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(syncp: &dstats->syncp);
139 dstats->rx_pkts++;
140 dstats->rx_bytes += len;
141 u64_stats_update_end(syncp: &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(syncp: &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(syncp: &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, id: 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(net: 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(head: 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(size: 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(objp: 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(list: &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(a: 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(a: 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(node: &me->hnode);
254}
255
256static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock)
257{
258 spin_lock(lock: &vmap->vmap_lock);
259}
260
261static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock)
262{
263 spin_unlock(lock: &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(me: new_me, table_id, ifindex: dev->ifindex, users: 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(new: &vrf->me_list, head: &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(me: 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(entry: &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, index: 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, info: 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(pf: NFPROTO_IPV6, hook: NF_INET_LOCAL_OUT, net,
450 sk, skb, NULL, outdev: skb_dst(skb)->dev, okfn: 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(dev: 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(hdr: iph);
480 fl6.flowi6_mark = skb->mark;
481 fl6.flowi6_proto = iph->nexthdr;
482
483 dst = ip6_dst_lookup_flow(net, NULL, fl6: &fl6, NULL);
484 if (IS_ERR(ptr: 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, len: skb_network_offset(skb));
499
500 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
501 ret = vrf_ip6_local_out(net, sk: 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(vrf_dev: 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(pf: NFPROTO_IPV4, hook: NF_INET_LOCAL_OUT, net, sk,
530 skb, NULL, outdev: skb_dst(skb)->dev, okfn: 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(dev: 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, flp: &fl4, NULL);
562 if (IS_ERR(ptr: 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, dev: vrf_dev, dst: &rt->dst);
572
573 skb_dst_set(skb, dst: &rt->dst);
574
575 /* strip the ethernet header added for pass through VRF device */
576 __skb_pull(skb, len: skb_network_offset(skb));
577
578 if (!ip4h->saddr) {
579 ip4h->saddr = inet_select_addr(dev: skb_dst(skb)->dev, dst: 0,
580 scope: RT_SCOPE_LINK);
581 }
582
583 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
584 ret = vrf_ip_local_out(net: dev_net(dev: skb_dst(skb)->dev), sk: 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, vrf_dev: dev);
602 case htons(ETH_P_IPV6):
603 return vrf_process_v6_outbound(skb, dev);
604 default:
605 vrf_tx_error(vrf_dev: 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(syncp: &dstats->syncp);
619 dstats->tx_pkts++;
620 dstats->tx_bytes += len;
621 u64_stats_update_end(syncp: &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(head: &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(dst: eth->h_source, src: vrf_dev->dev_addr);
638 eth_zero_addr(addr: eth->h_dest);
639 eth->h_proto = skb->protocol;
640
641 dev_queue_xmit_nit(skb, dev: vrf_dev);
642
643 skb_pull(skb, ETH_HLEN);
644 }
645
646 vrf_nf_reset_ct(skb);
647}
648
649#if IS_ENABLED(CONFIG_IPV6)
650/* modelled after ip6_finish_output2 */
651static int vrf_finish_output6(struct net *net, struct sock *sk,
652 struct sk_buff *skb)
653{
654 struct dst_entry *dst = skb_dst(skb);
655 struct net_device *dev = dst->dev;
656 const struct in6_addr *nexthop;
657 struct neighbour *neigh;
658 int ret;
659
660 vrf_nf_reset_ct(skb);
661
662 skb->protocol = htons(ETH_P_IPV6);
663 skb->dev = dev;
664
665 rcu_read_lock();
666 nexthop = rt6_nexthop(rt: (struct rt6_info *)dst, daddr: &ipv6_hdr(skb)->daddr);
667 neigh = __ipv6_neigh_lookup_noref(dev: dst->dev, pkey: nexthop);
668 if (unlikely(!neigh))
669 neigh = __neigh_create(tbl: &nd_tbl, pkey: nexthop, dev: dst->dev, want_ref: false);
670 if (!IS_ERR(ptr: neigh)) {
671 sock_confirm_neigh(skb, n: neigh);
672 ret = neigh_output(n: neigh, skb, skip_cache: false);
673 rcu_read_unlock();
674 return ret;
675 }
676 rcu_read_unlock();
677
678 IP6_INC_STATS(dev_net(dst->dev),
679 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
680 kfree_skb(skb);
681 return -EINVAL;
682}
683
684/* modelled after ip6_output */
685static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
686{
687 return NF_HOOK_COND(pf: NFPROTO_IPV6, hook: NF_INET_POST_ROUTING,
688 net, sk, skb, NULL, out: skb_dst(skb)->dev,
689 okfn: vrf_finish_output6,
690 cond: !(IP6CB(skb)->flags & IP6SKB_REROUTED));
691}
692
693/* set dst on skb to send packet to us via dev_xmit path. Allows
694 * packet to go through device based features such as qdisc, netfilter
695 * hooks and packet sockets with skb->dev set to vrf device.
