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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);
v6.13.7
   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#include <linux/skbuff_ref.h>
  30#include <net/page_pool/helpers.h>
  31
  32#define DRV_NAME	"veth"
  33#define DRV_VERSION	"1.0"
  34
  35#define VETH_XDP_FLAG		BIT(0)
  36#define VETH_RING_SIZE		256
  37#define VETH_XDP_HEADROOM	(XDP_PACKET_HEADROOM + NET_IP_ALIGN)
  38
  39#define VETH_XDP_TX_BULK_SIZE	16
  40#define VETH_XDP_BATCH		16
  41
  42struct veth_stats {
  43	u64	rx_drops;
  44	/* xdp */
  45	u64	xdp_packets;
  46	u64	xdp_bytes;
  47	u64	xdp_redirect;
  48	u64	xdp_drops;
  49	u64	xdp_tx;
  50	u64	xdp_tx_err;
  51	u64	peer_tq_xdp_xmit;
  52	u64	peer_tq_xdp_xmit_err;
  53};
  54
  55struct veth_rq_stats {
  56	struct veth_stats	vs;
  57	struct u64_stats_sync	syncp;
  58};
  59
  60struct veth_rq {
  61	struct napi_struct	xdp_napi;
  62	struct napi_struct __rcu *napi; /* points to xdp_napi when the latter is initialized */
  63	struct net_device	*dev;
  64	struct bpf_prog __rcu	*xdp_prog;
  65	struct xdp_mem_info	xdp_mem;
  66	struct veth_rq_stats	stats;
  67	bool			rx_notify_masked;
  68	struct ptr_ring		xdp_ring;
  69	struct xdp_rxq_info	xdp_rxq;
  70	struct page_pool	*page_pool;
  71};
  72
  73struct veth_priv {
  74	struct net_device __rcu	*peer;
  75	atomic64_t		dropped;
  76	struct bpf_prog		*_xdp_prog;
  77	struct veth_rq		*rq;
  78	unsigned int		requested_headroom;
  79};
  80
  81struct veth_xdp_tx_bq {
  82	struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
  83	unsigned int count;
  84};
  85
  86/*
  87 * ethtool interface
  88 */
  89
  90struct veth_q_stat_desc {
  91	char	desc[ETH_GSTRING_LEN];
  92	size_t	offset;
  93};
  94
  95#define VETH_RQ_STAT(m)	offsetof(struct veth_stats, m)
  96
  97static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
  98	{ "xdp_packets",	VETH_RQ_STAT(xdp_packets) },
  99	{ "xdp_bytes",		VETH_RQ_STAT(xdp_bytes) },
 100	{ "drops",		VETH_RQ_STAT(rx_drops) },
 101	{ "xdp_redirect",	VETH_RQ_STAT(xdp_redirect) },
 102	{ "xdp_drops",		VETH_RQ_STAT(xdp_drops) },
 103	{ "xdp_tx",		VETH_RQ_STAT(xdp_tx) },
 104	{ "xdp_tx_errors",	VETH_RQ_STAT(xdp_tx_err) },
 105};
 106
 107#define VETH_RQ_STATS_LEN	ARRAY_SIZE(veth_rq_stats_desc)
 108
 109static const struct veth_q_stat_desc veth_tq_stats_desc[] = {
 110	{ "xdp_xmit",		VETH_RQ_STAT(peer_tq_xdp_xmit) },
 111	{ "xdp_xmit_errors",	VETH_RQ_STAT(peer_tq_xdp_xmit_err) },
 112};
 113
 114#define VETH_TQ_STATS_LEN	ARRAY_SIZE(veth_tq_stats_desc)
 115
 116static struct {
 117	const char string[ETH_GSTRING_LEN];
 118} ethtool_stats_keys[] = {
 119	{ "peer_ifindex" },
 120};
 121
 122struct veth_xdp_buff {
 123	struct xdp_buff xdp;
 124	struct sk_buff *skb;
 125};
 126
 127static int veth_get_link_ksettings(struct net_device *dev,
 128				   struct ethtool_link_ksettings *cmd)
 129{
 130	cmd->base.speed		= SPEED_10000;
 131	cmd->base.duplex	= DUPLEX_FULL;
 132	cmd->base.port		= PORT_TP;
 133	cmd->base.autoneg	= AUTONEG_DISABLE;
 134	return 0;
 135}
 136
 137static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 138{
 139	strscpy(info->driver, DRV_NAME, sizeof(info->driver));
 140	strscpy(info->version, DRV_VERSION, sizeof(info->version));
 141}
 142
 143static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
 144{
 145	u8 *p = buf;
 146	int i, j;
 147
 148	switch(stringset) {
 149	case ETH_SS_STATS:
 150		memcpy(p, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
 151		p += sizeof(ethtool_stats_keys);
 152		for (i = 0; i < dev->real_num_rx_queues; i++)
