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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);
v4.10.11
  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_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 
 49{
 50	cmd->supported		= 0;
 51	cmd->advertising	= 0;
 52	ethtool_cmd_speed_set(cmd, SPEED_10000);
 53	cmd->duplex		= DUPLEX_FULL;
 54	cmd->port		= PORT_TP;
 55	cmd->phy_address	= 0;
 56	cmd->transceiver	= XCVR_INTERNAL;
 57	cmd->autoneg		= AUTONEG_DISABLE;
 58	cmd->maxtxpkt		= 0;
 59	cmd->maxrxpkt		= 0;
 60	return 0;
 61}
 62
 63static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 64{
 65	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
 66	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
 67}
 68
 69static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
 70{
 71	switch(stringset) {
 72	case ETH_SS_STATS:
 73		memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
 74		break;
 75	}
 76}
 77
 78static int veth_get_sset_count(struct net_device *dev, int sset)
 79{
 80	switch (sset) {
 81	case ETH_SS_STATS:
 82		return ARRAY_SIZE(ethtool_stats_keys);
 83	default:
 84		return -EOPNOTSUPP;
 85	}
 86}
 87
 88static void veth_get_ethtool_stats(struct net_device *dev,
 89		struct ethtool_stats *stats, u64 *data)
 90{
 91	struct veth_priv *priv = netdev_priv(dev);
 92	struct net_device *peer = rtnl_dereference(priv->peer);
 93
 94	data[0] = peer ? peer->ifindex : 0;
 95}
 96
 97static const struct ethtool_ops veth_ethtool_ops = {
 98	.get_settings		= veth_get_settings,
 99	.get_drvinfo		= veth_get_drvinfo,
100	.get_link		= ethtool_op_get_link,
101	.get_strings		= veth_get_strings,
102	.get_sset_count		= veth_get_sset_count,
103	.get_ethtool_stats	= veth_get_ethtool_stats,
 
