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/netdev_lock.h>
38#include <net/sch_generic.h>
39#include <net/netns/generic.h>
40#include <net/netfilter/nf_conntrack.h>
41#include <net/inet_dscp.h>
42
43#define DRV_NAME "vrf"
44#define DRV_VERSION "1.1"
45
46#define FIB_RULE_PREF 1000 /* default preference for FIB rules */
47
48#define HT_MAP_BITS 4
49#define HASH_INITVAL ((u32)0xcafef00d)
50
51struct vrf_map {
52 DECLARE_HASHTABLE(ht, HT_MAP_BITS);
53 spinlock_t vmap_lock;
54
55 /* shared_tables:
56 * count how many distinct tables do not comply with the strict mode
57 * requirement.
58 * shared_tables value must be 0 in order to enable the strict mode.
59 *
60 * example of the evolution of shared_tables:
61 * | time
62 * add vrf0 --> table 100 shared_tables = 0 | t0
63 * add vrf1 --> table 101 shared_tables = 0 | t1
64 * add vrf2 --> table 100 shared_tables = 1 | t2
65 * add vrf3 --> table 100 shared_tables = 1 | t3
66 * add vrf4 --> table 101 shared_tables = 2 v t4
67 *
68 * shared_tables is a "step function" (or "staircase function")
69 * and it is increased by one when the second vrf is associated to a
70 * table.
71 *
72 * at t2, vrf0 and vrf2 are bound to table 100: shared_tables = 1.
73 *
74 * at t3, another dev (vrf3) is bound to the same table 100 but the
75 * value of shared_tables is still 1.
76 * This means that no matter how many new vrfs will register on the
77 * table 100, the shared_tables will not increase (considering only
78 * table 100).
79 *
80 * at t4, vrf4 is bound to table 101, and shared_tables = 2.
81 *
82 * Looking at the value of shared_tables we can immediately know if
83 * the strict_mode can or cannot be enforced. Indeed, strict_mode
84 * can be enforced iff shared_tables = 0.
85 *
86 * Conversely, shared_tables is decreased when a vrf is de-associated
87 * from a table with exactly two associated vrfs.
88 */
89 u32 shared_tables;
90
91 bool strict_mode;
92};
93
94struct vrf_map_elem {
95 struct hlist_node hnode;
96 struct list_head vrf_list; /* VRFs registered to this table */
97
98 u32 table_id;
99 int users;
100 int ifindex;
101};
102
103static unsigned int vrf_net_id;
104
105/* per netns vrf data */
106struct netns_vrf {
107 /* protected by rtnl lock */
108 bool add_fib_rules;
109
110 struct vrf_map vmap;
111 struct ctl_table_header *ctl_hdr;
112};
113
114struct net_vrf {
115 struct rtable __rcu *rth;
116 struct rt6_info __rcu *rt6;
117#if IS_ENABLED(CONFIG_IPV6)
118 struct fib6_table *fib6_table;
119#endif
120 u32 tb_id;
121
122 struct list_head me_list; /* entry in vrf_map_elem */
123 int ifindex;
124};
125
126static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
127{
128 vrf_dev->stats.tx_errors++;
129 kfree_skb(skb);
130}
131
132static struct vrf_map *netns_vrf_map(struct net *net)
133{
134 struct netns_vrf *nn_vrf = net_generic(net, id: vrf_net_id);
135
136 return &nn_vrf->vmap;
137}
138
139static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev)
140{
141 return netns_vrf_map(net: dev_net(dev));
142}
143
144static int vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem *me)
145{
146 struct list_head *me_head = &me->vrf_list;
147 struct net_vrf *vrf;
148
149 if (list_empty(head: me_head))
150 return -ENODEV;
151
152 vrf = list_first_entry(me_head, struct net_vrf, me_list);
153
154 return vrf->ifindex;
155}
156
157static struct vrf_map_elem *vrf_map_elem_alloc(gfp_t flags)
158{
159 struct vrf_map_elem *me;
160
161 me = kmalloc(sizeof(*me), flags);
162 if (!me)
163 return NULL;
164
165 return me;
166}
167
168static void vrf_map_elem_free(struct vrf_map_elem *me)
169{
170 kfree(objp: me);
171}
172
173static void vrf_map_elem_init(struct vrf_map_elem *me, int table_id,
174 int ifindex, int users)
175{
176 me->table_id = table_id;
177 me->ifindex = ifindex;
178 me->users = users;
179 INIT_LIST_HEAD(list: &me->vrf_list);
180}
181
182static struct vrf_map_elem *vrf_map_lookup_elem(struct vrf_map *vmap,
183 u32 table_id)
184{
185 struct vrf_map_elem *me;
186 u32 key;
187
188 key = jhash_1word(a: table_id, HASH_INITVAL);
189 hash_for_each_possible(vmap->ht, me, hnode, key) {
190 if (me->table_id == table_id)
191 return me;
192 }
193
194 return NULL;
195}
196
197static void vrf_map_add_elem(struct vrf_map *vmap, struct vrf_map_elem *me)
198{
199 u32 table_id = me->table_id;
200 u32 key;
201
202 key = jhash_1word(a: table_id, HASH_INITVAL);
203 hash_add(vmap->ht, &me->hnode, key);
204}
205
206static void vrf_map_del_elem(struct vrf_map_elem *me)
207{
208 hash_del(node: &me->hnode);
209}
210
211static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock)
212{
213 spin_lock(lock: &vmap->vmap_lock);
214}
215
216static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock)
217{
218 spin_unlock(lock: &vmap->vmap_lock);
219}
220
221/* called with rtnl lock held */
222static int
223vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack)
224{
225 struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
226 struct net_vrf *vrf = netdev_priv(dev);
227 struct vrf_map_elem *new_me, *me;
228 u32 table_id = vrf->tb_id;
229 bool free_new_me = false;
230 int users;
231 int res;
232
233 /* we pre-allocate elements used in the spin-locked section (so that we
234 * keep the spinlock as short as possible).
235 */
236 new_me = vrf_map_elem_alloc(GFP_KERNEL);
237 if (!new_me)
238 return -ENOMEM;
239
240 vrf_map_elem_init(me: new_me, table_id, ifindex: dev->ifindex, users: 0);
241
242 vrf_map_lock(vmap);
243
244 me = vrf_map_lookup_elem(vmap, table_id);
245 if (!me) {
246 me = new_me;
247 vrf_map_add_elem(vmap, me);
248 goto link_vrf;
249 }
250
251 /* we already have an entry in the vrf_map, so it means there is (at
252 * least) a vrf registered on the specific table.
253 */
254 free_new_me = true;
255 if (vmap->strict_mode) {
256 /* vrfs cannot share the same table */
257 NL_SET_ERR_MSG(extack, "Table is used by another VRF");
258 res = -EBUSY;
259 goto unlock;
260 }
261
262link_vrf:
263 users = ++me->users;
264 if (users == 2)
265 ++vmap->shared_tables;
266
267 list_add(new: &vrf->me_list, head: &me->vrf_list);
268
269 res = 0;
270
271unlock:
272 vrf_map_unlock(vmap);
273
274 /* clean-up, if needed */
275 if (free_new_me)
276 vrf_map_elem_free(me: new_me);
277
278 return res;
279}
280
281/* called with rtnl lock held */
282static void vrf_map_unregister_dev(struct net_device *dev)
283{
284 struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
285 struct net_vrf *vrf = netdev_priv(dev);
286 u32 table_id = vrf->tb_id;
287 struct vrf_map_elem *me;
288 int users;
289
290 vrf_map_lock(vmap);
291
292 me = vrf_map_lookup_elem(vmap, table_id);
293 if (!me)
294 goto unlock;
295
296 list_del(entry: &vrf->me_list);
297
298 users = --me->users;
299 if (users == 1) {
300 --vmap->shared_tables;
301 } else if (users == 0) {
302 vrf_map_del_elem(me);
303
304 /* no one will refer to this element anymore */
305 vrf_map_elem_free(me);
306 }
307
308unlock:
309 vrf_map_unlock(vmap);
310}
311
312/* return the vrf device index associated with the table_id */
313static int vrf_ifindex_lookup_by_table_id(struct net *net, u32 table_id)
314{
315 struct vrf_map *vmap = netns_vrf_map(net);
316 struct vrf_map_elem *me;
317 int ifindex;
318
319 vrf_map_lock(vmap);
320
321 if (!vmap->strict_mode) {
322 ifindex = -EPERM;
323 goto unlock;
324 }
325
326 me = vrf_map_lookup_elem(vmap, table_id);
327 if (!me) {
328 ifindex = -ENODEV;
329 goto unlock;
330 }
331
332 ifindex = vrf_map_elem_get_vrf_ifindex(me);
333
334unlock:
335 vrf_map_unlock(vmap);
336
337 return ifindex;
338}
339
340/* by default VRF devices do not have a qdisc and are expected
341 * to be created with only a single queue.