696 */
697static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev,
698 struct sk_buff *skb)
699{
700 struct net_vrf *vrf = netdev_priv(dev: vrf_dev);
701 struct dst_entry *dst = NULL;
702 struct rt6_info *rt6;
703
704 rcu_read_lock();
705
706 rt6 = rcu_dereference(vrf->rt6);
707 if (likely(rt6)) {
708 dst = &rt6->dst;
709 dst_hold(dst);
710 }
711
712 rcu_read_unlock();
713
714 if (unlikely(!dst)) {
715 vrf_tx_error(vrf_dev, skb);
716 return NULL;
717 }
718
719 skb_dst_drop(skb);
720 skb_dst_set(skb, dst);
721
722 return skb;
723}
724
725static int vrf_output6_direct_finish(struct net *net, struct sock *sk,
726 struct sk_buff *skb)
727{
728 vrf_finish_direct(skb);
729
730 return vrf_ip6_local_out(net, sk, skb);
731}
732
733static int vrf_output6_direct(struct net *net, struct sock *sk,
734 struct sk_buff *skb)
735{
736 int err = 1;
737
738 skb->protocol = htons(ETH_P_IPV6);
739
740 if (!(IPCB(skb)->flags & IPSKB_REROUTED))
741 err = nf_hook(pf: NFPROTO_IPV6, hook: NF_INET_POST_ROUTING, net, sk, skb,
742 NULL, outdev: skb->dev, okfn: vrf_output6_direct_finish);
743
744 if (likely(err == 1))
745 vrf_finish_direct(skb);
746
747 return err;
748}
749
750static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk,
751 struct sk_buff *skb)
752{
753 int err;
754
755 err = vrf_output6_direct(net, sk, skb);
756 if (likely(err == 1))
757 err = vrf_ip6_local_out(net, sk, skb);
758
759 return err;
760}
761
762static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
763 struct sock *sk,
764 struct sk_buff *skb)
765{
766 struct net *net = dev_net(dev: vrf_dev);
767 int err;
768
769 skb->dev = vrf_dev;
770
771 err = nf_hook(pf: NFPROTO_IPV6, hook: NF_INET_LOCAL_OUT, net, sk,
772 skb, NULL, outdev: vrf_dev, okfn: vrf_ip6_out_direct_finish);
773
774 if (likely(err == 1))
775 err = vrf_output6_direct(net, sk, skb);
776
777 if (likely(err == 1))
778 return skb;
779
780 return NULL;
781}
782
783static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
784 struct sock *sk,
785 struct sk_buff *skb)
786{
787 /* don't divert link scope packets */
788 if (rt6_need_strict(daddr: &ipv6_hdr(skb)->daddr))
789 return skb;
790
791 vrf_nf_set_untracked(skb);
792
793 if (qdisc_tx_is_default(dev: vrf_dev) ||
794 IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
795 return vrf_ip6_out_direct(vrf_dev, sk, skb);
796
797 return vrf_ip6_out_redirect(vrf_dev, skb);
798}
799
800/* holding rtnl */
801static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
802{
803 struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
804 struct net *net = dev_net(dev);
805 struct dst_entry *dst;
806
807 RCU_INIT_POINTER(vrf->rt6, NULL);
808 synchronize_rcu();
809
810 /* move dev in dst's to loopback so this VRF device can be deleted
811 * - based on dst_ifdown
812 */
813 if (rt6) {
814 dst = &rt6->dst;
815 netdev_ref_replace(odev: dst->dev, ndev: net->loopback_dev,
816 tracker: &dst->dev_tracker, GFP_KERNEL);
817 dst->dev = net->loopback_dev;
818 dst_release(dst);
819 }
820}
821
822static int vrf_rt6_create(struct net_device *dev)
823{
824 int flags = DST_NOPOLICY | DST_NOXFRM;
825 struct net_vrf *vrf = netdev_priv(dev);
826 struct net *net = dev_net(dev);
827 struct rt6_info *rt6;
828 int rc = -ENOMEM;
829
830 /* IPv6 can be CONFIG enabled and then disabled runtime */
831 if (!ipv6_mod_enabled())
832 return 0;
833
834 vrf->fib6_table = fib6_new_table(net, id: vrf->tb_id);
835 if (!vrf->fib6_table)
836 goto out;
837
838 /* create a dst for routing packets out a VRF device */
839 rt6 = ip6_dst_alloc(net, dev, flags);
840 if (!rt6)
841 goto out;
842
843 rt6->dst.output = vrf_output6;
844
845 rcu_assign_pointer(vrf->rt6, rt6);
846
847 rc = 0;
848out:
849 return rc;
850}
851#else
852static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
853 struct sock *sk,
854 struct sk_buff *skb)
855{
856 return skb;
857}
858
859static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
860{
861}
862
863static int vrf_rt6_create(struct net_device *dev)
864{
865 return 0;
866}
867#endif
868
869/* modelled after ip_finish_output2 */
870static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
871{
872 struct dst_entry *dst = skb_dst(skb);
873 struct rtable *rt = (struct rtable *)dst;
874 struct net_device *dev = dst->dev;
875 unsigned int hh_len = LL_RESERVED_SPACE(dev);
876 struct neighbour *neigh;
877 bool is_v6gw = false;
878
879 vrf_nf_reset_ct(skb);
880
881 /* Be paranoid, rather than too clever. */
882 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
883 skb = skb_expand_head(skb, headroom: hh_len);
884 if (!skb) {
885 dev->stats.tx_errors++;
886 return -ENOMEM;
887 }
888 }
889
890 rcu_read_lock();
891
892 neigh = ip_neigh_for_gw(rt, skb, is_v6gw: &is_v6gw);
893 if (!IS_ERR(ptr: neigh)) {
894 int ret;
895
896 sock_confirm_neigh(skb, n: neigh);
897 /* if crossing protocols, can not use the cached header */
898 ret = neigh_output(n: neigh, skb, skip_cache: is_v6gw);
899 rcu_read_unlock();
900 return ret;
901 }
902
903 rcu_read_unlock();
904 vrf_tx_error(vrf_dev: skb->dev, skb);
905 return -EINVAL;
906}
907
908static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
909{
910 struct net_device *dev = skb_dst(skb)->dev;
911
912 IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
913
914 skb->dev = dev;
915 skb->protocol = htons(ETH_P_IP);
916
917 return NF_HOOK_COND(pf: NFPROTO_IPV4, hook: NF_INET_POST_ROUTING,
918 net, sk, skb, NULL, out: dev,
919 okfn: vrf_finish_output,
920 cond: !(IPCB(skb)->flags & IPSKB_REROUTED));
921}
922
923/* set dst on skb to send packet to us via dev_xmit path. Allows
924 * packet to go through device based features such as qdisc, netfilter
925 * hooks and packet sockets with skb->dev set to vrf device.
