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v4.17
 
  1/*
  2 *  drivers/net/veth.c
  3 *
  4 *  Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
  5 *
  6 * Author: Pavel Emelianov <xemul@openvz.org>
  7 * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
  8 *
  9 */
 10
 11#include <linux/netdevice.h>
 12#include <linux/slab.h>
 13#include <linux/ethtool.h>
 14#include <linux/etherdevice.h>
 15#include <linux/u64_stats_sync.h>
 16
 17#include <net/rtnetlink.h>
 18#include <net/dst.h>
 19#include <net/xfrm.h>
 
 20#include <linux/veth.h>
 21#include <linux/module.h>
 
 
 
 
 
 22
 23#define DRV_NAME	"veth"
 24#define DRV_VERSION	"1.0"
 25
 26struct pcpu_vstats {
 27	u64			packets;
 28	u64			bytes;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 29	struct u64_stats_sync	syncp;
 30};
 31
 
 
 
 
 
 
 
 
 
 
 
 32struct veth_priv {
 33	struct net_device __rcu	*peer;
 34	atomic64_t		dropped;
 35	unsigned		requested_headroom;
 
 
 
 
 
 
 
 36};
 37
 38/*
 39 * ethtool interface
 40 */
 41
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 42static struct {
 43	const char string[ETH_GSTRING_LEN];
 44} ethtool_stats_keys[] = {
 45	{ "peer_ifindex" },
 46};
 47
 48static int veth_get_link_ksettings(struct net_device *dev,
 49				   struct ethtool_link_ksettings *cmd)
 50{
 51	cmd->base.speed		= SPEED_10000;
 52	cmd->base.duplex	= DUPLEX_FULL;
 53	cmd->base.port		= PORT_TP;
 54	cmd->base.autoneg	= AUTONEG_DISABLE;
 55	return 0;
 56}
 57
 58static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 59{
 60	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
 61	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
 62}
 63
 64static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
 65{
 
 
 
 66	switch(stringset) {
 67	case ETH_SS_STATS:
 68		memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 69		break;
 70	}
 71}
 72
 73static int veth_get_sset_count(struct net_device *dev, int sset)
 74{
 75	switch (sset) {
 76	case ETH_SS_STATS:
 77		return ARRAY_SIZE(ethtool_stats_keys);
 
 
 78	default:
 79		return -EOPNOTSUPP;
 80	}
 81}
 82
 83static void veth_get_ethtool_stats(struct net_device *dev,
 84		struct ethtool_stats *stats, u64 *data)
 85{
 86	struct veth_priv *priv = netdev_priv(dev);
 87	struct net_device *peer = rtnl_dereference(priv->peer);
 
 88
 89	data[0] = peer ? peer->ifindex : 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 90}
 91
 92static const struct ethtool_ops veth_ethtool_ops = {
 93	.get_drvinfo		= veth_get_drvinfo,
 94	.get_link		= ethtool_op_get_link,
 95	.get_strings		= veth_get_strings,
 96	.get_sset_count		= veth_get_sset_count,
 97	.get_ethtool_stats	= veth_get_ethtool_stats,
 98	.get_link_ksettings	= veth_get_link_ksettings,
 
 99};
100
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
101static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
102{
103	struct veth_priv *priv = netdev_priv(dev);
 
104	struct net_device *rcv;
105	int length = skb->len;
 
 
106
107	rcu_read_lock();
108	rcv = rcu_dereference(priv->peer);
109	if (unlikely(!rcv)) {
110		kfree_skb(skb);
111		goto drop;
112	}
113
114	if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) {
115		struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
 
 
 
 
 
 
116
117		u64_stats_update_begin(&stats->syncp);
118		stats->bytes += length;
119		stats->packets++;
120		u64_stats_update_end(&stats->syncp);
121	} else {
122drop:
123		atomic64_inc(&priv->dropped);
124	}
 
 
 
 
125	rcu_read_unlock();
 
126	return NETDEV_TX_OK;
127}
128
129/*
130 * general routines
131 */
132
133static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev)
 
 
 
 
134{
135	struct veth_priv *priv = netdev_priv(dev);
136	int cpu;
137
138	result->packets = 0;
139	result->bytes = 0;
140	for_each_possible_cpu(cpu) {
141		struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
142		u64 packets, bytes;
 
 
 
143		unsigned int start;
144
145		do {
146			start = u64_stats_fetch_begin_irq(&stats->syncp);
147			packets = stats->packets;
148			bytes = stats->bytes;
 
 
 
149		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
150		result->packets += packets;
151		result->bytes += bytes;
 
 
 
152	}
153	return atomic64_read(&priv->dropped);
154}
155
156static void veth_get_stats64(struct net_device *dev,
157			     struct rtnl_link_stats64 *tot)
158{
159	struct veth_priv *priv = netdev_priv(dev);
160	struct net_device *peer;
161	struct pcpu_vstats one;
 
162
163	tot->tx_dropped = veth_stats_one(&one, dev);
164	tot->tx_bytes = one.bytes;
165	tot->tx_packets = one.packets;
 
 
 
 
 
 
166
167	rcu_read_lock();
168	peer = rcu_dereference(priv->peer);
169	if (peer) {
170		tot->rx_dropped = veth_stats_one(&one, peer);
171		tot->rx_bytes = one.bytes;
172		tot->rx_packets = one.packets;
 
 
 
 
 
 
173	}
174	rcu_read_unlock();
175}
176
177/* fake multicast ability */
178static void veth_set_multicast_list(struct net_device *dev)
179{
180}
181
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
182static int veth_open(struct net_device *dev)
183{
184	struct veth_priv *priv = netdev_priv(dev);
185	struct net_device *peer = rtnl_dereference(priv->peer);
 
186
187	if (!peer)
188		return -ENOTCONN;
189
 
 
 
 
 
 
190	if (peer->flags & IFF_UP) {
191		netif_carrier_on(dev);
192		netif_carrier_on(peer);
193	}
 
194	return 0;
195}
196
197static int veth_close(struct net_device *dev)
198{
199	struct veth_priv *priv = netdev_priv(dev);
200	struct net_device *peer = rtnl_dereference(priv->peer);
201
202	netif_carrier_off(dev);
203	if (peer)
204		netif_carrier_off(peer);
205
 
 
 
206	return 0;
207}
208
209static int is_valid_veth_mtu(int mtu)
210{
211	return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
212}
213
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
214static int veth_dev_init(struct net_device *dev)
215{
216	dev->vstats = netdev_alloc_pcpu_stats(struct pcpu_vstats);
217	if (!dev->vstats)
 
 
218		return -ENOMEM;
 
 
 
 
 
 
 
219	return 0;
220}
221
222static void veth_dev_free(struct net_device *dev)
223{
224	free_percpu(dev->vstats);
 
225}
226
227#ifdef CONFIG_NET_POLL_CONTROLLER
228static void veth_poll_controller(struct net_device *dev)
229{
230	/* veth only receives frames when its peer sends one
231	 * Since it's a synchronous operation, we are guaranteed
232	 * never to have pending data when we poll for it so
233	 * there is nothing to do here.
234	 *
235	 * We need this though so netpoll recognizes us as an interface that
236	 * supports polling, which enables bridge devices in virt setups to
237	 * still use netconsole
238	 */
239}
240#endif	/* CONFIG_NET_POLL_CONTROLLER */
241
242static int veth_get_iflink(const struct net_device *dev)
243{
244	struct veth_priv *priv = netdev_priv(dev);
245	struct net_device *peer;
246	int iflink;
247
248	rcu_read_lock();
249	peer = rcu_dereference(priv->peer);
250	iflink = peer ? peer->ifindex : 0;
251	rcu_read_unlock();
252
253	return iflink;
254}
255
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
256static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
257{
258	struct veth_priv *peer_priv, *priv = netdev_priv(dev);
259	struct net_device *peer;
260
261	if (new_hr < 0)
262		new_hr = 0;
263
264	rcu_read_lock();
265	peer = rcu_dereference(priv->peer);
266	if (unlikely(!peer))
267		goto out;
268
269	peer_priv = netdev_priv(peer);
270	priv->requested_headroom = new_hr;
271	new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
272	dev->needed_headroom = new_hr;
273	peer->needed_headroom = new_hr;
274
275out:
276	rcu_read_unlock();
277}
278
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
279static const struct net_device_ops veth_netdev_ops = {
280	.ndo_init            = veth_dev_init,
281	.ndo_open            = veth_open,
282	.ndo_stop            = veth_close,
283	.ndo_start_xmit      = veth_xmit,
284	.ndo_get_stats64     = veth_get_stats64,
285	.ndo_set_rx_mode     = veth_set_multicast_list,
286	.ndo_set_mac_address = eth_mac_addr,
287#ifdef CONFIG_NET_POLL_CONTROLLER
288	.ndo_poll_controller	= veth_poll_controller,
289#endif
290	.ndo_get_iflink		= veth_get_iflink,
 