342 */
343static bool qdisc_tx_is_default(const struct net_device *dev)
344{
345 struct netdev_queue *txq;
346
347 if (dev->num_tx_queues > 1)
348 return false;
349
350 txq = netdev_get_tx_queue(dev, index: 0);
351
352 return qdisc_txq_has_no_queue(txq);
353}
354
355/* Local traffic destined to local address. Reinsert the packet to rx
356 * path, similar to loopback handling.
357 */
358static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
359 struct dst_entry *dst)
360{
361 unsigned int len = skb->len;
362
363 skb_orphan(skb);
364
365 skb_dst_set(skb, dst);
366
367 /* set pkt_type to avoid skb hitting packet taps twice -
368 * once on Tx and again in Rx processing
369 */
370 skb->pkt_type = PACKET_LOOPBACK;
371
372 skb->protocol = eth_type_trans(skb, dev);
373
374 if (likely(__netif_rx(skb) == NET_RX_SUCCESS))
375 dev_dstats_rx_add(dev, len);
376 else
377 dev_dstats_rx_dropped(dev);
378
379 return NETDEV_TX_OK;
380}
381
382static void vrf_nf_set_untracked(struct sk_buff *skb)
383{
384 if (skb_get_nfct(skb) == 0)
385 nf_ct_set(skb, NULL, info: IP_CT_UNTRACKED);
386}
387
388static void vrf_nf_reset_ct(struct sk_buff *skb)
389{
390 if (skb_get_nfct(skb) == IP_CT_UNTRACKED)
391 nf_reset_ct(skb);
392}
393
394#if IS_ENABLED(CONFIG_IPV6)
395static int vrf_ip6_local_out(struct net *net, struct sock *sk,
396 struct sk_buff *skb)
397{
398 int err;
399
400 vrf_nf_reset_ct(skb);
401
402 err = nf_hook(pf: NFPROTO_IPV6, hook: NF_INET_LOCAL_OUT, net,
403 sk, skb, NULL, outdev: skb_dst(skb)->dev, okfn: dst_output);
404
405 if (likely(err == 1))
406 err = dst_output(net, sk, skb);
407
408 return err;
409}
410
411static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
412 struct net_device *dev)
413{
414 const struct ipv6hdr *iph;
415 struct net *net = dev_net(dev: skb->dev);
416 struct flowi6 fl6;
417 int ret = NET_XMIT_DROP;
418 struct dst_entry *dst;
419 struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
420
421 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
422 goto err;
423
424 iph = ipv6_hdr(skb);
425
426 memset(&fl6, 0, sizeof(fl6));
427 /* needed to match OIF rule */
428 fl6.flowi6_l3mdev = dev->ifindex;
429 fl6.flowi6_iif = LOOPBACK_IFINDEX;
430 fl6.daddr = iph->daddr;
431 fl6.saddr = iph->saddr;
432 fl6.flowlabel = ip6_flowinfo(hdr: iph);
433 fl6.flowi6_mark = skb->mark;
434 fl6.flowi6_proto = iph->nexthdr;
435
436 dst = ip6_dst_lookup_flow(net, NULL, fl6: &fl6, NULL);
437 if (IS_ERR(ptr: dst) || dst == dst_null)
438 goto err;
439
440 skb_dst_drop(skb);
441
442 /* if dst.dev is the VRF device again this is locally originated traffic
443 * destined to a local address. Short circuit to Rx path.
444 */
445 if (dst->dev == dev)
446 return vrf_local_xmit(skb, dev, dst);
447
448 skb_dst_set(skb, dst);
449
450 /* strip the ethernet header added for pass through VRF device */
451 __skb_pull(skb, len: skb_network_offset(skb));
452
453 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
454 ret = vrf_ip6_local_out(net, sk: skb->sk, skb);
455 if (unlikely(net_xmit_eval(ret)))
456 dev->stats.tx_errors++;
457 else
458 ret = NET_XMIT_SUCCESS;
459
460 return ret;
461err:
462 vrf_tx_error(vrf_dev: dev, skb);
463 return NET_XMIT_DROP;
464}
465#else
466static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
467 struct net_device *dev)
468{
469 vrf_tx_error(dev, skb);
470 return NET_XMIT_DROP;
471}
472#endif
473
474/* based on ip_local_out; can't use it b/c the dst is switched pointing to us */
475static int vrf_ip_local_out(struct net *net, struct sock *sk,
476 struct sk_buff *skb)
477{
478 int err;
479
480 vrf_nf_reset_ct(skb);
481
482 err = nf_hook(pf: NFPROTO_IPV4, hook: NF_INET_LOCAL_OUT, net, sk,
483 skb, NULL, outdev: skb_dst(skb)->dev, okfn: dst_output);
484 if (likely(err == 1))
485 err = dst_output(net, sk, skb);
486
487 return err;
488}
489
490static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
491 struct net_device *vrf_dev)
492{
493 struct iphdr *ip4h;
494 int ret = NET_XMIT_DROP;
495 struct flowi4 fl4;
496 struct net *net = dev_net(dev: vrf_dev);
497 struct rtable *rt;
498
499 if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
500 goto err;
501
502 ip4h = ip_hdr(skb);
503
504 memset(&fl4, 0, sizeof(fl4));
505 /* needed to match OIF rule */
506 fl4.flowi4_l3mdev = vrf_dev->ifindex;
507 fl4.flowi4_iif = LOOPBACK_IFINDEX;
508 fl4.flowi4_tos = inet_dscp_to_dsfield(dscp: ip4h_dscp(ip4h));
509 fl4.flowi4_flags = FLOWI_FLAG_ANYSRC;
510 fl4.flowi4_proto = ip4h->protocol;
511 fl4.daddr = ip4h->daddr;
512 fl4.saddr = ip4h->saddr;
513
514 rt = ip_route_output_flow(net, flp: &fl4, NULL);
515 if (IS_ERR(ptr: rt))
516 goto err;
517
518 skb_dst_drop(skb);
519
520 /* if dst.dev is the VRF device again this is locally originated traffic
521 * destined to a local address. Short circuit to Rx path.
