1056 rcu_assign_pointer(vrf->rth, rth);
1057
1058 return 0;
1059}
1060
1061/**************************** device handling ********************/
1062
1063/* cycle interface to flush neighbor cache and move routes across tables */
1064static void cycle_netdev(struct net_device *dev,
1065 struct netlink_ext_ack *extack)
1066{
1067 unsigned int flags = dev->flags;
1068 int ret;
1069
1070 if (!netif_running(dev))
1071 return;
1072
1073 ret = dev_change_flags(dev, flags & ~IFF_UP, extack);
1074 if (ret >= 0)
1075 ret = dev_change_flags(dev, flags, extack);
1076
1077 if (ret < 0) {
1078 netdev_err(dev,
1079 "Failed to cycle device %s; route tables might be wrong!\n",
1080 dev->name);
1081 }
1082}
1083
1084static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1085 struct netlink_ext_ack *extack)
1086{
1087 int ret;
1088
1089 /* do not allow loopback device to be enslaved to a VRF.
1090 * The vrf device acts as the loopback for the vrf.
1091 */
1092 if (port_dev == dev_net(dev)->loopback_dev) {
1093 NL_SET_ERR_MSG(extack,
1094 "Can not enslave loopback device to a VRF");
1095 return -EOPNOTSUPP;
1096 }
1097
1098 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
1099 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack);
1100 if (ret < 0)
1101 goto err;
1102
1103 cycle_netdev(port_dev, extack);
1104
1105 return 0;
1106
1107err:
1108 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1109 return ret;
1110}
1111
1112static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1113 struct netlink_ext_ack *extack)
1114{
1115 if (netif_is_l3_master(port_dev)) {
1116 NL_SET_ERR_MSG(extack,
1117 "Can not enslave an L3 master device to a VRF");
1118 return -EINVAL;
1119 }
1120
1121 if (netif_is_l3_slave(port_dev))
1122 return -EINVAL;
1123
1124 return do_vrf_add_slave(dev, port_dev, extack);
1125}
1126
1127/* inverse of do_vrf_add_slave */
1128static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1129{
1130 netdev_upper_dev_unlink(port_dev, dev);
1131 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1132
1133 cycle_netdev(port_dev, NULL);
1134
1135 return 0;
1136}
1137
1138static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1139{
1140 return do_vrf_del_slave(dev, port_dev);
1141}
1142
1143static void vrf_dev_uninit(struct net_device *dev)
1144{
1145 struct net_vrf *vrf = netdev_priv(dev);
1146
1147 vrf_rtable_release(dev, vrf);
1148 vrf_rt6_release(dev, vrf);
1149}
1150
1151static int vrf_dev_init(struct net_device *dev)
1152{
1153 struct net_vrf *vrf = netdev_priv(dev);
1154
1155 /* create the default dst which points back to us */
1156 if (vrf_rtable_create(dev) != 0)
1157 goto out_nomem;
1158
1159 if (vrf_rt6_create(dev) != 0)
1160 goto out_rth;
1161
1162 dev->flags = IFF_MASTER | IFF_NOARP;
1163
1164 /* similarly, oper state is irrelevant; set to up to avoid confusion */
1165 dev->operstate = IF_OPER_UP;
1166 netdev_lockdep_set_classes(dev);
1167 return 0;
1168
1169out_rth:
1170 vrf_rtable_release(dev, vrf);
1171out_nomem:
1172 return -ENOMEM;
1173}
1174
1175static const struct net_device_ops vrf_netdev_ops = {
1176 .ndo_init = vrf_dev_init,
1177 .ndo_uninit = vrf_dev_uninit,
1178 .ndo_start_xmit = vrf_xmit,
1179 .ndo_set_mac_address = eth_mac_addr,
1180 .ndo_add_slave = vrf_add_slave,
1181 .ndo_del_slave = vrf_del_slave,
1182};
1183
1184static u32 vrf_fib_table(const struct net_device *dev)
1185{
1186 struct net_vrf *vrf = netdev_priv(dev);
1187
1188 return vrf->tb_id;
1189}
1190
1191static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
1192{
1193 kfree_skb(skb);
1194 return 0;
1195}
1196
1197static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
1198 struct sk_buff *skb,
1199 struct net_device *dev)
1200{
1201 struct net *net = dev_net(dev);
1202
1203 if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1)
1204 skb = NULL; /* kfree_skb(skb) handled by nf code */
1205
1206 return skb;
1207}
1208
1209static int vrf_prepare_mac_header(struct sk_buff *skb,
1210 struct net_device *vrf_dev, u16 proto)
1211{
1212 struct ethhdr *eth;
1213 int err;
1214
1215 /* in general, we do not know if there is enough space in the head of
1216 * the packet for hosting the mac header.