291	.ndo_features_check	= passthru_features_check,
292	.ndo_set_rx_headroom	= veth_set_rx_headroom,
 
 
293};
294
295#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
296		       NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
297		       NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
298		       NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
299		       NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
300
301static void veth_setup(struct net_device *dev)
302{
303	ether_setup(dev);
304
305	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
306	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
307	dev->priv_flags |= IFF_NO_QUEUE;
308	dev->priv_flags |= IFF_PHONY_HEADROOM;
309
310	dev->netdev_ops = &veth_netdev_ops;
311	dev->ethtool_ops = &veth_ethtool_ops;
312	dev->features |= NETIF_F_LLTX;
313	dev->features |= VETH_FEATURES;
314	dev->vlan_features = dev->features &
315			     ~(NETIF_F_HW_VLAN_CTAG_TX |
316			       NETIF_F_HW_VLAN_STAG_TX |
317			       NETIF_F_HW_VLAN_CTAG_RX |
318			       NETIF_F_HW_VLAN_STAG_RX);
319	dev->needs_free_netdev = true;
320	dev->priv_destructor = veth_dev_free;
321	dev->max_mtu = ETH_MAX_MTU;
322
323	dev->hw_features = VETH_FEATURES;
324	dev->hw_enc_features = VETH_FEATURES;
325	dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
326}
327
328/*
329 * netlink interface
330 */
331
332static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
333			 struct netlink_ext_ack *extack)
334{
335	if (tb[IFLA_ADDRESS]) {
336		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
337			return -EINVAL;
338		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
339			return -EADDRNOTAVAIL;
340	}
341	if (tb[IFLA_MTU]) {
342		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
343			return -EINVAL;
344	}
345	return 0;
346}
347
348static struct rtnl_link_ops veth_link_ops;
349
350static int veth_newlink(struct net *src_net, struct net_device *dev,
351			struct nlattr *tb[], struct nlattr *data[],
352			struct netlink_ext_ack *extack)
353{
354	int err;
355	struct net_device *peer;
356	struct veth_priv *priv;
357	char ifname[IFNAMSIZ];
358	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
359	unsigned char name_assign_type;
360	struct ifinfomsg *ifmp;
361	struct net *net;
362
363	/*
364	 * create and register peer first
365	 */
366	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
367		struct nlattr *nla_peer;
368
369		nla_peer = data[VETH_INFO_PEER];
370		ifmp = nla_data(nla_peer);
371		err = rtnl_nla_parse_ifla(peer_tb,
372					  nla_data(nla_peer) + sizeof(struct ifinfomsg),
373					  nla_len(nla_peer) - sizeof(struct ifinfomsg),
374					  NULL);
375		if (err < 0)
376			return err;
377
378		err = veth_validate(peer_tb, NULL, extack);
379		if (err < 0)
380			return err;
381
382		tbp = peer_tb;
383	} else {
384		ifmp = NULL;
385		tbp = tb;
386	}
387
388	if (ifmp && tbp[IFLA_IFNAME]) {
389		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
390		name_assign_type = NET_NAME_USER;
391	} else {
392		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
393		name_assign_type = NET_NAME_ENUM;
394	}
395
396	net = rtnl_link_get_net(src_net, tbp);
397	if (IS_ERR(net))
398		return PTR_ERR(net);
399
400	peer = rtnl_create_link(net, ifname, name_assign_type,
401				&veth_link_ops, tbp);
402	if (IS_ERR(peer)) {
403		put_net(net);
404		return PTR_ERR(peer);
405	}
406
407	if (!ifmp || !tbp[IFLA_ADDRESS])
408		eth_hw_addr_random(peer);
409
410	if (ifmp && (dev->ifindex != 0))
411		peer->ifindex = ifmp->ifi_index;
412
413	peer->gso_max_size = dev->gso_max_size;
414	peer->gso_max_segs = dev->gso_max_segs;
415
416	err = register_netdevice(peer);
417	put_net(net);
418	net = NULL;
419	if (err < 0)
420		goto err_register_peer;
421
422	netif_carrier_off(peer);
423
424	err = rtnl_configure_link(peer, ifmp);
425	if (err < 0)
426		goto err_configure_peer;
427
428	/*
429	 * register dev last
430	 *
431	 * note, that since we've registered new device the dev's name
432	 * should be re-allocated
433	 */
434
435	if (tb[IFLA_ADDRESS] == NULL)
436		eth_hw_addr_random(dev);
437
438	if (tb[IFLA_IFNAME])
439		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
440	else
441		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
442
443	err = register_netdevice(dev);
444	if (err < 0)
445		goto err_register_dev;
446
447	netif_carrier_off(dev);
448
449	/*
450	 * tie the deviced together
451	 */
452
453	priv = netdev_priv(dev);
454	rcu_assign_pointer(priv->peer, peer);
455
456	priv = netdev_priv(peer);
457	rcu_assign_pointer(priv->peer, dev);
 