104};
105
106static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
107{
108	struct veth_priv *priv = netdev_priv(dev);
109	struct net_device *rcv;
110	int length = skb->len;
111
112	rcu_read_lock();
113	rcv = rcu_dereference(priv->peer);
114	if (unlikely(!rcv)) {
115		kfree_skb(skb);
116		goto drop;
117	}
118
119	if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) {
120		struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
121
122		u64_stats_update_begin(&stats->syncp);
123		stats->bytes += length;
124		stats->packets++;
125		u64_stats_update_end(&stats->syncp);
126	} else {
127drop:
128		atomic64_inc(&priv->dropped);
129	}
130	rcu_read_unlock();
131	return NETDEV_TX_OK;
132}
133
134/*
135 * general routines
136 */
137
138static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev)
139{
140	struct veth_priv *priv = netdev_priv(dev);
141	int cpu;
142
143	result->packets = 0;
144	result->bytes = 0;
145	for_each_possible_cpu(cpu) {
146		struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
147		u64 packets, bytes;
148		unsigned int start;
149
150		do {
151			start = u64_stats_fetch_begin_irq(&stats->syncp);
152			packets = stats->packets;
153			bytes = stats->bytes;
154		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
155		result->packets += packets;
156		result->bytes += bytes;
157	}
158	return atomic64_read(&priv->dropped);
159}
160
161static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev,
162						  struct rtnl_link_stats64 *tot)
163{
164	struct veth_priv *priv = netdev_priv(dev);
165	struct net_device *peer;
166	struct pcpu_vstats one;
167
168	tot->tx_dropped = veth_stats_one(&one, dev);
169	tot->tx_bytes = one.bytes;
170	tot->tx_packets = one.packets;
171
172	rcu_read_lock();
173	peer = rcu_dereference(priv->peer);
174	if (peer) {
175		tot->rx_dropped = veth_stats_one(&one, peer);
176		tot->rx_bytes = one.bytes;
177		tot->rx_packets = one.packets;
178	}
179	rcu_read_unlock();
180
181	return tot;
182}
183
184/* fake multicast ability */
185static void veth_set_multicast_list(struct net_device *dev)
186{
187}
188
189static int veth_open(struct net_device *dev)
190{
191	struct veth_priv *priv = netdev_priv(dev);
192	struct net_device *peer = rtnl_dereference(priv->peer);
193
194	if (!peer)
195		return -ENOTCONN;
196
197	if (peer->flags & IFF_UP) {
198		netif_carrier_on(dev);
199		netif_carrier_on(peer);
200	}
201	return 0;
202}
203
204static int veth_close(struct net_device *dev)
205{
206	struct veth_priv *priv = netdev_priv(dev);
207	struct net_device *peer = rtnl_dereference(priv->peer);
208
209	netif_carrier_off(dev);
210	if (peer)
211		netif_carrier_off(peer);
212
213	return 0;
214}
215
216static int is_valid_veth_mtu(int mtu)
217{
218	return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
219}
220
221static int veth_dev_init(struct net_device *dev)
222{
223	dev->vstats = netdev_alloc_pcpu_stats(struct pcpu_vstats);
224	if (!dev->vstats)
225		return -ENOMEM;
226	return 0;
227}
228
229static void veth_dev_free(struct net_device *dev)
230{
231	free_percpu(dev->vstats);
232	free_netdev(dev);
233}
234
235#ifdef CONFIG_NET_POLL_CONTROLLER
236static void veth_poll_controller(struct net_device *dev)
237{
238	/* veth only receives frames when its peer sends one
239	 * Since it's a synchronous operation, we are guaranteed
240	 * never to have pending data when we poll for it so
241	 * there is nothing to do here.
242	 *
243	 * We need this though so netpoll recognizes us as an interface that
244	 * supports polling, which enables bridge devices in virt setups to
245	 * still use netconsole
246	 */
247}
248#endif	/* CONFIG_NET_POLL_CONTROLLER */
249
250static int veth_get_iflink(const struct net_device *dev)
251{
252	struct veth_priv *priv = netdev_priv(dev);
253	struct net_device *peer;
254	int iflink;
255
256	rcu_read_lock();
257	peer = rcu_dereference(priv->peer);
258	iflink = peer ? peer->ifindex : 0;
259	rcu_read_unlock();
260
261	return iflink;
262}
263
264static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
265{
266	struct veth_priv *peer_priv, *priv = netdev_priv(dev);
267	struct net_device *peer;
268
269	if (new_hr < 0)
270		new_hr = 0;
271
272	rcu_read_lock();
273	peer = rcu_dereference(priv->peer);
274	if (unlikely(!peer))
275		goto out;
276
277	peer_priv = netdev_priv(peer);
278	priv->requested_headroom = new_hr;
279	new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
280	dev->needed_headroom = new_hr;
281	peer->needed_headroom = new_hr;
282
283out:
284	rcu_read_unlock();
285}
286
287static const struct net_device_ops veth_netdev_ops = {
288	.ndo_init            = veth_dev_init,
289	.ndo_open            = veth_open,
290	.ndo_stop            = veth_close,
291	.ndo_start_xmit      = veth_xmit,
292	.ndo_get_stats64     = veth_get_stats64,
293	.ndo_set_rx_mode     = veth_set_multicast_list,
294	.ndo_set_mac_address = eth_mac_addr,
295#ifdef CONFIG_NET_POLL_CONTROLLER
296	.ndo_poll_controller	= veth_poll_controller,
297#endif
298	.ndo_get_iflink		= veth_get_iflink,
299	.ndo_features_check	= passthru_features_check,
300	.ndo_set_rx_headroom	= veth_set_rx_headroom,
301};
302
303#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
304		       NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
305		       NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
306		       NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
307		       NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
308
309static void veth_setup(struct net_device *dev)
310{
311	ether_setup(dev);
312
313	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
314	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
315	dev->priv_flags |= IFF_NO_QUEUE;
316	dev->priv_flags |= IFF_PHONY_HEADROOM;
317
318	dev->netdev_ops = &veth_netdev_ops;
319	dev->ethtool_ops = &veth_ethtool_ops;
320	dev->features |= NETIF_F_LLTX;
321	dev->features |= VETH_FEATURES;
322	dev->vlan_features = dev->features &
323			     ~(NETIF_F_HW_VLAN_CTAG_TX |
324			       NETIF_F_HW_VLAN_STAG_TX |
325			       NETIF_F_HW_VLAN_CTAG_RX |
326			       NETIF_F_HW_VLAN_STAG_RX);
327	dev->destructor = veth_dev_free;
 
328	dev->max_mtu = ETH_MAX_MTU;
329
330	dev->hw_features = VETH_FEATURES;
331	dev->hw_enc_features = VETH_FEATURES;
332	dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
333}
334
335/*
336 * netlink interface
337 */
338
339static int veth_validate(struct nlattr *tb[], struct nlattr *data[])
 
340{
341	if (tb[IFLA_ADDRESS]) {
342		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
343			return -EINVAL;
344		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
345			return -EADDRNOTAVAIL;
346	}
347	if (tb[IFLA_MTU]) {
348		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
349			return -EINVAL;
350	}
351	return 0;
352}
353
354static struct rtnl_link_ops veth_link_ops;
355
356static int veth_newlink(struct net *src_net, struct net_device *dev,
357			 struct nlattr *tb[], struct nlattr *data[])
 
