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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/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
124struct pcpu_dstats {
125 u64 tx_pkts;
126 u64 tx_bytes;
127 u64 tx_drps;
128 u64 rx_pkts;
129 u64 rx_bytes;
130 u64 rx_drps;
131 struct u64_stats_sync syncp;
132};
133
134static void vrf_rx_stats(struct net_device *dev, int len)
135{
136 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
137
138 u64_stats_update_begin(&dstats->syncp);
139 dstats->rx_pkts++;
140 dstats->rx_bytes += len;
141 u64_stats_update_end(&dstats->syncp);
142}
143
144static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
145{
146 vrf_dev->stats.tx_errors++;
147 kfree_skb(skb);
148}
149
150static void vrf_get_stats64(struct net_device *dev,
151 struct rtnl_link_stats64 *stats)
152{
153 int i;
154
155 for_each_possible_cpu(i) {
156 const struct pcpu_dstats *dstats;
157 u64 tbytes, tpkts, tdrops, rbytes, rpkts;
158 unsigned int start;
159
160 dstats = per_cpu_ptr(dev->dstats, i);
161 do {
162 start = u64_stats_fetch_begin(&dstats->syncp);
163 tbytes = dstats->tx_bytes;
164 tpkts = dstats->tx_pkts;
165 tdrops = dstats->tx_drps;
166 rbytes = dstats->rx_bytes;
167 rpkts = dstats->rx_pkts;
168 } while (u64_stats_fetch_retry(&dstats->syncp, start));
169 stats->tx_bytes += tbytes;
170 stats->tx_packets += tpkts;
171 stats->tx_dropped += tdrops;
172 stats->rx_bytes += rbytes;
173 stats->rx_packets += rpkts;
174 }
175}
176
177static struct vrf_map *netns_vrf_map(struct net *net)
178{
179 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
180
181 return &nn_vrf->vmap;
182}
183
184static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev)
185{
186 return netns_vrf_map(dev_net(dev));
187}
188
189static int vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem *me)
190{
191 struct list_head *me_head = &me->vrf_list;
192 struct net_vrf *vrf;
193
194 if (list_empty(me_head))
195 return -ENODEV;
196
197 vrf = list_first_entry(me_head, struct net_vrf, me_list);
198
199 return vrf->ifindex;
200}
201
202static struct vrf_map_elem *vrf_map_elem_alloc(gfp_t flags)
203{
204 struct vrf_map_elem *me;
205
206 me = kmalloc(sizeof(*me), flags);
207 if (!me)
208 return NULL;
209
210 return me;
211}
212
213static void vrf_map_elem_free(struct vrf_map_elem *me)
214{
215 kfree(me);
216}
217
218static void vrf_map_elem_init(struct vrf_map_elem *me, int table_id,
219 int ifindex, int users)
220{
221 me->table_id = table_id;
222 me->ifindex = ifindex;
223 me->users = users;
224 INIT_LIST_HEAD(&me->vrf_list);
225}
226
227static struct vrf_map_elem *vrf_map_lookup_elem(struct vrf_map *vmap,
228 u32 table_id)
229{
230 struct vrf_map_elem *me;
231 u32 key;
232
233 key = jhash_1word(table_id, HASH_INITVAL);
234 hash_for_each_possible(vmap->ht, me, hnode, key) {
235 if (me->table_id == table_id)
236 return me;
237 }
238
239 return NULL;
240}
241
242static void vrf_map_add_elem(struct vrf_map *vmap, struct vrf_map_elem *me)
243{
244 u32 table_id = me->table_id;
245 u32 key;
246
247 key = jhash_1word(table_id, HASH_INITVAL);
248 hash_add(vmap->ht, &me->hnode, key);
249}
250
251static void vrf_map_del_elem(struct vrf_map_elem *me)
252{
253 hash_del(&me->hnode);
254}
255
256static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock)
257{
258 spin_lock(&vmap->vmap_lock);
259}
260
261static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock)
262{
263 spin_unlock(&vmap->vmap_lock);
264}
265
266/* called with rtnl lock held */
267static int
268vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack)
269{
270 struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
271 struct net_vrf *vrf = netdev_priv(dev);
272 struct vrf_map_elem *new_me, *me;
273 u32 table_id = vrf->tb_id;
274 bool free_new_me = false;
275 int users;
276 int res;
277
278 /* we pre-allocate elements used in the spin-locked section (so that we
279 * keep the spinlock as short as possible).
280 */
281 new_me = vrf_map_elem_alloc(GFP_KERNEL);
282 if (!new_me)
283 return -ENOMEM;
284
285 vrf_map_elem_init(new_me, table_id, dev->ifindex, 0);
286
287 vrf_map_lock(vmap);
288
289 me = vrf_map_lookup_elem(vmap, table_id);
290 if (!me) {
291 me = new_me;
292 vrf_map_add_elem(vmap, me);
293 goto link_vrf;
294 }
295
296 /* we already have an entry in the vrf_map, so it means there is (at
297 * least) a vrf registered on the specific table.
298 */
299 free_new_me = true;
300 if (vmap->strict_mode) {
301 /* vrfs cannot share the same table */
302 NL_SET_ERR_MSG(extack, "Table is used by another VRF");
303 res = -EBUSY;
304 goto unlock;
305 }
306
307link_vrf:
308 users = ++me->users;
309 if (users == 2)
310 ++vmap->shared_tables;
311
312 list_add(&vrf->me_list, &me->vrf_list);
313
314 res = 0;
315
316unlock:
317 vrf_map_unlock(vmap);
318
319 /* clean-up, if needed */
320 if (free_new_me)
321 vrf_map_elem_free(new_me);
322
323 return res;
324}
325
326/* called with rtnl lock held */
327static void vrf_map_unregister_dev(struct net_device *dev)
328{
329 struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
330 struct net_vrf *vrf = netdev_priv(dev);
331 u32 table_id = vrf->tb_id;
332 struct vrf_map_elem *me;
333 int users;
334
335 vrf_map_lock(vmap);
336
337 me = vrf_map_lookup_elem(vmap, table_id);
338 if (!me)
339 goto unlock;
340
341 list_del(&vrf->me_list);
342
343 users = --me->users;
344 if (users == 1) {
345 --vmap->shared_tables;
346 } else if (users == 0) {
347 vrf_map_del_elem(me);
348
349 /* no one will refer to this element anymore */
350 vrf_map_elem_free(me);
351 }
352
353unlock:
354 vrf_map_unlock(vmap);
355}
356
357/* return the vrf device index associated with the table_id */
358static int vrf_ifindex_lookup_by_table_id(struct net *net, u32 table_id)
359{
360 struct vrf_map *vmap = netns_vrf_map(net);
361 struct vrf_map_elem *me;
362 int ifindex;
363
364 vrf_map_lock(vmap);
365
366 if (!vmap->strict_mode) {
367 ifindex = -EPERM;
368 goto unlock;
369 }
370
371 me = vrf_map_lookup_elem(vmap, table_id);
372 if (!me) {
373 ifindex = -ENODEV;
374 goto unlock;
375 }
376
377 ifindex = vrf_map_elem_get_vrf_ifindex(me);
378
379unlock:
380 vrf_map_unlock(vmap);
381
382 return ifindex;
383}
384
385/* by default VRF devices do not have a qdisc and are expected
386 * to be created with only a single queue.
