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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * vrf.c: device driver to encapsulate a VRF space
4  *
5  * Copyright (c) 2015 Cumulus Networks. All rights reserved.
6  * Copyright (c) 2015 Shrijeet Mukherjee <shm@cumulusnetworks.com>
7  * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com>
8  *
9  * Based on dummy, team and ipvlan drivers
10  */
11 
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/netdevice.h>
15 #include <linux/etherdevice.h>
16 #include <linux/ip.h>
17 #include <linux/init.h>
18 #include <linux/moduleparam.h>
19 #include <linux/netfilter.h>
20 #include <linux/rtnetlink.h>
21 #include <net/rtnetlink.h>
22 #include <linux/u64_stats_sync.h>
23 #include <linux/hashtable.h>
24 #include <linux/spinlock_types.h>
25 
26 #include <linux/inetdevice.h>
27 #include <net/arp.h>
28 #include <net/ip.h>
29 #include <net/ip_fib.h>
30 #include <net/ip6_fib.h>
31 #include <net/ip6_route.h>
32 #include <net/route.h>
33 #include <net/addrconf.h>
34 #include <net/l3mdev.h>
35 #include <net/fib_rules.h>
36 #include <net/netns/generic.h>
37 #include <net/netfilter/nf_conntrack.h>
38 
39 #define DRV_NAME	"vrf"
40 #define DRV_VERSION	"1.1"
41 
42 #define FIB_RULE_PREF  1000       /* default preference for FIB rules */
43 
44 #define HT_MAP_BITS	4
45 #define HASH_INITVAL	((u32)0xcafef00d)
46 
47 struct  vrf_map {
48 	DECLARE_HASHTABLE(ht, HT_MAP_BITS);
49 	spinlock_t vmap_lock;
50 
51 	/* shared_tables:
52 	 * count how many distinct tables do not comply with the strict mode
53 	 * requirement.
54 	 * shared_tables value must be 0 in order to enable the strict mode.
55 	 *
56 	 * example of the evolution of shared_tables:
57 	 *                                                        | time
58 	 * add  vrf0 --> table 100        shared_tables = 0       | t0
59 	 * add  vrf1 --> table 101        shared_tables = 0       | t1
60 	 * add  vrf2 --> table 100        shared_tables = 1       | t2
61 	 * add  vrf3 --> table 100        shared_tables = 1       | t3
62 	 * add  vrf4 --> table 101        shared_tables = 2       v t4
63 	 *
64 	 * shared_tables is a "step function" (or "staircase function")
65 	 * and it is increased by one when the second vrf is associated to a
66 	 * table.
67 	 *
68 	 * at t2, vrf0 and vrf2 are bound to table 100: shared_tables = 1.
69 	 *
70 	 * at t3, another dev (vrf3) is bound to the same table 100 but the
71 	 * value of shared_tables is still 1.
72 	 * This means that no matter how many new vrfs will register on the
73 	 * table 100, the shared_tables will not increase (considering only
74 	 * table 100).
75 	 *
76 	 * at t4, vrf4 is bound to table 101, and shared_tables = 2.
77 	 *
78 	 * Looking at the value of shared_tables we can immediately know if
79 	 * the strict_mode can or cannot be enforced. Indeed, strict_mode
80 	 * can be enforced iff shared_tables = 0.
81 	 *
82 	 * Conversely, shared_tables is decreased when a vrf is de-associated
83 	 * from a table with exactly two associated vrfs.
84 	 */
85 	u32 shared_tables;
86 
87 	bool strict_mode;
88 };
89 
90 struct vrf_map_elem {
91 	struct hlist_node hnode;
92 	struct list_head vrf_list;  /* VRFs registered to this table */
93 
94 	u32 table_id;
95 	int users;
96 	int ifindex;
97 };
98 
99 static unsigned int vrf_net_id;
100 
101 /* per netns vrf data */
102 struct netns_vrf {
103 	/* protected by rtnl lock */
104 	bool add_fib_rules;
105 
106 	struct vrf_map vmap;
107 	struct ctl_table_header	*ctl_hdr;
108 };
109 
110 struct net_vrf {
111 	struct rtable __rcu	*rth;
112 	struct rt6_info	__rcu	*rt6;
113 #if IS_ENABLED(CONFIG_IPV6)
114 	struct fib6_table	*fib6_table;
115 #endif
116 	u32                     tb_id;
117 
118 	struct list_head	me_list;   /* entry in vrf_map_elem */
119 	int			ifindex;
120 };
121 
122 struct pcpu_dstats {
123 	u64			tx_pkts;
124 	u64			tx_bytes;
125 	u64			tx_drps;
126 	u64			rx_pkts;
127 	u64			rx_bytes;
128 	u64			rx_drps;
129 	struct u64_stats_sync	syncp;
130 };
131 
vrf_rx_stats(struct net_device * dev,int len)132 static void vrf_rx_stats(struct net_device *dev, int len)
133 {
134 	struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
135 
136 	u64_stats_update_begin(&dstats->syncp);
137 	dstats->rx_pkts++;
138 	dstats->rx_bytes += len;
139 	u64_stats_update_end(&dstats->syncp);
140 }
141 
vrf_tx_error(struct net_device * vrf_dev,struct sk_buff * skb)142 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
143 {
144 	vrf_dev->stats.tx_errors++;
145 	kfree_skb(skb);
146 }
147 
vrf_get_stats64(struct net_device * dev,struct rtnl_link_stats64 * stats)148 static void vrf_get_stats64(struct net_device *dev,
149 			    struct rtnl_link_stats64 *stats)
150 {
151 	int i;
152 
153 	for_each_possible_cpu(i) {
154 		const struct pcpu_dstats *dstats;
155 		u64 tbytes, tpkts, tdrops, rbytes, rpkts;
156 		unsigned int start;
157 
158 		dstats = per_cpu_ptr(dev->dstats, i);
159 		do {
160 			start = u64_stats_fetch_begin_irq(&dstats->syncp);
161 			tbytes = dstats->tx_bytes;
162 			tpkts = dstats->tx_pkts;
163 			tdrops = dstats->tx_drps;
164 			rbytes = dstats->rx_bytes;
165 			rpkts = dstats->rx_pkts;
166 		} while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
167 		stats->tx_bytes += tbytes;
168 		stats->tx_packets += tpkts;
169 		stats->tx_dropped += tdrops;
170 		stats->rx_bytes += rbytes;
171 		stats->rx_packets += rpkts;
172 	}
173 }
174 
netns_vrf_map(struct net * net)175 static struct vrf_map *netns_vrf_map(struct net *net)
176 {
177 	struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
178 
179 	return &nn_vrf->vmap;
180 }
181 
netns_vrf_map_by_dev(struct net_device * dev)182 static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev)
183 {
184 	return netns_vrf_map(dev_net(dev));
185 }
186 
vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem * me)187 static int vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem *me)
188 {
189 	struct list_head *me_head = &me->vrf_list;
190 	struct net_vrf *vrf;
191 
192 	if (list_empty(me_head))
193 		return -ENODEV;
194 
195 	vrf = list_first_entry(me_head, struct net_vrf, me_list);
196 
197 	return vrf->ifindex;
198 }
199 
vrf_map_elem_alloc(gfp_t flags)200 static struct vrf_map_elem *vrf_map_elem_alloc(gfp_t flags)
201 {
202 	struct vrf_map_elem *me;
203 
204 	me = kmalloc(sizeof(*me), flags);
205 	if (!me)
206 		return NULL;
207 
208 	return me;
209 }
210 
vrf_map_elem_free(struct vrf_map_elem * me)211 static void vrf_map_elem_free(struct vrf_map_elem *me)
212 {
213 	kfree(me);
214 }
215 
vrf_map_elem_init(struct vrf_map_elem * me,int table_id,int ifindex,int users)216 static void vrf_map_elem_init(struct vrf_map_elem *me, int table_id,
217 			      int ifindex, int users)
218 {
219 	me->table_id = table_id;
220 	me->ifindex = ifindex;
221 	me->users = users;
222 	INIT_LIST_HEAD(&me->vrf_list);
223 }
224 
vrf_map_lookup_elem(struct vrf_map * vmap,u32 table_id)225 static struct vrf_map_elem *vrf_map_lookup_elem(struct vrf_map *vmap,
226 						u32 table_id)
227 {
228 	struct vrf_map_elem *me;
229 	u32 key;
230 
231 	key = jhash_1word(table_id, HASH_INITVAL);
232 	hash_for_each_possible(vmap->ht, me, hnode, key) {
233 		if (me->table_id == table_id)
234 			return me;
235 	}
236 
237 	return NULL;
238 }
239 
vrf_map_add_elem(struct vrf_map * vmap,struct vrf_map_elem * me)240 static void vrf_map_add_elem(struct vrf_map *vmap, struct vrf_map_elem *me)
241 {
242 	u32 table_id = me->table_id;
243 	u32 key;
244 
245 	key = jhash_1word(table_id, HASH_INITVAL);
246 	hash_add(vmap->ht, &me->hnode, key);
247 }
248 
vrf_map_del_elem(struct vrf_map_elem * me)249 static void vrf_map_del_elem(struct vrf_map_elem *me)
250 {
251 	hash_del(&me->hnode);
252 }
253 
vrf_map_lock(struct vrf_map * vmap)254 static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock)
255 {
256 	spin_lock(&vmap->vmap_lock);
257 }
258 
vrf_map_unlock(struct vrf_map * vmap)259 static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock)
260 {
261 	spin_unlock(&vmap->vmap_lock);
262 }
263 
264 /* called with rtnl lock held */
265 static int
vrf_map_register_dev(struct net_device * dev,struct netlink_ext_ack * extack)266 vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack)
267 {
268 	struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
269 	struct net_vrf *vrf = netdev_priv(dev);
270 	struct vrf_map_elem *new_me, *me;
271 	u32 table_id = vrf->tb_id;
272 	bool free_new_me = false;
273 	int users;
274 	int res;
275 
276 	/* we pre-allocate elements used in the spin-locked section (so that we
277 	 * keep the spinlock as short as possibile).