1217 */
1218 err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev));
1219 if (unlikely(err))
1220 /* no space in the skb head */
1221 return -ENOBUFS;
1222
1223 __skb_push(skb, ETH_HLEN);
1224 eth = (struct ethhdr *)skb->data;
1225
1226 skb_reset_mac_header(skb);
1227 skb_reset_mac_len(skb);
1228
1229 /* we set the ethernet destination and the source addresses to the
1230 * address of the VRF device.
1231 */
1232 ether_addr_copy(eth->h_dest, vrf_dev->dev_addr);
1233 ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
1234 eth->h_proto = htons(proto);
1235
1236 /* the destination address of the Ethernet frame corresponds to the
1237 * address set on the VRF interface; therefore, the packet is intended
1238 * to be processed locally.
1239 */
1240 skb->protocol = eth->h_proto;
1241 skb->pkt_type = PACKET_HOST;
1242
1243 skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
1244
1245 skb_pull_inline(skb, ETH_HLEN);
1246
1247 return 0;
1248}
1249
1250/* prepare and add the mac header to the packet if it was not set previously.
1251 * In this way, packet sniffers such as tcpdump can parse the packet correctly.
1252 * If the mac header was already set, the original mac header is left
1253 * untouched and the function returns immediately.
1254 */
1255static int vrf_add_mac_header_if_unset(struct sk_buff *skb,
1256 struct net_device *vrf_dev,
1257 u16 proto, struct net_device *orig_dev)
1258{
1259 if (skb_mac_header_was_set(skb) && dev_has_header(orig_dev))
1260 return 0;
1261
1262 return vrf_prepare_mac_header(skb, vrf_dev, proto);
1263}
1264
1265#if IS_ENABLED(CONFIG_IPV6)
1266/* neighbor handling is done with actual device; do not want
1267 * to flip skb->dev for those ndisc packets. This really fails
1268 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
1269 * a start.
1270 */
1271static bool ipv6_ndisc_frame(const struct sk_buff *skb)
1272{
1273 const struct ipv6hdr *iph = ipv6_hdr(skb);
1274 bool rc = false;
1275
1276 if (iph->nexthdr == NEXTHDR_ICMP) {
1277 const struct icmp6hdr *icmph;
1278 struct icmp6hdr _icmph;
1279
1280 icmph = skb_header_pointer(skb, sizeof(*iph),
1281 sizeof(_icmph), &_icmph);
1282 if (!icmph)
1283 goto out;
1284
1285 switch (icmph->icmp6_type) {
1286 case NDISC_ROUTER_SOLICITATION:
1287 case NDISC_ROUTER_ADVERTISEMENT:
1288 case NDISC_NEIGHBOUR_SOLICITATION:
1289 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1290 case NDISC_REDIRECT:
1291 rc = true;
1292 break;
1293 }
1294 }
1295
1296out:
1297 return rc;
1298}
1299
1300static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
1301 const struct net_device *dev,
1302 struct flowi6 *fl6,
1303 int ifindex,
1304 const struct sk_buff *skb,
1305 int flags)
1306{
1307 struct net_vrf *vrf = netdev_priv(dev);
1308
1309 return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags);
1310}
1311
1312static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
1313 int ifindex)
1314{
1315 const struct ipv6hdr *iph = ipv6_hdr(skb);
1316 struct flowi6 fl6 = {
1317 .flowi6_iif = ifindex,
1318 .flowi6_mark = skb->mark,
1319 .flowi6_proto = iph->nexthdr,
1320 .daddr = iph->daddr,
1321 .saddr = iph->saddr,
1322 .flowlabel = ip6_flowinfo(iph),
1323 };
1324 struct net *net = dev_net(vrf_dev);
1325 struct rt6_info *rt6;
1326
1327 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb,
1328 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
1329 if (unlikely(!rt6))
1330 return;
1331
1332 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
1333 return;
1334
1335 skb_dst_set(skb, &rt6->dst);
1336}
1337
1338static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1339 struct sk_buff *skb)
1340{
1341 int orig_iif = skb->skb_iif;
1342 bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
1343 bool is_ndisc = ipv6_ndisc_frame(skb);
1344
1345 /* loopback, multicast & non-ND link-local traffic; do not push through
1346 * packet taps again. Reset pkt_type for upper layers to process skb.