387 */
388static bool qdisc_tx_is_default(const struct net_device *dev)
389{
390 struct netdev_queue *txq;
391 struct Qdisc *qdisc;
392
393 if (dev->num_tx_queues > 1)
394 return false;
395
396 txq = netdev_get_tx_queue(dev, 0);
397 qdisc = rcu_access_pointer(txq->qdisc);
398
399 return !qdisc->enqueue;
400}
401
402/* Local traffic destined to local address. Reinsert the packet to rx
403 * path, similar to loopback handling.
404 */
405static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
406 struct dst_entry *dst)
407{
408 int len = skb->len;
409
410 skb_orphan(skb);
411
412 skb_dst_set(skb, dst);
413
414 /* set pkt_type to avoid skb hitting packet taps twice -
415 * once on Tx and again in Rx processing
416 */
417 skb->pkt_type = PACKET_LOOPBACK;
418
419 skb->protocol = eth_type_trans(skb, dev);
420
421 if (likely(__netif_rx(skb) == NET_RX_SUCCESS))
422 vrf_rx_stats(dev, len);
423 else
424 this_cpu_inc(dev->dstats->rx_drps);
425
426 return NETDEV_TX_OK;
427}
428
429static void vrf_nf_set_untracked(struct sk_buff *skb)
430{
431 if (skb_get_nfct(skb) == 0)
432 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
433}
434
435static void vrf_nf_reset_ct(struct sk_buff *skb)
436{
437 if (skb_get_nfct(skb) == IP_CT_UNTRACKED)
438 nf_reset_ct(skb);
439}
440
441#if IS_ENABLED(CONFIG_IPV6)
442static int vrf_ip6_local_out(struct net *net, struct sock *sk,
443 struct sk_buff *skb)
444{
445 int err;
446
447 vrf_nf_reset_ct(skb);
448
449 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net,
450 sk, skb, NULL, skb_dst(skb)->dev, dst_output);
451
452 if (likely(err == 1))
453 err = dst_output(net, sk, skb);
454
455 return err;
456}
457
458static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
459 struct net_device *dev)
460{
461 const struct ipv6hdr *iph;
462 struct net *net = dev_net(skb->dev);
463 struct flowi6 fl6;
464 int ret = NET_XMIT_DROP;
465 struct dst_entry *dst;
466 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
467
468 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
469 goto err;
470
471 iph = ipv6_hdr(skb);
472
473 memset(&fl6, 0, sizeof(fl6));
474 /* needed to match OIF rule */
475 fl6.flowi6_l3mdev = dev->ifindex;
476 fl6.flowi6_iif = LOOPBACK_IFINDEX;
477 fl6.daddr = iph->daddr;
478 fl6.saddr = iph->saddr;
479 fl6.flowlabel = ip6_flowinfo(iph);
480 fl6.flowi6_mark = skb->mark;
481 fl6.flowi6_proto = iph->nexthdr;
482
483 dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL);
484 if (IS_ERR(dst) || dst == dst_null)
485 goto err;
486
487 skb_dst_drop(skb);
488
489 /* if dst.dev is the VRF device again this is locally originated traffic
490 * destined to a local address. Short circuit to Rx path.
491 */
492 if (dst->dev == dev)
493 return vrf_local_xmit(skb, dev, dst);
494
495 skb_dst_set(skb, dst);
496
497 /* strip the ethernet header added for pass through VRF device */
498 __skb_pull(skb, skb_network_offset(skb));
499
500 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
501 ret = vrf_ip6_local_out(net, skb->sk, skb);
502 if (unlikely(net_xmit_eval(ret)))
503 dev->stats.tx_errors++;
504 else
505 ret = NET_XMIT_SUCCESS;
506
507 return ret;
508err:
509 vrf_tx_error(dev, skb);
510 return NET_XMIT_DROP;
511}
512#else
513static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
514 struct net_device *dev)
515{
516 vrf_tx_error(dev, skb);
517 return NET_XMIT_DROP;
518}
519#endif
520
521/* based on ip_local_out; can't use it b/c the dst is switched pointing to us */
522static int vrf_ip_local_out(struct net *net, struct sock *sk,
523 struct sk_buff *skb)
524{
525 int err;
526
527 vrf_nf_reset_ct(skb);
528
529 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
530 skb, NULL, skb_dst(skb)->dev, dst_output);
531 if (likely(err == 1))
532 err = dst_output(net, sk, skb);
533
534 return err;
535}
536
537static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
538 struct net_device *vrf_dev)
539{
540 struct iphdr *ip4h;
541 int ret = NET_XMIT_DROP;
542 struct flowi4 fl4;
543 struct net *net = dev_net(vrf_dev);
544 struct rtable *rt;
545
546 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
547 goto err;
548
549 ip4h = ip_hdr(skb);
550
551 memset(&fl4, 0, sizeof(fl4));
552 /* needed to match OIF rule */
553 fl4.flowi4_l3mdev = vrf_dev->ifindex;
554 fl4.flowi4_iif = LOOPBACK_IFINDEX;
555 fl4.flowi4_tos = RT_TOS(ip4h->tos);
556 fl4.flowi4_flags = FLOWI_FLAG_ANYSRC;
557 fl4.flowi4_proto = ip4h->protocol;
558 fl4.daddr = ip4h->daddr;
559 fl4.saddr = ip4h->saddr;
560
561 rt = ip_route_output_flow(net, &fl4, NULL);
562 if (IS_ERR(rt))
563 goto err;
564
565 skb_dst_drop(skb);
566
567 /* if dst.dev is the VRF device again this is locally originated traffic
568 * destined to a local address. Short circuit to Rx path.