278 	 */
279 	new_me = vrf_map_elem_alloc(GFP_KERNEL);
280 	if (!new_me)
281 		return -ENOMEM;
282 
283 	vrf_map_elem_init(new_me, table_id, dev->ifindex, 0);
284 
285 	vrf_map_lock(vmap);
286 
287 	me = vrf_map_lookup_elem(vmap, table_id);
288 	if (!me) {
289 		me = new_me;
290 		vrf_map_add_elem(vmap, me);
291 		goto link_vrf;
292 	}
293 
294 	/* we already have an entry in the vrf_map, so it means there is (at
295 	 * least) a vrf registered on the specific table.
296 	 */
297 	free_new_me = true;
298 	if (vmap->strict_mode) {
299 		/* vrfs cannot share the same table */
300 		NL_SET_ERR_MSG(extack, "Table is used by another VRF");
301 		res = -EBUSY;
302 		goto unlock;
303 	}
304 
305 link_vrf:
306 	users = ++me->users;
307 	if (users == 2)
308 		++vmap->shared_tables;
309 
310 	list_add(&vrf->me_list, &me->vrf_list);
311 
312 	res = 0;
313 
314 unlock:
315 	vrf_map_unlock(vmap);
316 
317 	/* clean-up, if needed */
318 	if (free_new_me)
319 		vrf_map_elem_free(new_me);
320 
321 	return res;
322 }
323 
324 /* called with rtnl lock held */
vrf_map_unregister_dev(struct net_device * dev)325 static void vrf_map_unregister_dev(struct net_device *dev)
326 {
327 	struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
328 	struct net_vrf *vrf = netdev_priv(dev);
329 	u32 table_id = vrf->tb_id;
330 	struct vrf_map_elem *me;
331 	int users;
332 
333 	vrf_map_lock(vmap);
334 
335 	me = vrf_map_lookup_elem(vmap, table_id);
336 	if (!me)
337 		goto unlock;
338 
339 	list_del(&vrf->me_list);
340 
341 	users = --me->users;
342 	if (users == 1) {
343 		--vmap->shared_tables;
344 	} else if (users == 0) {
345 		vrf_map_del_elem(me);
346 
347 		/* no one will refer to this element anymore */
348 		vrf_map_elem_free(me);
349 	}
350 
351 unlock:
352 	vrf_map_unlock(vmap);
353 }
354 
355 /* return the vrf device index associated with the table_id */
vrf_ifindex_lookup_by_table_id(struct net * net,u32 table_id)356 static int vrf_ifindex_lookup_by_table_id(struct net *net, u32 table_id)
357 {
358 	struct vrf_map *vmap = netns_vrf_map(net);
359 	struct vrf_map_elem *me;
360 	int ifindex;
361 
362 	vrf_map_lock(vmap);
363 
364 	if (!vmap->strict_mode) {
365 		ifindex = -EPERM;
366 		goto unlock;
367 	}
368 
369 	me = vrf_map_lookup_elem(vmap, table_id);
370 	if (!me) {
371 		ifindex = -ENODEV;
372 		goto unlock;
373 	}
374 
375 	ifindex = vrf_map_elem_get_vrf_ifindex(me);
376 
377 unlock:
378 	vrf_map_unlock(vmap);
379 
380 	return ifindex;
381 }
382 
383 /* by default VRF devices do not have a qdisc and are expected
384  * to be created with only a single queue.
385  */
qdisc_tx_is_default(const struct net_device * dev)386 static bool qdisc_tx_is_default(const struct net_device *dev)
387 {
388 	struct netdev_queue *txq;
389 	struct Qdisc *qdisc;
390 
391 	if (dev->num_tx_queues > 1)
392 		return false;
393 
394 	txq = netdev_get_tx_queue(dev, 0);
395 	qdisc = rcu_access_pointer(txq->qdisc);
396 
397 	return !qdisc->enqueue;
398 }
399 
400 /* Local traffic destined to local address. Reinsert the packet to rx
401  * path, similar to loopback handling.
402  */
vrf_local_xmit(struct sk_buff * skb,struct net_device * dev,struct dst_entry * dst)403 static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
404 			  struct dst_entry *dst)
405 {
406 	int len = skb->len;
407 
408 	skb_orphan(skb);
409 
410 	skb_dst_set(skb, dst);
411 
412 	/* set pkt_type to avoid skb hitting packet taps twice -
413 	 * once on Tx and again in Rx processing
414 	 */
415 	skb->pkt_type = PACKET_LOOPBACK;
416 
417 	skb->protocol = eth_type_trans(skb, dev);
418 
419 	if (likely(netif_rx(skb) == NET_RX_SUCCESS))
420 		vrf_rx_stats(dev, len);
421 	else
422 		this_cpu_inc(dev->dstats->rx_drps);
423 
424 	return NETDEV_TX_OK;
425 }
426 
vrf_nf_set_untracked(struct sk_buff * skb)427 static void vrf_nf_set_untracked(struct sk_buff *skb)
428 {
429 	if (skb_get_nfct(skb) == 0)
430 		nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
431 }
432 
vrf_nf_reset_ct(struct sk_buff * skb)433 static void vrf_nf_reset_ct(struct sk_buff *skb)
434 {
435 	if (skb_get_nfct(skb) == IP_CT_UNTRACKED)
436 		nf_reset_ct(skb);
437 }
438 
439 #if IS_ENABLED(CONFIG_IPV6)
vrf_ip6_local_out(struct net * net,struct sock * sk,struct sk_buff * skb)440 static int vrf_ip6_local_out(struct net *net, struct sock *sk,
441 			     struct sk_buff *skb)
442 {
443 	int err;
444 
445 	vrf_nf_reset_ct(skb);
446 
447 	err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net,
448 		      sk, skb, NULL, skb_dst(skb)->dev, dst_output);
449 
450 	if (likely(err == 1))
451 		err = dst_output(net, sk, skb);
452 
453 	return err;
454 }
455 
vrf_process_v6_outbound(struct sk_buff * skb,struct net_device * dev)456 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
457 					   struct net_device *dev)
458 {
459 	const struct ipv6hdr *iph;
460 	struct net *net = dev_net(skb->dev);
461 	struct flowi6 fl6;
462 	int ret = NET_XMIT_DROP;
463 	struct dst_entry *dst;
464 	struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
465 
466 	if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
467 		goto err;
468 
469 	iph = ipv6_hdr(skb);
470 
471 	memset(&fl6, 0, sizeof(fl6));
472 	/* needed to match OIF rule */
473 	fl6.flowi6_oif = dev->ifindex;
474 	fl6.flowi6_iif = LOOPBACK_IFINDEX;
475 	fl6.daddr = iph->daddr;
476 	fl6.saddr = iph->saddr;
477 	fl6.flowlabel = ip6_flowinfo(iph);
478 	fl6.flowi6_mark = skb->mark;
479 	fl6.flowi6_proto = iph->nexthdr;
480 	fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF;
481 
482 	dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL);
483 	if (IS_ERR(dst) || dst == dst_null)
484 		goto err;
485 
486 	skb_dst_drop(skb);
487 
488 	/* if dst.dev is loopback or the VRF device again this is locally
489 	 * originated traffic destined to a local address. Short circuit
490 	 * to Rx path
491 	 */
492 	if (dst->dev == dev)
493 		return vrf_local_xmit(skb, dev, dst);
494 
495 	skb_dst_set(skb, dst);
496 
497 	/* strip the ethernet header added for pass through VRF device */