458	return 0;
459
460err_register_dev:
461	/* nothing to do */
462err_configure_peer:
463	unregister_netdevice(peer);
464	return err;
465
466err_register_peer:
467	free_netdev(peer);
468	return err;
469}
470
471static void veth_dellink(struct net_device *dev, struct list_head *head)
472{
473	struct veth_priv *priv;
474	struct net_device *peer;
475
476	priv = netdev_priv(dev);
477	peer = rtnl_dereference(priv->peer);
478
479	/* Note : dellink() is called from default_device_exit_batch(),
480	 * before a rcu_synchronize() point. The devices are guaranteed
481	 * not being freed before one RCU grace period.
482	 */
483	RCU_INIT_POINTER(priv->peer, NULL);
484	unregister_netdevice_queue(dev, head);
485
486	if (peer) {
487		priv = netdev_priv(peer);
488		RCU_INIT_POINTER(priv->peer, NULL);
489		unregister_netdevice_queue(peer, head);
490	}
491}
492
493static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
494	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },
495};
496
497static struct net *veth_get_link_net(const struct net_device *dev)
498{
499	struct veth_priv *priv = netdev_priv(dev);
500	struct net_device *peer = rtnl_dereference(priv->peer);
501
502	return peer ? dev_net(peer) : dev_net(dev);
503}
504
505static struct rtnl_link_ops veth_link_ops = {
506	.kind		= DRV_NAME,
507	.priv_size	= sizeof(struct veth_priv),
508	.setup		= veth_setup,
509	.validate	= veth_validate,
510	.newlink	= veth_newlink,
511	.dellink	= veth_dellink,
512	.policy		= veth_policy,
513	.maxtype	= VETH_INFO_MAX,
514	.get_link_net	= veth_get_link_net,
515};
516
517/*
518 * init/fini
519 */
520
521static __init int veth_init(void)
522{
523	return rtnl_link_register(&veth_link_ops);
524}
525
526static __exit void veth_exit(void)
527{
528	rtnl_link_unregister(&veth_link_ops);
529}
530
531module_init(veth_init);
532module_exit(veth_exit);
533
534MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
535MODULE_LICENSE("GPL v2");
536MODULE_ALIAS_RTNL_LINK(DRV_NAME);
v5.9
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  drivers/net/veth.c
   4 *
   5 *  Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
   6 *
   7 * Author: Pavel Emelianov <xemul@openvz.org>
   8 * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
   9 *
  10 */
  11
  12#include <linux/netdevice.h>
  13#include <linux/slab.h>
  14#include <linux/ethtool.h>
  15#include <linux/etherdevice.h>
  16#include <linux/u64_stats_sync.h>
  17
  18#include <net/rtnetlink.h>
  19#include <net/dst.h>
  20#include <net/xfrm.h>
  21#include <net/xdp.h>
  22#include <linux/veth.h>
  23#include <linux/module.h>
  24#include <linux/bpf.h>
  25#include <linux/filter.h>
  26#include <linux/ptr_ring.h>
  27#include <linux/bpf_trace.h>
  28#include <linux/net_tstamp.h>
  29
  30#define DRV_NAME	"veth"
  31#define DRV_VERSION	"1.0"
  32
  33#define VETH_XDP_FLAG		BIT(0)
  34#define VETH_RING_SIZE		256
  35#define VETH_XDP_HEADROOM	(XDP_PACKET_HEADROOM + NET_IP_ALIGN)
  36
  37#define VETH_XDP_TX_BULK_SIZE	16
  38
  39struct veth_stats {
  40	u64	rx_drops;
  41	/* xdp */
  42	u64	xdp_packets;
  43	u64	xdp_bytes;
  44	u64	xdp_redirect;
  45	u64	xdp_drops;
  46	u64	xdp_tx;
  47	u64	xdp_tx_err;
  48	u64	peer_tq_xdp_xmit;
  49	u64	peer_tq_xdp_xmit_err;
  50};
  51
  52struct veth_rq_stats {
  53	struct veth_stats	vs;
  54	struct u64_stats_sync	syncp;
  55};
  56
  57struct veth_rq {
  58	struct napi_struct	xdp_napi;
  59	struct net_device	*dev;
  60	struct bpf_prog __rcu	*xdp_prog;
  61	struct xdp_mem_info	xdp_mem;
  62	struct veth_rq_stats	stats;
  63	bool			rx_notify_masked;
  64	struct ptr_ring		xdp_ring;
  65	struct xdp_rxq_info	xdp_rxq;
  66};
  67
  68struct veth_priv {
  69	struct net_device __rcu	*peer;
  70	atomic64_t		dropped;
  71	struct bpf_prog		*_xdp_prog;
  72	struct veth_rq		*rq;
  73	unsigned int		requested_headroom;
  74};
  75
  76struct veth_xdp_tx_bq {
  77	struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
  78	unsigned int count;
  79};
  80
  81/*
  82 * ethtool interface
  83 */
  84
  85struct veth_q_stat_desc {
  86	char	desc[ETH_GSTRING_LEN];
  87	size_t	offset;
  88};
  89
  90#define VETH_RQ_STAT(m)	offsetof(struct veth_stats, m)
  91
  92static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
  93	{ "xdp_packets",	VETH_RQ_STAT(xdp_packets) },
  94	{ "xdp_bytes",		VETH_RQ_STAT(xdp_bytes) },
  95	{ "drops",		VETH_RQ_STAT(rx_drops) },
  96	{ "xdp_redirect",	VETH_RQ_STAT(xdp_redirect) },
  97	{ "xdp_drops",		VETH_RQ_STAT(xdp_drops) },
  98	{ "xdp_tx",		VETH_RQ_STAT(xdp_tx) },
  99	{ "xdp_tx_errors",	VETH_RQ_STAT(xdp_tx_err) },
 100};
 101
 102#define VETH_RQ_STATS_LEN	ARRAY_SIZE(veth_rq_stats_desc)
 103
 104static const struct veth_q_stat_desc veth_tq_stats_desc[] = {
 105	{ "xdp_xmit",		VETH_RQ_STAT(peer_tq_xdp_xmit) },
 106	{ "xdp_xmit_errors",	VETH_RQ_STAT(peer_tq_xdp_xmit_err) },
 107};
 108
 109#define VETH_TQ_STATS_LEN	ARRAY_SIZE(veth_tq_stats_desc)
 110
 111static struct {
 112	const char string[ETH_GSTRING_LEN];
 113} ethtool_stats_keys[] = {
 114	{ "peer_ifindex" },
 115};
 116
 117static int veth_get_link_ksettings(struct net_device *dev,
 118				   struct ethtool_link_ksettings *cmd)
 119{
 120	cmd->base.speed		= SPEED_10000;
 121	cmd->base.duplex	= DUPLEX_FULL;
 122	cmd->base.port		= PORT_TP;
 123	cmd->base.autoneg	= AUTONEG_DISABLE;
 124	return 0;
 125}
 126
 127static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 128{
 129	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
 130	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
 131}
 132
 133static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
 134{
 135	char *p = (char *)buf;
 136	int i, j;
 137
 138	switch(stringset) {
 139	case ETH_SS_STATS:
 140		memcpy(p, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
 141		p += sizeof(ethtool_stats_keys);
 142		for (i = 0; i < dev->real_num_rx_queues; i++) {
 143			for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
 144				snprintf(p, ETH_GSTRING_LEN,
 145					 "rx_queue_%u_%.18s",
 146					 i, veth_rq_stats_desc[j].desc);
 147				p += ETH_GSTRING_LEN;
 148			}
 149		}
 150		for (i = 0; i < dev->real_num_tx_queues; i++) {