569 */
570 if (rt->dst.dev == vrf_dev)
571 return vrf_local_xmit(skb, vrf_dev, &rt->dst);
572
573 skb_dst_set(skb, &rt->dst);
574
575 /* strip the ethernet header added for pass through VRF device */
576 __skb_pull(skb, skb_network_offset(skb));
577
578 if (!ip4h->saddr) {
579 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
580 RT_SCOPE_LINK);
581 }
582
583 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
584 ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
585 if (unlikely(net_xmit_eval(ret)))
586 vrf_dev->stats.tx_errors++;
587 else
588 ret = NET_XMIT_SUCCESS;
589
590out:
591 return ret;
592err:
593 vrf_tx_error(vrf_dev, skb);
594 goto out;
595}
596
597static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
598{
599 switch (skb->protocol) {
600 case htons(ETH_P_IP):
601 return vrf_process_v4_outbound(skb, dev);
602 case htons(ETH_P_IPV6):
603 return vrf_process_v6_outbound(skb, dev);
604 default:
605 vrf_tx_error(dev, skb);
606 return NET_XMIT_DROP;
607 }
608}
609
610static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
611{
612 int len = skb->len;
613 netdev_tx_t ret = is_ip_tx_frame(skb, dev);
614
615 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
616 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
617
618 u64_stats_update_begin(&dstats->syncp);
619 dstats->tx_pkts++;
620 dstats->tx_bytes += len;
621 u64_stats_update_end(&dstats->syncp);
622 } else {
623 this_cpu_inc(dev->dstats->tx_drps);
624 }
625
626 return ret;
627}
628
629static void vrf_finish_direct(struct sk_buff *skb)
630{
631 struct net_device *vrf_dev = skb->dev;
632
633 if (!list_empty(&vrf_dev->ptype_all) &&
634 likely(skb_headroom(skb) >= ETH_HLEN)) {
635 struct ethhdr *eth = skb_push(skb, ETH_HLEN);
636
637 ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
638 eth_zero_addr(eth->h_dest);
639 eth->h_proto = skb->protocol;
640
641 rcu_read_lock_bh();
642 dev_queue_xmit_nit(skb, vrf_dev);
643 rcu_read_unlock_bh();
644
645 skb_pull(skb, ETH_HLEN);
646 }
647
648 vrf_nf_reset_ct(skb);
649}
650
651#if IS_ENABLED(CONFIG_IPV6)
652/* modelled after ip6_finish_output2 */
653static int vrf_finish_output6(struct net *net, struct sock *sk,
654 struct sk_buff *skb)
655{
656 struct dst_entry *dst = skb_dst(skb);
657 struct net_device *dev = dst->dev;
658 const struct in6_addr *nexthop;
659 struct neighbour *neigh;
660 int ret;
661
662 vrf_nf_reset_ct(skb);
663
664 skb->protocol = htons(ETH_P_IPV6);
665 skb->dev = dev;
666
667 rcu_read_lock_bh();
668 nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
669 neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
670 if (unlikely(!neigh))
671 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
672 if (!IS_ERR(neigh)) {
673 sock_confirm_neigh(skb, neigh);
674 ret = neigh_output(neigh, skb, false);
675 rcu_read_unlock_bh();
676 return ret;
677 }
678 rcu_read_unlock_bh();
679
680 IP6_INC_STATS(dev_net(dst->dev),
681 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
682 kfree_skb(skb);
683 return -EINVAL;
684}
685
686/* modelled after ip6_output */
687static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
688{
689 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
690 net, sk, skb, NULL, skb_dst(skb)->dev,
691 vrf_finish_output6,
692 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
693}
694
695/* set dst on skb to send packet to us via dev_xmit path. Allows
696 * packet to go through device based features such as qdisc, netfilter
697 * hooks and packet sockets with skb->dev set to vrf device.
698 */
699static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev,
700 struct sk_buff *skb)
701{
702 struct net_vrf *vrf = netdev_priv(vrf_dev);
703 struct dst_entry *dst = NULL;
704 struct rt6_info *rt6;
705
706 rcu_read_lock();
707
708 rt6 = rcu_dereference(vrf->rt6);
709 if (likely(rt6)) {
710 dst = &rt6->dst;
711 dst_hold(dst);
712 }
713
714 rcu_read_unlock();
715
716 if (unlikely(!dst)) {
717 vrf_tx_error(vrf_dev, skb);
718 return NULL;
719 }
720
721 skb_dst_drop(skb);
722 skb_dst_set(skb, dst);
723
724 return skb;
725}
726
727static int vrf_output6_direct_finish(struct net *net, struct sock *sk,
728 struct sk_buff *skb)
729{
730 vrf_finish_direct(skb);
731
732 return vrf_ip6_local_out(net, sk, skb);
733}
734
735static int vrf_output6_direct(struct net *net, struct sock *sk,
736 struct sk_buff *skb)
737{
738 int err = 1;
739
740 skb->protocol = htons(ETH_P_IPV6);
741
742 if (!(IPCB(skb)->flags & IPSKB_REROUTED))
743 err = nf_hook(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb,
744 NULL, skb->dev, vrf_output6_direct_finish);
745
746 if (likely(err == 1))
747 vrf_finish_direct(skb);
748
749 return err;
750}
751
752static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk,
753 struct sk_buff *skb)
754{
755 int err;
756
757 err = vrf_output6_direct(net, sk, skb);
758 if (likely(err == 1))
759 err = vrf_ip6_local_out(net, sk, skb);
760
761 return err;
762}
763
764static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
765 struct sock *sk,
766 struct sk_buff *skb)
767{
768 struct net *net = dev_net(vrf_dev);
769 int err;
770
771 skb->dev = vrf_dev;
772
773 err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk,
774 skb, NULL, vrf_dev, vrf_ip6_out_direct_finish);
775
776 if (likely(err == 1))
777 err = vrf_output6_direct(net, sk, skb);
778
779 if (likely(err == 1))
780 return skb;
781
782 return NULL;
783}
784
785static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
786 struct sock *sk,
787 struct sk_buff *skb)
788{
789 /* don't divert link scope packets */
790 if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
791 return skb;
792
793 vrf_nf_set_untracked(skb);
794
795 if (qdisc_tx_is_default(vrf_dev) ||
796 IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
797 return vrf_ip6_out_direct(vrf_dev, sk, skb);
798
799 return vrf_ip6_out_redirect(vrf_dev, skb);
800}
801
802/* holding rtnl */
803static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
804{
805 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
806 struct net *net = dev_net(dev);
807 struct dst_entry *dst;
808
809 RCU_INIT_POINTER(vrf->rt6, NULL);
810 synchronize_rcu();
811
812 /* move dev in dst's to loopback so this VRF device can be deleted
813 * - based on dst_ifdown
814 */
815 if (rt6) {
816 dst = &rt6->dst;
817 netdev_ref_replace(dst->dev, net->loopback_dev,
818 &dst->dev_tracker, GFP_KERNEL);
819 dst->dev = net->loopback_dev;
820 dst_release(dst);
821 }
822}
823
824static int vrf_rt6_create(struct net_device *dev)
825{
826 int flags = DST_NOPOLICY | DST_NOXFRM;
827 struct net_vrf *vrf = netdev_priv(dev);
828 struct net *net = dev_net(dev);
829 struct rt6_info *rt6;
830 int rc = -ENOMEM;
831
832 /* IPv6 can be CONFIG enabled and then disabled runtime */
833 if (!ipv6_mod_enabled())
834 return 0;
835
836 vrf->fib6_table = fib6_new_table(net, vrf->tb_id);
837 if (!vrf->fib6_table)
838 goto out;
839
840 /* create a dst for routing packets out a VRF device */
841 rt6 = ip6_dst_alloc(net, dev, flags);
842 if (!rt6)
843 goto out;
844
845 rt6->dst.output = vrf_output6;
846
847 rcu_assign_pointer(vrf->rt6, rt6);
848
849 rc = 0;
850out:
851 return rc;
852}
853#else
854static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
855 struct sock *sk,
856 struct sk_buff *skb)
857{
858 return skb;
859}
860
861static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
862{
863}
864
865static int vrf_rt6_create(struct net_device *dev)
866{
867 return 0;
868}
869#endif
870
871/* modelled after ip_finish_output2 */
872static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
873{
874 struct dst_entry *dst = skb_dst(skb);
875 struct rtable *rt = (struct rtable *)dst;
876 struct net_device *dev = dst->dev;
877 unsigned int hh_len = LL_RESERVED_SPACE(dev);
878 struct neighbour *neigh;
879 bool is_v6gw = false;
880
881 vrf_nf_reset_ct(skb);
882
883 /* Be paranoid, rather than too clever. */
884 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
885 skb = skb_expand_head(skb, hh_len);
886 if (!skb) {
887 dev->stats.tx_errors++;
888 return -ENOMEM;
889 }
890 }
891
892 rcu_read_lock_bh();
893
894 neigh = ip_neigh_for_gw(rt, skb, &is_v6gw);
895 if (!IS_ERR(neigh)) {
896 int ret;
897
898 sock_confirm_neigh(skb, neigh);
899 /* if crossing protocols, can not use the cached header */
900 ret = neigh_output(neigh, skb, is_v6gw);
901 rcu_read_unlock_bh();
902 return ret;
903 }
904
905 rcu_read_unlock_bh();
906 vrf_tx_error(skb->dev, skb);
907 return -EINVAL;
908}
909
910static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
911{
912 struct net_device *dev = skb_dst(skb)->dev;
913
914 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
915
916 skb->dev = dev;
917 skb->protocol = htons(ETH_P_IP);
918
919 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
920 net, sk, skb, NULL, dev,
921 vrf_finish_output,
922 !(IPCB(skb)->flags & IPSKB_REROUTED));
923}
924
925/* set dst on skb to send packet to us via dev_xmit path. Allows
926 * packet to go through device based features such as qdisc, netfilter
927 * hooks and packet sockets with skb->dev set to vrf device.