1347 * For non-loopback strict packets, determine the dst using the original
1348 * ifindex.
1349 */
1350 if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) {
1351 skb->dev = vrf_dev;
1352 skb->skb_iif = vrf_dev->ifindex;
1353 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1354
1355 if (skb->pkt_type == PACKET_LOOPBACK)
1356 skb->pkt_type = PACKET_HOST;
1357 else
1358 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1359
1360 goto out;
1361 }
1362
1363 /* if packet is NDISC then keep the ingress interface */
1364 if (!is_ndisc) {
1365 struct net_device *orig_dev = skb->dev;
1366
1367 vrf_rx_stats(vrf_dev, skb->len);
1368 skb->dev = vrf_dev;
1369 skb->skb_iif = vrf_dev->ifindex;
1370
1371 if (!list_empty(&vrf_dev->ptype_all)) {
1372 int err;
1373
1374 err = vrf_add_mac_header_if_unset(skb, vrf_dev,
1375 ETH_P_IPV6,
1376 orig_dev);
1377 if (likely(!err)) {
1378 skb_push(skb, skb->mac_len);
1379 dev_queue_xmit_nit(skb, vrf_dev);
1380 skb_pull(skb, skb->mac_len);
1381 }
1382 }
1383
1384 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1385 }
1386
1387 if (need_strict)
1388 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1389
1390 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
1391out:
1392 return skb;
1393}
1394
1395#else
1396static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1397 struct sk_buff *skb)
1398{
1399 return skb;
1400}
1401#endif
1402
1403static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
1404 struct sk_buff *skb)
1405{
1406 struct net_device *orig_dev = skb->dev;
1407
1408 skb->dev = vrf_dev;
1409 skb->skb_iif = vrf_dev->ifindex;
1410 IPCB(skb)->flags |= IPSKB_L3SLAVE;
1411
1412 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
1413 goto out;
1414
1415 /* loopback traffic; do not push through packet taps again.
1416 * Reset pkt_type for upper layers to process skb
1417 */
1418 if (skb->pkt_type == PACKET_LOOPBACK) {
1419 skb->pkt_type = PACKET_HOST;
1420 goto out;
1421 }
1422
1423 vrf_rx_stats(vrf_dev, skb->len);
1424
1425 if (!list_empty(&vrf_dev->ptype_all)) {
1426 int err;
1427
1428 err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP,
1429 orig_dev);
1430 if (likely(!err)) {
1431 skb_push(skb, skb->mac_len);
1432 dev_queue_xmit_nit(skb, vrf_dev);
1433 skb_pull(skb, skb->mac_len);
1434 }
1435 }
1436
1437 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
1438out:
1439 return skb;
1440}
1441
1442/* called with rcu lock held */
1443static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1444 struct sk_buff *skb,
1445 u16 proto)
1446{
1447 switch (proto) {
1448 case AF_INET:
1449 return vrf_ip_rcv(vrf_dev, skb);
1450 case AF_INET6:
1451 return vrf_ip6_rcv(vrf_dev, skb);
1452 }
1453
1454 return skb;
1455}
1456
1457#if IS_ENABLED(CONFIG_IPV6)
1458/* send to link-local or multicast address via interface enslaved to
1459 * VRF device. Force lookup to VRF table without changing flow struct
1460 * Note: Caller to this function must hold rcu_read_lock() and no refcnt
1461 * is taken on the dst by this function.