498 	__skb_pull(skb, skb_network_offset(skb));
499 
500 	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
501 	ret = vrf_ip6_local_out(net, skb->sk, skb);
502 	if (unlikely(net_xmit_eval(ret)))
503 		dev->stats.tx_errors++;
504 	else
505 		ret = NET_XMIT_SUCCESS;
506 
507 	return ret;
508 err:
509 	vrf_tx_error(dev, skb);
510 	return NET_XMIT_DROP;
511 }
512 #else
vrf_process_v6_outbound(struct sk_buff * skb,struct net_device * dev)513 static 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 */
vrf_ip_local_out(struct net * net,struct sock * sk,struct sk_buff * skb)522 static int vrf_ip_local_out(struct net *net, struct sock *sk,
523 			    struct sk_buff *skb)
524 {
525 	int err;
526 
527 	vrf_nf_reset_ct(skb);
528 
529 	err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
530 		      skb, NULL, skb_dst(skb)->dev, dst_output);
531 	if (likely(err == 1))
532 		err = dst_output(net, sk, skb);
533 
534 	return err;
535 }
536 
vrf_process_v4_outbound(struct sk_buff * skb,struct net_device * vrf_dev)537 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
538 					   struct net_device *vrf_dev)
539 {
540 	struct iphdr *ip4h;
541 	int ret = NET_XMIT_DROP;
542 	struct flowi4 fl4;
543 	struct net *net = dev_net(vrf_dev);
544 	struct rtable *rt;
545 
546 	if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
547 		goto err;
548 
549 	ip4h = ip_hdr(skb);
550 
551 	memset(&fl4, 0, sizeof(fl4));
552 	/* needed to match OIF rule */
553 	fl4.flowi4_oif = vrf_dev->ifindex;
554 	fl4.flowi4_iif = LOOPBACK_IFINDEX;
555 	fl4.flowi4_tos = RT_TOS(ip4h->tos);
556 	fl4.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF;
557 	fl4.flowi4_proto = ip4h->protocol;
558 	fl4.daddr = ip4h->daddr;
559 	fl4.saddr = ip4h->saddr;
560 
561 	rt = ip_route_output_flow(net, &fl4, NULL);
562 	if (IS_ERR(rt))
563 		goto err;
564 
565 	skb_dst_drop(skb);
566 
567 	/* if dst.dev is loopback or the VRF device again this is locally
568 	 * originated traffic destined to a local address. Short circuit
569 	 * to Rx path
570 	 */
571 	if (rt->dst.dev == vrf_dev)
572 		return vrf_local_xmit(skb, vrf_dev, &rt->dst);
573 
574 	skb_dst_set(skb, &rt->dst);
575 
576 	/* strip the ethernet header added for pass through VRF device */
577 	__skb_pull(skb, skb_network_offset(skb));
578 
579 	if (!ip4h->saddr) {
580 		ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
581 					       RT_SCOPE_LINK);
582 	}
583 
584 	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
585 	ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
586 	if (unlikely(net_xmit_eval(ret)))
587 		vrf_dev->stats.tx_errors++;
588 	else
589 		ret = NET_XMIT_SUCCESS;
590 
591 out:
592 	return ret;
593 err:
594 	vrf_tx_error(vrf_dev, skb);
595 	goto out;
596 }
597 
is_ip_tx_frame(struct sk_buff * skb,struct net_device * dev)598 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
599 {
600 	switch (skb->protocol) {
601 	case htons(ETH_P_IP):
602 		return vrf_process_v4_outbound(skb, dev);
603 	case htons(ETH_P_IPV6):
604 		return vrf_process_v6_outbound(skb, dev);
605 	default:
606 		vrf_tx_error(dev, skb);
607 		return NET_XMIT_DROP;
608 	}
609 }
610 
vrf_xmit(struct sk_buff * skb,struct net_device * dev)611 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
612 {
613 	int len = skb->len;
614 	netdev_tx_t ret = is_ip_tx_frame(skb, dev);
615 
616 	if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
617 		struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
618 
619 		u64_stats_update_begin(&dstats->syncp);
620 		dstats->tx_pkts++;
621 		dstats->tx_bytes += len;
622 		u64_stats_update_end(&dstats->syncp);
623 	} else {
624 		this_cpu_inc(dev->dstats->tx_drps);
625 	}
626 
627 	return ret;
628 }
629 
vrf_finish_direct(struct sk_buff * skb)630 static void vrf_finish_direct(struct sk_buff *skb)
631 {
632 	struct net_device *vrf_dev = skb->dev;
633 
634 	if (!list_empty(&vrf_dev->ptype_all) &&
635 	    likely(skb_headroom(skb) >= ETH_HLEN)) {
636 		struct ethhdr *eth = skb_push(skb, ETH_HLEN);
637 
638 		ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
639 		eth_zero_addr(eth->h_dest);
640 		eth->h_proto = skb->protocol;
641 
642 		rcu_read_lock_bh();
643 		dev_queue_xmit_nit(skb, vrf_dev);
644 		rcu_read_unlock_bh();
645 
646 		skb_pull(skb, ETH_HLEN);
647 	}
648 
649 	vrf_nf_reset_ct(skb);
650 }
651 
652 #if IS_ENABLED(CONFIG_IPV6)
653 /* modelled after ip6_finish_output2 */
vrf_finish_output6(struct net * net,struct sock * sk,struct sk_buff * skb)654 static int vrf_finish_output6(struct net *net, struct sock *sk,
655 			      struct sk_buff *skb)
656 {
657 	struct dst_entry *dst = skb_dst(skb);
658 	struct net_device *dev = dst->dev;
659 	const struct in6_addr *nexthop;
660 	struct neighbour *neigh;
661 	int ret;
662 
663 	vrf_nf_reset_ct(skb);
664 
665 	skb->protocol = htons(ETH_P_IPV6);
666 	skb->dev = dev;
667 
668 	rcu_read_lock_bh();
669 	nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
670 	neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
671 	if (unlikely(!neigh))
672 		neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
673 	if (!IS_ERR(neigh)) {
674 		sock_confirm_neigh(skb, neigh);
675 		ret = neigh_output(neigh, skb, false);
676 		rcu_read_unlock_bh();
677 		return ret;
678 	}
679 	rcu_read_unlock_bh();
680 
681 	IP6_INC_STATS(dev_net(dst->dev),
682 		      ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
683 	kfree_skb(skb);
684 	return -EINVAL;
685 }
686 
687 /* modelled after ip6_output */
vrf_output6(struct net * net,struct sock * sk,struct sk_buff * skb)688 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
689 {
690 	return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
691 			    net, sk, skb, NULL, skb_dst(skb)->dev,
692 			    vrf_finish_output6,
693 			    !(IP6CB(skb)->flags & IP6SKB_REROUTED));
694 }
695 
696 /* set dst on skb to send packet to us via dev_xmit path. Allows
697  * packet to go through device based features such as qdisc, netfilter
698  * hooks and packet sockets with skb->dev set to vrf device.