928 */
929static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev,
930 struct sk_buff *skb)
931{
932 struct net_vrf *vrf = netdev_priv(vrf_dev);
933 struct dst_entry *dst = NULL;
934 struct rtable *rth;
935
936 rcu_read_lock();
937
938 rth = rcu_dereference(vrf->rth);
939 if (likely(rth)) {
940 dst = &rth->dst;
941 dst_hold(dst);
942 }
943
944 rcu_read_unlock();
945
946 if (unlikely(!dst)) {
947 vrf_tx_error(vrf_dev, skb);
948 return NULL;
949 }
950
951 skb_dst_drop(skb);
952 skb_dst_set(skb, dst);
953
954 return skb;
955}
956
957static int vrf_output_direct_finish(struct net *net, struct sock *sk,
958 struct sk_buff *skb)
959{
960 vrf_finish_direct(skb);
961
962 return vrf_ip_local_out(net, sk, skb);
963}
964
965static int vrf_output_direct(struct net *net, struct sock *sk,
966 struct sk_buff *skb)
967{
968 int err = 1;
969
970 skb->protocol = htons(ETH_P_IP);
971
972 if (!(IPCB(skb)->flags & IPSKB_REROUTED))
973 err = nf_hook(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb,
974 NULL, skb->dev, vrf_output_direct_finish);
975
976 if (likely(err == 1))
977 vrf_finish_direct(skb);
978
979 return err;
980}
981
982static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk,
983 struct sk_buff *skb)
984{
985 int err;
986
987 err = vrf_output_direct(net, sk, skb);
988 if (likely(err == 1))
989 err = vrf_ip_local_out(net, sk, skb);
990
991 return err;
992}
993
994static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
995 struct sock *sk,
996 struct sk_buff *skb)
997{
998 struct net *net = dev_net(vrf_dev);
999 int err;
1000
1001 skb->dev = vrf_dev;
1002
1003 err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
1004 skb, NULL, vrf_dev, vrf_ip_out_direct_finish);
1005
1006 if (likely(err == 1))
1007 err = vrf_output_direct(net, sk, skb);
1008
1009 if (likely(err == 1))
1010 return skb;
1011
1012 return NULL;
1013}
1014
1015static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
1016 struct sock *sk,
1017 struct sk_buff *skb)
1018{
1019 /* don't divert multicast or local broadcast */
1020 if (ipv4_is_multicast(ip_hdr(skb)->daddr) ||
1021 ipv4_is_lbcast(ip_hdr(skb)->daddr))
1022 return skb;
1023
1024 vrf_nf_set_untracked(skb);
1025
1026 if (qdisc_tx_is_default(vrf_dev) ||
1027 IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
1028 return vrf_ip_out_direct(vrf_dev, sk, skb);
1029
1030 return vrf_ip_out_redirect(vrf_dev, skb);
1031}
1032
1033/* called with rcu lock held */
1034static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
1035 struct sock *sk,
1036 struct sk_buff *skb,
1037 u16 proto)
1038{
1039 switch (proto) {
1040 case AF_INET:
1041 return vrf_ip_out(vrf_dev, sk, skb);
1042 case AF_INET6:
1043 return vrf_ip6_out(vrf_dev, sk, skb);
1044 }
1045
1046 return skb;
1047}
1048
1049/* holding rtnl */
1050static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
1051{
1052 struct rtable *rth = rtnl_dereference(vrf->rth);
1053 struct net *net = dev_net(dev);
1054 struct dst_entry *dst;
1055
1056 RCU_INIT_POINTER(vrf->rth, NULL);
1057 synchronize_rcu();
1058
1059 /* move dev in dst's to loopback so this VRF device can be deleted
1060 * - based on dst_ifdown
1061 */
1062 if (rth) {
1063 dst = &rth->dst;
1064 netdev_ref_replace(dst->dev, net->loopback_dev,
1065 &dst->dev_tracker, GFP_KERNEL);
1066 dst->dev = net->loopback_dev;
1067 dst_release(dst);
1068 }
1069}
1070
1071static int vrf_rtable_create(struct net_device *dev)
1072{
1073 struct net_vrf *vrf = netdev_priv(dev);
1074 struct rtable *rth;
1075
1076 if (!fib_new_table(dev_net(dev), vrf->tb_id))
1077 return -ENOMEM;
1078
1079 /* create a dst for routing packets out through a VRF device */
1080 rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1);
1081 if (!rth)
1082 return -ENOMEM;
1083
1084 rth->dst.output = vrf_output;
1085
1086 rcu_assign_pointer(vrf->rth, rth);
1087
1088 return 0;
1089}
1090
1091/**************************** device handling ********************/
1092
1093/* cycle interface to flush neighbor cache and move routes across tables */
1094static void cycle_netdev(struct net_device *dev,
1095 struct netlink_ext_ack *extack)
1096{
1097 unsigned int flags = dev->flags;
1098 int ret;
1099
1100 if (!netif_running(dev))
1101 return;
1102
1103 ret = dev_change_flags(dev, flags & ~IFF_UP, extack);
1104 if (ret >= 0)
1105 ret = dev_change_flags(dev, flags, extack);
1106
1107 if (ret < 0) {
1108 netdev_err(dev,
1109 "Failed to cycle device %s; route tables might be wrong!\n",
1110 dev->name);
1111 }
1112}
1113
1114static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1115 struct netlink_ext_ack *extack)
1116{
1117 int ret;
1118
1119 /* do not allow loopback device to be enslaved to a VRF.
1120 * The vrf device acts as the loopback for the vrf.