926 */
927static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev,
928 struct sk_buff *skb)
929{
930 struct net_vrf *vrf = netdev_priv(dev: vrf_dev);
931 struct dst_entry *dst = NULL;
932 struct rtable *rth;
933
934 rcu_read_lock();
935
936 rth = rcu_dereference(vrf->rth);
937 if (likely(rth)) {
938 dst = &rth->dst;
939 dst_hold(dst);
940 }
941
942 rcu_read_unlock();
943
944 if (unlikely(!dst)) {
945 vrf_tx_error(vrf_dev, skb);
946 return NULL;
947 }
948
949 skb_dst_drop(skb);
950 skb_dst_set(skb, dst);
951
952 return skb;
953}
954
955static int vrf_output_direct_finish(struct net *net, struct sock *sk,
956 struct sk_buff *skb)
957{
958 vrf_finish_direct(skb);
959
960 return vrf_ip_local_out(net, sk, skb);
961}
962
963static int vrf_output_direct(struct net *net, struct sock *sk,
964 struct sk_buff *skb)
965{
966 int err = 1;
967
968 skb->protocol = htons(ETH_P_IP);
969
970 if (!(IPCB(skb)->flags & IPSKB_REROUTED))
971 err = nf_hook(pf: NFPROTO_IPV4, hook: NF_INET_POST_ROUTING, net, sk, skb,
972 NULL, outdev: skb->dev, okfn: vrf_output_direct_finish);
973
974 if (likely(err == 1))
975 vrf_finish_direct(skb);
976
977 return err;
978}
979
980static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk,
981 struct sk_buff *skb)
982{
983 int err;
984
985 err = vrf_output_direct(net, sk, skb);
986 if (likely(err == 1))
987 err = vrf_ip_local_out(net, sk, skb);
988
989 return err;
990}
991
992static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
993 struct sock *sk,
994 struct sk_buff *skb)
995{
996 struct net *net = dev_net(dev: vrf_dev);
997 int err;
998
999 skb->dev = vrf_dev;
1000
1001 err = nf_hook(pf: NFPROTO_IPV4, hook: NF_INET_LOCAL_OUT, net, sk,
1002 skb, NULL, outdev: vrf_dev, okfn: vrf_ip_out_direct_finish);
1003
1004 if (likely(err == 1))
1005 err = vrf_output_direct(net, sk, skb);
1006
1007 if (likely(err == 1))
1008 return skb;
1009
1010 return NULL;
1011}
1012
1013static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
1014 struct sock *sk,
1015 struct sk_buff *skb)
1016{
1017 /* don't divert multicast or local broadcast */
1018 if (ipv4_is_multicast(addr: ip_hdr(skb)->daddr) ||
1019 ipv4_is_lbcast(addr: ip_hdr(skb)->daddr))
1020 return skb;
1021
1022 vrf_nf_set_untracked(skb);
1023
1024 if (qdisc_tx_is_default(dev: vrf_dev) ||
1025 IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
1026 return vrf_ip_out_direct(vrf_dev, sk, skb);
1027
1028 return vrf_ip_out_redirect(vrf_dev, skb);
1029}
1030
1031/* called with rcu lock held */
1032static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
1033 struct sock *sk,
1034 struct sk_buff *skb,
1035 u16 proto)
1036{
1037 switch (proto) {
1038 case AF_INET:
1039 return vrf_ip_out(vrf_dev, sk, skb);
1040 case AF_INET6:
1041 return vrf_ip6_out(vrf_dev, sk, skb);
1042 }
1043
1044 return skb;
1045}
1046
1047/* holding rtnl */
1048static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
1049{
1050 struct rtable *rth = rtnl_dereference(vrf->rth);
1051 struct net *net = dev_net(dev);
1052 struct dst_entry *dst;
1053
1054 RCU_INIT_POINTER(vrf->rth, NULL);
1055 synchronize_rcu();
1056
1057 /* move dev in dst's to loopback so this VRF device can be deleted
1058 * - based on dst_ifdown
1059 */
1060 if (rth) {
1061 dst = &rth->dst;
1062 netdev_ref_replace(odev: dst->dev, ndev: net->loopback_dev,
1063 tracker: &dst->dev_tracker, GFP_KERNEL);
1064 dst->dev = net->loopback_dev;
1065 dst_release(dst);
1066 }
1067}
1068
1069static int vrf_rtable_create(struct net_device *dev)
1070{
1071 struct net_vrf *vrf = netdev_priv(dev);
1072 struct rtable *rth;
1073
1074 if (!fib_new_table(net: dev_net(dev), id: vrf->tb_id))
1075 return -ENOMEM;
1076
1077 /* create a dst for routing packets out through a VRF device */
1078 rth = rt_dst_alloc(dev, flags: 0, type: RTN_UNICAST, noxfrm: 1);
1079 if (!rth)
1080 return -ENOMEM;
1081
1082 rth->dst.output = vrf_output;
1083
1084 rcu_assign_pointer(vrf->rth, rth);
1085
1086 return 0;
1087}
1088
1089/**************************** device handling ********************/
1090
1091/* cycle interface to flush neighbor cache and move routes across tables */
1092static void cycle_netdev(struct net_device *dev,
1093 struct netlink_ext_ack *extack)
1094{
1095 unsigned int flags = dev->flags;
1096 int ret;
1097
1098 if (!netif_running(dev))
1099 return;
1100
1101 ret = dev_change_flags(dev, flags: flags & ~IFF_UP, extack);
1102 if (ret >= 0)
1103 ret = dev_change_flags(dev, flags, extack);
1104
1105 if (ret < 0) {
1106 netdev_err(dev,
1107 format: "Failed to cycle device %s; route tables might be wrong!\n",
1108 dev->name);
1109 }
1110}
1111
1112static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1113 struct netlink_ext_ack *extack)
1114{
1115 int ret;
1116
1117 /* do not allow loopback device to be enslaved to a VRF.
1118 * The vrf device acts as the loopback for the vrf.