1462 */
1463static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1464 struct flowi6 *fl6)
1465{
1466 struct net *net = dev_net(dev);
1467 int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF;
1468 struct dst_entry *dst = NULL;
1469 struct rt6_info *rt;
1470
1471 /* VRF device does not have a link-local address and
1472 * sending packets to link-local or mcast addresses over
1473 * a VRF device does not make sense
1474 */
1475 if (fl6->flowi6_oif == dev->ifindex) {
1476 dst = &net->ipv6.ip6_null_entry->dst;
1477 return dst;
1478 }
1479
1480 if (!ipv6_addr_any(&fl6->saddr))
1481 flags |= RT6_LOOKUP_F_HAS_SADDR;
1482
1483 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags);
1484 if (rt)
1485 dst = &rt->dst;
1486
1487 return dst;
1488}
1489#endif
1490
1491static const struct l3mdev_ops vrf_l3mdev_ops = {
1492 .l3mdev_fib_table = vrf_fib_table,
1493 .l3mdev_l3_rcv = vrf_l3_rcv,
1494 .l3mdev_l3_out = vrf_l3_out,
1495#if IS_ENABLED(CONFIG_IPV6)
1496 .l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1497#endif
1498};
1499
1500static void vrf_get_drvinfo(struct net_device *dev,
1501 struct ethtool_drvinfo *info)
1502{
1503 strscpy(info->driver, DRV_NAME, sizeof(info->driver));
1504 strscpy(info->version, DRV_VERSION, sizeof(info->version));
1505}
1506
1507static const struct ethtool_ops vrf_ethtool_ops = {
1508 .get_drvinfo = vrf_get_drvinfo,
1509};
1510
1511static inline size_t vrf_fib_rule_nl_size(void)
1512{
1513 size_t sz;
1514
1515 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1516 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */
1517 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */
1518 sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */
1519
1520 return sz;
1521}
1522
1523static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1524{
1525 struct fib_rule_hdr *frh;
1526 struct nlmsghdr *nlh;
1527 struct sk_buff *skb;
1528 int err;
1529
1530 if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) &&
1531 !ipv6_mod_enabled())
1532 return 0;
1533
1534 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
1535 if (!skb)
1536 return -ENOMEM;
1537
1538 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
1539 if (!nlh)
1540 goto nla_put_failure;
1541
1542 /* rule only needs to appear once */
1543 nlh->nlmsg_flags |= NLM_F_EXCL;
1544
1545 frh = nlmsg_data(nlh);
1546 memset(frh, 0, sizeof(*frh));
1547 frh->family = family;
1548 frh->action = FR_ACT_TO_TBL;
1549
1550 if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL))
1551 goto nla_put_failure;
1552
1553 if (nla_put_u8(skb, FRA_L3MDEV, 1))
1554 goto nla_put_failure;
1555
1556 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
1557 goto nla_put_failure;
1558
1559 nlmsg_end(skb, nlh);
1560
1561 /* fib_nl_{new,del}rule handling looks for net from skb->sk */
1562 skb->sk = dev_net(dev)->rtnl;
1563 if (add_it) {
1564 err = fib_nl_newrule(skb, nlh, NULL);
1565 if (err == -EEXIST)
1566 err = 0;
1567 } else {
1568 err = fib_nl_delrule(skb, nlh, NULL);
1569 if (err == -ENOENT)
1570 err = 0;
1571 }
1572 nlmsg_free(skb);
1573
1574 return err;
1575
1576nla_put_failure:
1577 nlmsg_free(skb);
1578
1579 return -EMSGSIZE;
1580}
1581
1582static int vrf_add_fib_rules(const struct net_device *dev)
1583{
1584 int err;
1585
1586 err = vrf_fib_rule(dev, AF_INET, true);
1587 if (err < 0)
1588 goto out_err;
1589
1590 err = vrf_fib_rule(dev, AF_INET6, true);
1591 if (err < 0)
1592 goto ipv6_err;
1593
1594#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1595 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true);
1596 if (err < 0)
1597 goto ipmr_err;
1598#endif
1599
1600#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1601 err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, true);
1602 if (err < 0)
1603 goto ip6mr_err;