699  */
vrf_ip6_out_redirect(struct net_device * vrf_dev,struct sk_buff * skb)700 static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev,
701 					    struct sk_buff *skb)
702 {
703 	struct net_vrf *vrf = netdev_priv(vrf_dev);
704 	struct dst_entry *dst = NULL;
705 	struct rt6_info *rt6;
706 
707 	rcu_read_lock();
708 
709 	rt6 = rcu_dereference(vrf->rt6);
710 	if (likely(rt6)) {
711 		dst = &rt6->dst;
712 		dst_hold(dst);
713 	}
714 
715 	rcu_read_unlock();
716 
717 	if (unlikely(!dst)) {
718 		vrf_tx_error(vrf_dev, skb);
719 		return NULL;
720 	}
721 
722 	skb_dst_drop(skb);
723 	skb_dst_set(skb, dst);
724 
725 	return skb;
726 }
727 
vrf_output6_direct_finish(struct net * net,struct sock * sk,struct sk_buff * skb)728 static int vrf_output6_direct_finish(struct net *net, struct sock *sk,
729 				     struct sk_buff *skb)
730 {
731 	vrf_finish_direct(skb);
732 
733 	return vrf_ip6_local_out(net, sk, skb);
734 }
735 
vrf_output6_direct(struct net * net,struct sock * sk,struct sk_buff * skb)736 static int vrf_output6_direct(struct net *net, struct sock *sk,
737 			      struct sk_buff *skb)
738 {
739 	int err = 1;
740 
741 	skb->protocol = htons(ETH_P_IPV6);
742 
743 	if (!(IPCB(skb)->flags & IPSKB_REROUTED))
744 		err = nf_hook(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb,
745 			      NULL, skb->dev, vrf_output6_direct_finish);
746 
747 	if (likely(err == 1))
748 		vrf_finish_direct(skb);
749 
750 	return err;
751 }
752 
vrf_ip6_out_direct_finish(struct net * net,struct sock * sk,struct sk_buff * skb)753 static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk,
754 				     struct sk_buff *skb)
755 {
756 	int err;
757 
758 	err = vrf_output6_direct(net, sk, skb);
759 	if (likely(err == 1))
760 		err = vrf_ip6_local_out(net, sk, skb);
761 
762 	return err;
763 }
764 
vrf_ip6_out_direct(struct net_device * vrf_dev,struct sock * sk,struct sk_buff * skb)765 static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
766 					  struct sock *sk,
767 					  struct sk_buff *skb)
768 {
769 	struct net *net = dev_net(vrf_dev);
770 	int err;
771 
772 	skb->dev = vrf_dev;
773 
774 	err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk,
775 		      skb, NULL, vrf_dev, vrf_ip6_out_direct_finish);
776 
777 	if (likely(err == 1))
778 		err = vrf_output6_direct(net, sk, skb);
779 
780 	if (likely(err == 1))
781 		return skb;
782 
783 	return NULL;
784 }
785 
vrf_ip6_out(struct net_device * vrf_dev,struct sock * sk,struct sk_buff * skb)786 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
787 				   struct sock *sk,
788 				   struct sk_buff *skb)
789 {
790 	/* don't divert link scope packets */
791 	if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
792 		return skb;
793 
794 	vrf_nf_set_untracked(skb);
795 
796 	if (qdisc_tx_is_default(vrf_dev) ||
797 	    IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
798 		return vrf_ip6_out_direct(vrf_dev, sk, skb);
799 
800 	return vrf_ip6_out_redirect(vrf_dev, skb);
801 }
802 
803 /* holding rtnl */
vrf_rt6_release(struct net_device * dev,struct net_vrf * vrf)804 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
805 {
806 	struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
807 	struct net *net = dev_net(dev);
808 	struct dst_entry *dst;
809 
810 	RCU_INIT_POINTER(vrf->rt6, NULL);
811 	synchronize_rcu();
812 
813 	/* move dev in dst's to loopback so this VRF device can be deleted
814 	 * - based on dst_ifdown
815 	 */
816 	if (rt6) {
817 		dst = &rt6->dst;
818 		dev_put(dst->dev);
819 		dst->dev = net->loopback_dev;
820 		dev_hold(dst->dev);
821 		dst_release(dst);
822 	}
823 }
824 
vrf_rt6_create(struct net_device * dev)825 static int vrf_rt6_create(struct net_device *dev)
826 {
827 	int flags = DST_NOPOLICY | DST_NOXFRM;
828 	struct net_vrf *vrf = netdev_priv(dev);
829 	struct net *net = dev_net(dev);
830 	struct rt6_info *rt6;
831 	int rc = -ENOMEM;
832 
833 	/* IPv6 can be CONFIG enabled and then disabled runtime */
834 	if (!ipv6_mod_enabled())
835 		return 0;
836 
837 	vrf->fib6_table = fib6_new_table(net, vrf->tb_id);
838 	if (!vrf->fib6_table)
839 		goto out;
840 
841 	/* create a dst for routing packets out a VRF device */
842 	rt6 = ip6_dst_alloc(net, dev, flags);
843 	if (!rt6)
844 		goto out;
845 
846 	rt6->dst.output	= vrf_output6;
847 
848 	rcu_assign_pointer(vrf->rt6, rt6);
849 
850 	rc = 0;
851 out:
852 	return rc;
853 }
854 #else
vrf_ip6_out(struct net_device * vrf_dev,struct sock * sk,struct sk_buff * skb)855 static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
856 				   struct sock *sk,
857 				   struct sk_buff *skb)
858 {
859 	return skb;
860 }
861 
vrf_rt6_release(struct net_device * dev,struct net_vrf * vrf)862 static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
863 {
864 }
865 
vrf_rt6_create(struct net_device * dev)866 static int vrf_rt6_create(struct net_device *dev)
867 {
868 	return 0;
869 }
870 #endif
871 
872 /* modelled after ip_finish_output2 */
vrf_finish_output(struct net * net,struct sock * sk,struct sk_buff * skb)873 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
874 {
875 	struct dst_entry *dst = skb_dst(skb);
876 	struct rtable *rt = (struct rtable *)dst;
877 	struct net_device *dev = dst->dev;
878 	unsigned int hh_len = LL_RESERVED_SPACE(dev);
879 	struct neighbour *neigh;
880 	bool is_v6gw = false;
881 	int ret = -EINVAL;
882 
883 	vrf_nf_reset_ct(skb);
884 
885 	/* Be paranoid, rather than too clever. */
886 	if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
887 		struct sk_buff *skb2;
888 
889 		skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
890 		if (!skb2) {
891 			ret = -ENOMEM;
892 			goto err;
893 		}
894 		if (skb->sk)
895 			skb_set_owner_w(skb2, skb->sk);
896 
897 		consume_skb(skb);
898 		skb = skb2;
899 	}
900 
901 	rcu_read_lock_bh();
902 
903 	neigh = ip_neigh_for_gw(rt, skb, &is_v6gw);
904 	if (!IS_ERR(neigh)) {
905 		sock_confirm_neigh(skb, neigh);
906 		/* if crossing protocols, can not use the cached header */
907 		ret = neigh_output(neigh, skb, is_v6gw);
908 		rcu_read_unlock_bh();
909 		return ret;
910 	}
911 
912 	rcu_read_unlock_bh();
913 err:
914 	vrf_tx_error(skb->dev, skb);
915 	return ret;
916 }
917 
vrf_output(struct net * net,struct sock * sk,struct sk_buff * skb)918 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
919 {
920 	struct net_device *dev = skb_dst(skb)->dev;
921 
922 	IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
923 
924 	skb->dev = dev;
925 	skb->protocol = htons(ETH_P_IP);
926 
927 	return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
928 			    net, sk, skb, NULL, dev,
929 			    vrf_finish_output,
930 			    !(IPCB(skb)->flags & IPSKB_REROUTED));
931 }
932 
933 /* set dst on skb to send packet to us via dev_xmit path. Allows
934  * packet to go through device based features such as qdisc, netfilter
935  * hooks and packet sockets with skb->dev set to vrf device.