 151			for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
 152				snprintf(p, ETH_GSTRING_LEN,
 153					 "tx_queue_%u_%.18s",
 154					 i, veth_tq_stats_desc[j].desc);
 155				p += ETH_GSTRING_LEN;
 156			}
 157		}
 158		break;
 159	}
 160}
 161
 162static int veth_get_sset_count(struct net_device *dev, int sset)
 163{
 164	switch (sset) {
 165	case ETH_SS_STATS:
 166		return ARRAY_SIZE(ethtool_stats_keys) +
 167		       VETH_RQ_STATS_LEN * dev->real_num_rx_queues +
 168		       VETH_TQ_STATS_LEN * dev->real_num_tx_queues;
 169	default:
 170		return -EOPNOTSUPP;
 171	}
 172}
 173
 174static void veth_get_ethtool_stats(struct net_device *dev,
 175		struct ethtool_stats *stats, u64 *data)
 176{
 177	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 178	struct net_device *peer = rtnl_dereference(priv->peer);
 179	int i, j, idx;
 180
 181	data[0] = peer ? peer->ifindex : 0;
 182	idx = 1;
 183	for (i = 0; i < dev->real_num_rx_queues; i++) {
 184		const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
 185		const void *stats_base = (void *)&rq_stats->vs;
 186		unsigned int start;
 187		size_t offset;
 188
 189		do {
 190			start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
 191			for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
 192				offset = veth_rq_stats_desc[j].offset;
 193				data[idx + j] = *(u64 *)(stats_base + offset);
 194			}
 195		} while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
 196		idx += VETH_RQ_STATS_LEN;
 197	}
 198
 199	if (!peer)
 200		return;
 201
 202	rcv_priv = netdev_priv(peer);
 203	for (i = 0; i < peer->real_num_rx_queues; i++) {
 204		const struct veth_rq_stats *rq_stats = &rcv_priv->rq[i].stats;
 205		const void *base = (void *)&rq_stats->vs;
 206		unsigned int start, tx_idx = idx;
 207		size_t offset;
 208
 209		tx_idx += (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN;
 210		do {
 211			start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
 212			for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
 213				offset = veth_tq_stats_desc[j].offset;
 214				data[tx_idx + j] += *(u64 *)(base + offset);
 215			}
 216		} while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
 217	}
 218}
 219
 220static const struct ethtool_ops veth_ethtool_ops = {
 221	.get_drvinfo		= veth_get_drvinfo,
 222	.get_link		= ethtool_op_get_link,
 223	.get_strings		= veth_get_strings,
 224	.get_sset_count		= veth_get_sset_count,
 225	.get_ethtool_stats	= veth_get_ethtool_stats,
 226	.get_link_ksettings	= veth_get_link_ksettings,
 227	.get_ts_info		= ethtool_op_get_ts_info,
 228};
 229
 230/* general routines */
 231
 232static bool veth_is_xdp_frame(void *ptr)
 233{
 234	return (unsigned long)ptr & VETH_XDP_FLAG;
 235}
 236
 237static void *veth_ptr_to_xdp(void *ptr)
 238{
 239	return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
 240}
 241
 242static void *veth_xdp_to_ptr(void *ptr)
 243{
 244	return (void *)((unsigned long)ptr | VETH_XDP_FLAG);
 245}
 246
 247static void veth_ptr_free(void *ptr)
 248{
 249	if (veth_is_xdp_frame(ptr))
 250		xdp_return_frame(veth_ptr_to_xdp(ptr));
 251	else
 252		kfree_skb(ptr);
 253}
 254
 255static void __veth_xdp_flush(struct veth_rq *rq)
 256{
 257	/* Write ptr_ring before reading rx_notify_masked */
 258	smp_mb();
 259	if (!rq->rx_notify_masked) {
 260		rq->rx_notify_masked = true;
 261		napi_schedule(&rq->xdp_napi);
 262	}
 263}
 264
 265static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
 266{
 267	if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
 268		dev_kfree_skb_any(skb);
 269		return NET_RX_DROP;
 270	}
 271
 272	return NET_RX_SUCCESS;
 273}
 274
 275static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
 276			    struct veth_rq *rq, bool xdp)
 277{
 278	return __dev_forward_skb(dev, skb) ?: xdp ?
 279		veth_xdp_rx(rq, skb) :
 280		netif_rx(skb);
 281}
 282
 283static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 284{
 285	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 286	struct veth_rq *rq = NULL;
 287	struct net_device *rcv;
 288	int length = skb->len;
 289	bool rcv_xdp = false;
 290	int rxq;
 291
 292	rcu_read_lock();
 293	rcv = rcu_dereference(priv->peer);
 294	if (unlikely(!rcv)) {
 295		kfree_skb(skb);
 296		goto drop;
 297	}
 298
 299	rcv_priv = netdev_priv(rcv);
 300	rxq = skb_get_queue_mapping(skb);
 301	if (rxq < rcv->real_num_rx_queues) {
 302		rq = &rcv_priv->rq[rxq];
 303		rcv_xdp = rcu_access_pointer(rq->xdp_prog);
 304		if (rcv_xdp)
 305			skb_record_rx_queue(skb, rxq);
 306	}
 307
 308	skb_tx_timestamp(skb);
 309	if (likely(veth_forward_skb(rcv, skb, rq, rcv_xdp) == NET_RX_SUCCESS)) {
 310		if (!rcv_xdp)
 311			dev_lstats_add(dev, length);
 312	} else {
 313drop:
 314		atomic64_inc(&priv->dropped);
 315	}
 316
 317	if (rcv_xdp)
 318		__veth_xdp_flush(rq);
 319
 320	rcu_read_unlock();
 321
 322	return NETDEV_TX_OK;
 323}
 324
 325static u64 veth_stats_tx(struct net_device *dev, u64 *packets, u64 *bytes)
 326{
 327	struct veth_priv *priv = netdev_priv(dev);
 328
 329	dev_lstats_read(dev, packets, bytes);
 330	return atomic64_read(&priv->dropped);
 331}
 332
 333static void veth_stats_rx(struct veth_stats *result, struct net_device *dev)
 334{
 335	struct veth_priv *priv = netdev_priv(dev);
 336	int i;
 337
 338	result->peer_tq_xdp_xmit_err = 0;
 339	result->xdp_packets = 0;
 340	result->xdp_tx_err = 0;
 341	result->xdp_bytes = 0;
 342	result->rx_drops = 0;
 343	for (i = 0; i < dev->num_rx_queues; i++) {
 344		u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err;
 345		struct veth_rq_stats *stats = &priv->rq[i].stats;
 346		unsigned int start;
 347
 348		do {
 349			start = u64_stats_fetch_begin_irq(&stats->syncp);
 350			peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err;
 351			xdp_tx_err = stats->vs.xdp_tx_err;
 352			packets = stats->vs.xdp_packets;
 353			bytes = stats->vs.xdp_bytes;
 354			drops = stats->vs.rx_drops;
 355		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
 356		result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err;
 357		result->xdp_tx_err += xdp_tx_err;
 358		result->xdp_packets += packets;
 359		result->xdp_bytes += bytes;
 360		result->rx_drops += drops;
 361	}
 