522 */
523 if (rt->dst.dev == vrf_dev)
524 return vrf_local_xmit(skb, dev: vrf_dev, dst: &rt->dst);
525
526 skb_dst_set(skb, dst: &rt->dst);
527
528 /* strip the ethernet header added for pass through VRF device */
529 __skb_pull(skb, len: skb_network_offset(skb));
530
531 if (!ip4h->saddr) {
532 ip4h->saddr = inet_select_addr(dev: skb_dst(skb)->dev, dst: 0,
533 scope: RT_SCOPE_LINK);
534 }
535
536 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
537 ret = vrf_ip_local_out(net: dev_net(dev: skb_dst(skb)->dev), sk: skb->sk, skb);
538 if (unlikely(net_xmit_eval(ret)))
539 vrf_dev->stats.tx_errors++;
540 else
541 ret = NET_XMIT_SUCCESS;
542
543out:
544 return ret;
545err:
546 vrf_tx_error(vrf_dev, skb);
547 goto out;
548}
549
550static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
551{
552 switch (skb->protocol) {
553 case htons(ETH_P_IP):
554 return vrf_process_v4_outbound(skb, vrf_dev: dev);
555 case htons(ETH_P_IPV6):
556 return vrf_process_v6_outbound(skb, dev);
557 default:
558 vrf_tx_error(vrf_dev: dev, skb);
559 return NET_XMIT_DROP;
560 }
561}
562
563static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
564{
565 unsigned int len = skb->len;
566 netdev_tx_t ret;
567
568 ret = is_ip_tx_frame(skb, dev);
569 if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN))
570 dev_dstats_tx_add(dev, len);
571 else
572 dev_dstats_tx_dropped(dev);
573
574 return ret;
575}
576
577static void vrf_finish_direct(struct sk_buff *skb)
578{
579 struct net_device *vrf_dev = skb->dev;
580
581 if (!list_empty(head: &vrf_dev->ptype_all) &&
582 likely(skb_headroom(skb) >= ETH_HLEN)) {
583 struct ethhdr *eth = skb_push(skb, ETH_HLEN);
584
585 ether_addr_copy(dst: eth->h_source, src: vrf_dev->dev_addr);
586 eth_zero_addr(addr: eth->h_dest);
587 eth->h_proto = skb->protocol;
588
589 rcu_read_lock_bh();
590 dev_queue_xmit_nit(skb, dev: vrf_dev);
591 rcu_read_unlock_bh();
592
593 skb_pull(skb, ETH_HLEN);
594 }
595
596 vrf_nf_reset_ct(skb);
597}
598
599#if IS_ENABLED(CONFIG_IPV6)
600/* modelled after ip6_finish_output2 */
601static int vrf_finish_output6(struct net *net, struct sock *sk,
602 struct sk_buff *skb)
603{
604 struct dst_entry *dst = skb_dst(skb);
605 struct net_device *dev = dst->dev;
606 const struct in6_addr *nexthop;
607 struct neighbour *neigh;
608 int ret;
609
610 vrf_nf_reset_ct(skb);
611
612 skb->protocol = htons(ETH_P_IPV6);
613 skb->dev = dev;
614
615 rcu_read_lock();
616 nexthop = rt6_nexthop(dst_rt6_info(dst), daddr: &ipv6_hdr(skb)->daddr);
617 neigh = __ipv6_neigh_lookup_noref(dev: dst->dev, pkey: nexthop);
618 if (unlikely(!neigh))
619 neigh = __neigh_create(tbl: &nd_tbl, pkey: nexthop, dev: dst->dev, want_ref: false);
620 if (!IS_ERR(ptr: neigh)) {
621 sock_confirm_neigh(skb, n: neigh);
622 ret = neigh_output(n: neigh, skb, skip_cache: false);
623 rcu_read_unlock();
624 return ret;
625 }
626 rcu_read_unlock();
627
628 IP6_INC_STATS(dev_net(dst->dev),
629 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
630 kfree_skb(skb);
631 return -EINVAL;
632}
633
634/* modelled after ip6_output */
635static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
636{
637 return NF_HOOK_COND(pf: NFPROTO_IPV6, hook: NF_INET_POST_ROUTING,
638 net, sk, skb, NULL, out: skb_dst(skb)->dev,
639 okfn: vrf_finish_output6,
640 cond: !(IP6CB(skb)->flags & IP6SKB_REROUTED));
641}
642
643/* set dst on skb to send packet to us via dev_xmit path. Allows
644 * packet to go through device based features such as qdisc, netfilter
645 * hooks and packet sockets with skb->dev set to vrf device.
646 */
647static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev,
648 struct sk_buff *skb)
649{
650 struct net_vrf *vrf = netdev_priv(dev: vrf_dev);
651 struct dst_entry *dst = NULL;
652 struct rt6_info *rt6;
653
654 rcu_read_lock();
655
656 rt6 = rcu_dereference(vrf->rt6);
657 if (likely(rt6)) {
658 dst = &rt6->dst;
659 dst_hold(dst);
660 }
661
662 rcu_read_unlock();
663
664 if (unlikely(!dst)) {
665 vrf_tx_error(vrf_dev, skb);
666 return NULL;
667 }
668
669 skb_dst_drop(skb);
670 skb_dst_set(skb, dst);
671
672 return skb;
673}
674
675static int vrf_output6_direct_finish(struct net *net, struct sock *sk,
676 struct sk_buff *skb)
677{
678 vrf_finish_direct(skb);
679
680 return vrf_ip6_local_out(net, sk, skb);
681}
682
683static int vrf_output6_direct(struct net *net, struct sock *sk,
684 struct sk_buff *skb)
685{
686 int err = 1;
687
688 skb->protocol = htons(ETH_P_IPV6);
689
690 if (!(IPCB(skb)->flags & IPSKB_REROUTED))
691 err = nf_hook(pf: NFPROTO_IPV6, hook: NF_INET_POST_ROUTING, net, sk, skb,
692 NULL, outdev: skb->dev, okfn: vrf_output6_direct_finish);
693
694 if (likely(err == 1))
695 vrf_finish_direct(skb);
696
697 return err;
698}
699
700static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk,
701 struct sk_buff *skb)
702{
703 int err;
704
705 err = vrf_output6_direct(net, sk, skb);
706 if (likely(err == 1))
707 err = vrf_ip6_local_out(net, sk, skb);
708
709 return err;
710}
711
712static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
713 struct sock *sk,
714 struct sk_buff *skb)
715{
716 struct net *net = dev_net(dev: vrf_dev);
717 int err;
718
719 skb->dev = vrf_dev;
720
721 err = nf_hook(pf: NFPROTO_IPV6, hook: NF_INET_LOCAL_OUT, net, sk,
722 skb, NULL, outdev: vrf_dev, okfn: vrf_ip6_out_direct_finish);
723
724 if (likely(err == 1))
725 err = vrf_output6_direct(net, sk, skb);
726
727 if (likely(err == 1))
728 return skb;
729
730 return NULL;
731}
732
733static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
734 struct sock *sk,
735 struct sk_buff *skb)
736{
737 /* don't divert link scope packets */
738 if (rt6_need_strict(daddr: &ipv6_hdr(skb)->daddr))
739 return skb;
740
741 vrf_nf_set_untracked(skb);
742
743 if (qdisc_tx_is_default(dev: vrf_dev) ||
744 IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
745 return vrf_ip6_out_direct(vrf_dev, sk, skb);
746
747 return vrf_ip6_out_redirect(vrf_dev, skb);
748}
749
750/* holding rtnl */
751static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
752{
753 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
754 struct net *net = dev_net(dev);
755 struct dst_entry *dst;
756
757 RCU_INIT_POINTER(vrf->rt6, NULL);
758 synchronize_rcu();
759
760 /* move dev in dst's to loopback so this VRF device can be deleted
761 * - based on dst_ifdown
762 */
763 if (rt6) {
764 dst = &rt6->dst;
765 netdev_ref_replace(odev: dst->dev, ndev: net->loopback_dev,
766 tracker: &dst->dev_tracker, GFP_KERNEL);
767 dst->dev = net->loopback_dev;
768 dst_release(dst);
769 }
770}
771
772static int vrf_rt6_create(struct net_device *dev)
773{
774 int flags = DST_NOPOLICY | DST_NOXFRM;
775 struct net_vrf *vrf = netdev_priv(dev);
776 struct net *net = dev_net(dev);
777 struct rt6_info *rt6;
778 int rc = -ENOMEM;
779
780 /* IPv6 can be CONFIG enabled and then disabled runtime */
781 if (!ipv6_mod_enabled())
782 return 0;
783
784 vrf->fib6_table = fib6_new_table(net, id: vrf->tb_id);
785 if (!vrf->fib6_table)
786 goto out;
787