1119 */
1120 if (port_dev == dev_net(dev)->loopback_dev) {
1121 NL_SET_ERR_MSG(extack,
1122 "Can not enslave loopback device to a VRF");
1123 return -EOPNOTSUPP;
1124 }
1125
1126 port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
1127 ret = netdev_master_upper_dev_link(dev: port_dev, upper_dev: dev, NULL, NULL, extack);
1128 if (ret < 0)
1129 goto err;
1130
1131 cycle_netdev(dev: port_dev, extack);
1132
1133 return 0;
1134
1135err:
1136 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1137 return ret;
1138}
1139
1140static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1141 struct netlink_ext_ack *extack)
1142{
1143 if (netif_is_l3_master(dev: port_dev)) {
1144 NL_SET_ERR_MSG(extack,
1145 "Can not enslave an L3 master device to a VRF");
1146 return -EINVAL;
1147 }
1148
1149 if (netif_is_l3_slave(dev: port_dev))
1150 return -EINVAL;
1151
1152 return do_vrf_add_slave(dev, port_dev, extack);
1153}
1154
1155/* inverse of do_vrf_add_slave */
1156static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1157{
1158 netdev_upper_dev_unlink(dev: port_dev, upper_dev: dev);
1159 port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1160
1161 cycle_netdev(dev: port_dev, NULL);
1162
1163 return 0;
1164}
1165
1166static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1167{
1168 return do_vrf_del_slave(dev, port_dev);
1169}
1170
1171static void vrf_dev_uninit(struct net_device *dev)
1172{
1173 struct net_vrf *vrf = netdev_priv(dev);
1174
1175 vrf_rtable_release(dev, vrf);
1176 vrf_rt6_release(dev, vrf);
1177
1178 free_percpu(pdata: dev->dstats);
1179 dev->dstats = NULL;
1180}
1181
1182static int vrf_dev_init(struct net_device *dev)
1183{
1184 struct net_vrf *vrf = netdev_priv(dev);
1185
1186 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
1187 if (!dev->dstats)
1188 goto out_nomem;
1189
1190 /* create the default dst which points back to us */
1191 if (vrf_rtable_create(dev) != 0)
1192 goto out_stats;
1193
1194 if (vrf_rt6_create(dev) != 0)
1195 goto out_rth;
1196
1197 dev->flags = IFF_MASTER | IFF_NOARP;
1198
1199 /* similarly, oper state is irrelevant; set to up to avoid confusion */
1200 dev->operstate = IF_OPER_UP;
1201 netdev_lockdep_set_classes(dev);
1202 return 0;
1203
1204out_rth:
1205 vrf_rtable_release(dev, vrf);
1206out_stats:
1207 free_percpu(pdata: dev->dstats);
1208 dev->dstats = NULL;
1209out_nomem:
1210 return -ENOMEM;
1211}
1212
1213static const struct net_device_ops vrf_netdev_ops = {
1214 .ndo_init = vrf_dev_init,
1215 .ndo_uninit = vrf_dev_uninit,
1216 .ndo_start_xmit = vrf_xmit,
1217 .ndo_set_mac_address = eth_mac_addr,
1218 .ndo_get_stats64 = vrf_get_stats64,
1219 .ndo_add_slave = vrf_add_slave,
1220 .ndo_del_slave = vrf_del_slave,
1221};
1222
1223static u32 vrf_fib_table(const struct net_device *dev)
1224{
1225 struct net_vrf *vrf = netdev_priv(dev);
1226
1227 return vrf->tb_id;
1228}
1229
1230static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
1231{
1232 kfree_skb(skb);
1233 return 0;
1234}
1235
1236static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
1237 struct sk_buff *skb,
1238 struct net_device *dev)
1239{
1240 struct net *net = dev_net(dev);
1241
1242 if (nf_hook(pf, hook, net, NULL, skb, indev: dev, NULL, okfn: vrf_rcv_finish) != 1)
1243 skb = NULL; /* kfree_skb(skb) handled by nf code */
1244
1245 return skb;
1246}
1247
1248static int vrf_prepare_mac_header(struct sk_buff *skb,
1249 struct net_device *vrf_dev, u16 proto)
1250{
1251 struct ethhdr *eth;
1252 int err;
1253
1254 /* in general, we do not know if there is enough space in the head of
1255 * the packet for hosting the mac header.
1256 */
1257 err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev));
1258 if (unlikely(err))
1259 /* no space in the skb head */
1260 return -ENOBUFS;
1261
1262 __skb_push(skb, ETH_HLEN);
1263 eth = (struct ethhdr *)skb->data;
1264
1265 skb_reset_mac_header(skb);
1266 skb_reset_mac_len(skb);
1267
1268 /* we set the ethernet destination and the source addresses to the
1269 * address of the VRF device.
1270 */
1271 ether_addr_copy(dst: eth->h_dest, src: vrf_dev->dev_addr);
1272 ether_addr_copy(dst: eth->h_source, src: vrf_dev->dev_addr);
1273 eth->h_proto = htons(proto);
1274
1275 /* the destination address of the Ethernet frame corresponds to the
1276 * address set on the VRF interface; therefore, the packet is intended
1277 * to be processed locally.
1278 */
1279 skb->protocol = eth->h_proto;
1280 skb->pkt_type = PACKET_HOST;
1281
1282 skb_postpush_rcsum(skb, start: skb->data, ETH_HLEN);
1283
1284 skb_pull_inline(skb, ETH_HLEN);
1285
1286 return 0;
1287}
1288
1289/* prepare and add the mac header to the packet if it was not set previously.
1290 * In this way, packet sniffers such as tcpdump can parse the packet correctly.
1291 * If the mac header was already set, the original mac header is left
1292 * untouched and the function returns immediately.
1293 */
1294static int vrf_add_mac_header_if_unset(struct sk_buff *skb,
1295 struct net_device *vrf_dev,
1296 u16 proto, struct net_device *orig_dev)
1297{
1298 if (skb_mac_header_was_set(skb) && dev_has_header(dev: orig_dev))
1299 return 0;
1300
1301 return vrf_prepare_mac_header(skb, vrf_dev, proto);
1302}
1303
1304#if IS_ENABLED(CONFIG_IPV6)
1305/* neighbor handling is done with actual device; do not want
1306 * to flip skb->dev for those ndisc packets. This really fails
1307 * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
1308 * a start.