 362}
 363
 364static void veth_get_stats64(struct net_device *dev,
 365			     struct rtnl_link_stats64 *tot)
 366{
 367	struct veth_priv *priv = netdev_priv(dev);
 368	struct net_device *peer;
 369	struct veth_stats rx;
 370	u64 packets, bytes;
 371
 372	tot->tx_dropped = veth_stats_tx(dev, &packets, &bytes);
 373	tot->tx_bytes = bytes;
 374	tot->tx_packets = packets;
 375
 376	veth_stats_rx(&rx, dev);
 377	tot->tx_dropped += rx.xdp_tx_err;
 378	tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err;
 379	tot->rx_bytes = rx.xdp_bytes;
 380	tot->rx_packets = rx.xdp_packets;
 381
 382	rcu_read_lock();
 383	peer = rcu_dereference(priv->peer);
 384	if (peer) {
 385		veth_stats_tx(peer, &packets, &bytes);
 386		tot->rx_bytes += bytes;
 387		tot->rx_packets += packets;
 388
 389		veth_stats_rx(&rx, peer);
 390		tot->tx_dropped += rx.peer_tq_xdp_xmit_err;
 391		tot->rx_dropped += rx.xdp_tx_err;
 392		tot->tx_bytes += rx.xdp_bytes;
 393		tot->tx_packets += rx.xdp_packets;
 394	}
 395	rcu_read_unlock();
 396}
 397
 398/* fake multicast ability */
 399static void veth_set_multicast_list(struct net_device *dev)
 400{
 401}
 402
 403static struct sk_buff *veth_build_skb(void *head, int headroom, int len,
 404				      int buflen)
 405{
 406	struct sk_buff *skb;
 407
 408	skb = build_skb(head, buflen);
 409	if (!skb)
 410		return NULL;
 411
 412	skb_reserve(skb, headroom);
 413	skb_put(skb, len);
 414
 415	return skb;
 416}
 417
 418static int veth_select_rxq(struct net_device *dev)
 419{
 420	return smp_processor_id() % dev->real_num_rx_queues;
 421}
 422
 423static int veth_xdp_xmit(struct net_device *dev, int n,
 424			 struct xdp_frame **frames,
 425			 u32 flags, bool ndo_xmit)
 426{
 427	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 428	int i, ret = -ENXIO, drops = 0;
 429	struct net_device *rcv;
 430	unsigned int max_len;
 431	struct veth_rq *rq;
 432
 433	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
 434		return -EINVAL;
 435
 436	rcu_read_lock();
 437	rcv = rcu_dereference(priv->peer);
 438	if (unlikely(!rcv))
 439		goto out;
 440
 441	rcv_priv = netdev_priv(rcv);
 442	rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 443	/* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive
 444	 * side. This means an XDP program is loaded on the peer and the peer
 445	 * device is up.
 446	 */
 447	if (!rcu_access_pointer(rq->xdp_prog))
 448		goto out;
 449
 450	max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
 451
 452	spin_lock(&rq->xdp_ring.producer_lock);
 453	for (i = 0; i < n; i++) {
 454		struct xdp_frame *frame = frames[i];
 455		void *ptr = veth_xdp_to_ptr(frame);
 456
 457		if (unlikely(frame->len > max_len ||
 458			     __ptr_ring_produce(&rq->xdp_ring, ptr))) {
 459			xdp_return_frame_rx_napi(frame);
 460			drops++;
 461		}
 462	}
 463	spin_unlock(&rq->xdp_ring.producer_lock);
 464
 465	if (flags & XDP_XMIT_FLUSH)
 466		__veth_xdp_flush(rq);
 467
 468	ret = n - drops;
 469	if (ndo_xmit) {
 470		u64_stats_update_begin(&rq->stats.syncp);
 471		rq->stats.vs.peer_tq_xdp_xmit += n - drops;
 472		rq->stats.vs.peer_tq_xdp_xmit_err += drops;
 473		u64_stats_update_end(&rq->stats.syncp);
 474	}
 475
 476out:
 477	rcu_read_unlock();
 478
 479	return ret;
 480}
 481
 482static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
 483			     struct xdp_frame **frames, u32 flags)
 484{
 485	int err;
 486
 487	err = veth_xdp_xmit(dev, n, frames, flags, true);
 488	if (err < 0) {
 489		struct veth_priv *priv = netdev_priv(dev);
 490
 491		atomic64_add(n, &priv->dropped);
 492	}
 493
 494	return err;
 495}
 496
 497static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 498{
 499	int sent, i, err = 0;
 500
 501	sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false);
 502	if (sent < 0) {
 503		err = sent;
 504		sent = 0;
 505		for (i = 0; i < bq->count; i++)
 506			xdp_return_frame(bq->q[i]);
 507	}
 508	trace_xdp_bulk_tx(rq->dev, sent, bq->count - sent, err);
 509
 510	u64_stats_update_begin(&rq->stats.syncp);
 511	rq->stats.vs.xdp_tx += sent;
 512	rq->stats.vs.xdp_tx_err += bq->count - sent;
 513	u64_stats_update_end(&rq->stats.syncp);
 514
 515	bq->count = 0;
 516}
 517
 518static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 519{
 520	struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev);
 521	struct net_device *rcv;
 522	struct veth_rq *rcv_rq;
 523
 524	rcu_read_lock();
 525	veth_xdp_flush_bq(rq, bq);
 526	rcv = rcu_dereference(priv->peer);
 527	if (unlikely(!rcv))
 528		goto out;
 529
 530	rcv_priv = netdev_priv(rcv);
 531	rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 532	/* xdp_ring is initialized on receive side? */
 533	if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
 534		goto out;
 535
 536	__veth_xdp_flush(rcv_rq);
 537out:
 538	rcu_read_unlock();
 539}
 540
 541static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
 542		       struct veth_xdp_tx_bq *bq)
 543{
 544	struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
 545
 546	if (unlikely(!frame))
 547		return -EOVERFLOW;
 548
 549	if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
 550		veth_xdp_flush_bq(rq, bq);
 551
 552	bq->q[bq->count++] = frame;
 553
 554	return 0;
 555}
 556
 557static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
 558					struct xdp_frame *frame,
 559					struct veth_xdp_tx_bq *bq,
 560					struct veth_stats *stats)
 561{
 562	void *hard_start = frame->data - frame->headroom;
 563	int len = frame->len, delta = 0;
 564	struct xdp_frame orig_frame;
 565	struct bpf_prog *xdp_prog;
 566	unsigned int headroom;
 567	struct sk_buff *skb;
 568
 569	/* bpf_xdp_adjust_head() assures BPF cannot access xdp_frame area */
 570	hard_start -= sizeof(struct xdp_frame);
 571
 572	rcu_read_lock();
 573	xdp_prog = rcu_dereference(rq->xdp_prog);
 574	if (likely(xdp_prog)) {
 575		struct xdp_buff xdp;
 576		u32 act;
 577
 578		xdp_convert_frame_to_buff(frame, &xdp);
 579		xdp.rxq = &rq->xdp_rxq;
 580
 581		act = bpf_prog_run_xdp(xdp_prog, &xdp);
 582
 583		switch (act) {
 584		case XDP_PASS:
 585			delta = frame->data - xdp.data;
 586			len = xdp.data_end - xdp.data;
 587			break;
 588		case XDP_TX:
 589			orig_frame = *frame;
 590			xdp.rxq->mem = frame->mem;
 591			if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {
 592				trace_xdp_exception(rq->dev, xdp_prog, act);
 593				frame = &orig_frame;
 594				stats->rx_drops++;
 595				goto err_xdp;
 596			}
 597			stats->xdp_tx++;
 598			rcu_read_unlock();
 599			goto xdp_xmit;
 600		case XDP_REDIRECT:
 601			orig_frame = *frame;
 602			xdp.rxq->mem = frame->mem;
 603			if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
 604				frame = &orig_frame;
 605				stats->rx_drops++;
 606				goto err_xdp;
 607			}
 608			stats->xdp_redirect++;
 609			rcu_read_unlock();
 610			goto xdp_xmit;
 611		default:
 612			bpf_warn_invalid_xdp_action(act);
 613			fallthrough;
 614		case XDP_ABORTED:
 615			trace_xdp_exception(rq->dev, xdp_prog, act);
 616			fallthrough;
 617		case XDP_DROP:
 618			stats->xdp_drops++;
 619			goto err_xdp;
 620		}
 621	}
 622	rcu_read_unlock();
 623
 624	headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
 625	skb = veth_build_skb(hard_start, headroom, len, frame->frame_sz);
 626	if (!skb) {
 627		xdp_return_frame(frame);
 628		stats->rx_drops++;
 629		goto err;
 630	}
 631
 632	xdp_release_frame(frame);
 633	xdp_scrub_frame(frame);
 634	skb->protocol = eth_type_trans(skb, rq->dev);