788 /* create a dst for routing packets out a VRF device */
789 rt6 = ip6_dst_alloc(net, dev, flags);
790 if (!rt6)
791 goto out;
792
793 rt6->dst.output = vrf_output6;
794
795 rcu_assign_pointer(vrf->rt6, rt6);
796
797 rc = 0;
798out:
799 return rc;
800}
801#else
802static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
803 struct sock *sk,
804 struct sk_buff *skb)
805{
806 return skb;
807}
808
809static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
810{
811}
812
813static int vrf_rt6_create(struct net_device *dev)
814{
815 return 0;
816}
817#endif
818
819/* modelled after ip_finish_output2 */
820static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
821{
822 struct dst_entry *dst = skb_dst(skb);
823 struct rtable *rt = dst_rtable(dst);
824 struct net_device *dev = dst->dev;
825 unsigned int hh_len = LL_RESERVED_SPACE(dev);
826 struct neighbour *neigh;
827 bool is_v6gw = false;
828
829 vrf_nf_reset_ct(skb);
830
831 /* Be paranoid, rather than too clever. */
832 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
833 skb = skb_expand_head(skb, headroom: hh_len);
834 if (!skb) {
835 dev->stats.tx_errors++;
836 return -ENOMEM;
837 }
838 }
839
840 rcu_read_lock();
841
842 neigh = ip_neigh_for_gw(rt, skb, is_v6gw: &is_v6gw);
843 if (!IS_ERR(ptr: neigh)) {
844 int ret;
845
846 sock_confirm_neigh(skb, n: neigh);
847 /* if crossing protocols, can not use the cached header */
848 ret = neigh_output(n: neigh, skb, skip_cache: is_v6gw);
849 rcu_read_unlock();
850 return ret;
851 }
852
853 rcu_read_unlock();
854 vrf_tx_error(vrf_dev: skb->dev, skb);
855 return -EINVAL;
856}
857
858static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
859{
860 struct net_device *dev = skb_dst(skb)->dev;
861
862 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
863
864 skb->dev = dev;
865 skb->protocol = htons(ETH_P_IP);
866
867 return NF_HOOK_COND(pf: NFPROTO_IPV4, hook: NF_INET_POST_ROUTING,
868 net, sk, skb, NULL, out: dev,
869 okfn: vrf_finish_output,
870 cond: !(IPCB(skb)->flags & IPSKB_REROUTED));
871}
872
873/* set dst on skb to send packet to us via dev_xmit path. Allows
874 * packet to go through device based features such as qdisc, netfilter
875 * hooks and packet sockets with skb->dev set to vrf device.
876 */
877static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev,
878 struct sk_buff *skb)
879{
880 struct net_vrf *vrf = netdev_priv(dev: vrf_dev);
881 struct dst_entry *dst = NULL;
882 struct rtable *rth;
883
884 rcu_read_lock();
885
886 rth = rcu_dereference(vrf->rth);
887 if (likely(rth)) {
888 dst = &rth->dst;
889 dst_hold(dst);
890 }
891
892 rcu_read_unlock();
893
894 if (unlikely(!dst)) {
895 vrf_tx_error(vrf_dev, skb);
896 return NULL;
897 }
898
899 skb_dst_drop(skb);
900 skb_dst_set(skb, dst);
901
902 return skb;
903}
904
905static int vrf_output_direct_finish(struct net *net, struct sock *sk,
906 struct sk_buff *skb)
907{
908 vrf_finish_direct(skb);
909
910 return vrf_ip_local_out(net, sk, skb);
911}
912
913static int vrf_output_direct(struct net *net, struct sock *sk,
914 struct sk_buff *skb)
915{
916 int err = 1;
917
918 skb->protocol = htons(ETH_P_IP);
919
920 if (!(IPCB(skb)->flags & IPSKB_REROUTED))
921 err = nf_hook(pf: NFPROTO_IPV4, hook: NF_INET_POST_ROUTING, net, sk, skb,
922 NULL, outdev: skb->dev, okfn: vrf_output_direct_finish);
923
924 if (likely(err == 1))
925 vrf_finish_direct(skb);
926
927 return err;
928}
929
930static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk,
931 struct sk_buff *skb)
932{
933 int err;
934
935 err = vrf_output_direct(net, sk, skb);
936 if (likely(err == 1))
937 err = vrf_ip_local_out(net, sk, skb);
938
939 return err;
940}
941
942static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
943 struct sock *sk,
944 struct sk_buff *skb)
945{
946 struct net *net = dev_net(dev: vrf_dev);
947 int err;
948
949 skb->dev = vrf_dev;
950
951 err = nf_hook(pf: NFPROTO_IPV4, hook: NF_INET_LOCAL_OUT, net, sk,
952 skb, NULL, outdev: vrf_dev, okfn: vrf_ip_out_direct_finish);
953
954 if (likely(err == 1))
955 err = vrf_output_direct(net, sk, skb);
956
957 if (likely(err == 1))
958 return skb;
959
960 return NULL;
961}
962
963static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
964 struct sock *sk,
965 struct sk_buff *skb)
966{
967 /* don't divert multicast or local broadcast */
968 if (ipv4_is_multicast(addr: ip_hdr(skb)->daddr) ||
969 ipv4_is_lbcast(addr: ip_hdr(skb)->daddr))
970 return skb;
971
972 vrf_nf_set_untracked(skb);
973
974 if (qdisc_tx_is_default(dev: vrf_dev) ||
975 IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
976 return vrf_ip_out_direct(vrf_dev, sk, skb);
977
978 return vrf_ip_out_redirect(vrf_dev, skb);
979}
980
981/* called with rcu lock held */
982static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
983 struct sock *sk,
984 struct sk_buff *skb,
985 u16 proto)
986{
987 switch (proto) {
988 case AF_INET:
989 return vrf_ip_out(vrf_dev, sk, skb);
990 case AF_INET6:
991 return vrf_ip6_out(vrf_dev, sk, skb);
992 }
993
994 return skb;
995}
996
997/* holding rtnl */
998static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
999{
1000 struct rtable *rth = rtnl_dereference(vrf->rth);
1001 struct net *net = dev_net(dev);
1002 struct dst_entry *dst;
1003
1004 RCU_INIT_POINTER(vrf->rth, NULL);
1005 synchronize_rcu();
1006
1007 /* move dev in dst's to loopback so this VRF device can be deleted
1008 * - based on dst_ifdown
1009 */
1010 if (rth) {
1011 dst = &rth->dst;
1012 netdev_ref_replace(odev: dst->dev, ndev: net->loopback_dev,
1013 tracker: &dst->dev_tracker, GFP_KERNEL);
1014 dst->dev = net->loopback_dev;
1015 dst_release(dst);
1016 }
1017}
1018
1019static int vrf_rtable_create(struct net_device *dev)
1020{
1021 struct net_vrf *vrf = netdev_priv(dev);
1022 struct rtable *rth;
1023
1024 if (!fib_new_table(net: dev_net(dev), id: vrf->tb_id))
1025 return -ENOMEM;
1026
1027 /* create a dst for routing packets out through a VRF device */
1028 rth = rt_dst_alloc(dev, flags: 0, type: RTN_UNICAST, noxfrm: 1);
1029 if (!rth)
1030 return -ENOMEM;
1031
1032 rth->dst.output = vrf_output;
1033
1034 rcu_assign_pointer(vrf->rth, rth);
1035
1036 return 0;
1037}
1038
1039/**************************** device handling ********************/
1040
1041/* cycle interface to flush neighbor cache and move routes across tables */
1042static void cycle_netdev(struct net_device *dev,
1043 struct netlink_ext_ack *extack)
1044{
1045 unsigned int flags = dev->flags;
1046 int ret;
1047
1048 if (!netif_running(dev))
1049 return;
1050
1051 ret = dev_change_flags(dev, flags: flags & ~IFF_UP, extack);
1052 if (ret >= 0)
1053 ret = dev_change_flags(dev, flags, extack);
1054
1055 if (ret < 0) {
1056 netdev_err(dev,
1057 format: "Failed to cycle device %s; route tables might be wrong!\n",
1058 dev->name);
1059 }
1060}
1061
1062static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1063 struct netlink_ext_ack *extack)
1064{
1065 int ret;
1066
1067 /* do not allow loopback device to be enslaved to a VRF.