 153			for (j = 0; j < VETH_RQ_STATS_LEN; j++)
 154				ethtool_sprintf(&p, "rx_queue_%u_%.18s",
 155						i, veth_rq_stats_desc[j].desc);
 156
 157		for (i = 0; i < dev->real_num_tx_queues; i++)
 158			for (j = 0; j < VETH_TQ_STATS_LEN; j++)
 159				ethtool_sprintf(&p, "tx_queue_%u_%.18s",
 160						i, veth_tq_stats_desc[j].desc);
 161
 162		page_pool_ethtool_stats_get_strings(p);
 163		break;
 164	}
 165}
 166
 167static int veth_get_sset_count(struct net_device *dev, int sset)
 168{
 169	switch (sset) {
 170	case ETH_SS_STATS:
 171		return ARRAY_SIZE(ethtool_stats_keys) +
 172		       VETH_RQ_STATS_LEN * dev->real_num_rx_queues +
 173		       VETH_TQ_STATS_LEN * dev->real_num_tx_queues +
 174		       page_pool_ethtool_stats_get_count();
 175	default:
 176		return -EOPNOTSUPP;
 177	}
 178}
 179
 180static void veth_get_page_pool_stats(struct net_device *dev, u64 *data)
 181{
 182#ifdef CONFIG_PAGE_POOL_STATS
 183	struct veth_priv *priv = netdev_priv(dev);
 184	struct page_pool_stats pp_stats = {};
 185	int i;
 186
 187	for (i = 0; i < dev->real_num_rx_queues; i++) {
 188		if (!priv->rq[i].page_pool)
 189			continue;
 190		page_pool_get_stats(priv->rq[i].page_pool, &pp_stats);
 191	}
 192	page_pool_ethtool_stats_get(data, &pp_stats);
 193#endif /* CONFIG_PAGE_POOL_STATS */
 194}
 195
 196static void veth_get_ethtool_stats(struct net_device *dev,
 197		struct ethtool_stats *stats, u64 *data)
 198{
 199	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 200	struct net_device *peer = rtnl_dereference(priv->peer);
 201	int i, j, idx, pp_idx;
 202
 203	data[0] = peer ? peer->ifindex : 0;
 204	idx = 1;
 205	for (i = 0; i < dev->real_num_rx_queues; i++) {
 206		const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
 207		const void *stats_base = (void *)&rq_stats->vs;
 208		unsigned int start;
 209		size_t offset;
 210
 211		do {
 212			start = u64_stats_fetch_begin(&rq_stats->syncp);
 213			for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
 214				offset = veth_rq_stats_desc[j].offset;
 215				data[idx + j] = *(u64 *)(stats_base + offset);
 216			}
 217		} while (u64_stats_fetch_retry(&rq_stats->syncp, start));
 218		idx += VETH_RQ_STATS_LEN;
 219	}
 220	pp_idx = idx;
 221
 222	if (!peer)
 223		goto page_pool_stats;
 224
 225	rcv_priv = netdev_priv(peer);
 226	for (i = 0; i < peer->real_num_rx_queues; i++) {
 227		const struct veth_rq_stats *rq_stats = &rcv_priv->rq[i].stats;
 228		const void *base = (void *)&rq_stats->vs;
 229		unsigned int start, tx_idx = idx;
 230		size_t offset;
 231
 232		tx_idx += (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN;
 233		do {
 234			start = u64_stats_fetch_begin(&rq_stats->syncp);
 235			for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
 236				offset = veth_tq_stats_desc[j].offset;
 237				data[tx_idx + j] += *(u64 *)(base + offset);
 238			}
 239		} while (u64_stats_fetch_retry(&rq_stats->syncp, start));
 240	}
 241	pp_idx = idx + dev->real_num_tx_queues * VETH_TQ_STATS_LEN;
 242
 243page_pool_stats:
 244	veth_get_page_pool_stats(dev, &data[pp_idx]);
 245}
 246
 247static void veth_get_channels(struct net_device *dev,
 248			      struct ethtool_channels *channels)
 249{
 250	channels->tx_count = dev->real_num_tx_queues;
 251	channels->rx_count = dev->real_num_rx_queues;
 252	channels->max_tx = dev->num_tx_queues;
 253	channels->max_rx = dev->num_rx_queues;
 254}
 255
 256static int veth_set_channels(struct net_device *dev,
 257			     struct ethtool_channels *ch);
 258
 259static const struct ethtool_ops veth_ethtool_ops = {
 260	.get_drvinfo		= veth_get_drvinfo,