936  */
vrf_ip_out_redirect(struct net_device * vrf_dev,struct sk_buff * skb)937 static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev,
938 					   struct sk_buff *skb)
939 {
940 	struct net_vrf *vrf = netdev_priv(vrf_dev);
941 	struct dst_entry *dst = NULL;
942 	struct rtable *rth;
943 
944 	rcu_read_lock();
945 
946 	rth = rcu_dereference(vrf->rth);
947 	if (likely(rth)) {
948 		dst = &rth->dst;
949 		dst_hold(dst);
950 	}
951 
952 	rcu_read_unlock();
953 
954 	if (unlikely(!dst)) {
955 		vrf_tx_error(vrf_dev, skb);
956 		return NULL;
957 	}
958 
959 	skb_dst_drop(skb);
960 	skb_dst_set(skb, dst);
961 
962 	return skb;
963 }
964 
vrf_output_direct_finish(struct net * net,struct sock * sk,struct sk_buff * skb)965 static int vrf_output_direct_finish(struct net *net, struct sock *sk,
966 				    struct sk_buff *skb)
967 {
968 	vrf_finish_direct(skb);
969 
970 	return vrf_ip_local_out(net, sk, skb);
971 }
972 
vrf_output_direct(struct net * net,struct sock * sk,struct sk_buff * skb)973 static int vrf_output_direct(struct net *net, struct sock *sk,
974 			     struct sk_buff *skb)
975 {
976 	int err = 1;
977 
978 	skb->protocol = htons(ETH_P_IP);
979 
980 	if (!(IPCB(skb)->flags & IPSKB_REROUTED))
981 		err = nf_hook(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb,
982 			      NULL, skb->dev, vrf_output_direct_finish);
983 
984 	if (likely(err == 1))
985 		vrf_finish_direct(skb);
986 
987 	return err;
988 }
989 
vrf_ip_out_direct_finish(struct net * net,struct sock * sk,struct sk_buff * skb)990 static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk,
991 				    struct sk_buff *skb)
992 {
993 	int err;
994 
995 	err = vrf_output_direct(net, sk, skb);
996 	if (likely(err == 1))
997 		err = vrf_ip_local_out(net, sk, skb);
998 
999 	return err;
1000 }
1001 
vrf_ip_out_direct(struct net_device * vrf_dev,struct sock * sk,struct sk_buff * skb)1002 static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
1003 					 struct sock *sk,
1004 					 struct sk_buff *skb)
1005 {
1006 	struct net *net = dev_net(vrf_dev);
1007 	int err;
1008 
1009 	skb->dev = vrf_dev;
1010 
1011 	err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
1012 		      skb, NULL, vrf_dev, vrf_ip_out_direct_finish);
1013 
1014 	if (likely(err == 1))
1015 		err = vrf_output_direct(net, sk, skb);
1016 
1017 	if (likely(err == 1))
1018 		return skb;
1019 
1020 	return NULL;
1021 }
1022 
vrf_ip_out(struct net_device * vrf_dev,struct sock * sk,struct sk_buff * skb)1023 static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
1024 				  struct sock *sk,
1025 				  struct sk_buff *skb)
1026 {
1027 	/* don't divert multicast or local broadcast */
1028 	if (ipv4_is_multicast(ip_hdr(skb)->daddr) ||
1029 	    ipv4_is_lbcast(ip_hdr(skb)->daddr))
1030 		return skb;
1031 
1032 	vrf_nf_set_untracked(skb);
1033 
1034 	if (qdisc_tx_is_default(vrf_dev) ||
1035 	    IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
1036 		return vrf_ip_out_direct(vrf_dev, sk, skb);
1037 
1038 	return vrf_ip_out_redirect(vrf_dev, skb);
1039 }
1040 
1041 /* called with rcu lock held */
vrf_l3_out(struct net_device * vrf_dev,struct sock * sk,struct sk_buff * skb,u16 proto)1042 static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
1043 				  struct sock *sk,
1044 				  struct sk_buff *skb,
1045 				  u16 proto)
1046 {
1047 	switch (proto) {
1048 	case AF_INET:
1049 		return vrf_ip_out(vrf_dev, sk, skb);
1050 	case AF_INET6:
1051 		return vrf_ip6_out(vrf_dev, sk, skb);
1052 	}
1053 
1054 	return skb;
1055 }
1056 
1057 /* holding rtnl */
vrf_rtable_release(struct net_device * dev,struct net_vrf * vrf)1058 static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
1059 {
1060 	struct rtable *rth = rtnl_dereference(vrf->rth);
1061 	struct net *net = dev_net(dev);
1062 	struct dst_entry *dst;
1063 
1064 	RCU_INIT_POINTER(vrf->rth, NULL);
1065 	synchronize_rcu();
1066 
1067 	/* move dev in dst's to loopback so this VRF device can be deleted
1068 	 * - based on dst_ifdown
1069 	 */
1070 	if (rth) {
1071 		dst = &rth->dst;
1072 		dev_put(dst->dev);
1073 		dst->dev = net->loopback_dev;
1074 		dev_hold(dst->dev);
1075 		dst_release(dst);
1076 	}
1077 }
1078 
vrf_rtable_create(struct net_device * dev)1079 static int vrf_rtable_create(struct net_device *dev)
1080 {
1081 	struct net_vrf *vrf = netdev_priv(dev);
1082 	struct rtable *rth;
1083 
1084 	if (!fib_new_table(dev_net(dev), vrf->tb_id))
1085 		return -ENOMEM;
1086 
1087 	/* create a dst for routing packets out through a VRF device */
1088 	rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1);
1089 	if (!rth)
1090 		return -ENOMEM;
1091 
1092 	rth->dst.output	= vrf_output;
1093 
1094 	rcu_assign_pointer(vrf->rth, rth);
1095 
1096 	return 0;
1097 }
1098 
1099 /**************************** device handling ********************/
1100 
1101 /* cycle interface to flush neighbor cache and move routes across tables */
cycle_netdev(struct net_device * dev,struct netlink_ext_ack * extack)1102 static void cycle_netdev(struct net_device *dev,
1103 			 struct netlink_ext_ack *extack)
1104 {
1105 	unsigned int flags = dev->flags;
1106 	int ret;
1107 
1108 	if (!netif_running(dev))
1109 		return;
1110 
1111 	ret = dev_change_flags(dev, flags & ~IFF_UP, extack);
1112 	if (ret >= 0)
1113 		ret = dev_change_flags(dev, flags, extack);
1114 
1115 	if (ret < 0) {
1116 		netdev_err(dev,
1117 			   "Failed to cycle device %s; route tables might be wrong!\n",
1118 			   dev->name);
1119 	}
1120 }
1121 
do_vrf_add_slave(struct net_device * dev,struct net_device * port_dev,struct netlink_ext_ack * extack)1122 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1123 			    struct netlink_ext_ack *extack)
1124 {
1125 	int ret;
1126 
1127 	/* do not allow loopback device to be enslaved to a VRF.
1128 	 * The vrf device acts as the loopback for the vrf.
1129 	 */
1130 	if (port_dev == dev_net(dev)->loopback_dev) {
1131 		NL_SET_ERR_MSG(extack,
1132 			       "Can not enslave loopback device to a VRF");
1133 		return -EOPNOTSUPP;
1134 	}
1135 
1136 	port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
1137 	ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack);
1138 	if (ret < 0)
1139 		goto err;
1140 
1141 	cycle_netdev(port_dev, extack);
1142 
1143 	return 0;
1144 
1145 err:
1146 	port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1147 	return ret;
1148 }
1149 
vrf_add_slave(struct net_device * dev,struct net_device * port_dev,struct netlink_ext_ack * extack)1150 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
1151 			 struct netlink_ext_ack *extack)
1152 {
1153 	if (netif_is_l3_master(port_dev)) {
1154 		NL_SET_ERR_MSG(extack,
1155 			       "Can not enslave an L3 master device to a VRF");
1156 		return -EINVAL;
1157 	}
1158 
1159 	if (netif_is_l3_slave(port_dev))
1160 		return -EINVAL;
1161 
1162 	return do_vrf_add_slave(dev, port_dev, extack);
1163 }
1164 
1165 /* inverse of do_vrf_add_slave */
do_vrf_del_slave(struct net_device * dev,struct net_device * port_dev)1166 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1167 {
1168 	netdev_upper_dev_unlink(port_dev, dev);
1169 	port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
1170 
1171 	cycle_netdev(port_dev, NULL);
1172 
1173 	return 0;
1174 }
1175 
vrf_del_slave(struct net_device * dev,struct net_device * port_dev)1176 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
1177 {
1178 	return do_vrf_del_slave(dev, port_dev);
1179 }
1180 
vrf_dev_uninit(struct net_device * dev)1181 static void vrf_dev_uninit(struct net_device *dev)
1182 {
1183 	struct net_vrf *vrf = netdev_priv(dev);
1184 
1185 	vrf_rtable_release(dev, vrf);
1186 	vrf_rt6_release(dev, vrf);
1187 
1188 	free_percpu(dev->dstats);
1189 	dev->dstats = NULL;
1190 }
1191 
vrf_dev_init(struct net_device * dev)1192 static int vrf_dev_init(struct net_device *dev)
1193 {
1194 	struct net_vrf *vrf = netdev_priv(dev);
1195 
1196 	dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
1197 	if (!dev->dstats)
1198 		goto out_nomem;
1199 
1200 	/* create the default dst which points back to us */
1201 	if (vrf_rtable_create(dev) != 0)
1202 		goto out_stats;
1203 
1204 	if (vrf_rt6_create(dev) != 0)
1205 		goto out_rth;
1206 
1207 	dev->flags = IFF_MASTER | IFF_NOARP;
1208 
1209 	/* similarly, oper state is irrelevant; set to up to avoid confusion */
1210 	dev->operstate = IF_OPER_UP;
1211 	netdev_lockdep_set_classes(dev);
1212 	return 0;
1213 
1214 out_rth:
1215 	vrf_rtable_release(dev, vrf);
1216 out_stats:
1217 	free_percpu(dev->dstats);
1218 	dev->dstats = NULL;
1219 out_nomem:
1220 	return -ENOMEM;
1221 }
1222 
1223 static const struct net_device_ops vrf_netdev_ops = {
1224 	.ndo_init		= vrf_dev_init,
1225 	.ndo_uninit		= vrf_dev_uninit,
1226 	.ndo_start_xmit		= vrf_xmit,
1227 	.ndo_set_mac_address	= eth_mac_addr,
1228 	.ndo_get_stats64	= vrf_get_stats64,
1229 	.ndo_add_slave		= vrf_add_slave,
1230 	.ndo_del_slave		= vrf_del_slave,
1231 };
1232 
vrf_fib_table(const struct net_device * dev)1233 static u32 vrf_fib_table(const struct net_device *dev)
1234 {
1235 	struct net_vrf *vrf = netdev_priv(dev);
1236 
1237 	return vrf->tb_id;
1238 }
1239 
vrf_rcv_finish(struct net * net,struct sock * sk,struct sk_buff * skb)1240 static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
1241 {
1242 	kfree_skb(skb);
1243 	return 0;
1244 }
1245 
vrf_rcv_nfhook(u8 pf,unsigned int hook,struct sk_buff * skb,struct net_device * dev)1246 static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
1247 				      struct sk_buff *skb,
1248 				      struct net_device *dev)
1249 {
1250 	struct net *net = dev_net(dev);
1251 
1252 	if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1)
1253 		skb = NULL;    /* kfree_skb(skb) handled by nf code */
1254 
1255 	return skb;
1256 }
1257 
1258 #if IS_ENABLED(CONFIG_IPV6)
1259 /* neighbor handling is done with actual device; do not want
1260  * to flip skb->dev for those ndisc packets. This really fails
1261  * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
1262  * a start.