1068 * The vrf device acts as the loopback for the vrf.
1069 */
1070 if (port_dev == dev_net(dev)->loopback_dev) {
1071 NL_SET_ERR_MSG(extack,
1072 "Can not enslave loopback device to a VRF");
1073 return -EOPNOTSUPP;
1074 }
1075
1076 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
1077 ret = netdev_master_upper_dev_link(dev: port_dev, upper_dev: dev, NULL, NULL, extack);
1078 if (ret < 0)
1079 goto err;
1080
1081 cycle_netdev(dev: port_dev, extack);
1082
1083 return 0;
1084
1085err:
1086 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1087 return ret;
1088}
1089
1090static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1091 struct netlink_ext_ack *extack)
1092{
1093 if (netif_is_l3_master(dev: port_dev)) {
1094 NL_SET_ERR_MSG(extack,
1095 "Can not enslave an L3 master device to a VRF");
1096 return -EINVAL;
1097 }
1098
1099 if (netif_is_l3_slave(dev: port_dev))
1100 return -EINVAL;
1101
1102 return do_vrf_add_slave(dev, port_dev, extack);
1103}
1104
1105/* inverse of do_vrf_add_slave */
1106static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1107{
1108 netdev_upper_dev_unlink(dev: port_dev, upper_dev: dev);
1109 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1110
1111 cycle_netdev(dev: port_dev, NULL);
1112
1113 return 0;
1114}
1115
1116static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1117{
1118 return do_vrf_del_slave(dev, port_dev);
1119}
1120
1121static void vrf_dev_uninit(struct net_device *dev)
1122{
1123 struct net_vrf *vrf = netdev_priv(dev);
1124
1125 vrf_rtable_release(dev, vrf);
1126 vrf_rt6_release(dev, vrf);
1127}
1128
1129static int vrf_dev_init(struct net_device *dev)
1130{
1131 struct net_vrf *vrf = netdev_priv(dev);
1132
1133 /* create the default dst which points back to us */
1134 if (vrf_rtable_create(dev) != 0)
1135 goto out_nomem;
1136
1137 if (vrf_rt6_create(dev) != 0)
1138 goto out_rth;
1139
1140 dev->flags = IFF_MASTER | IFF_NOARP;
1141
1142 /* similarly, oper state is irrelevant; set to up to avoid confusion */
1143 dev->operstate = IF_OPER_UP;
1144 netdev_lockdep_set_classes(dev);
1145 return 0;
1146
1147out_rth:
1148 vrf_rtable_release(dev, vrf);
1149out_nomem:
1150 return -ENOMEM;
1151}
1152
1153static const struct net_device_ops vrf_netdev_ops = {
1154 .ndo_init = vrf_dev_init,
1155 .ndo_uninit = vrf_dev_uninit,
1156 .ndo_start_xmit = vrf_xmit,
1157 .ndo_set_mac_address = eth_mac_addr,
1158 .ndo_add_slave = vrf_add_slave,
1159 .ndo_del_slave = vrf_del_slave,
1160};
1161
1162static u32 vrf_fib_table(const struct net_device *dev)
1163{
1164 struct net_vrf *vrf = netdev_priv(dev);
1165
1166 return vrf->tb_id;
1167}
1168
1169static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
1170{
1171 kfree_skb(skb);
1172 return 0;
1173}
1174
1175static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
1176 struct sk_buff *skb,
1177 struct net_device *dev)
1178{
1179 struct net *net = dev_net(dev);
1180
1181 if (nf_hook(pf, hook, net, NULL, skb, indev: dev, NULL, okfn: vrf_rcv_finish) != 1)
1182 skb = NULL; /* kfree_skb(skb) handled by nf code */
1183
1184 return skb;
1185}
1186
1187static int vrf_prepare_mac_header(struct sk_buff *skb,
1188 struct net_device *vrf_dev, u16 proto)
1189{
1190 struct ethhdr *eth;
1191 int err;
1192
1193 /* in general, we do not know if there is enough space in the head of
1194 * the packet for hosting the mac header.
1195 */
1196 err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev));
1197 if (unlikely(err))
1198 /* no space in the skb head */
1199 return -ENOBUFS;
1200
1201 __skb_push(skb, ETH_HLEN);
1202 eth = (struct ethhdr *)skb->data;
1203
1204 skb_reset_mac_header(skb);
1205 skb_reset_mac_len(skb);
1206
1207 /* we set the ethernet destination and the source addresses to the
1208 * address of the VRF device.
1209 */
1210 ether_addr_copy(dst: eth->h_dest, src: vrf_dev->dev_addr);
1211 ether_addr_copy(dst: eth->h_source, src: vrf_dev->dev_addr);
1212 eth->h_proto = htons(proto);
1213
1214 /* the destination address of the Ethernet frame corresponds to the
1215 * address set on the VRF interface; therefore, the packet is intended
1216 * to be processed locally.
1217 */
1218 skb->protocol = eth->h_proto;
1219 skb->pkt_type = PACKET_HOST;
1220
1221 skb_postpush_rcsum(skb, start: skb->data, ETH_HLEN);
1222
1223 skb_pull_inline(skb, ETH_HLEN);
1224
1225 return 0;
1226}
1227
1228/* prepare and add the mac header to the packet if it was not set previously.
1229 * In this way, packet sniffers such as tcpdump can parse the packet correctly.
1230 * If the mac header was already set, the original mac header is left
1231 * untouched and the function returns immediately.
1232 */
1233static int vrf_add_mac_header_if_unset(struct sk_buff *skb,
1234 struct net_device *vrf_dev,
1235 u16 proto, struct net_device *orig_dev)
1236{
1237 if (skb_mac_header_was_set(skb) && dev_has_header(dev: orig_dev))
1238 return 0;
1239
1240 return vrf_prepare_mac_header(skb, vrf_dev, proto);
1241}
1242
1243#if IS_ENABLED(CONFIG_IPV6)
1244/* neighbor handling is done with actual device; do not want
1245 * to flip skb->dev for those ndisc packets. This really fails
1246 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
1247 * a start.
1248 */
1249static bool ipv6_ndisc_frame(const struct sk_buff *skb)
1250{
1251 const struct ipv6hdr *iph = ipv6_hdr(skb);
1252 bool rc = false;
1253
1254 if (iph->nexthdr == NEXTHDR_ICMP) {
1255 const struct icmp6hdr *icmph;
1256 struct icmp6hdr _icmph;
1257
1258 icmph = skb_header_pointer(skb, offset: sizeof(*iph),
1259 len: sizeof(_icmph), buffer: &_icmph);
1260 if (!icmph)
1261 goto out;
1262
1263 switch (icmph->icmp6_type) {
1264 case NDISC_ROUTER_SOLICITATION:
1265 case NDISC_ROUTER_ADVERTISEMENT:
1266 case NDISC_NEIGHBOUR_SOLICITATION:
1267 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1268 case NDISC_REDIRECT:
1269 rc = true;
1270 break;
1271 }
1272 }
1273
1274out:
1275 return rc;
1276}
1277
1278static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
1279 const struct net_device *dev,
1280 struct flowi6 *fl6,
1281 int ifindex,
1282 const struct sk_buff *skb,
1283 int flags)
1284{
1285 struct net_vrf *vrf = netdev_priv(dev);
1286
1287 return ip6_pol_route(net, table: vrf->fib6_table, ifindex, fl6, skb, flags);
1288}
1289
1290static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
1291 int ifindex)
1292{
1293 const struct ipv6hdr *iph = ipv6_hdr(skb);
1294 struct flowi6 fl6 = {
1295 .flowi6_iif = ifindex,
1296 .flowi6_mark = skb->mark,
1297 .flowi6_proto = iph->nexthdr,
1298 .daddr = iph->daddr,
1299 .saddr = iph->saddr,
1300 .flowlabel = ip6_flowinfo(hdr: iph),
1301 };
1302 struct net *net = dev_net(dev: vrf_dev);
1303 struct rt6_info *rt6;
1304
1305 rt6 = vrf_ip6_route_lookup(net, dev: vrf_dev, fl6: &fl6, ifindex, skb,
1306 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
1307 if (unlikely(!rt6))
1308 return;
1309
1310 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
1311 return;
1312
1313 skb_dst_set(skb, dst: &rt6->dst);
1314}
1315
1316static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1317 struct sk_buff *skb)
1318{
1319 int orig_iif = skb->skb_iif;
1320 bool need_strict = rt6_need_strict(daddr: &ipv6_hdr(skb)->daddr);
1321 bool is_ndisc = ipv6_ndisc_frame(skb);
1322
1323 /* loopback, multicast & non-ND link-local traffic; do not push through
1324 * packet taps again. Reset pkt_type for upper layers to process skb.