 635err:
 636	return skb;
 637err_xdp:
 638	rcu_read_unlock();
 639	xdp_return_frame(frame);
 640xdp_xmit:
 641	return NULL;
 642}
 643
 644static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 645					struct sk_buff *skb,
 646					struct veth_xdp_tx_bq *bq,
 647					struct veth_stats *stats)
 648{
 649	u32 pktlen, headroom, act, metalen;
 650	void *orig_data, *orig_data_end;
 651	struct bpf_prog *xdp_prog;
 652	int mac_len, delta, off;
 653	struct xdp_buff xdp;
 654
 655	skb_orphan(skb);
 656
 657	rcu_read_lock();
 658	xdp_prog = rcu_dereference(rq->xdp_prog);
 659	if (unlikely(!xdp_prog)) {
 660		rcu_read_unlock();
 661		goto out;
 662	}
 663
 664	mac_len = skb->data - skb_mac_header(skb);
 665	pktlen = skb->len + mac_len;
 666	headroom = skb_headroom(skb) - mac_len;
 667
 668	if (skb_shared(skb) || skb_head_is_locked(skb) ||
 669	    skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) {
 670		struct sk_buff *nskb;
 671		int size, head_off;
 672		void *head, *start;
 673		struct page *page;
 674
 675		size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) +
 676		       SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 677		if (size > PAGE_SIZE)
 678			goto drop;
 679
 680		page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
 681		if (!page)
 682			goto drop;
 683
 684		head = page_address(page);
 685		start = head + VETH_XDP_HEADROOM;
 686		if (skb_copy_bits(skb, -mac_len, start, pktlen)) {
 687			page_frag_free(head);
 688			goto drop;
 689		}
 690
 691		nskb = veth_build_skb(head, VETH_XDP_HEADROOM + mac_len,
 692				      skb->len, PAGE_SIZE);
 693		if (!nskb) {
 694			page_frag_free(head);
 695			goto drop;
 696		}
 697
 698		skb_copy_header(nskb, skb);
 699		head_off = skb_headroom(nskb) - skb_headroom(skb);
 700		skb_headers_offset_update(nskb, head_off);
 701		consume_skb(skb);
 702		skb = nskb;
 703	}
 704
 705	xdp.data_hard_start = skb->head;
 706	xdp.data = skb_mac_header(skb);
 707	xdp.data_end = xdp.data + pktlen;
 708	xdp.data_meta = xdp.data;
 709	xdp.rxq = &rq->xdp_rxq;
 710
 711	/* SKB "head" area always have tailroom for skb_shared_info */
 712	xdp.frame_sz = (void *)skb_end_pointer(skb) - xdp.data_hard_start;
 713	xdp.frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 714
 715	orig_data = xdp.data;
 716	orig_data_end = xdp.data_end;
 717
 718	act = bpf_prog_run_xdp(xdp_prog, &xdp);
 719
 720	switch (act) {
 721	case XDP_PASS:
 722		break;
 723	case XDP_TX:
 724		get_page(virt_to_page(xdp.data));
 725		consume_skb(skb);
 726		xdp.rxq->mem = rq->xdp_mem;
 727		if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {
 728			trace_xdp_exception(rq->dev, xdp_prog, act);
 729			stats->rx_drops++;
 730			goto err_xdp;
 731		}
 732		stats->xdp_tx++;
 733		rcu_read_unlock();
 734		goto xdp_xmit;
 735	case XDP_REDIRECT:
 736		get_page(virt_to_page(xdp.data));
 737		consume_skb(skb);
 738		xdp.rxq->mem = rq->xdp_mem;
 739		if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
 740			stats->rx_drops++;
 741			goto err_xdp;
 742		}
 743		stats->xdp_redirect++;
 744		rcu_read_unlock();
 745		goto xdp_xmit;
 746	default:
 747		bpf_warn_invalid_xdp_action(act);
 748		fallthrough;
 749	case XDP_ABORTED:
 750		trace_xdp_exception(rq->dev, xdp_prog, act);
 751		fallthrough;
 752	case XDP_DROP:
 753		stats->xdp_drops++;
 754		goto xdp_drop;
 755	}
 756	rcu_read_unlock();
 757
 758	/* check if bpf_xdp_adjust_head was used */
 759	delta = orig_data - xdp.data;
 760	off = mac_len + delta;
 761	if (off > 0)
 762		__skb_push(skb, off);
 763	else if (off < 0)
 764		__skb_pull(skb, -off);
 765	skb->mac_header -= delta;
 766
 767	/* check if bpf_xdp_adjust_tail was used */
 768	off = xdp.data_end - orig_data_end;
 769	if (off != 0)
 770		__skb_put(skb, off); /* positive on grow, negative on shrink */
 771	skb->protocol = eth_type_trans(skb, rq->dev);
 772
 773	metalen = xdp.data - xdp.data_meta;
 774	if (metalen)
 775		skb_metadata_set(skb, metalen);
 776out:
 777	return skb;
 778drop:
 779	stats->rx_drops++;
 780xdp_drop:
 781	rcu_read_unlock();
 782	kfree_skb(skb);
 783	return NULL;
 784err_xdp:
 785	rcu_read_unlock();
 786	page_frag_free(xdp.data);
 787xdp_xmit:
 788	return NULL;
 789}
 790
 791static int veth_xdp_rcv(struct veth_rq *rq, int budget,
 792			struct veth_xdp_tx_bq *bq,
 793			struct veth_stats *stats)
 794{
 795	int i, done = 0;
 796
 797	for (i = 0; i < budget; i++) {
 798		void *ptr = __ptr_ring_consume(&rq->xdp_ring);
 799		struct sk_buff *skb;
 800
 801		if (!ptr)
 802			break;
 803
 804		if (veth_is_xdp_frame(ptr)) {
 805			struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
 806
 807			stats->xdp_bytes += frame->len;
 808			skb = veth_xdp_rcv_one(rq, frame, bq, stats);
 809		} else {
 810			skb = ptr;
 811			stats->xdp_bytes += skb->len;
 812			skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
 813		}
 814
 815		if (skb)
 816			napi_gro_receive(&rq->xdp_napi, skb);
 817
 818		done++;
 819	}
 820
 821	u64_stats_update_begin(&rq->stats.syncp);
 822	rq->stats.vs.xdp_redirect += stats->xdp_redirect;
 823	rq->stats.vs.xdp_bytes += stats->xdp_bytes;
 824	rq->stats.vs.xdp_drops += stats->xdp_drops;
 825	rq->stats.vs.rx_drops += stats->rx_drops;
 826	rq->stats.vs.xdp_packets += done;
 827	u64_stats_update_end(&rq->stats.syncp);
 828
 829	return done;
 830}
 831
 832static int veth_poll(struct napi_struct *napi, int budget)
 833{
 834	struct veth_rq *rq =
 835		container_of(napi, struct veth_rq, xdp_napi);
 836	struct veth_stats stats = {};
 837	struct veth_xdp_tx_bq bq;
 838	int done;
 839
 840	bq.count = 0;
 841
 842	xdp_set_return_frame_no_direct();
 843	done = veth_xdp_rcv(rq, budget, &bq, &stats);
 844
 845	if (done < budget && napi_complete_done(napi, done)) {
 846		/* Write rx_notify_masked before reading ptr_ring */
 847		smp_store_mb(rq->rx_notify_masked, false);
 848		if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
 849			rq->rx_notify_masked = true;
 850			napi_schedule(&rq->xdp_napi);
 851		}
 852	}
 853
 854	if (stats.xdp_tx > 0)
 855		veth_xdp_flush(rq, &bq);
 856	if (stats.xdp_redirect > 0)
 857		xdp_do_flush();
 858	xdp_clear_return_frame_no_direct();
 859
 860	return done;
 861}
 862
 863static int veth_napi_add(struct net_device *dev)
 864{
 865	struct veth_priv *priv = netdev_priv(dev);
 866	int err, i;
 867
 868	for (i = 0; i < dev->real_num_rx_queues; i++) {
 869		struct veth_rq *rq = &priv->rq[i];
 870
 871		err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
 872		if (err)
 873			goto err_xdp_ring;
 874	}
 875
 876	for (i = 0; i < dev->real_num_rx_queues; i++) {
 877		struct veth_rq *rq = &priv->rq[i];
 878
 879		netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
 880		napi_enable(&rq->xdp_napi);
 881	}
 882
 883	return 0;
 884err_xdp_ring:
 885	for (i--; i >= 0; i--)
 886		ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
 887
 888	return err;
 889}
 890
 891static void veth_napi_del(struct net_device *dev)
 892{
 893	struct veth_priv *priv = netdev_priv(dev);
 894	int i;
 895
 896	for (i = 0; i < dev->real_num_rx_queues; i++) {
 897		struct veth_rq *rq = &priv->rq[i];
 898
 899		napi_disable(&rq->xdp_napi);
 900		napi_hash_del(&rq->xdp_napi);
 901	}
 902	synchronize_net();
 903
 904	for (i = 0; i < dev->real_num_rx_queues; i++) {
 905		struct veth_rq *rq = &priv->rq[i];
 906
 907		netif_napi_del(&rq->xdp_napi);
 908		rq->rx_notify_masked = false;
 909		ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