1263  */
ipv6_ndisc_frame(const struct sk_buff * skb)1264 static bool ipv6_ndisc_frame(const struct sk_buff *skb)
1265 {
1266 	const struct ipv6hdr *iph = ipv6_hdr(skb);
1267 	bool rc = false;
1268 
1269 	if (iph->nexthdr == NEXTHDR_ICMP) {
1270 		const struct icmp6hdr *icmph;
1271 		struct icmp6hdr _icmph;
1272 
1273 		icmph = skb_header_pointer(skb, sizeof(*iph),
1274 					   sizeof(_icmph), &_icmph);
1275 		if (!icmph)
1276 			goto out;
1277 
1278 		switch (icmph->icmp6_type) {
1279 		case NDISC_ROUTER_SOLICITATION:
1280 		case NDISC_ROUTER_ADVERTISEMENT:
1281 		case NDISC_NEIGHBOUR_SOLICITATION:
1282 		case NDISC_NEIGHBOUR_ADVERTISEMENT:
1283 		case NDISC_REDIRECT:
1284 			rc = true;
1285 			break;
1286 		}
1287 	}
1288 
1289 out:
1290 	return rc;
1291 }
1292 
vrf_ip6_route_lookup(struct net * net,const struct net_device * dev,struct flowi6 * fl6,int ifindex,const struct sk_buff * skb,int flags)1293 static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
1294 					     const struct net_device *dev,
1295 					     struct flowi6 *fl6,
1296 					     int ifindex,
1297 					     const struct sk_buff *skb,
1298 					     int flags)
1299 {
1300 	struct net_vrf *vrf = netdev_priv(dev);
1301 
1302 	return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags);
1303 }
1304 
vrf_ip6_input_dst(struct sk_buff * skb,struct net_device * vrf_dev,int ifindex)1305 static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
1306 			      int ifindex)
1307 {
1308 	const struct ipv6hdr *iph = ipv6_hdr(skb);
1309 	struct flowi6 fl6 = {
1310 		.flowi6_iif     = ifindex,
1311 		.flowi6_mark    = skb->mark,
1312 		.flowi6_proto   = iph->nexthdr,
1313 		.daddr          = iph->daddr,
1314 		.saddr          = iph->saddr,
1315 		.flowlabel      = ip6_flowinfo(iph),
1316 	};
1317 	struct net *net = dev_net(vrf_dev);
1318 	struct rt6_info *rt6;
1319 
1320 	rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb,
1321 				   RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
1322 	if (unlikely(!rt6))
1323 		return;
1324 
1325 	if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
1326 		return;
1327 
1328 	skb_dst_set(skb, &rt6->dst);
1329 }
1330 
vrf_ip6_rcv(struct net_device * vrf_dev,struct sk_buff * skb)1331 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1332 				   struct sk_buff *skb)
1333 {
1334 	int orig_iif = skb->skb_iif;
1335 	bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
1336 	bool is_ndisc = ipv6_ndisc_frame(skb);
1337 
1338 	/* loopback, multicast & non-ND link-local traffic; do not push through
1339 	 * packet taps again. Reset pkt_type for upper layers to process skb.
1340 	 * For strict packets with a source LLA, determine the dst using the
1341 	 * original ifindex.
1342 	 */
1343 	if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) {
1344 		skb->dev = vrf_dev;
1345 		skb->skb_iif = vrf_dev->ifindex;
1346 		IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1347 
1348 		if (skb->pkt_type == PACKET_LOOPBACK)
1349 			skb->pkt_type = PACKET_HOST;
1350 		else if (ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)
1351 			vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1352 
1353 		goto out;
1354 	}
1355 
1356 	/* if packet is NDISC then keep the ingress interface */
1357 	if (!is_ndisc) {
1358 		vrf_rx_stats(vrf_dev, skb->len);
1359 		skb->dev = vrf_dev;
1360 		skb->skb_iif = vrf_dev->ifindex;
1361 
1362 		if (!list_empty(&vrf_dev->ptype_all)) {
1363 			skb_push(skb, skb->mac_len);
1364 			dev_queue_xmit_nit(skb, vrf_dev);
1365 			skb_pull(skb, skb->mac_len);
1366 		}
1367 
1368 		IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
1369 	}
1370 
1371 	if (need_strict)
1372 		vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
1373 
1374 	skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
1375 out:
1376 	return skb;
1377 }
1378 
1379 #else
vrf_ip6_rcv(struct net_device * vrf_dev,struct sk_buff * skb)1380 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
1381 				   struct sk_buff *skb)
1382 {
1383 	return skb;
1384 }
1385 #endif
1386 
vrf_ip_rcv(struct net_device * vrf_dev,struct sk_buff * skb)1387 static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
1388 				  struct sk_buff *skb)
1389 {
1390 	skb->dev = vrf_dev;
1391 	skb->skb_iif = vrf_dev->ifindex;
1392 	IPCB(skb)->flags |= IPSKB_L3SLAVE;
1393 
1394 	if (ipv4_is_multicast(ip_hdr(skb)->daddr))
1395 		goto out;
1396 
1397 	/* loopback traffic; do not push through packet taps again.
1398 	 * Reset pkt_type for upper layers to process skb
1399 	 */
1400 	if (skb->pkt_type == PACKET_LOOPBACK) {
1401 		skb->pkt_type = PACKET_HOST;
1402 		goto out;
1403 	}
1404 
1405 	vrf_rx_stats(vrf_dev, skb->len);
1406 
1407 	if (!list_empty(&vrf_dev->ptype_all)) {
1408 		skb_push(skb, skb->mac_len);
1409 		dev_queue_xmit_nit(skb, vrf_dev);
1410 		skb_pull(skb, skb->mac_len);
1411 	}
1412 
1413 	skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
1414 out:
1415 	return skb;
1416 }
1417 
1418 /* called with rcu lock held */
vrf_l3_rcv(struct net_device * vrf_dev,struct sk_buff * skb,u16 proto)1419 static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
1420 				  struct sk_buff *skb,
1421 				  u16 proto)
1422 {
1423 	switch (proto) {
1424 	case AF_INET:
1425 		return vrf_ip_rcv(vrf_dev, skb);
1426 	case AF_INET6:
1427 		return vrf_ip6_rcv(vrf_dev, skb);
1428 	}
1429 
1430 	return skb;
1431 }
1432 
1433 #if IS_ENABLED(CONFIG_IPV6)
1434 /* send to link-local or multicast address via interface enslaved to
1435  * VRF device. Force lookup to VRF table without changing flow struct
1436  * Note: Caller to this function must hold rcu_read_lock() and no refcnt
1437  * is taken on the dst by this function.