1309 */
1310static bool ipv6_ndisc_frame(const struct sk_buff *skb)
1311{
1312 const struct ipv6hdr *iph = ipv6_hdr(skb);
1313 bool rc = false;
1314
1315 if (iph->nexthdr == NEXTHDR_ICMP) {
1316 const struct icmp6hdr *icmph;
1317 struct icmp6hdr _icmph;
1318
1319 icmph = skb_header_pointer(skb, offset: sizeof(*iph),
1320 len: sizeof(_icmph), buffer: &_icmph);
1321 if (!icmph)
1322 goto out;
1323
1324 switch (icmph->icmp6_type) {
1325 case NDISC_ROUTER_SOLICITATION:
1326 case NDISC_ROUTER_ADVERTISEMENT:
1327 case NDISC_NEIGHBOUR_SOLICITATION:
1328 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1329 case NDISC_REDIRECT:
1330 rc = true;
1331 break;
1332 }
1333 }
1334
1335out:
1336 return rc;
1337}
1338
1339static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
1340 const struct net_device *dev,
1341 struct flowi6 *fl6,
1342 int ifindex,
1343 const struct sk_buff *skb,
1344 int flags)
1345{
1346 struct net_vrf *vrf = netdev_priv(dev);
1347
1348 return ip6_pol_route(net, table: vrf->fib6_table, ifindex, fl6, skb, flags);
1349}
1350
1351static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
1352 int ifindex)
1353{
1354 const struct ipv6hdr *iph = ipv6_hdr(skb);
1355 struct flowi6 fl6 = {
1356 .flowi6_iif = ifindex,
1357 .flowi6_mark = skb->mark,
1358 .flowi6_proto = iph->nexthdr,
1359 .daddr = iph->daddr,
1360 .saddr = iph->saddr,
1361 .flowlabel = ip6_flowinfo(hdr: iph),
1362 };
1363 struct net *net = dev_net(dev: vrf_dev);
1364 struct rt6_info *rt6;
1365
1366 rt6 = vrf_ip6_route_lookup(net, dev: vrf_dev, fl6: &fl6, ifindex, skb,
1367 RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
1368 if (unlikely(!rt6))
1369 return;
1370
1371 if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
1372 return;
1373
1374 skb_dst_set(skb, dst: &rt6->dst);
1375}
1376
1377static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1378 struct sk_buff *skb)
1379{
1380 int orig_iif = skb->skb_iif;
1381 bool need_strict = rt6_need_strict(daddr: &ipv6_hdr(skb)->daddr);
1382 bool is_ndisc = ipv6_ndisc_frame(skb);
1383
1384 /* loopback, multicast & non-ND link-local traffic; do not push through
1385 * packet taps again. Reset pkt_type for upper layers to process skb.
1386 * For non-loopback strict packets, determine the dst using the original
1387 * ifindex.
1388 */
1389 if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) {
1390 skb->dev = vrf_dev;
1391 skb->skb_iif = vrf_dev->ifindex;
1392 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1393
1394 if (skb->pkt_type == PACKET_LOOPBACK)
1395 skb->pkt_type = PACKET_HOST;
1396 else
1397 vrf_ip6_input_dst(skb, vrf_dev, ifindex: orig_iif);
1398
1399 goto out;
1400 }
1401
1402 /* if packet is NDISC then keep the ingress interface */
1403 if (!is_ndisc) {
1404 struct net_device *orig_dev = skb->dev;
1405
1406 vrf_rx_stats(dev: vrf_dev, len: skb->len);
1407 skb->dev = vrf_dev;
1408 skb->skb_iif = vrf_dev->ifindex;
1409
1410 if (!list_empty(head: &vrf_dev->ptype_all)) {
1411 int err;
1412
1413 err = vrf_add_mac_header_if_unset(skb, vrf_dev,
1414 ETH_P_IPV6,
1415 orig_dev);
1416 if (likely(!err)) {
1417 skb_push(skb, len: skb->mac_len);
1418 dev_queue_xmit_nit(skb, dev: vrf_dev);
1419 skb_pull(skb, len: skb->mac_len);
1420 }
1421 }
1422
1423 IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1424 }
1425
1426 if (need_strict)
1427 vrf_ip6_input_dst(skb, vrf_dev, ifindex: orig_iif);
1428
1429 skb = vrf_rcv_nfhook(pf: NFPROTO_IPV6, hook: NF_INET_PRE_ROUTING, skb, dev: vrf_dev);
1430out:
1431 return skb;
1432}
1433
1434#else
1435static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1436 struct sk_buff *skb)
1437{
1438 return skb;
1439}
1440#endif
1441
1442static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
1443 struct sk_buff *skb)
1444{
1445 struct net_device *orig_dev = skb->dev;
1446
1447 skb->dev = vrf_dev;
1448 skb->skb_iif = vrf_dev->ifindex;
1449 IPCB(skb)->flags |= IPSKB_L3SLAVE;
1450
1451 if (ipv4_is_multicast(addr: ip_hdr(skb)->daddr))
1452 goto out;
1453
1454 /* loopback traffic; do not push through packet taps again.
1455 * Reset pkt_type for upper layers to process skb
1456 */
1457 if (skb->pkt_type == PACKET_LOOPBACK) {
1458 skb->pkt_type = PACKET_HOST;
1459 goto out;
1460 }
1461
1462 vrf_rx_stats(dev: vrf_dev, len: skb->len);
1463
1464 if (!list_empty(head: &vrf_dev->ptype_all)) {
1465 int err;
1466
1467 err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP,
1468 orig_dev);
1469 if (likely(!err)) {
1470 skb_push(skb, len: skb->mac_len);
1471 dev_queue_xmit_nit(skb, dev: vrf_dev);
1472 skb_pull(skb, len: skb->mac_len);
1473 }
1474 }
1475
1476 skb = vrf_rcv_nfhook(pf: NFPROTO_IPV4, hook: NF_INET_PRE_ROUTING, skb, dev: vrf_dev);
1477out:
1478 return skb;
1479}
1480
1481/* called with rcu lock held */
1482static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1483 struct sk_buff *skb,
1484 u16 proto)
1485{
1486 switch (proto) {
1487 case AF_INET:
1488 return vrf_ip_rcv(vrf_dev, skb);
1489 case AF_INET6:
1490 return vrf_ip6_rcv(vrf_dev, skb);
1491 }
1492
1493 return skb;
1494}
1495
1496#if IS_ENABLED(CONFIG_IPV6)
1497/* send to link-local or multicast address via interface enslaved to
1498 * VRF device. Force lookup to VRF table without changing flow struct
1499 * Note: Caller to this function must hold rcu_read_lock() and no refcnt
1500 * is taken on the dst by this function.