358{
359	int err;
360	struct net_device *peer;
361	struct veth_priv *priv;
362	char ifname[IFNAMSIZ];
363	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
364	unsigned char name_assign_type;
365	struct ifinfomsg *ifmp;
366	struct net *net;
367
368	/*
369	 * create and register peer first
370	 */
371	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
372		struct nlattr *nla_peer;
373
374		nla_peer = data[VETH_INFO_PEER];
375		ifmp = nla_data(nla_peer);
376		err = rtnl_nla_parse_ifla(peer_tb,
377					  nla_data(nla_peer) + sizeof(struct ifinfomsg),
378					  nla_len(nla_peer) - sizeof(struct ifinfomsg));
 
379		if (err < 0)
380			return err;
381
382		err = veth_validate(peer_tb, NULL);
383		if (err < 0)
384			return err;
385
386		tbp = peer_tb;
387	} else {
388		ifmp = NULL;
389		tbp = tb;
390	}
391
392	if (tbp[IFLA_IFNAME]) {
393		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
394		name_assign_type = NET_NAME_USER;
395	} else {
396		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
397		name_assign_type = NET_NAME_ENUM;
398	}
399
400	net = rtnl_link_get_net(src_net, tbp);
401	if (IS_ERR(net))
402		return PTR_ERR(net);
403
404	peer = rtnl_create_link(net, ifname, name_assign_type,
405				&veth_link_ops, tbp);
406	if (IS_ERR(peer)) {
407		put_net(net);
408		return PTR_ERR(peer);
409	}
410
411	if (tbp[IFLA_ADDRESS] == NULL)
412		eth_hw_addr_random(peer);
413
414	if (ifmp && (dev->ifindex != 0))
415		peer->ifindex = ifmp->ifi_index;
 
 
 
416
417	err = register_netdevice(peer);
418	put_net(net);
419	net = NULL;
420	if (err < 0)
421		goto err_register_peer;
422
423	netif_carrier_off(peer);
424
425	err = rtnl_configure_link(peer, ifmp);
426	if (err < 0)
427		goto err_configure_peer;
428
429	/*
430	 * register dev last
431	 *
432	 * note, that since we've registered new device the dev's name
433	 * should be re-allocated
434	 */
435
436	if (tb[IFLA_ADDRESS] == NULL)
437		eth_hw_addr_random(dev);
438
439	if (tb[IFLA_IFNAME])
440		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
441	else
442		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
443
444	err = register_netdevice(dev);
445	if (err < 0)
446		goto err_register_dev;
447
448	netif_carrier_off(dev);
449
450	/*
451	 * tie the deviced together
452	 */
453
454	priv = netdev_priv(dev);
455	rcu_assign_pointer(priv->peer, peer);
456
457	priv = netdev_priv(peer);
458	rcu_assign_pointer(priv->peer, dev);
459	return 0;
460
461err_register_dev:
462	/* nothing to do */
463err_configure_peer:
464	unregister_netdevice(peer);
465	return err;
466
467err_register_peer:
468	free_netdev(peer);
469	return err;
470}
471
472static void veth_dellink(struct net_device *dev, struct list_head *head)
473{
474	struct veth_priv *priv;
475	struct net_device *peer;
476
477	priv = netdev_priv(dev);
478	peer = rtnl_dereference(priv->peer);
479
480	/* Note : dellink() is called from default_device_exit_batch(),
481	 * before a rcu_synchronize() point. The devices are guaranteed
482	 * not being freed before one RCU grace period.
483	 */
484	RCU_INIT_POINTER(priv->peer, NULL);
485	unregister_netdevice_queue(dev, head);
486
487	if (peer) {
488		priv = netdev_priv(peer);
489		RCU_INIT_POINTER(priv->peer, NULL);
490		unregister_netdevice_queue(peer, head);
491	}
492}
493
494static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
495	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },
496};
497
498static struct net *veth_get_link_net(const struct net_device *dev)
499{
500	struct veth_priv *priv = netdev_priv(dev);
501	struct net_device *peer = rtnl_dereference(priv->peer);
502
503	return peer ? dev_net(peer) : dev_net(dev);
504}
505
506static struct rtnl_link_ops veth_link_ops = {
507	.kind		= DRV_NAME,
508	.priv_size	= sizeof(struct veth_priv),
509	.setup		= veth_setup,
510	.validate	= veth_validate,
511	.newlink	= veth_newlink,
512	.dellink	= veth_dellink,
513	.policy		= veth_policy,
514	.maxtype	= VETH_INFO_MAX,
515	.get_link_net	= veth_get_link_net,
516};
517
518/*
519 * init/fini
520 */
521
522static __init int veth_init(void)
523{
524	return rtnl_link_register(&veth_link_ops);
525}
526
527static __exit void veth_exit(void)
528{
529	rtnl_link_unregister(&veth_link_ops);
530}
531
532module_init(veth_init);
533module_exit(veth_exit);
534
535MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
536MODULE_LICENSE("GPL v2");
537MODULE_ALIAS_RTNL_LINK(DRV_NAME);