1325 * For non-loopback strict packets, determine the dst using the original
1326 * ifindex.
1327 */
1328 if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) {
1329 skb->dev = vrf_dev;
1330 skb->skb_iif = vrf_dev->ifindex;
1331 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1332
1333 if (skb->pkt_type == PACKET_LOOPBACK)
1334 skb->pkt_type = PACKET_HOST;
1335 else
1336 vrf_ip6_input_dst(skb, vrf_dev, ifindex: orig_iif);
1337
1338 goto out;
1339 }
1340
1341 /* if packet is NDISC then keep the ingress interface */
1342 if (!is_ndisc) {
1343 struct net_device *orig_dev = skb->dev;
1344
1345 dev_dstats_rx_add(dev: vrf_dev, len: skb->len);
1346 skb->dev = vrf_dev;
1347 skb->skb_iif = vrf_dev->ifindex;
1348
1349 if (!list_empty(head: &vrf_dev->ptype_all)) {
1350 int err;
1351
1352 err = vrf_add_mac_header_if_unset(skb, vrf_dev,
1353 ETH_P_IPV6,
1354 orig_dev);
1355 if (likely(!err)) {
1356 skb_push(skb, len: skb->mac_len);
1357 dev_queue_xmit_nit(skb, dev: vrf_dev);
1358 skb_pull(skb, len: skb->mac_len);
1359 }
1360 }
1361
1362 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1363 }
1364
1365 if (need_strict)
1366 vrf_ip6_input_dst(skb, vrf_dev, ifindex: orig_iif);
1367
1368 skb = vrf_rcv_nfhook(pf: NFPROTO_IPV6, hook: NF_INET_PRE_ROUTING, skb, dev: vrf_dev);
1369out:
1370 return skb;
1371}
1372
1373#else
1374static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1375 struct sk_buff *skb)
1376{
1377 return skb;
1378}
1379#endif
1380
1381static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
1382 struct sk_buff *skb)
1383{
1384 struct net_device *orig_dev = skb->dev;
1385
1386 skb->dev = vrf_dev;
1387 skb->skb_iif = vrf_dev->ifindex;
1388 IPCB(skb)->flags |= IPSKB_L3SLAVE;
1389
1390 if (ipv4_is_multicast(addr: ip_hdr(skb)->daddr))
1391 goto out;
1392
1393 /* loopback traffic; do not push through packet taps again.
1394 * Reset pkt_type for upper layers to process skb
1395 */
1396 if (skb->pkt_type == PACKET_LOOPBACK) {
1397 skb->pkt_type = PACKET_HOST;
1398 goto out;
1399 }
1400
1401 dev_dstats_rx_add(dev: vrf_dev, len: skb->len);
1402
1403 if (!list_empty(head: &vrf_dev->ptype_all)) {
1404 int err;
1405
1406 err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP,
1407 orig_dev);
1408 if (likely(!err)) {
1409 skb_push(skb, len: skb->mac_len);
1410 dev_queue_xmit_nit(skb, dev: vrf_dev);
1411 skb_pull(skb, len: skb->mac_len);
1412 }
1413 }
1414
1415 skb = vrf_rcv_nfhook(pf: NFPROTO_IPV4, hook: NF_INET_PRE_ROUTING, skb, dev: vrf_dev);
1416out:
1417 return skb;
1418}
1419
1420/* called with rcu lock held */
1421static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1422 struct sk_buff *skb,
1423 u16 proto)
1424{
1425 switch (proto) {
1426 case AF_INET:
1427 return vrf_ip_rcv(vrf_dev, skb);
1428 case AF_INET6:
1429 return vrf_ip6_rcv(vrf_dev, skb);
1430 }
1431
1432 return skb;
1433}
1434
1435#if IS_ENABLED(CONFIG_IPV6)
1436/* send to link-local or multicast address via interface enslaved to
1437 * VRF device. Force lookup to VRF table without changing flow struct
1438 * Note: Caller to this function must hold rcu_read_lock() and no refcnt
1439 * is taken on the dst by this function.
1440 */
1441static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1442 struct flowi6 *fl6)
1443{
1444 struct net *net = dev_net(dev);
1445 int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF;
1446 struct dst_entry *dst = NULL;
1447 struct rt6_info *rt;
1448
1449 /* VRF device does not have a link-local address and
1450 * sending packets to link-local or mcast addresses over
1451 * a VRF device does not make sense
1452 */
1453 if (fl6->flowi6_oif == dev->ifindex) {
1454 dst = &net->ipv6.ip6_null_entry->dst;
1455 return dst;
1456 }
1457
1458 if (!ipv6_addr_any(a: &fl6->saddr))
1459 flags |= RT6_LOOKUP_F_HAS_SADDR;
1460
1461 rt = vrf_ip6_route_lookup(net, dev, fl6, ifindex: fl6->flowi6_oif, NULL, flags);
1462 if (rt)
1463 dst = &rt->dst;
1464
1465 return dst;
1466}
1467#endif
1468
1469static const struct l3mdev_ops vrf_l3mdev_ops = {
1470 .l3mdev_fib_table = vrf_fib_table,
1471 .l3mdev_l3_rcv = vrf_l3_rcv,
1472 .l3mdev_l3_out = vrf_l3_out,
1473#if IS_ENABLED(CONFIG_IPV6)
1474 .l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1475#endif
1476};
1477
1478static void vrf_get_drvinfo(struct net_device *dev,
1479 struct ethtool_drvinfo *info)
1480{
1481 strscpy(info->driver, DRV_NAME, sizeof(info->driver));
1482 strscpy(info->version, DRV_VERSION, sizeof(info->version));
1483}
1484
1485static const struct ethtool_ops vrf_ethtool_ops = {
1486 .get_drvinfo = vrf_get_drvinfo,
1487};
1488
1489static inline size_t vrf_fib_rule_nl_size(void)
1490{
1491 size_t sz;
1492
1493 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1494 sz += nla_total_size(payload: sizeof(u8)); /* FRA_L3MDEV */
1495 sz += nla_total_size(payload: sizeof(u32)); /* FRA_PRIORITY */
1496 sz += nla_total_size(payload: sizeof(u8)); /* FRA_PROTOCOL */
1497
1498 return sz;
1499}
1500
1501static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1502{
1503 struct fib_rule_hdr *frh;
1504 struct nlmsghdr *nlh;
1505 struct sk_buff *skb;
1506 int err;
1507
1508 if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) &&
1509 !ipv6_mod_enabled())
1510 return 0;
1511
1512 skb = nlmsg_new(payload: vrf_fib_rule_nl_size(), GFP_KERNEL);
1513 if (!skb)
1514 return -ENOMEM;
1515
1516 nlh = nlmsg_put(skb, portid: 0, seq: 0, type: 0, payload: sizeof(*frh), flags: 0);
1517 if (!nlh)