1121 */
1122 if (port_dev == dev_net(dev)->loopback_dev) {
1123 NL_SET_ERR_MSG(extack,
1124 "Can not enslave loopback device to a VRF");
1125 return -EOPNOTSUPP;
1126 }
1127
1128 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
1129 ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack);
1130 if (ret < 0)
1131 goto err;
1132
1133 cycle_netdev(port_dev, extack);
1134
1135 return 0;
1136
1137err:
1138 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1139 return ret;
1140}
1141
1142static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1143 struct netlink_ext_ack *extack)
1144{
1145 if (netif_is_l3_master(port_dev)) {
1146 NL_SET_ERR_MSG(extack,
1147 "Can not enslave an L3 master device to a VRF");
1148 return -EINVAL;
1149 }
1150
1151 if (netif_is_l3_slave(port_dev))
1152 return -EINVAL;
1153
1154 return do_vrf_add_slave(dev, port_dev, extack);
1155}
1156
1157/* inverse of do_vrf_add_slave */
1158static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1159{
1160 netdev_upper_dev_unlink(port_dev, dev);
1161 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1162
1163 cycle_netdev(port_dev, NULL);
1164
1165 return 0;
1166}
1167
1168static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1169{
1170 return do_vrf_del_slave(dev, port_dev);
1171}
1172
1173static void vrf_dev_uninit(struct net_device *dev)
1174{
1175 struct net_vrf *vrf = netdev_priv(dev);
1176
1177 vrf_rtable_release(dev, vrf);
1178 vrf_rt6_release(dev, vrf);
1179
1180 free_percpu(dev->dstats);
1181 dev->dstats = NULL;
1182}
1183
1184static int vrf_dev_init(struct net_device *dev)
1185{
1186 struct net_vrf *vrf = netdev_priv(dev);
1187
1188 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
1189 if (!dev->dstats)
1190 goto out_nomem;
1191
1192 /* create the default dst which points back to us */
1193 if (vrf_rtable_create(dev) != 0)
1194 goto out_stats;
1195
1196 if (vrf_rt6_create(dev) != 0)
1197 goto out_rth;
1198
1199 dev->flags = IFF_MASTER | IFF_NOARP;
1200
1201 /* similarly, oper state is irrelevant; set to up to avoid confusion */
1202 dev->operstate = IF_OPER_UP;
1203 netdev_lockdep_set_classes(dev);
1204 return 0;
1205
1206out_rth:
1207 vrf_rtable_release(dev, vrf);
1208out_stats:
1209 free_percpu(dev->dstats);
1210 dev->dstats = NULL;
1211out_nomem:
1212 return -ENOMEM;
1213}
1214
1215static const struct net_device_ops vrf_netdev_ops = {
1216 .ndo_init = vrf_dev_init,
1217 .ndo_uninit = vrf_dev_uninit,
1218 .ndo_start_xmit = vrf_xmit,
1219 .ndo_set_mac_address = eth_mac_addr,
1220 .ndo_get_stats64 = vrf_get_stats64,
1221 .ndo_add_slave = vrf_add_slave,
1222 .ndo_del_slave = vrf_del_slave,
1223};
1224
1225static u32 vrf_fib_table(const struct net_device *dev)
1226{
1227 struct net_vrf *vrf = netdev_priv(dev);
1228
1229 return vrf->tb_id;
1230}
1231
1232static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
1233{
1234 kfree_skb(skb);
1235 return 0;
1236}
1237
1238static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
1239 struct sk_buff *skb,
1240 struct net_device *dev)
1241{
1242 struct net *net = dev_net(dev);
1243
1244 if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1)
1245 skb = NULL; /* kfree_skb(skb) handled by nf code */
1246
1247 return skb;
1248}
1249
1250static int vrf_prepare_mac_header(struct sk_buff *skb,
1251 struct net_device *vrf_dev, u16 proto)
1252{
1253 struct ethhdr *eth;
1254 int err;
1255
1256 /* in general, we do not know if there is enough space in the head of
1257 * the packet for hosting the mac header.
1258 */
1259 err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev));
1260 if (unlikely(err))
1261 /* no space in the skb head */
1262 return -ENOBUFS;
1263
1264 __skb_push(skb, ETH_HLEN);
1265 eth = (struct ethhdr *)skb->data;
1266
1267 skb_reset_mac_header(skb);
1268 skb_reset_mac_len(skb);
1269
1270 /* we set the ethernet destination and the source addresses to the
1271 * address of the VRF device.
1272 */
1273 ether_addr_copy(eth->h_dest, vrf_dev->dev_addr);
1274 ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
1275 eth->h_proto = htons(proto);
1276
1277 /* the destination address of the Ethernet frame corresponds to the
1278 * address set on the VRF interface; therefore, the packet is intended
1279 * to be processed locally.
1280 */
1281 skb->protocol = eth->h_proto;
1282 skb->pkt_type = PACKET_HOST;
1283
1284 skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
1285
1286 skb_pull_inline(skb, ETH_HLEN);
1287
1288 return 0;
1289}
1290
1291/* prepare and add the mac header to the packet if it was not set previously.
1292 * In this way, packet sniffers such as tcpdump can parse the packet correctly.
1293 * If the mac header was already set, the original mac header is left
1294 * untouched and the function returns immediately.
1295 */
1296static int vrf_add_mac_header_if_unset(struct sk_buff *skb,
1297 struct net_device *vrf_dev,
1298 u16 proto, struct net_device *orig_dev)
1299{
1300 if (skb_mac_header_was_set(skb) && dev_has_header(orig_dev))
1301 return 0;
1302
1303 return vrf_prepare_mac_header(skb, vrf_dev, proto);
1304}
1305
1306#if IS_ENABLED(CONFIG_IPV6)
1307/* neighbor handling is done with actual device; do not want
1308 * to flip skb->dev for those ndisc packets. This really fails
1309 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
1310 * a start.
1311 */
1312static bool ipv6_ndisc_frame(const struct sk_buff *skb)
1313{
1314 const struct ipv6hdr *iph = ipv6_hdr(skb);
1315 bool rc = false;
1316
1317 if (iph->nexthdr == NEXTHDR_ICMP) {
1318 const struct icmp6hdr *icmph;
1319 struct icmp6hdr _icmph;
1320
1321 icmph = skb_header_pointer(skb, sizeof(*iph),
1322 sizeof(_icmph), &_icmph);
1323 if (!icmph)
1324 goto out;
1325
1326 switch (icmph->icmp6_type) {
1327 case NDISC_ROUTER_SOLICITATION:
1328 case NDISC_ROUTER_ADVERTISEMENT:
1329 case NDISC_NEIGHBOUR_SOLICITATION:
1330 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1331 case NDISC_REDIRECT:
1332 rc = true;
1333 break;
1334 }
1335 }
1336
1337out:
1338 return rc;
1339}
1340
1341static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
1342 const struct net_device *dev,
1343 struct flowi6 *fl6,
1344 int ifindex,
1345 const struct sk_buff *skb,
1346 int flags)
1347{
1348 struct net_vrf *vrf = netdev_priv(dev);
1349
1350 return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags);
1351}
1352
1353static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
1354 int ifindex)
1355{
1356 const struct ipv6hdr *iph = ipv6_hdr(skb);
1357 struct flowi6 fl6 = {
1358 .flowi6_iif = ifindex,
1359 .flowi6_mark = skb->mark,
1360 .flowi6_proto = iph->nexthdr,
1361 .daddr = iph->daddr,
1362 .saddr = iph->saddr,
1363 .flowlabel = ip6_flowinfo(iph),
1364 };
1365 struct net *net = dev_net(vrf_dev);
1366 struct rt6_info *rt6;
1367
1368 rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb,
1369 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
1370 if (unlikely(!rt6))
1371 return;
1372
1373 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
1374 return;
1375
1376 skb_dst_set(skb, &rt6->dst);
1377}
1378
1379static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1380 struct sk_buff *skb)
1381{
1382 int orig_iif = skb->skb_iif;
1383 bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
1384 bool is_ndisc = ipv6_ndisc_frame(skb);
1385
1386 /* loopback, multicast & non-ND link-local traffic; do not push through
1387 * packet taps again. Reset pkt_type for upper layers to process skb.