1501 */
1502static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1503 struct flowi6 *fl6)
1504{
1505 struct net *net = dev_net(dev);
1506 int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF;
1507 struct dst_entry *dst = NULL;
1508 struct rt6_info *rt;
1509
1510 /* VRF device does not have a link-local address and
1511 * sending packets to link-local or mcast addresses over
1512 * a VRF device does not make sense
1513 */
1514 if (fl6->flowi6_oif == dev->ifindex) {
1515 dst = &net->ipv6.ip6_null_entry->dst;
1516 return dst;
1517 }
1518
1519 if (!ipv6_addr_any(a: &fl6->saddr))
1520 flags |= RT6_LOOKUP_F_HAS_SADDR;
1521
1522 rt = vrf_ip6_route_lookup(net, dev, fl6, ifindex: fl6->flowi6_oif, NULL, flags);
1523 if (rt)
1524 dst = &rt->dst;
1525
1526 return dst;
1527}
1528#endif
1529
1530static const struct l3mdev_ops vrf_l3mdev_ops = {
1531 .l3mdev_fib_table = vrf_fib_table,
1532 .l3mdev_l3_rcv = vrf_l3_rcv,
1533 .l3mdev_l3_out = vrf_l3_out,
1534#if IS_ENABLED(CONFIG_IPV6)
1535 .l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1536#endif
1537};
1538
1539static void vrf_get_drvinfo(struct net_device *dev,
1540 struct ethtool_drvinfo *info)
1541{
1542 strscpy(p: info->driver, DRV_NAME, size: sizeof(info->driver));
1543 strscpy(p: info->version, DRV_VERSION, size: sizeof(info->version));
1544}
1545
1546static const struct ethtool_ops vrf_ethtool_ops = {
1547 .get_drvinfo = vrf_get_drvinfo,
1548};
1549
1550static inline size_t vrf_fib_rule_nl_size(void)
1551{
1552 size_t sz;
1553
1554 sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1555 sz += nla_total_size(payload: sizeof(u8)); /* FRA_L3MDEV */
1556 sz += nla_total_size(payload: sizeof(u32)); /* FRA_PRIORITY */
1557 sz += nla_total_size(payload: sizeof(u8)); /* FRA_PROTOCOL */
1558
1559 return sz;
1560}
1561
1562static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1563{
1564 struct fib_rule_hdr *frh;
1565 struct nlmsghdr *nlh;
1566 struct sk_buff *skb;
1567 int err;
1568
1569 if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) &&
1570 !ipv6_mod_enabled())
1571 return 0;
1572
1573 skb = nlmsg_new(payload: vrf_fib_rule_nl_size(), GFP_KERNEL);
1574 if (!skb)
1575 return -ENOMEM;
1576
1577 nlh = nlmsg_put(skb, portid: 0, seq: 0, type: 0, payload: sizeof(*frh), flags: 0);
1578 if (!nlh)
1579 goto nla_put_failure;
1580
1581 /* rule only needs to appear once */
1582 nlh->nlmsg_flags |= NLM_F_EXCL;
1583
1584 frh = nlmsg_data(nlh);
1585 memset(frh, 0, sizeof(*frh));
1586 frh->family = family;
1587 frh->action = FR_ACT_TO_TBL;
1588
1589 if (nla_put_u8(skb, attrtype: FRA_PROTOCOL, RTPROT_KERNEL))
1590 goto nla_put_failure;
1591
1592 if (nla_put_u8(skb, attrtype: FRA_L3MDEV, value: 1))
1593 goto nla_put_failure;
1594
1595 if (nla_put_u32(skb, attrtype: FRA_PRIORITY, FIB_RULE_PREF))
1596 goto nla_put_failure;
1597
1598 nlmsg_end(skb, nlh);
1599
1600 /* fib_nl_{new,del}rule handling looks for net from skb->sk */
1601 skb->sk = dev_net(dev)->rtnl;
1602 if (add_it) {
1603 err = fib_nl_newrule(skb, nlh, NULL);
1604 if (err == -EEXIST)
1605 err = 0;
1606 } else {
1607 err = fib_nl_delrule(skb, nlh, NULL);
1608 if (err == -ENOENT)
1609 err = 0;
1610 }
1611 nlmsg_free(skb);
1612
1613 return err;
1614
1615nla_put_failure:
1616 nlmsg_free(skb);
1617
1618 return -EMSGSIZE;
1619}
1620
1621static int vrf_add_fib_rules(const struct net_device *dev)
1622{
1623 int err;
1624
1625 err = vrf_fib_rule(dev, AF_INET, add_it: true);
1626 if (err < 0)
1627 goto out_err;
1628
1629 err = vrf_fib_rule(dev, AF_INET6, add_it: true);
1630 if (err < 0)
1631 goto ipv6_err;
1632
1633#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1634 err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, add_it: true);
1635 if (err < 0)
1636 goto ipmr_err;
1637#endif
1638
1639#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1640 err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, add_it: true);
1641 if (err < 0)
1642 goto ip6mr_err;
1643#endif
1644
1645 return 0;
1646
1647#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
1648ip6mr_err:
1649 vrf_fib_rule(dev, RTNL_FAMILY_IPMR, add_it: false);
1650#endif
1651
1652#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1653ipmr_err:
1654 vrf_fib_rule(dev, AF_INET6, add_it: false);
1655#endif
1656
1657ipv6_err:
1658 vrf_fib_rule(dev, AF_INET, add_it: false);
1659
1660out_err:
1661 netdev_err(dev, format: "Failed to add FIB rules.\n");
1662 return err;
1663}
1664
1665static void vrf_setup(struct net_device *dev)
1666{
1667 ether_setup(dev);
1668
1669 /* Initialize the device structure. */
1670 dev->netdev_ops = &vrf_netdev_ops;
1671 dev->l3mdev_ops = &vrf_l3mdev_ops;
1672 dev->ethtool_ops = &vrf_ethtool_ops;
1673 dev->needs_free_netdev = true;
1674
1675 /* Fill in device structure with ethernet-generic values. */
1676 eth_hw_addr_random(dev);
1677
1678 /* don't acquire vrf device's netif_tx_lock when transmitting */
1679 dev->features |= NETIF_F_LLTX;
1680
1681 /* don't allow vrf devices to change network namespaces. */
1682 dev->features |= NETIF_F_NETNS_LOCAL;
1683
1684 /* does not make sense for a VLAN to be added to a vrf device */
1685 dev->features |= NETIF_F_VLAN_CHALLENGED;
1686
1687 /* enable offload features */
1688 dev->features |= NETIF_F_GSO_SOFTWARE;
1689 dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC;
1690 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
1691
1692 dev->hw_features = dev->features;
1693 dev->hw_enc_features = dev->features;
1694
1695 /* default to no qdisc; user can add if desired */
1696 dev->priv_flags |= IFF_NO_QUEUE;
1697 dev->priv_flags |= IFF_NO_RX_HANDLER;
1698 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1699
1700 /* VRF devices do not care about MTU, but if the MTU is set
1701 * too low then the ipv4 and ipv6 protocols are disabled
1702 * which breaks networking.