1518 goto nla_put_failure;
1519
1520 /* rule only needs to appear once */
1521 nlh->nlmsg_flags |= NLM_F_EXCL;
1522
1523 frh = nlmsg_data(nlh);
1524 memset(frh, 0, sizeof(*frh));
1525 frh->family = family;
1526 frh->action = FR_ACT_TO_TBL;
1527
1528 if (nla_put_u8(skb, attrtype: FRA_PROTOCOL, RTPROT_KERNEL))
1529 goto nla_put_failure;
1530
1531 if (nla_put_u8(skb, attrtype: FRA_L3MDEV, value: 1))
1532 goto nla_put_failure;
1533
1534 if (nla_put_u32(skb, attrtype: FRA_PRIORITY, FIB_RULE_PREF))
1535 goto nla_put_failure;
1536
1537 nlmsg_end(skb, nlh);
1538
1539 if (add_it) {
1540 err = fib_newrule(net: dev_net(dev), skb, nlh, NULL, rtnl_held: true);
1541 if (err == -EEXIST)
1542 err = 0;
1543 } else {
1544 err = fib_delrule(net: dev_net(dev), skb, nlh, NULL, rtnl_held: true);
1545 if (err == -ENOENT)
1546 err = 0;
1547 }
1548 nlmsg_free(skb);
1549
1550 return err;
1551
1552nla_put_failure:
1553 nlmsg_free(skb);
1554
1555 return -EMSGSIZE;
1556}
1557
1558static int vrf_add_fib_rules(const struct net_device *dev)
1559{
1560 int err;
1561
1562 err = vrf_fib_rule(dev, AF_INET, add_it: true);
1563 if (err < 0)
1564 goto out_err;
1565
1566 err = vrf_fib_rule(dev, AF_INET6, add_it: true);
1567 if (err < 0)
1568 goto ipv6_err;
1569
1570#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1571 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, add_it: true);
1572 if (err < 0)
1573 goto ipmr_err;
1574#endif
1575
1576#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1577 err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, add_it: true);
1578 if (err < 0)
1579 goto ip6mr_err;
1580#endif
1581
1582 return 0;
1583
1584#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1585ip6mr_err:
1586 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, add_it: false);
1587#endif
1588
1589#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1590ipmr_err:
1591 vrf_fib_rule(dev, AF_INET6, add_it: false);
1592#endif
1593
1594ipv6_err:
1595 vrf_fib_rule(dev, AF_INET, add_it: false);
1596
1597out_err:
1598 netdev_err(dev, format: "Failed to add FIB rules.\n");
1599 return err;
1600}
1601
1602static void vrf_setup(struct net_device *dev)
1603{
1604 ether_setup(dev);
1605
1606 /* Initialize the device structure. */
1607 dev->netdev_ops = &vrf_netdev_ops;
1608 dev->l3mdev_ops = &vrf_l3mdev_ops;
1609 dev->ethtool_ops = &vrf_ethtool_ops;
1610 dev->needs_free_netdev = true;
1611
1612 /* Fill in device structure with ethernet-generic values. */
1613 eth_hw_addr_random(dev);
1614
1615 /* don't acquire vrf device's netif_tx_lock when transmitting */
1616 dev->lltx = true;
1617
1618 /* don't allow vrf devices to change network namespaces. */
1619 dev->netns_immutable = true;
1620
1621 /* does not make sense for a VLAN to be added to a vrf device */
1622 dev->features |= NETIF_F_VLAN_CHALLENGED;
1623
1624 /* enable offload features */
1625 dev->features |= NETIF_F_GSO_SOFTWARE;
1626 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC;
1627 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1628
1629 dev->hw_features = dev->features;
1630 dev->hw_enc_features = dev->features;
1631
1632 /* default to no qdisc; user can add if desired */
1633 dev->priv_flags |= IFF_NO_QUEUE;
1634 dev->priv_flags |= IFF_NO_RX_HANDLER;
1635 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1636
1637 /* VRF devices do not care about MTU, but if the MTU is set
1638 * too low then the ipv4 and ipv6 protocols are disabled
1639 * which breaks networking.
1640 */
1641 dev->min_mtu = IPV6_MIN_MTU;
1642 dev->max_mtu = IP6_MAX_MTU;
1643 dev->mtu = dev->max_mtu;
1644
1645 dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS;
1646}
1647
1648static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],
1649 struct netlink_ext_ack *extack)
1650{
1651 if (tb[IFLA_ADDRESS]) {
1652 if (nla_len(nla: tb[IFLA_ADDRESS]) != ETH_ALEN) {
1653 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1654 return -EINVAL;
1655 }
1656 if (!is_valid_ether_addr(addr: nla_data(nla: tb[IFLA_ADDRESS]))) {
1657 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1658 return -EADDRNOTAVAIL;
1659 }
1660 }
1661 return 0;
1662}
1663
1664static void vrf_dellink(struct net_device *dev, struct list_head *head)
1665{
1666 struct net_device *port_dev;
1667 struct list_head *iter;
1668
1669 netdev_for_each_lower_dev(dev, port_dev, iter)
1670 vrf_del_slave(dev, port_dev);
1671
1672 vrf_map_unregister_dev(dev);
1673
1674 unregister_netdevice_queue(dev, head);
1675}
1676
1677static int vrf_newlink(struct net_device *dev,
1678 struct rtnl_newlink_params *params,
1679 struct netlink_ext_ack *extack)
1680{
1681 struct net_vrf *vrf = netdev_priv(dev);
1682 struct nlattr **data = params->data;
1683 struct netns_vrf *nn_vrf;
1684 bool *add_fib_rules;
1685 struct net *net;
1686 int err;
1687
1688 if (!data || !data[IFLA_VRF_TABLE]) {
1689 NL_SET_ERR_MSG(extack, "VRF table id is missing");
1690 return -EINVAL;
1691 }
1692
1693 vrf->tb_id = nla_get_u32(nla: data[IFLA_VRF_TABLE]);
1694 if (vrf->tb_id == RT_TABLE_UNSPEC) {
1695 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE],
1696 "Invalid VRF table id");
1697 return -EINVAL;
1698 }
1699
1700 dev->priv_flags |= IFF_L3MDEV_MASTER;
1701
1702 err = register_netdevice(dev);
1703 if (err)
1704 goto out;
1705
1706 /* mapping between table_id and vrf;
1707 * note: such binding could not be done in the dev init function
1708 * because dev->ifindex id is not available yet.