1604#endif
1605
1606 return 0;
1607
1608#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1609ip6mr_err:
1610 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, false);
1611#endif
1612
1613#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1614ipmr_err:
1615 vrf_fib_rule(dev, AF_INET6, false);
1616#endif
1617
1618ipv6_err:
1619 vrf_fib_rule(dev, AF_INET, false);
1620
1621out_err:
1622 netdev_err(dev, "Failed to add FIB rules.\n");
1623 return err;
1624}
1625
1626static void vrf_setup(struct net_device *dev)
1627{
1628 ether_setup(dev);
1629
1630 /* Initialize the device structure. */
1631 dev->netdev_ops = &vrf_netdev_ops;
1632 dev->l3mdev_ops = &vrf_l3mdev_ops;
1633 dev->ethtool_ops = &vrf_ethtool_ops;
1634 dev->needs_free_netdev = true;
1635
1636 /* Fill in device structure with ethernet-generic values. */
1637 eth_hw_addr_random(dev);
1638
1639 /* don't acquire vrf device's netif_tx_lock when transmitting */
1640 dev->lltx = true;
1641
1642 /* don't allow vrf devices to change network namespaces. */
1643 dev->netns_local = true;
1644
1645 /* does not make sense for a VLAN to be added to a vrf device */
1646 dev->features |= NETIF_F_VLAN_CHALLENGED;
1647
1648 /* enable offload features */
1649 dev->features |= NETIF_F_GSO_SOFTWARE;
1650 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC;
1651 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1652
1653 dev->hw_features = dev->features;
1654 dev->hw_enc_features = dev->features;
1655
1656 /* default to no qdisc; user can add if desired */
1657 dev->priv_flags |= IFF_NO_QUEUE;
1658 dev->priv_flags |= IFF_NO_RX_HANDLER;
1659 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1660
1661 /* VRF devices do not care about MTU, but if the MTU is set
1662 * too low then the ipv4 and ipv6 protocols are disabled
1663 * which breaks networking.
1664 */
1665 dev->min_mtu = IPV6_MIN_MTU;
1666 dev->max_mtu = IP6_MAX_MTU;
1667 dev->mtu = dev->max_mtu;
1668
1669 dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS;
1670}
1671
1672static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],
1673 struct netlink_ext_ack *extack)
1674{
1675 if (tb[IFLA_ADDRESS]) {
1676 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
1677 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1678 return -EINVAL;
1679 }
1680 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
1681 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1682 return -EADDRNOTAVAIL;
1683 }
1684 }
1685 return 0;
1686}
1687
1688static void vrf_dellink(struct net_device *dev, struct list_head *head)
1689{
1690 struct net_device *port_dev;
1691 struct list_head *iter;
1692
1693 netdev_for_each_lower_dev(dev, port_dev, iter)
1694 vrf_del_slave(dev, port_dev);
1695
1696 vrf_map_unregister_dev(dev);
1697
1698 unregister_netdevice_queue(dev, head);
1699}
1700
1701static int vrf_newlink(struct net *src_net, struct net_device *dev,
1702 struct nlattr *tb[], struct nlattr *data[],
1703 struct netlink_ext_ack *extack)
1704{
1705 struct net_vrf *vrf = netdev_priv(dev);
1706 struct netns_vrf *nn_vrf;
1707 bool *add_fib_rules;
1708 struct net *net;
1709 int err;
1710
1711 if (!data || !data[IFLA_VRF_TABLE]) {
1712 NL_SET_ERR_MSG(extack, "VRF table id is missing");
1713 return -EINVAL;
1714 }
1715
1716 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
1717 if (vrf->tb_id == RT_TABLE_UNSPEC) {
1718 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE],
1719 "Invalid VRF table id");
1720 return -EINVAL;
1721 }
1722
1723 dev->priv_flags |= IFF_L3MDEV_MASTER;
1724
1725 err = register_netdevice(dev);
1726 if (err)
1727 goto out;
1728
1729 /* mapping between table_id and vrf;
1730 * note: such binding could not be done in the dev init function
1731 * because dev->ifindex id is not available yet.