 910	}
 911}
 912
 913static int veth_enable_xdp(struct net_device *dev)
 914{
 915	struct veth_priv *priv = netdev_priv(dev);
 916	int err, i;
 917
 918	if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
 919		for (i = 0; i < dev->real_num_rx_queues; i++) {
 920			struct veth_rq *rq = &priv->rq[i];
 921
 922			err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i);
 923			if (err < 0)
 924				goto err_rxq_reg;
 925
 926			err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
 927							 MEM_TYPE_PAGE_SHARED,
 928							 NULL);
 929			if (err < 0)
 930				goto err_reg_mem;
 931
 932			/* Save original mem info as it can be overwritten */
 933			rq->xdp_mem = rq->xdp_rxq.mem;
 934		}
 935
 936		err = veth_napi_add(dev);
 937		if (err)
 938			goto err_rxq_reg;
 939	}
 940
 941	for (i = 0; i < dev->real_num_rx_queues; i++)
 942		rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
 943
 944	return 0;
 945err_reg_mem:
 946	xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
 947err_rxq_reg:
 948	for (i--; i >= 0; i--)
 949		xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
 950
 951	return err;
 952}
 953
 954static void veth_disable_xdp(struct net_device *dev)
 955{
 956	struct veth_priv *priv = netdev_priv(dev);
 957	int i;
 958
 959	for (i = 0; i < dev->real_num_rx_queues; i++)
 960		rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
 961	veth_napi_del(dev);
 962	for (i = 0; i < dev->real_num_rx_queues; i++) {
 963		struct veth_rq *rq = &priv->rq[i];
 964
 965		rq->xdp_rxq.mem = rq->xdp_mem;
 966		xdp_rxq_info_unreg(&rq->xdp_rxq);
 967	}
 968}
 969
 970static int veth_open(struct net_device *dev)
 971{
 972	struct veth_priv *priv = netdev_priv(dev);
 973	struct net_device *peer = rtnl_dereference(priv->peer);
 974	int err;
 975
 976	if (!peer)
 977		return -ENOTCONN;
 978
 979	if (priv->_xdp_prog) {
 980		err = veth_enable_xdp(dev);
 981		if (err)
 982			return err;
 983	}
 984
 985	if (peer->flags & IFF_UP) {
 986		netif_carrier_on(dev);
 987		netif_carrier_on(peer);
 988	}
 989
 990	return 0;
 991}
 992
 993static int veth_close(struct net_device *dev)
 994{
 995	struct veth_priv *priv = netdev_priv(dev);
 996	struct net_device *peer = rtnl_dereference(priv->peer);
 997
 998	netif_carrier_off(dev);
 999	if (peer)
1000		netif_carrier_off(peer);
1001
1002	if (priv->_xdp_prog)
1003		veth_disable_xdp(dev);
1004
1005	return 0;
1006}
1007
1008static int is_valid_veth_mtu(int mtu)
1009{
1010	return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1011}
1012
1013static int veth_alloc_queues(struct net_device *dev)
1014{
1015	struct veth_priv *priv = netdev_priv(dev);
1016	int i;
1017
1018	priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
1019	if (!priv->rq)
1020		return -ENOMEM;
1021
1022	for (i = 0; i < dev->num_rx_queues; i++) {
1023		priv->rq[i].dev = dev;
1024		u64_stats_init(&priv->rq[i].stats.syncp);
1025	}
1026
1027	return 0;
1028}
1029
1030static void veth_free_queues(struct net_device *dev)
1031{
1032	struct veth_priv *priv = netdev_priv(dev);
1033
1034	kfree(priv->rq);
1035}
1036
1037static int veth_dev_init(struct net_device *dev)
1038{
1039	int err;
1040
1041	dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
1042	if (!dev->lstats)
1043		return -ENOMEM;
1044
1045	err = veth_alloc_queues(dev);
1046	if (err) {
1047		free_percpu(dev->lstats);
1048		return err;
1049	}
1050
1051	return 0;
1052}
1053
1054static void veth_dev_free(struct net_device *dev)
1055{
1056	veth_free_queues(dev);
1057	free_percpu(dev->lstats);
1058}
1059
1060#ifdef CONFIG_NET_POLL_CONTROLLER
1061static void veth_poll_controller(struct net_device *dev)
1062{
1063	/* veth only receives frames when its peer sends one
1064	 * Since it has nothing to do with disabling irqs, we are guaranteed
1065	 * never to have pending data when we poll for it so
1066	 * there is nothing to do here.
1067	 *
1068	 * We need this though so netpoll recognizes us as an interface that
1069	 * supports polling, which enables bridge devices in virt setups to
1070	 * still use netconsole
1071	 */
1072}
1073#endif	/* CONFIG_NET_POLL_CONTROLLER */
1074
1075static int veth_get_iflink(const struct net_device *dev)
1076{
1077	struct veth_priv *priv = netdev_priv(dev);
1078	struct net_device *peer;
1079	int iflink;
1080
1081	rcu_read_lock();
1082	peer = rcu_dereference(priv->peer);
1083	iflink = peer ? peer->ifindex : 0;
1084	rcu_read_unlock();
1085
1086	return iflink;
1087}
1088
1089static netdev_features_t veth_fix_features(struct net_device *dev,
1090					   netdev_features_t features)
1091{
1092	struct veth_priv *priv = netdev_priv(dev);
1093	struct net_device *peer;
1094
1095	peer = rtnl_dereference(priv->peer);
1096	if (peer) {
1097		struct veth_priv *peer_priv = netdev_priv(peer);
1098
1099		if (peer_priv->_xdp_prog)
1100			features &= ~NETIF_F_GSO_SOFTWARE;
1101	}
1102
1103	return features;
1104}
1105
1106static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1107{
1108	struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1109	struct net_device *peer;
1110
1111	if (new_hr < 0)
1112		new_hr = 0;
1113
1114	rcu_read_lock();
1115	peer = rcu_dereference(priv->peer);
1116	if (unlikely(!peer))
1117		goto out;
1118
1119	peer_priv = netdev_priv(peer);
1120	priv->requested_headroom = new_hr;
1121	new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1122	dev->needed_headroom = new_hr;
1123	peer->needed_headroom = new_hr;
1124
1125out:
1126	rcu_read_unlock();
1127}
1128
1129static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1130			struct netlink_ext_ack *extack)
1131{
1132	struct veth_priv *priv = netdev_priv(dev);
1133	struct bpf_prog *old_prog;
1134	struct net_device *peer;
1135	unsigned int max_mtu;
1136	int err;
1137
1138	old_prog = priv->_xdp_prog;
1139	priv->_xdp_prog = prog;
1140	peer = rtnl_dereference(priv->peer);
1141
1142	if (prog) {
1143		if (!peer) {
1144			NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1145			err = -ENOTCONN;
1146			goto err;
1147		}
1148
1149		max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
1150			  peer->hard_header_len -
1151			  SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1152		if (peer->mtu > max_mtu) {
1153			NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1154			err = -ERANGE;
1155			goto err;
1156		}
1157
1158		if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1159			NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1160			err = -ENOSPC;
1161			goto err;
1162		}
1163
1164		if (dev->flags & IFF_UP) {
1165			err = veth_enable_xdp(dev);
1166			if (err) {
1167				NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1168				goto err;
1169			}
1170		}
1171
1172		if (!old_prog) {
1173			peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1174			peer->max_mtu = max_mtu;
1175		}
1176	}
1177
1178	if (old_prog) {
1179		if (!prog) {
1180			if (dev->flags & IFF_UP)
1181				veth_disable_xdp(dev);
1182
1183			if (peer) {
1184				peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1185				peer->max_mtu = ETH_MAX_MTU;
1186			}
1187		}
1188		bpf_prog_put(old_prog);
1189	}
1190
1191	if ((!!old_prog ^ !!prog) && peer)
1192		netdev_update_features(peer);
1193
1194	return 0;
1195err:
1196	priv->_xdp_prog = old_prog;
1197
1198	return err;
1199}
1200
1201static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1202{
1203	switch (xdp->command) {
1204	case XDP_SETUP_PROG:
1205		return veth_xdp_set(dev, xdp->prog, xdp->extack);