1709 */
1710 vrf->ifindex = dev->ifindex;
1711
1712 err = vrf_map_register_dev(dev, extack);
1713 if (err) {
1714 unregister_netdevice(dev);
1715 goto out;
1716 }
1717
1718 net = dev_net(dev);
1719 nn_vrf = net_generic(net, id: vrf_net_id);
1720
1721 add_fib_rules = &nn_vrf->add_fib_rules;
1722 if (*add_fib_rules) {
1723 err = vrf_add_fib_rules(dev);
1724 if (err) {
1725 vrf_map_unregister_dev(dev);
1726 unregister_netdevice(dev);
1727 goto out;
1728 }
1729 *add_fib_rules = false;
1730 }
1731
1732out:
1733 return err;
1734}
1735
1736static size_t vrf_nl_getsize(const struct net_device *dev)
1737{
1738 return nla_total_size(payload: sizeof(u32)); /* IFLA_VRF_TABLE */
1739}
1740
1741static int vrf_fillinfo(struct sk_buff *skb,
1742 const struct net_device *dev)
1743{
1744 struct net_vrf *vrf = netdev_priv(dev);
1745
1746 return nla_put_u32(skb, attrtype: IFLA_VRF_TABLE, value: vrf->tb_id);
1747}
1748
1749static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1750 const struct net_device *slave_dev)
1751{
1752 return nla_total_size(payload: sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1753}
1754
1755static int vrf_fill_slave_info(struct sk_buff *skb,
1756 const struct net_device *vrf_dev,
1757 const struct net_device *slave_dev)
1758{
1759 struct net_vrf *vrf = netdev_priv(dev: vrf_dev);
1760
1761 if (nla_put_u32(skb, attrtype: IFLA_VRF_PORT_TABLE, value: vrf->tb_id))
1762 return -EMSGSIZE;
1763
1764 return 0;
1765}
1766
1767static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1768 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1769};
1770
1771static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1772 .kind = DRV_NAME,
1773 .priv_size = sizeof(struct net_vrf),
1774
1775 .get_size = vrf_nl_getsize,
1776 .policy = vrf_nl_policy,
1777 .validate = vrf_validate,
1778 .fill_info = vrf_fillinfo,
1779
1780 .get_slave_size = vrf_get_slave_size,
1781 .fill_slave_info = vrf_fill_slave_info,
1782
1783 .newlink = vrf_newlink,
1784 .dellink = vrf_dellink,
1785 .setup = vrf_setup,
1786 .maxtype = IFLA_VRF_MAX,
1787};
1788
1789static int vrf_device_event(struct notifier_block *unused,
1790 unsigned long event, void *ptr)
1791{
1792 struct net_device *dev = netdev_notifier_info_to_dev(info: ptr);
1793
1794 /* only care about unregister events to drop slave references */
1795 if (event == NETDEV_UNREGISTER) {
1796 struct net_device *vrf_dev;
1797
1798 if (!netif_is_l3_slave(dev))
1799 goto out;
1800
1801 vrf_dev = netdev_master_upper_dev_get(dev);
1802 vrf_del_slave(dev: vrf_dev, port_dev: dev);
1803 }
1804out:
1805 return NOTIFY_DONE;
1806}
1807
1808static struct notifier_block vrf_notifier_block __read_mostly = {
1809 .notifier_call = vrf_device_event,
1810};
1811
1812static int vrf_map_init(struct vrf_map *vmap)
1813{
1814 spin_lock_init(&vmap->vmap_lock);
1815 hash_init(vmap->ht);
1816
1817 vmap->strict_mode = false;
1818
1819 return 0;
1820}
1821
1822#ifdef CONFIG_SYSCTL
1823static bool vrf_strict_mode(struct vrf_map *vmap)
1824{
1825 bool strict_mode;
1826
1827 vrf_map_lock(vmap);
1828 strict_mode = vmap->strict_mode;
1829 vrf_map_unlock(vmap);
1830
1831 return strict_mode;
1832}
1833
1834static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode)
1835{
1836 bool *cur_mode;
1837 int res = 0;
1838
1839 vrf_map_lock(vmap);
1840
1841 cur_mode = &vmap->strict_mode;
1842 if (*cur_mode == new_mode)
1843 goto unlock;
1844
1845 if (*cur_mode) {
1846 /* disable strict mode */
1847 *cur_mode = false;
1848 } else {
1849 if (vmap->shared_tables) {
1850 /* we cannot allow strict_mode because there are some
1851 * vrfs that share one or more tables.
1852 */
1853 res = -EBUSY;
1854 goto unlock;
1855 }
1856
1857 /* no tables are shared among vrfs, so we can go back
1858 * to 1:1 association between a vrf with its table.
1859 */
1860 *cur_mode = true;
1861 }
1862
1863unlock:
1864 vrf_map_unlock(vmap);
1865
1866 return res;
1867}
1868
1869static int vrf_shared_table_handler(const struct ctl_table *table, int write,
1870 void *buffer, size_t *lenp, loff_t *ppos)
1871{
1872 struct net *net = (struct net *)table->extra1;
1873 struct vrf_map *vmap = netns_vrf_map(net);
1874 int proc_strict_mode = 0;
1875 struct ctl_table tmp = {
1876 .procname = table->procname,
1877 .data = &proc_strict_mode,
1878 .maxlen = sizeof(int),
1879 .mode = table->mode,
1880 .extra1 = SYSCTL_ZERO,
1881 .extra2 = SYSCTL_ONE,
1882 };
1883 int ret;
1884
1885 if (!write)
1886 proc_strict_mode = vrf_strict_mode(vmap);
1887
1888 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
1889
1890 if (write && ret == 0)
1891 ret = vrf_strict_mode_change(vmap, new_mode: (bool)proc_strict_mode);
1892
1893 return ret;
1894}
1895
1896static const struct ctl_table vrf_table[] = {
1897 {
1898 .procname = "strict_mode",
1899 .data = NULL,
1900 .maxlen = sizeof(int),
1901 .mode = 0644,
1902 .proc_handler = vrf_shared_table_handler,
1903 /* set by the vrf_netns_init */
1904 .extra1 = NULL,
1905 },
1906};
1907
1908static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1909{
1910 struct ctl_table *table;
1911
1912 table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL);
1913 if (!table)
1914 return -ENOMEM;
1915
1916 /* init the extra1 parameter with the reference to current netns */
1917 table[0].extra1 = net;
1918
1919 nn_vrf->ctl_hdr = register_net_sysctl_sz(net, path: "net/vrf", table,
1920 ARRAY_SIZE(vrf_table));
1921 if (!nn_vrf->ctl_hdr) {
1922 kfree(objp: table);
1923 return -ENOMEM;
1924 }
1925
1926 return 0;
1927}
1928
1929static void vrf_netns_exit_sysctl(struct net *net)
1930{
1931 struct netns_vrf *nn_vrf = net_generic(net, id: vrf_net_id);
1932 const struct ctl_table *table;
1933
1934 table = nn_vrf->ctl_hdr->ctl_table_arg;
1935 unregister_net_sysctl_table(header: nn_vrf->ctl_hdr);
1936 kfree(objp: table);
1937}
1938#else
1939static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1940{
1941 return 0;
1942}
1943
1944static void vrf_netns_exit_sysctl(struct net *net)
1945{
1946}
1947#endif
1948
1949/* Initialize per network namespace state */
1950static int __net_init vrf_netns_init(struct net *net)
1951{
1952 struct netns_vrf *nn_vrf = net_generic(net, id: vrf_net_id);
1953
1954 nn_vrf->add_fib_rules = true;
1955 vrf_map_init(vmap: &nn_vrf->vmap);
1956
1957 return vrf_netns_init_sysctl(net, nn_vrf);
1958}
1959
1960static void __net_exit vrf_netns_exit(struct net *net)
1961{
1962 vrf_netns_exit_sysctl(net);
1963}
1964
1965static struct pernet_operations vrf_net_ops __net_initdata = {
1966 .init = vrf_netns_init,
1967 .exit = vrf_netns_exit,
1968 .id = &vrf_net_id,
1969 .size = sizeof(struct netns_vrf),
1970};
1971
1972static int __init vrf_init_module(void)
1973{
1974 int rc;
1975
1976 register_netdevice_notifier(nb: &vrf_notifier_block);
1977
1978 rc = register_pernet_subsys(&vrf_net_ops);
1979 if (rc < 0)
1980 goto error;
1981
1982 rc = l3mdev_table_lookup_register(l3type: L3MDEV_TYPE_VRF,
1983 fn: vrf_ifindex_lookup_by_table_id);
1984 if (rc < 0)
1985 goto unreg_pernet;
1986
1987 rc = rtnl_link_register(ops: &vrf_link_ops);
1988 if (rc < 0)
1989 goto table_lookup_unreg;
1990
1991 return 0;
1992
1993table_lookup_unreg:
1994 l3mdev_table_lookup_unregister(l3type: L3MDEV_TYPE_VRF,
1995 fn: vrf_ifindex_lookup_by_table_id);
1996
1997unreg_pernet:
1998 unregister_pernet_subsys(&vrf_net_ops);
1999
2000error:
2001 unregister_netdevice_notifier(nb: &vrf_notifier_block);
2002 return rc;
2003}
2004
2005module_init(vrf_init_module);
2006MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
2007MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
2008MODULE_LICENSE("GPL");
2009MODULE_ALIAS_RTNL_LINK(DRV_NAME);
2010MODULE_VERSION(DRV_VERSION);
2011

source code of linux/drivers/net/vrf.c