1732 */
1733 vrf->ifindex = dev->ifindex;
1734
1735 err = vrf_map_register_dev(dev, extack);
1736 if (err) {
1737 unregister_netdevice(dev);
1738 goto out;
1739 }
1740
1741 net = dev_net(dev);
1742 nn_vrf = net_generic(net, vrf_net_id);
1743
1744 add_fib_rules = &nn_vrf->add_fib_rules;
1745 if (*add_fib_rules) {
1746 err = vrf_add_fib_rules(dev);
1747 if (err) {
1748 vrf_map_unregister_dev(dev);
1749 unregister_netdevice(dev);
1750 goto out;
1751 }
1752 *add_fib_rules = false;
1753 }
1754
1755out:
1756 return err;
1757}
1758
1759static size_t vrf_nl_getsize(const struct net_device *dev)
1760{
1761 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
1762}
1763
1764static int vrf_fillinfo(struct sk_buff *skb,
1765 const struct net_device *dev)
1766{
1767 struct net_vrf *vrf = netdev_priv(dev);
1768
1769 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
1770}
1771
1772static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1773 const struct net_device *slave_dev)
1774{
1775 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1776}
1777
1778static int vrf_fill_slave_info(struct sk_buff *skb,
1779 const struct net_device *vrf_dev,
1780 const struct net_device *slave_dev)
1781{
1782 struct net_vrf *vrf = netdev_priv(vrf_dev);
1783
1784 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
1785 return -EMSGSIZE;
1786
1787 return 0;
1788}
1789
1790static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1791 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1792};
1793
1794static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1795 .kind = DRV_NAME,
1796 .priv_size = sizeof(struct net_vrf),
1797
1798 .get_size = vrf_nl_getsize,
1799 .policy = vrf_nl_policy,
1800 .validate = vrf_validate,
1801 .fill_info = vrf_fillinfo,
1802
1803 .get_slave_size = vrf_get_slave_size,
1804 .fill_slave_info = vrf_fill_slave_info,
1805
1806 .newlink = vrf_newlink,
1807 .dellink = vrf_dellink,
1808 .setup = vrf_setup,
1809 .maxtype = IFLA_VRF_MAX,
1810};
1811
1812static int vrf_device_event(struct notifier_block *unused,
1813 unsigned long event, void *ptr)
1814{
1815 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1816
1817 /* only care about unregister events to drop slave references */
1818 if (event == NETDEV_UNREGISTER) {
1819 struct net_device *vrf_dev;
1820
1821 if (!netif_is_l3_slave(dev))
1822 goto out;
1823
1824 vrf_dev = netdev_master_upper_dev_get(dev);
1825 vrf_del_slave(vrf_dev, dev);
1826 }
1827out:
1828 return NOTIFY_DONE;
1829}
1830
1831static struct notifier_block vrf_notifier_block __read_mostly = {
1832 .notifier_call = vrf_device_event,
1833};
1834
1835static int vrf_map_init(struct vrf_map *vmap)
1836{
1837 spin_lock_init(&vmap->vmap_lock);
1838 hash_init(vmap->ht);
1839
1840 vmap->strict_mode = false;
1841
1842 return 0;
1843}
1844
1845#ifdef CONFIG_SYSCTL
1846static bool vrf_strict_mode(struct vrf_map *vmap)
1847{
1848 bool strict_mode;
1849
1850 vrf_map_lock(vmap);
1851 strict_mode = vmap->strict_mode;
1852 vrf_map_unlock(vmap);
1853
1854 return strict_mode;
1855}
1856
1857static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode)
1858{
1859 bool *cur_mode;
1860 int res = 0;
1861
1862 vrf_map_lock(vmap);
1863
1864 cur_mode = &vmap->strict_mode;
1865 if (*cur_mode == new_mode)
1866 goto unlock;
1867
1868 if (*cur_mode) {
1869 /* disable strict mode */
1870 *cur_mode = false;
1871 } else {
1872 if (vmap->shared_tables) {
1873 /* we cannot allow strict_mode because there are some
1874 * vrfs that share one or more tables.
1875 */
1876 res = -EBUSY;
1877 goto unlock;
1878 }
1879
1880 /* no tables are shared among vrfs, so we can go back
1881 * to 1:1 association between a vrf with its table.