1388 * For non-loopback strict packets, determine the dst using the original
1389 * ifindex.
1390 */
1391 if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) {
1392 skb->dev = vrf_dev;
1393 skb->skb_iif = vrf_dev->ifindex;
1394 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1395
1396 if (skb->pkt_type == PACKET_LOOPBACK)
1397 skb->pkt_type = PACKET_HOST;
1398 else
1399 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1400
1401 goto out;
1402 }
1403
1404 /* if packet is NDISC then keep the ingress interface */
1405 if (!is_ndisc) {
1406 struct net_device *orig_dev = skb->dev;
1407
1408 vrf_rx_stats(vrf_dev, skb->len);
1409 skb->dev = vrf_dev;
1410 skb->skb_iif = vrf_dev->ifindex;
1411
1412 if (!list_empty(&vrf_dev->ptype_all)) {
1413 int err;
1414
1415 err = vrf_add_mac_header_if_unset(skb, vrf_dev,
1416 ETH_P_IPV6,
1417 orig_dev);
1418 if (likely(!err)) {
1419 skb_push(skb, skb->mac_len);
1420 dev_queue_xmit_nit(skb, vrf_dev);
1421 skb_pull(skb, skb->mac_len);
1422 }
1423 }
1424
1425 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1426 }
1427
1428 if (need_strict)
1429 vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1430
1431 skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
1432out:
1433 return skb;
1434}
1435
1436#else
1437static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1438 struct sk_buff *skb)
1439{
1440 return skb;
1441}
1442#endif
1443
1444static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
1445 struct sk_buff *skb)
1446{
1447 struct net_device *orig_dev = skb->dev;
1448
1449 skb->dev = vrf_dev;
1450 skb->skb_iif = vrf_dev->ifindex;
1451 IPCB(skb)->flags |= IPSKB_L3SLAVE;
1452
1453 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
1454 goto out;
1455
1456 /* loopback traffic; do not push through packet taps again.
1457 * Reset pkt_type for upper layers to process skb
1458 */
1459 if (skb->pkt_type == PACKET_LOOPBACK) {
1460 skb->pkt_type = PACKET_HOST;
1461 goto out;
1462 }
1463
1464 vrf_rx_stats(vrf_dev, skb->len);
1465
1466 if (!list_empty(&vrf_dev->ptype_all)) {
1467 int err;
1468
1469 err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP,
1470 orig_dev);
1471 if (likely(!err)) {
1472 skb_push(skb, skb->mac_len);
1473 dev_queue_xmit_nit(skb, vrf_dev);
1474 skb_pull(skb, skb->mac_len);
1475 }
1476 }
1477
1478 skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
1479out:
1480 return skb;
1481}
1482
1483/* called with rcu lock held */
1484static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1485 struct sk_buff *skb,
1486 u16 proto)
1487{
1488 switch (proto) {
1489 case AF_INET:
1490 return vrf_ip_rcv(vrf_dev, skb);
1491 case AF_INET6:
1492 return vrf_ip6_rcv(vrf_dev, skb);
1493 }
1494
1495 return skb;
1496}
1497
1498#if IS_ENABLED(CONFIG_IPV6)
1499/* send to link-local or multicast address via interface enslaved to
1500 * VRF device. Force lookup to VRF table without changing flow struct
1501 * Note: Caller to this function must hold rcu_read_lock() and no refcnt
1502 * is taken on the dst by this function.
1503 */
1504static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1505 struct flowi6 *fl6)
1506{
1507 struct net *net = dev_net(dev);
1508 int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF;
1509 struct dst_entry *dst = NULL;
1510 struct rt6_info *rt;
1511
1512 /* VRF device does not have a link-local address and
1513 * sending packets to link-local or mcast addresses over
1514 * a VRF device does not make sense
1515 */
1516 if (fl6->flowi6_oif == dev->ifindex) {
1517 dst = &net->ipv6.ip6_null_entry->dst;
1518 return dst;
1519 }
1520
1521 if (!ipv6_addr_any(&fl6->saddr))
1522 flags |= RT6_LOOKUP_F_HAS_SADDR;
1523
1524 rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags);
1525 if (rt)
1526 dst = &rt->dst;
1527
1528 return dst;
1529}
1530#endif
1531
1532static const struct l3mdev_ops vrf_l3mdev_ops = {
1533 .l3mdev_fib_table = vrf_fib_table,
1534 .l3mdev_l3_rcv = vrf_l3_rcv,
1535 .l3mdev_l3_out = vrf_l3_out,
1536#if IS_ENABLED(CONFIG_IPV6)
1537 .l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1538#endif
1539};
1540
1541static void vrf_get_drvinfo(struct net_device *dev,
1542 struct ethtool_drvinfo *info)
1543{
1544 strscpy(info->driver, DRV_NAME, sizeof(info->driver));
1545 strscpy(info->version, DRV_VERSION, sizeof(info->version));
1546}
1547
1548static const struct ethtool_ops vrf_ethtool_ops = {
1549 .get_drvinfo = vrf_get_drvinfo,
1550};
1551
1552static inline size_t vrf_fib_rule_nl_size(void)
1553{
1554 size_t sz;
1555
1556 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1557 sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */
1558 sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */
1559 sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */
1560
1561 return sz;
1562}
1563
1564static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1565{
1566 struct fib_rule_hdr *frh;
1567 struct nlmsghdr *nlh;
1568 struct sk_buff *skb;
1569 int err;
1570
1571 if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) &&
1572 !ipv6_mod_enabled())
1573 return 0;
1574
1575 skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
1576 if (!skb)
1577 return -ENOMEM;
1578
1579 nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
1580 if (!nlh)
1581 goto nla_put_failure;
1582