1703 */
1704 dev->min_mtu = IPV6_MIN_MTU;
1705 dev->max_mtu = IP6_MAX_MTU;
1706 dev->mtu = dev->max_mtu;
1707}
1708
1709static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],
1710 struct netlink_ext_ack *extack)
1711{
1712 if (tb[IFLA_ADDRESS]) {
1713 if (nla_len(nla: tb[IFLA_ADDRESS]) != ETH_ALEN) {
1714 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1715 return -EINVAL;
1716 }
1717 if (!is_valid_ether_addr(addr: nla_data(nla: tb[IFLA_ADDRESS]))) {
1718 NL_SET_ERR_MSG(extack, "Invalid hardware address");
1719 return -EADDRNOTAVAIL;
1720 }
1721 }
1722 return 0;
1723}
1724
1725static void vrf_dellink(struct net_device *dev, struct list_head *head)
1726{
1727 struct net_device *port_dev;
1728 struct list_head *iter;
1729
1730 netdev_for_each_lower_dev(dev, port_dev, iter)
1731 vrf_del_slave(dev, port_dev);
1732
1733 vrf_map_unregister_dev(dev);
1734
1735 unregister_netdevice_queue(dev, head);
1736}
1737
1738static int vrf_newlink(struct net *src_net, struct net_device *dev,
1739 struct nlattr *tb[], struct nlattr *data[],
1740 struct netlink_ext_ack *extack)
1741{
1742 struct net_vrf *vrf = netdev_priv(dev);
1743 struct netns_vrf *nn_vrf;
1744 bool *add_fib_rules;
1745 struct net *net;
1746 int err;
1747
1748 if (!data || !data[IFLA_VRF_TABLE]) {
1749 NL_SET_ERR_MSG(extack, "VRF table id is missing");
1750 return -EINVAL;
1751 }
1752
1753 vrf->tb_id = nla_get_u32(nla: data[IFLA_VRF_TABLE]);
1754 if (vrf->tb_id == RT_TABLE_UNSPEC) {
1755 NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE],
1756 "Invalid VRF table id");
1757 return -EINVAL;
1758 }
1759
1760 dev->priv_flags |= IFF_L3MDEV_MASTER;
1761
1762 err = register_netdevice(dev);
1763 if (err)
1764 goto out;
1765
1766 /* mapping between table_id and vrf;
1767 * note: such binding could not be done in the dev init function
1768 * because dev->ifindex id is not available yet.
1769 */
1770 vrf->ifindex = dev->ifindex;
1771
1772 err = vrf_map_register_dev(dev, extack);
1773 if (err) {
1774 unregister_netdevice(dev);
1775 goto out;
1776 }
1777
1778 net = dev_net(dev);
1779 nn_vrf = net_generic(net, id: vrf_net_id);
1780
1781 add_fib_rules = &nn_vrf->add_fib_rules;
1782 if (*add_fib_rules) {
1783 err = vrf_add_fib_rules(dev);
1784 if (err) {
1785 vrf_map_unregister_dev(dev);
1786 unregister_netdevice(dev);
1787 goto out;
1788 }
1789 *add_fib_rules = false;
1790 }
1791
1792out:
1793 return err;
1794}
1795
1796static size_t vrf_nl_getsize(const struct net_device *dev)
1797{
1798 return nla_total_size(payload: sizeof(u32)); /* IFLA_VRF_TABLE */
1799}
1800
1801static int vrf_fillinfo(struct sk_buff *skb,
1802 const struct net_device *dev)
1803{
1804 struct net_vrf *vrf = netdev_priv(dev);
1805
1806 return nla_put_u32(skb, attrtype: IFLA_VRF_TABLE, value: vrf->tb_id);
1807}
1808
1809static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1810 const struct net_device *slave_dev)
1811{
1812 return nla_total_size(payload: sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
1813}
1814
1815static int vrf_fill_slave_info(struct sk_buff *skb,
1816 const struct net_device *vrf_dev,
1817 const struct net_device *slave_dev)
1818{
1819 struct net_vrf *vrf = netdev_priv(dev: vrf_dev);
1820
1821 if (nla_put_u32(skb, attrtype: IFLA_VRF_PORT_TABLE, value: vrf->tb_id))
1822 return -EMSGSIZE;
1823
1824 return 0;
1825}
1826
1827static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1828 [IFLA_VRF_TABLE] = { .type = NLA_U32 },
1829};
1830
1831static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1832 .kind = DRV_NAME,
1833 .priv_size = sizeof(struct net_vrf),
1834
1835 .get_size = vrf_nl_getsize,
1836 .policy = vrf_nl_policy,
1837 .validate = vrf_validate,
1838 .fill_info = vrf_fillinfo,
1839
1840 .get_slave_size = vrf_get_slave_size,
1841 .fill_slave_info = vrf_fill_slave_info,
1842
1843 .newlink = vrf_newlink,
1844 .dellink = vrf_dellink,
1845 .setup = vrf_setup,
1846 .maxtype = IFLA_VRF_MAX,
1847};
1848
1849static int vrf_device_event(struct notifier_block *unused,
1850 unsigned long event, void *ptr)
1851{
1852 struct net_device *dev = netdev_notifier_info_to_dev(info: ptr);
1853
1854 /* only care about unregister events to drop slave references */
1855 if (event == NETDEV_UNREGISTER) {
1856 struct net_device *vrf_dev;
1857
1858 if (!netif_is_l3_slave(dev))
1859 goto out;
1860
1861 vrf_dev = netdev_master_upper_dev_get(dev);
1862 vrf_del_slave(dev: vrf_dev, port_dev: dev);
1863 }
1864out:
1865 return NOTIFY_DONE;
1866}
1867
1868static struct notifier_block vrf_notifier_block __read_mostly = {
1869 .notifier_call = vrf_device_event,
1870};
1871
1872static int vrf_map_init(struct vrf_map *vmap)
1873{
1874 spin_lock_init(&vmap->vmap_lock);
1875 hash_init(vmap->ht);
1876
1877 vmap->strict_mode = false;
1878
1879 return 0;
1880}
1881
1882#ifdef CONFIG_SYSCTL
1883static bool vrf_strict_mode(struct vrf_map *vmap)
1884{
1885 bool strict_mode;
1886
1887 vrf_map_lock(vmap);
1888 strict_mode = vmap->strict_mode;
1889 vrf_map_unlock(vmap);
1890
1891 return strict_mode;
1892}
1893
1894static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode)
1895{
1896 bool *cur_mode;
1897 int res = 0;
1898
1899 vrf_map_lock(vmap);
1900
1901 cur_mode = &vmap->strict_mode;
1902 if (*cur_mode == new_mode)
1903 goto unlock;
1904
1905 if (*cur_mode) {
1906 /* disable strict mode */
1907 *cur_mode = false;
1908 } else {
1909 if (vmap->shared_tables) {
1910 /* we cannot allow strict_mode because there are some
1911 * vrfs that share one or more tables.