1882 */
1883 *cur_mode = true;
1884 }
1885
1886unlock:
1887 vrf_map_unlock(vmap);
1888
1889 return res;
1890}
1891
1892static int vrf_shared_table_handler(const struct ctl_table *table, int write,
1893 void *buffer, size_t *lenp, loff_t *ppos)
1894{
1895 struct net *net = (struct net *)table->extra1;
1896 struct vrf_map *vmap = netns_vrf_map(net);
1897 int proc_strict_mode = 0;
1898 struct ctl_table tmp = {
1899 .procname = table->procname,
1900 .data = &proc_strict_mode,
1901 .maxlen = sizeof(int),
1902 .mode = table->mode,
1903 .extra1 = SYSCTL_ZERO,
1904 .extra2 = SYSCTL_ONE,
1905 };
1906 int ret;
1907
1908 if (!write)
1909 proc_strict_mode = vrf_strict_mode(vmap);
1910
1911 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
1912
1913 if (write && ret == 0)
1914 ret = vrf_strict_mode_change(vmap, (bool)proc_strict_mode);
1915
1916 return ret;
1917}
1918
1919static const struct ctl_table vrf_table[] = {
1920 {
1921 .procname = "strict_mode",
1922 .data = NULL,
1923 .maxlen = sizeof(int),
1924 .mode = 0644,
1925 .proc_handler = vrf_shared_table_handler,
1926 /* set by the vrf_netns_init */
1927 .extra1 = NULL,
1928 },
1929};
1930
1931static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1932{
1933 struct ctl_table *table;
1934
1935 table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL);
1936 if (!table)
1937 return -ENOMEM;
1938
1939 /* init the extra1 parameter with the reference to current netns */
1940 table[0].extra1 = net;
1941
1942 nn_vrf->ctl_hdr = register_net_sysctl_sz(net, "net/vrf", table,
1943 ARRAY_SIZE(vrf_table));
1944 if (!nn_vrf->ctl_hdr) {
1945 kfree(table);
1946 return -ENOMEM;
1947 }
1948
1949 return 0;
1950}
1951
1952static void vrf_netns_exit_sysctl(struct net *net)
1953{
1954 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
1955 const struct ctl_table *table;
1956
1957 table = nn_vrf->ctl_hdr->ctl_table_arg;
1958 unregister_net_sysctl_table(nn_vrf->ctl_hdr);
1959 kfree(table);
1960}
1961#else
1962static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1963{
1964 return 0;
1965}
1966
1967static void vrf_netns_exit_sysctl(struct net *net)
1968{
1969}
1970#endif
1971
1972/* Initialize per network namespace state */
1973static int __net_init vrf_netns_init(struct net *net)
1974{
1975 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
1976
1977 nn_vrf->add_fib_rules = true;
1978 vrf_map_init(&nn_vrf->vmap);
1979
1980 return vrf_netns_init_sysctl(net, nn_vrf);
1981}
1982
1983static void __net_exit vrf_netns_exit(struct net *net)
1984{
1985 vrf_netns_exit_sysctl(net);
1986}
1987
1988static struct pernet_operations vrf_net_ops __net_initdata = {
1989 .init = vrf_netns_init,
1990 .exit = vrf_netns_exit,
1991 .id = &vrf_net_id,
1992 .size = sizeof(struct netns_vrf),
1993};
1994
1995static int __init vrf_init_module(void)
1996{
1997 int rc;
1998
1999 register_netdevice_notifier(&vrf_notifier_block);
2000
2001 rc = register_pernet_subsys(&vrf_net_ops);
2002 if (rc < 0)
2003 goto error;
2004
2005 rc = l3mdev_table_lookup_register(L3MDEV_TYPE_VRF,
2006 vrf_ifindex_lookup_by_table_id);
2007 if (rc < 0)
2008 goto unreg_pernet;
2009
2010 rc = rtnl_link_register(&vrf_link_ops);
2011 if (rc < 0)
2012 goto table_lookup_unreg;
2013
2014 return 0;
2015
2016table_lookup_unreg:
2017 l3mdev_table_lookup_unregister(L3MDEV_TYPE_VRF,
2018 vrf_ifindex_lookup_by_table_id);
2019
2020unreg_pernet:
2021 unregister_pernet_subsys(&vrf_net_ops);
2022
2023error:
2024 unregister_netdevice_notifier(&vrf_notifier_block);
2025 return rc;
2026}
2027
2028module_init(vrf_init_module);
2029MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
2030MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
2031MODULE_LICENSE("GPL");
2032MODULE_ALIAS_RTNL_LINK(DRV_NAME);
2033MODULE_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);