1583 /* rule only needs to appear once */
1584 nlh->nlmsg_flags |= NLM_F_EXCL;
1585
1586 frh = nlmsg_data(nlh);
1587 memset(frh, 0, sizeof(*frh));
1588 frh->family = family;
1589 frh->action = FR_ACT_TO_TBL;
1590
1591 if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL))
1592 goto nla_put_failure;
1593
1594 if (nla_put_u8(skb, FRA_L3MDEV, 1))
1595 goto nla_put_failure;
1596
1597 if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
1598 goto nla_put_failure;
1599
1600 nlmsg_end(skb, nlh);
1601
1602 /* fib_nl_{new,del}rule handling looks for net from skb->sk */
1603 skb->sk = dev_net(dev)->rtnl;
1604 if (add_it) {
1605 err = fib_nl_newrule(skb, nlh, NULL);
1606 if (err == -EEXIST)
1607 err = 0;
1608 } else {
1609 err = fib_nl_delrule(skb, nlh, NULL);
1610 if (err == -ENOENT)
1611 err = 0;
1612 }
1613 nlmsg_free(skb);
1614
1615 return err;
1616
1617nla_put_failure:
1618 nlmsg_free(skb);
1619
1620 return -EMSGSIZE;
1621}
1622
1623static int vrf_add_fib_rules(const struct net_device *dev)
1624{
1625 int err;
1626
1627 err = vrf_fib_rule(dev, AF_INET, true);
1628 if (err < 0)
1629 goto out_err;
1630
1631 err = vrf_fib_rule(dev, AF_INET6, true);
1632 if (err < 0)
1633 goto ipv6_err;
1634
1635#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1636 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true);
1637 if (err < 0)
1638 goto ipmr_err;
1639#endif
1640
1641#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1642 err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, true);
1643 if (err < 0)
1644 goto ip6mr_err;
1645#endif
1646
1647 return 0;
1648
1649#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1650ip6mr_err:
1651 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, false);
1652#endif
1653
1654#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1655ipmr_err:
1656 vrf_fib_rule(dev, AF_INET6, false);
1657#endif
1658
1659ipv6_err:
1660 vrf_fib_rule(dev, AF_INET, false);
1661
1662out_err:
1663 netdev_err(dev, "Failed to add FIB rules.\n");
1664 return err;
1665}
1666
1667static void vrf_setup(struct net_device *dev)
1668{
1669 ether_setup(dev);
1670
1671 /* Initialize the device structure. */
1672 dev->netdev_ops = &vrf_netdev_ops;
1673 dev->l3mdev_ops = &vrf_l3mdev_ops;
1674 dev->ethtool_ops = &vrf_ethtool_ops;
1675 dev->needs_free_netdev = true;
1676
1677 /* Fill in device structure with ethernet-generic values. */
1678 eth_hw_addr_random(dev);
1679
1680 /* don't acquire vrf device's netif_tx_lock when transmitting */
1681 dev->features |= NETIF_F_LLTX;
1682
1683 /* don't allow vrf devices to change network namespaces. */
1684 dev->features |= NETIF_F_NETNS_LOCAL;
1685
1686 /* does not make sense for a VLAN to be added to a vrf device */
1687 dev->features |= NETIF_F_VLAN_CHALLENGED;
1688
1689 /* enable offload features */
1690 dev->features |= NETIF_F_GSO_SOFTWARE;
1691 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC;
1692 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1693
1694 dev->hw_features = dev->features;
1695 dev->hw_enc_features = dev->features;
1696
1697 /* default to no qdisc; user can add if desired */
1698 dev->priv_flags |= IFF_NO_QUEUE;
1699 dev->priv_flags |= IFF_NO_RX_HANDLER;
1700 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1701
1702 /* VRF devices do not care about MTU, but if the MTU is set
1703 * too low then the ipv4 and ipv6 protocols are disabled
1704 * which breaks networking.
1705 */
1706 dev->min_mtu = IPV6_MIN_MTU;
1707 dev->max_mtu = IP6_MAX_MTU;
1708 dev->mtu = dev->max_mtu;
1709}
1710
1711static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],
1712 struct netlink_ext_ack *extack)
1713{
1714 if (tb[IFLA_ADDRESS]) {
1715 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
1716 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1717 return -EINVAL;
1718 }
1719 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
1720 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1721 return -EADDRNOTAVAIL;
1722 }
1723 }
1724 return 0;
1725}
1726
1727static void vrf_dellink(struct net_device *dev, struct list_head *head)
1728{
1729 struct net_device *port_dev;
1730 struct list_head *iter;
1731
1732 netdev_for_each_lower_dev(dev, port_dev, iter)
1733 vrf_del_slave(dev, port_dev);
1734
1735 vrf_map_unregister_dev(dev);
1736
1737 unregister_netdevice_queue(dev, head);
1738}
1739
1740static int vrf_newlink(struct net *src_net, struct net_device *dev,
1741 struct nlattr *tb[], struct nlattr *data[],
1742 struct netlink_ext_ack *extack)
1743{
1744 struct net_vrf *vrf = netdev_priv(dev);
1745 struct netns_vrf *nn_vrf;
1746 bool *add_fib_rules;
1747 struct net *net;
1748 int err;
1749
1750 if (!data || !data[IFLA_VRF_TABLE]) {
1751 NL_SET_ERR_MSG(extack, "VRF table id is missing");
1752 return -EINVAL;
1753 }
1754
1755 vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
1756 if (vrf->tb_id == RT_TABLE_UNSPEC) {
1757 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE],
1758 "Invalid VRF table id");
1759 return -EINVAL;
1760 }
1761
1762 dev->priv_flags |= IFF_L3MDEV_MASTER;
1763
1764 err = register_netdevice(dev);
1765 if (err)
1766 goto out;
1767
1768 /* mapping between table_id and vrf;
1769 * note: such binding could not be done in the dev init function
1770 * because dev->ifindex id is not available yet.