1438  */
vrf_link_scope_lookup(const struct net_device * dev,struct flowi6 * fl6)1439 static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
1440 					      struct flowi6 *fl6)
1441 {
1442 	struct net *net = dev_net(dev);
1443 	int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF;
1444 	struct dst_entry *dst = NULL;
1445 	struct rt6_info *rt;
1446 
1447 	/* VRF device does not have a link-local address and
1448 	 * sending packets to link-local or mcast addresses over
1449 	 * a VRF device does not make sense
1450 	 */
1451 	if (fl6->flowi6_oif == dev->ifindex) {
1452 		dst = &net->ipv6.ip6_null_entry->dst;
1453 		return dst;
1454 	}
1455 
1456 	if (!ipv6_addr_any(&fl6->saddr))
1457 		flags |= RT6_LOOKUP_F_HAS_SADDR;
1458 
1459 	rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags);
1460 	if (rt)
1461 		dst = &rt->dst;
1462 
1463 	return dst;
1464 }
1465 #endif
1466 
1467 static const struct l3mdev_ops vrf_l3mdev_ops = {
1468 	.l3mdev_fib_table	= vrf_fib_table,
1469 	.l3mdev_l3_rcv		= vrf_l3_rcv,
1470 	.l3mdev_l3_out		= vrf_l3_out,
1471 #if IS_ENABLED(CONFIG_IPV6)
1472 	.l3mdev_link_scope_lookup = vrf_link_scope_lookup,
1473 #endif
1474 };
1475 
vrf_get_drvinfo(struct net_device * dev,struct ethtool_drvinfo * info)1476 static void vrf_get_drvinfo(struct net_device *dev,
1477 			    struct ethtool_drvinfo *info)
1478 {
1479 	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
1480 	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
1481 }
1482 
1483 static const struct ethtool_ops vrf_ethtool_ops = {
1484 	.get_drvinfo	= vrf_get_drvinfo,
1485 };
1486 
vrf_fib_rule_nl_size(void)1487 static inline size_t vrf_fib_rule_nl_size(void)
1488 {
1489 	size_t sz;
1490 
1491 	sz  = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
1492 	sz += nla_total_size(sizeof(u8));	/* FRA_L3MDEV */
1493 	sz += nla_total_size(sizeof(u32));	/* FRA_PRIORITY */
1494 	sz += nla_total_size(sizeof(u8));       /* FRA_PROTOCOL */
1495 
1496 	return sz;
1497 }
1498 
vrf_fib_rule(const struct net_device * dev,__u8 family,bool add_it)1499 static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
1500 {
1501 	struct fib_rule_hdr *frh;
1502 	struct nlmsghdr *nlh;
1503 	struct sk_buff *skb;
1504 	int err;
1505 
1506 	if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) &&
1507 	    !ipv6_mod_enabled())
1508 		return 0;
1509 
1510 	skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
1511 	if (!skb)
1512 		return -ENOMEM;
1513 
1514 	nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
1515 	if (!nlh)
1516 		goto nla_put_failure;
1517 
1518 	/* rule only needs to appear once */
1519 	nlh->nlmsg_flags |= NLM_F_EXCL;
1520 
1521 	frh = nlmsg_data(nlh);
1522 	memset(frh, 0, sizeof(*frh));
1523 	frh->family = family;
1524 	frh->action = FR_ACT_TO_TBL;
1525 
1526 	if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL))
1527 		goto nla_put_failure;
1528 
1529 	if (nla_put_u8(skb, FRA_L3MDEV, 1))
1530 		goto nla_put_failure;
1531 
1532 	if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
1533 		goto nla_put_failure;
1534 
1535 	nlmsg_end(skb, nlh);
1536 
1537 	/* fib_nl_{new,del}rule handling looks for net from skb->sk */
1538 	skb->sk = dev_net(dev)->rtnl;
1539 	if (add_it) {
1540 		err = fib_nl_newrule(skb, nlh, NULL);
1541 		if (err == -EEXIST)
1542 			err = 0;
1543 	} else {
1544 		err = fib_nl_delrule(skb, nlh, NULL);
1545 		if (err == -ENOENT)
1546 			err = 0;
1547 	}
1548 	nlmsg_free(skb);
1549 
1550 	return err;
1551 
1552 nla_put_failure:
1553 	nlmsg_free(skb);
1554 
1555 	return -EMSGSIZE;
1556 }
1557 
vrf_add_fib_rules(const struct net_device * dev)1558 static int vrf_add_fib_rules(const struct net_device *dev)
1559 {
1560 	int err;
1561 
1562 	err = vrf_fib_rule(dev, AF_INET,  true);
1563 	if (err < 0)
1564 		goto out_err;
1565 
1566 	err = vrf_fib_rule(dev, AF_INET6, 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, 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, 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)
1585 ip6mr_err:
1586 	vrf_fib_rule(dev, RTNL_FAMILY_IPMR,  false);
1587 #endif
1588 
1589 #if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
1590 ipmr_err:
1591 	vrf_fib_rule(dev, AF_INET6,  false);
1592 #endif
1593 
1594 ipv6_err:
1595 	vrf_fib_rule(dev, AF_INET,  false);
1596 
1597 out_err:
1598 	netdev_err(dev, "Failed to add FIB rules.\n");
1599 	return err;
1600 }
1601 
vrf_setup(struct net_device * dev)1602 static 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->features |= NETIF_F_LLTX;
1617 
1618 	/* don't allow vrf devices to change network namespaces. */
1619 	dev->features |= NETIF_F_NETNS_LOCAL;
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 
vrf_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1646 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],
1647 			struct netlink_ext_ack *extack)
1648 {
1649 	if (tb[IFLA_ADDRESS]) {
1650 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
1651 			NL_SET_ERR_MSG(extack, "Invalid hardware address");
1652 			return -EINVAL;
1653 		}
1654 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
1655 			NL_SET_ERR_MSG(extack, "Invalid hardware address");
1656 			return -EADDRNOTAVAIL;
1657 		}
1658 	}
1659 	return 0;
1660 }
1661 
vrf_dellink(struct net_device * dev,struct list_head * head)1662 static void vrf_dellink(struct net_device *dev, struct list_head *head)
1663 {
1664 	struct net_device *port_dev;
1665 	struct list_head *iter;
1666 
1667 	netdev_for_each_lower_dev(dev, port_dev, iter)
1668 		vrf_del_slave(dev, port_dev);
1669 
1670 	vrf_map_unregister_dev(dev);
1671 
1672 	unregister_netdevice_queue(dev, head);
1673 }
1674 
vrf_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1675 static int vrf_newlink(struct net *src_net, struct net_device *dev,
1676 		       struct nlattr *tb[], struct nlattr *data[],
1677 		       struct netlink_ext_ack *extack)
1678 {
1679 	struct net_vrf *vrf = netdev_priv(dev);
1680 	struct netns_vrf *nn_vrf;
1681 	bool *add_fib_rules;
1682 	struct net *net;
1683 	int err;
1684 
1685 	if (!data || !data[IFLA_VRF_TABLE]) {
1686 		NL_SET_ERR_MSG(extack, "VRF table id is missing");
1687 		return -EINVAL;
1688 	}
1689 
1690 	vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
1691 	if (vrf->tb_id == RT_TABLE_UNSPEC) {
1692 		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE],
1693 				    "Invalid VRF table id");
1694 		return -EINVAL;
1695 	}
1696 
1697 	dev->priv_flags |= IFF_L3MDEV_MASTER;
1698 
1699 	err = register_netdevice(dev);
1700 	if (err)
1701 		goto out;
1702 
1703 	/* mapping between table_id and vrf;
1704 	 * note: such binding could not be done in the dev init function
1705 	 * because dev->ifindex id is not available yet.