1206	default:
1207		return -EINVAL;
1208	}
1209}
1210
1211static const struct net_device_ops veth_netdev_ops = {
1212	.ndo_init            = veth_dev_init,
1213	.ndo_open            = veth_open,
1214	.ndo_stop            = veth_close,
1215	.ndo_start_xmit      = veth_xmit,
1216	.ndo_get_stats64     = veth_get_stats64,
1217	.ndo_set_rx_mode     = veth_set_multicast_list,
1218	.ndo_set_mac_address = eth_mac_addr,
1219#ifdef CONFIG_NET_POLL_CONTROLLER
1220	.ndo_poll_controller	= veth_poll_controller,
1221#endif
1222	.ndo_get_iflink		= veth_get_iflink,
1223	.ndo_fix_features	= veth_fix_features,
1224	.ndo_features_check	= passthru_features_check,
1225	.ndo_set_rx_headroom	= veth_set_rx_headroom,
1226	.ndo_bpf		= veth_xdp,
1227	.ndo_xdp_xmit		= veth_ndo_xdp_xmit,
1228};
1229
1230#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1231		       NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1232		       NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1233		       NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1234		       NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1235
1236static void veth_setup(struct net_device *dev)
1237{
1238	ether_setup(dev);
1239
1240	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1241	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1242	dev->priv_flags |= IFF_NO_QUEUE;
1243	dev->priv_flags |= IFF_PHONY_HEADROOM;
1244
1245	dev->netdev_ops = &veth_netdev_ops;
1246	dev->ethtool_ops = &veth_ethtool_ops;
1247	dev->features |= NETIF_F_LLTX;
1248	dev->features |= VETH_FEATURES;
1249	dev->vlan_features = dev->features &
1250			     ~(NETIF_F_HW_VLAN_CTAG_TX |
1251			       NETIF_F_HW_VLAN_STAG_TX |
1252			       NETIF_F_HW_VLAN_CTAG_RX |
1253			       NETIF_F_HW_VLAN_STAG_RX);
1254	dev->needs_free_netdev = true;
1255	dev->priv_destructor = veth_dev_free;
1256	dev->max_mtu = ETH_MAX_MTU;
1257
1258	dev->hw_features = VETH_FEATURES;
1259	dev->hw_enc_features = VETH_FEATURES;
1260	dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1261}
1262
1263/*
1264 * netlink interface
1265 */
1266
1267static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1268			 struct netlink_ext_ack *extack)
1269{
1270	if (tb[IFLA_ADDRESS]) {
1271		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1272			return -EINVAL;
1273		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1274			return -EADDRNOTAVAIL;
1275	}
1276	if (tb[IFLA_MTU]) {
1277		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1278			return -EINVAL;
1279	}
1280	return 0;
1281}
1282
1283static struct rtnl_link_ops veth_link_ops;
1284
1285static int veth_newlink(struct net *src_net, struct net_device *dev,
1286			struct nlattr *tb[], struct nlattr *data[],
1287			struct netlink_ext_ack *extack)
1288{
1289	int err;
1290	struct net_device *peer;
1291	struct veth_priv *priv;
1292	char ifname[IFNAMSIZ];
1293	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1294	unsigned char name_assign_type;
1295	struct ifinfomsg *ifmp;
1296	struct net *net;
1297
1298	/*
1299	 * create and register peer first
1300	 */
1301	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1302		struct nlattr *nla_peer;
1303
1304		nla_peer = data[VETH_INFO_PEER];
1305		ifmp = nla_data(nla_peer);
1306		err = rtnl_nla_parse_ifla(peer_tb,
1307					  nla_data(nla_peer) + sizeof(struct ifinfomsg),
1308					  nla_len(nla_peer) - sizeof(struct ifinfomsg),
1309					  NULL);
1310		if (err < 0)
1311			return err;
1312
1313		err = veth_validate(peer_tb, NULL, extack);
1314		if (err < 0)
1315			return err;
1316
1317		tbp = peer_tb;
1318	} else {
1319		ifmp = NULL;
1320		tbp = tb;
1321	}
1322
1323	if (ifmp && tbp[IFLA_IFNAME]) {
1324		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1325		name_assign_type = NET_NAME_USER;
1326	} else {
1327		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1328		name_assign_type = NET_NAME_ENUM;
1329	}
1330
1331	net = rtnl_link_get_net(src_net, tbp);
1332	if (IS_ERR(net))
1333		return PTR_ERR(net);
1334
1335	peer = rtnl_create_link(net, ifname, name_assign_type,
1336				&veth_link_ops, tbp, extack);
1337	if (IS_ERR(peer)) {
1338		put_net(net);
1339		return PTR_ERR(peer);
1340	}
1341
1342	if (!ifmp || !tbp[IFLA_ADDRESS])
1343		eth_hw_addr_random(peer);
1344
1345	if (ifmp && (dev->ifindex != 0))
1346		peer->ifindex = ifmp->ifi_index;
1347
1348	peer->gso_max_size = dev->gso_max_size;
1349	peer->gso_max_segs = dev->gso_max_segs;
1350
1351	err = register_netdevice(peer);
1352	put_net(net);
1353	net = NULL;
1354	if (err < 0)
1355		goto err_register_peer;
1356
1357	netif_carrier_off(peer);
1358
1359	err = rtnl_configure_link(peer, ifmp);
1360	if (err < 0)
1361		goto err_configure_peer;
1362
1363	/*
1364	 * register dev last
1365	 *
1366	 * note, that since we've registered new device the dev's name
1367	 * should be re-allocated
1368	 */
1369
1370	if (tb[IFLA_ADDRESS] == NULL)
1371		eth_hw_addr_random(dev);
1372
1373	if (tb[IFLA_IFNAME])
1374		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1375	else
1376		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1377
1378	err = register_netdevice(dev);
1379	if (err < 0)
1380		goto err_register_dev;
1381
1382	netif_carrier_off(dev);
1383
1384	/*
1385	 * tie the deviced together
1386	 */
1387
1388	priv = netdev_priv(dev);
1389	rcu_assign_pointer(priv->peer, peer);
1390
1391	priv = netdev_priv(peer);
1392	rcu_assign_pointer(priv->peer, dev);
1393
1394	return 0;
1395
1396err_register_dev:
1397	/* nothing to do */
1398err_configure_peer:
1399	unregister_netdevice(peer);
1400	return err;
1401
1402err_register_peer:
1403	free_netdev(peer);
1404	return err;
1405}
1406
1407static void veth_dellink(struct net_device *dev, struct list_head *head)
1408{
1409	struct veth_priv *priv;
1410	struct net_device *peer;
1411
1412	priv = netdev_priv(dev);
1413	peer = rtnl_dereference(priv->peer);
1414
1415	/* Note : dellink() is called from default_device_exit_batch(),
1416	 * before a rcu_synchronize() point. The devices are guaranteed
1417	 * not being freed before one RCU grace period.
1418	 */
1419	RCU_INIT_POINTER(priv->peer, NULL);
1420	unregister_netdevice_queue(dev, head);
1421
1422	if (peer) {
1423		priv = netdev_priv(peer);
1424		RCU_INIT_POINTER(priv->peer, NULL);
1425		unregister_netdevice_queue(peer, head);
1426	}
1427}
1428
1429static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1430	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },
1431};
1432
1433static struct net *veth_get_link_net(const struct net_device *dev)
1434{
1435	struct veth_priv *priv = netdev_priv(dev);
1436	struct net_device *peer = rtnl_dereference(priv->peer);
1437
1438	return peer ? dev_net(peer) : dev_net(dev);
1439}
1440
1441static struct rtnl_link_ops veth_link_ops = {
1442	.kind		= DRV_NAME,
1443	.priv_size	= sizeof(struct veth_priv),
1444	.setup		= veth_setup,
1445	.validate	= veth_validate,
1446	.newlink	= veth_newlink,
1447	.dellink	= veth_dellink,
1448	.policy		= veth_policy,
1449	.maxtype	= VETH_INFO_MAX,
1450	.get_link_net	= veth_get_link_net,
1451};
1452
1453/*
1454 * init/fini
1455 */
1456
1457static __init int veth_init(void)
1458{
1459	return rtnl_link_register(&veth_link_ops);
1460}
1461
1462static __exit void veth_exit(void)
1463{
1464	rtnl_link_unregister(&veth_link_ops);
1465}
1466
1467module_init(veth_init);
1468module_exit(veth_exit);
1469
1470MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1471MODULE_LICENSE("GPL v2");
1472MODULE_ALIAS_RTNL_LINK(DRV_NAME);