1912 */
1913 res = -EBUSY;
1914 goto unlock;
1915 }
1916
1917 /* no tables are shared among vrfs, so we can go back
1918 * to 1:1 association between a vrf with its table.
1919 */
1920 *cur_mode = true;
1921 }
1922
1923unlock:
1924 vrf_map_unlock(vmap);
1925
1926 return res;
1927}
1928
1929static int vrf_shared_table_handler(struct ctl_table *table, int write,
1930 void *buffer, size_t *lenp, loff_t *ppos)
1931{
1932 struct net *net = (struct net *)table->extra1;
1933 struct vrf_map *vmap = netns_vrf_map(net);
1934 int proc_strict_mode = 0;
1935 struct ctl_table tmp = {
1936 .procname = table->procname,
1937 .data = &proc_strict_mode,
1938 .maxlen = sizeof(int),
1939 .mode = table->mode,
1940 .extra1 = SYSCTL_ZERO,
1941 .extra2 = SYSCTL_ONE,
1942 };
1943 int ret;
1944
1945 if (!write)
1946 proc_strict_mode = vrf_strict_mode(vmap);
1947
1948 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
1949
1950 if (write && ret == 0)
1951 ret = vrf_strict_mode_change(vmap, new_mode: (bool)proc_strict_mode);
1952
1953 return ret;
1954}
1955
1956static const struct ctl_table vrf_table[] = {
1957 {
1958 .procname = "strict_mode",
1959 .data = NULL,
1960 .maxlen = sizeof(int),
1961 .mode = 0644,
1962 .proc_handler = vrf_shared_table_handler,
1963 /* set by the vrf_netns_init */
1964 .extra1 = NULL,
1965 },
1966};
1967
1968static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1969{
1970 struct ctl_table *table;
1971
1972 table = kmemdup(p: vrf_table, size: sizeof(vrf_table), GFP_KERNEL);
1973 if (!table)
1974 return -ENOMEM;
1975
1976 /* init the extra1 parameter with the reference to current netns */
1977 table[0].extra1 = net;
1978
1979 nn_vrf->ctl_hdr = register_net_sysctl_sz(net, path: "net/vrf", table,
1980 ARRAY_SIZE(vrf_table));
1981 if (!nn_vrf->ctl_hdr) {
1982 kfree(objp: table);
1983 return -ENOMEM;
1984 }
1985
1986 return 0;
1987}
1988
1989static void vrf_netns_exit_sysctl(struct net *net)
1990{
1991 struct netns_vrf *nn_vrf = net_generic(net, id: vrf_net_id);
1992 struct ctl_table *table;
1993
1994 table = nn_vrf->ctl_hdr->ctl_table_arg;
1995 unregister_net_sysctl_table(header: nn_vrf->ctl_hdr);
1996 kfree(objp: table);
1997}
1998#else
1999static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
2000{
2001 return 0;
2002}
2003
2004static void vrf_netns_exit_sysctl(struct net *net)
2005{
2006}
2007#endif
2008
2009/* Initialize per network namespace state */
2010static int __net_init vrf_netns_init(struct net *net)
2011{
2012 struct netns_vrf *nn_vrf = net_generic(net, id: vrf_net_id);
2013
2014 nn_vrf->add_fib_rules = true;
2015 vrf_map_init(vmap: &nn_vrf->vmap);
2016
2017 return vrf_netns_init_sysctl(net, nn_vrf);
2018}
2019
2020static void __net_exit vrf_netns_exit(struct net *net)
2021{
2022 vrf_netns_exit_sysctl(net);
2023}
2024
2025static struct pernet_operations vrf_net_ops __net_initdata = {
2026 .init = vrf_netns_init,
2027 .exit = vrf_netns_exit,
2028 .id = &vrf_net_id,
2029 .size = sizeof(struct netns_vrf),
2030};
2031
2032static int __init vrf_init_module(void)
2033{
2034 int rc;
2035
2036 register_netdevice_notifier(nb: &vrf_notifier_block);
2037
2038 rc = register_pernet_subsys(&vrf_net_ops);
2039 if (rc < 0)
2040 goto error;
2041
2042 rc = l3mdev_table_lookup_register(l3type: L3MDEV_TYPE_VRF,
2043 fn: vrf_ifindex_lookup_by_table_id);
2044 if (rc < 0)
2045 goto unreg_pernet;
2046
2047 rc = rtnl_link_register(ops: &vrf_link_ops);
2048 if (rc < 0)
2049 goto table_lookup_unreg;
2050
2051 return 0;
2052
2053table_lookup_unreg:
2054 l3mdev_table_lookup_unregister(l3type: L3MDEV_TYPE_VRF,
2055 fn: vrf_ifindex_lookup_by_table_id);
2056
2057unreg_pernet:
2058 unregister_pernet_subsys(&vrf_net_ops);
2059
2060error:
2061 unregister_netdevice_notifier(nb: &vrf_notifier_block);
2062 return rc;
2063}
2064
2065module_init(vrf_init_module);
2066MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
2067MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
2068MODULE_LICENSE("GPL");
2069MODULE_ALIAS_RTNL_LINK(DRV_NAME);
2070MODULE_VERSION(DRV_VERSION);
2071

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