1706 	 */
1707 	vrf->ifindex = dev->ifindex;
1708 
1709 	err = vrf_map_register_dev(dev, extack);
1710 	if (err) {
1711 		unregister_netdevice(dev);
1712 		goto out;
1713 	}
1714 
1715 	net = dev_net(dev);
1716 	nn_vrf = net_generic(net, vrf_net_id);
1717 
1718 	add_fib_rules = &nn_vrf->add_fib_rules;
1719 	if (*add_fib_rules) {
1720 		err = vrf_add_fib_rules(dev);
1721 		if (err) {
1722 			vrf_map_unregister_dev(dev);
1723 			unregister_netdevice(dev);
1724 			goto out;
1725 		}
1726 		*add_fib_rules = false;
1727 	}
1728 
1729 out:
1730 	return err;
1731 }
1732 
vrf_nl_getsize(const struct net_device * dev)1733 static size_t vrf_nl_getsize(const struct net_device *dev)
1734 {
1735 	return nla_total_size(sizeof(u32));  /* IFLA_VRF_TABLE */
1736 }
1737 
vrf_fillinfo(struct sk_buff * skb,const struct net_device * dev)1738 static int vrf_fillinfo(struct sk_buff *skb,
1739 			const struct net_device *dev)
1740 {
1741 	struct net_vrf *vrf = netdev_priv(dev);
1742 
1743 	return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
1744 }
1745 
vrf_get_slave_size(const struct net_device * bond_dev,const struct net_device * slave_dev)1746 static size_t vrf_get_slave_size(const struct net_device *bond_dev,
1747 				 const struct net_device *slave_dev)
1748 {
1749 	return nla_total_size(sizeof(u32));  /* IFLA_VRF_PORT_TABLE */
1750 }
1751 
vrf_fill_slave_info(struct sk_buff * skb,const struct net_device * vrf_dev,const struct net_device * slave_dev)1752 static int vrf_fill_slave_info(struct sk_buff *skb,
1753 			       const struct net_device *vrf_dev,
1754 			       const struct net_device *slave_dev)
1755 {
1756 	struct net_vrf *vrf = netdev_priv(vrf_dev);
1757 
1758 	if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
1759 		return -EMSGSIZE;
1760 
1761 	return 0;
1762 }
1763 
1764 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
1765 	[IFLA_VRF_TABLE] = { .type = NLA_U32 },
1766 };
1767 
1768 static struct rtnl_link_ops vrf_link_ops __read_mostly = {
1769 	.kind		= DRV_NAME,
1770 	.priv_size	= sizeof(struct net_vrf),
1771 
1772 	.get_size	= vrf_nl_getsize,
1773 	.policy		= vrf_nl_policy,
1774 	.validate	= vrf_validate,
1775 	.fill_info	= vrf_fillinfo,
1776 
1777 	.get_slave_size  = vrf_get_slave_size,
1778 	.fill_slave_info = vrf_fill_slave_info,
1779 
1780 	.newlink	= vrf_newlink,
1781 	.dellink	= vrf_dellink,
1782 	.setup		= vrf_setup,
1783 	.maxtype	= IFLA_VRF_MAX,
1784 };
1785 
vrf_device_event(struct notifier_block * unused,unsigned long event,void * ptr)1786 static int vrf_device_event(struct notifier_block *unused,
1787 			    unsigned long event, void *ptr)
1788 {
1789 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1790 
1791 	/* only care about unregister events to drop slave references */
1792 	if (event == NETDEV_UNREGISTER) {
1793 		struct net_device *vrf_dev;
1794 
1795 		if (!netif_is_l3_slave(dev))
1796 			goto out;
1797 
1798 		vrf_dev = netdev_master_upper_dev_get(dev);
1799 		vrf_del_slave(vrf_dev, dev);
1800 	}
1801 out:
1802 	return NOTIFY_DONE;
1803 }
1804 
1805 static struct notifier_block vrf_notifier_block __read_mostly = {
1806 	.notifier_call = vrf_device_event,
1807 };
1808 
vrf_map_init(struct vrf_map * vmap)1809 static int vrf_map_init(struct vrf_map *vmap)
1810 {
1811 	spin_lock_init(&vmap->vmap_lock);
1812 	hash_init(vmap->ht);
1813 
1814 	vmap->strict_mode = false;
1815 
1816 	return 0;
1817 }
1818 
1819 #ifdef CONFIG_SYSCTL
vrf_strict_mode(struct vrf_map * vmap)1820 static bool vrf_strict_mode(struct vrf_map *vmap)
1821 {
1822 	bool strict_mode;
1823 
1824 	vrf_map_lock(vmap);
1825 	strict_mode = vmap->strict_mode;
1826 	vrf_map_unlock(vmap);
1827 
1828 	return strict_mode;
1829 }
1830 
vrf_strict_mode_change(struct vrf_map * vmap,bool new_mode)1831 static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode)
1832 {
1833 	bool *cur_mode;
1834 	int res = 0;
1835 
1836 	vrf_map_lock(vmap);
1837 
1838 	cur_mode = &vmap->strict_mode;
1839 	if (*cur_mode == new_mode)
1840 		goto unlock;
1841 
1842 	if (*cur_mode) {
1843 		/* disable strict mode */
1844 		*cur_mode = false;
1845 	} else {
1846 		if (vmap->shared_tables) {
1847 			/* we cannot allow strict_mode because there are some
1848 			 * vrfs that share one or more tables.
1849 			 */
1850 			res = -EBUSY;
1851 			goto unlock;
1852 		}
1853 
1854 		/* no tables are shared among vrfs, so we can go back
1855 		 * to 1:1 association between a vrf with its table.
1856 		 */
1857 		*cur_mode = true;
1858 	}
1859 
1860 unlock:
1861 	vrf_map_unlock(vmap);
1862 
1863 	return res;
1864 }
1865 
vrf_shared_table_handler(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1866 static int vrf_shared_table_handler(struct ctl_table *table, int write,
1867 				    void *buffer, size_t *lenp, loff_t *ppos)
1868 {
1869 	struct net *net = (struct net *)table->extra1;
1870 	struct vrf_map *vmap = netns_vrf_map(net);
1871 	int proc_strict_mode = 0;
1872 	struct ctl_table tmp = {
1873 		.procname	= table->procname,
1874 		.data		= &proc_strict_mode,
1875 		.maxlen		= sizeof(int),
1876 		.mode		= table->mode,
1877 		.extra1		= SYSCTL_ZERO,
1878 		.extra2		= SYSCTL_ONE,
1879 	};
1880 	int ret;
1881 
1882 	if (!write)
1883 		proc_strict_mode = vrf_strict_mode(vmap);
1884 
1885 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
1886 
1887 	if (write && ret == 0)
1888 		ret = vrf_strict_mode_change(vmap, (bool)proc_strict_mode);
1889 
1890 	return ret;
1891 }
1892 
1893 static const struct ctl_table vrf_table[] = {
1894 	{
1895 		.procname	= "strict_mode",
1896 		.data		= NULL,
1897 		.maxlen		= sizeof(int),
1898 		.mode		= 0644,
1899 		.proc_handler	= vrf_shared_table_handler,
1900 		/* set by the vrf_netns_init */
1901 		.extra1		= NULL,
1902 	},
1903 	{ },
1904 };
1905 
vrf_netns_init_sysctl(struct net * net,struct netns_vrf * nn_vrf)1906 static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1907 {
1908 	struct ctl_table *table;
1909 
1910 	table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL);
1911 	if (!table)
1912 		return -ENOMEM;
1913 
1914 	/* init the extra1 parameter with the reference to current netns */
1915 	table[0].extra1 = net;
1916 
1917 	nn_vrf->ctl_hdr = register_net_sysctl(net, "net/vrf", table);
1918 	if (!nn_vrf->ctl_hdr) {
1919 		kfree(table);
1920 		return -ENOMEM;
1921 	}
1922 
1923 	return 0;
1924 }
1925 
vrf_netns_exit_sysctl(struct net * net)1926 static void vrf_netns_exit_sysctl(struct net *net)
1927 {
1928 	struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
1929 	struct ctl_table *table;
1930 
1931 	table = nn_vrf->ctl_hdr->ctl_table_arg;
1932 	unregister_net_sysctl_table(nn_vrf->ctl_hdr);
1933 	kfree(table);
1934 }
1935 #else
vrf_netns_init_sysctl(struct net * net,struct netns_vrf * nn_vrf)1936 static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
1937 {
1938 	return 0;
1939 }
1940 
vrf_netns_exit_sysctl(struct net * net)1941 static void vrf_netns_exit_sysctl(struct net *net)
1942 {
1943 }
1944 #endif
1945 
1946 /* Initialize per network namespace state */
vrf_netns_init(struct net * net)1947 static int __net_init vrf_netns_init(struct net *net)
1948 {
1949 	struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
1950 
1951 	nn_vrf->add_fib_rules = true;
1952 	vrf_map_init(&nn_vrf->vmap);
1953 
1954 	return vrf_netns_init_sysctl(net, nn_vrf);
1955 }
1956 
vrf_netns_exit(struct net * net)1957 static void __net_exit vrf_netns_exit(struct net *net)
1958 {
1959 	vrf_netns_exit_sysctl(net);
1960 }
1961 
1962 static struct pernet_operations vrf_net_ops __net_initdata = {
1963 	.init = vrf_netns_init,
1964 	.exit = vrf_netns_exit,
1965 	.id   = &vrf_net_id,
1966 	.size = sizeof(struct netns_vrf),
1967 };
1968 
vrf_init_module(void)1969 static int __init vrf_init_module(void)
1970 {
1971 	int rc;
1972 
1973 	register_netdevice_notifier(&vrf_notifier_block);
1974 
1975 	rc = register_pernet_subsys(&vrf_net_ops);
1976 	if (rc < 0)
1977 		goto error;
1978 
1979 	rc = l3mdev_table_lookup_register(L3MDEV_TYPE_VRF,
1980 					  vrf_ifindex_lookup_by_table_id);
1981 	if (rc < 0)
1982 		goto unreg_pernet;
1983 
1984 	rc = rtnl_link_register(&vrf_link_ops);
1985 	if (rc < 0)
1986 		goto table_lookup_unreg;
1987 
1988 	return 0;
1989 
1990 table_lookup_unreg:
1991 	l3mdev_table_lookup_unregister(L3MDEV_TYPE_VRF,
1992 				       vrf_ifindex_lookup_by_table_id);
1993 
1994 unreg_pernet:
1995 	unregister_pernet_subsys(&vrf_net_ops);
1996 
1997 error:
1998 	unregister_netdevice_notifier(&vrf_notifier_block);
1999 	return rc;
2000 }
2001 
2002 module_init(vrf_init_module);
2003 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
2004 MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
2005 MODULE_LICENSE("GPL");
2006 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
2007 MODULE_VERSION(DRV_VERSION);
2008