1771 */
1772 vrf->ifindex = dev->ifindex;
1773
1774 err = vrf_map_register_dev(dev, extack);
1775 if (err) {
1776 unregister_netdevice(dev);
1777 goto out;
1778 }
1779
1780 net = dev_net(dev);
1781 nn_vrf = net_generic(net, vrf_net_id);
1782
1783 add_fib_rules = &nn_vrf->add_fib_rules;
1784 if (*add_fib_rules) {
1785 err = vrf_add_fib_rules(dev);
1786 if (err) {
1787 vrf_map_unregister_dev(dev);
1788 unregister_netdevice(dev);
1789 goto out;
1790 }
1791 *add_fib_rules = false;
1792 }
1793
1794out:
1795 return err;
1796}
1797
1798static size_t vrf_nl_getsize(const struct net_device *dev)
1799{
1800 return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
1801}
1802
1803static int vrf_fillinfo(struct sk_buff *skb,
1804 const struct net_device *dev)
1805{
1806 struct net_vrf *vrf = netdev_priv(dev);
1807
1808 return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
1809}
1810
1811static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1812 const struct net_device *slave_dev)
1813{
1814 return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1815}
1816
1817static int vrf_fill_slave_info(struct sk_buff *skb,
1818 const struct net_device *vrf_dev,
1819 const struct net_device *slave_dev)
1820{
1821 struct net_vrf *vrf = netdev_priv(vrf_dev);
1822
1823 if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
1824 return -EMSGSIZE;
1825
1826 return 0;
1827}
1828
1829static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1830 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1831};
1832
1833static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1834 .kind = DRV_NAME,
1835 .priv_size = sizeof(struct net_vrf),
1836
1837 .get_size = vrf_nl_getsize,
1838 .policy = vrf_nl_policy,
1839 .validate = vrf_validate,
1840 .fill_info = vrf_fillinfo,
1841
1842 .get_slave_size = vrf_get_slave_size,
1843 .fill_slave_info = vrf_fill_slave_info,
1844
1845 .newlink = vrf_newlink,
1846 .dellink = vrf_dellink,
1847 .setup = vrf_setup,
1848 .maxtype = IFLA_VRF_MAX,
1849};
1850
1851static int vrf_device_event(struct notifier_block *unused,
1852 unsigned long event, void *ptr)
1853{
1854 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1855
1856 /* only care about unregister events to drop slave references */
1857 if (event == NETDEV_UNREGISTER) {
1858 struct net_device *vrf_dev;
1859
1860 if (!netif_is_l3_slave(dev))
1861 goto out;
1862
1863 vrf_dev = netdev_master_upper_dev_get(dev);
1864 vrf_del_slave(vrf_dev, dev);
1865 }
1866out:
1867 return NOTIFY_DONE;
1868}
1869
1870static struct notifier_block vrf_notifier_block __read_mostly = {
1871 .notifier_call = vrf_device_event,
1872};
1873
1874static int vrf_map_init(struct vrf_map *vmap)
1875{
1876 spin_lock_init(&vmap->vmap_lock);
1877 hash_init(vmap->ht);
1878
1879 vmap->strict_mode = false;
1880
1881 return 0;
1882}
1883
1884#ifdef CONFIG_SYSCTL
1885static bool vrf_strict_mode(struct vrf_map *vmap)
1886{
1887 bool strict_mode;
1888
1889 vrf_map_lock(vmap);
1890 strict_mode = vmap->strict_mode;
1891 vrf_map_unlock(vmap);
1892
1893 return strict_mode;
1894}
1895
1896static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode)
1897{
1898 bool *cur_mode;
1899 int res = 0;
1900
1901 vrf_map_lock(vmap);
1902
1903 cur_mode = &vmap->strict_mode;
1904 if (*cur_mode == new_mode)
1905 goto unlock;
1906
1907 if (*cur_mode) {
1908 /* disable strict mode */
1909 *cur_mode = false;
1910 } else {
1911 if (vmap->shared_tables) {
1912 /* we cannot allow strict_mode because there are some
1913 * vrfs that share one or more tables.
1914 */
1915 res = -EBUSY;
1916 goto unlock;
1917 }
1918
1919 /* no tables are shared among vrfs, so we can go back
1920 * to 1:1 association between a vrf with its table.
1921 */
1922 *cur_mode = true;
1923 }
1924
1925unlock:
1926 vrf_map_unlock(vmap);
1927
1928 return res;
1929}
1930
1931static int vrf_shared_table_handler(struct ctl_table *table, int write,
1932 void *buffer, size_t *lenp, loff_t *ppos)
1933{
1934 struct net *net = (struct net *)table->extra1;
1935 struct vrf_map *vmap = netns_vrf_map(net);
1936 int proc_strict_mode = 0;
1937 struct ctl_table tmp = {
1938 .procname = table->procname,
1939 .data = &proc_strict_mode,
1940 .maxlen = sizeof(int),
1941 .mode = table->mode,
1942 .extra1 = SYSCTL_ZERO,
1943 .extra2 = SYSCTL_ONE,
1944 };
1945 int ret;
1946
1947 if (!write)
1948 proc_strict_mode = vrf_strict_mode(vmap);
1949
1950 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
1951
1952 if (write && ret == 0)
1953 ret = vrf_strict_mode_change(vmap, (bool)proc_strict_mode);
1954
1955 return ret;
1956}
1957
1958static const struct ctl_table vrf_table[] = {
1959 {
1960 .procname = "strict_mode",
1961 .data = NULL,
1962 .maxlen = sizeof(int),
1963 .mode = 0644,
1964 .proc_handler = vrf_shared_table_handler,
1965 /* set by the vrf_netns_init */
1966 .extra1 = NULL,
1967 },
1968 { },
1969};
1970
1971static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1972{
1973 struct ctl_table *table;
1974
1975 table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL);
1976 if (!table)
1977 return -ENOMEM;
1978
1979 /* init the extra1 parameter with the reference to current netns */
1980 table[0].extra1 = net;
1981
1982 nn_vrf->ctl_hdr = register_net_sysctl(net, "net/vrf", table);
1983 if (!nn_vrf->ctl_hdr) {
1984 kfree(table);
1985 return -ENOMEM;
1986 }
1987
1988 return 0;
1989}
1990
1991static void vrf_netns_exit_sysctl(struct net *net)
1992{
1993 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
1994 struct ctl_table *table;
1995
1996 table = nn_vrf->ctl_hdr->ctl_table_arg;
1997 unregister_net_sysctl_table(nn_vrf->ctl_hdr);
1998 kfree(table);
1999}
2000#else
2001static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
2002{
2003 return 0;
2004}
2005
2006static void vrf_netns_exit_sysctl(struct net *net)
2007{
2008}
2009#endif
2010
2011/* Initialize per network namespace state */
2012static int __net_init vrf_netns_init(struct net *net)
2013{
2014 struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
2015
2016 nn_vrf->add_fib_rules = true;
2017 vrf_map_init(&nn_vrf->vmap);
2018
2019 return vrf_netns_init_sysctl(net, nn_vrf);
2020}
2021
2022static void __net_exit vrf_netns_exit(struct net *net)
2023{
2024 vrf_netns_exit_sysctl(net);
2025}
2026
2027static struct pernet_operations vrf_net_ops __net_initdata = {
2028 .init = vrf_netns_init,
2029 .exit = vrf_netns_exit,
2030 .id = &vrf_net_id,
2031 .size = sizeof(struct netns_vrf),
2032};
2033
2034static int __init vrf_init_module(void)
2035{
2036 int rc;
2037
2038 register_netdevice_notifier(&vrf_notifier_block);
2039
2040 rc = register_pernet_subsys(&vrf_net_ops);
2041 if (rc < 0)
2042 goto error;
2043
2044 rc = l3mdev_table_lookup_register(L3MDEV_TYPE_VRF,
2045 vrf_ifindex_lookup_by_table_id);
2046 if (rc < 0)
2047 goto unreg_pernet;
2048
2049 rc = rtnl_link_register(&vrf_link_ops);
2050 if (rc < 0)
2051 goto table_lookup_unreg;
2052
2053 return 0;
2054
2055table_lookup_unreg:
2056 l3mdev_table_lookup_unregister(L3MDEV_TYPE_VRF,
2057 vrf_ifindex_lookup_by_table_id);
2058
2059unreg_pernet:
2060 unregister_pernet_subsys(&vrf_net_ops);
2061
2062error:
2063 unregister_netdevice_notifier(&vrf_notifier_block);
2064 return rc;
2065}
2066
2067module_init(vrf_init_module);
2068MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
2069MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
2070MODULE_LICENSE("GPL");
2071MODULE_ALIAS_RTNL_LINK(DRV_NAME);
2072MODULE_VERSION(DRV_VERSION);