 261	.get_link		= ethtool_op_get_link,
 262	.get_strings		= veth_get_strings,
 263	.get_sset_count		= veth_get_sset_count,
 264	.get_ethtool_stats	= veth_get_ethtool_stats,
 265	.get_link_ksettings	= veth_get_link_ksettings,
 266	.get_ts_info		= ethtool_op_get_ts_info,
 267	.get_channels		= veth_get_channels,
 268	.set_channels		= veth_set_channels,
 269};
 270
 271/* general routines */
 272
 273static bool veth_is_xdp_frame(void *ptr)
 274{
 275	return (unsigned long)ptr & VETH_XDP_FLAG;
 276}
 277
 278static struct xdp_frame *veth_ptr_to_xdp(void *ptr)
 279{
 280	return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
 281}
 282
 283static void *veth_xdp_to_ptr(struct xdp_frame *xdp)
 284{
 285	return (void *)((unsigned long)xdp | VETH_XDP_FLAG);
 286}
 287
 288static void veth_ptr_free(void *ptr)
 289{
 290	if (veth_is_xdp_frame(ptr))
 291		xdp_return_frame(veth_ptr_to_xdp(ptr));
 292	else
 293		kfree_skb(ptr);
 294}
 295
 296static void __veth_xdp_flush(struct veth_rq *rq)
 297{
 298	/* Write ptr_ring before reading rx_notify_masked */
 299	smp_mb();
 300	if (!READ_ONCE(rq->rx_notify_masked) &&
 301	    napi_schedule_prep(&rq->xdp_napi)) {
 302		WRITE_ONCE(rq->rx_notify_masked, true);
 303		__napi_schedule(&rq->xdp_napi);
 304	}
 305}
 306
 307static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
 308{
 309	if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
 310		dev_kfree_skb_any(skb);
 311		return NET_RX_DROP;
 312	}
 313
 314	return NET_RX_SUCCESS;
 315}
 316
 317static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
 318			    struct veth_rq *rq, bool xdp)
 319{
 320	return __dev_forward_skb(dev, skb) ?: xdp ?
 321		veth_xdp_rx(rq, skb) :
 322		__netif_rx(skb);
 323}
 324
 325/* return true if the specified skb has chances of GRO aggregation
 326 * Don't strive for accuracy, but try to avoid GRO overhead in the most
 327 * common scenarios.
 328 * When XDP is enabled, all traffic is considered eligible, as the xmit
 329 * device has TSO off.
 330 * When TSO is enabled on the xmit device, we are likely interested only
 331 * in UDP aggregation, explicitly check for that if the skb is suspected
 332 * - the sock_wfree destructor is used by UDP, ICMP and XDP sockets -
 333 * to belong to locally generated UDP traffic.
 334 */
 335static bool veth_skb_is_eligible_for_gro(const struct net_device *dev,
 336					 const struct net_device *rcv,
 337					 const struct sk_buff *skb)
 338{
 339	return !(dev->features & NETIF_F_ALL_TSO) ||
 340		(skb->destructor == sock_wfree &&
 341		 rcv->features & (NETIF_F_GRO_FRAGLIST | NETIF_F_GRO_UDP_FWD));
 342}
 343
 344static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 345{
 346	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 347	struct veth_rq *rq = NULL;
 348	int ret = NETDEV_TX_OK;
 349	struct net_device *rcv;
 350	int length = skb->len;
 351	bool use_napi = false;
 352	int rxq;
 353
 354	rcu_read_lock();
 355	rcv = rcu_dereference(priv->peer);
 356	if (unlikely(!rcv) || !pskb_may_pull(skb, ETH_HLEN)) {
 357		kfree_skb(skb);
 358		goto drop;
 359	}
 360
 361	rcv_priv = netdev_priv(rcv);
 362	rxq = skb_get_queue_mapping(skb);
 363	if (rxq < rcv->real_num_rx_queues) {
 364		rq = &rcv_priv->rq[rxq];
 365
 366		/* The napi pointer is available when an XDP program is
 367		 * attached or when GRO is enabled
 368		 * Don't bother with napi/GRO if the skb can't be aggregated
 369		 */
 370		use_napi = rcu_access_pointer(rq->napi) &&
 371			   veth_skb_is_eligible_for_gro(dev, rcv, skb);
 372	}
 373
 374	skb_tx_timestamp(skb);
 375	if (likely(veth_forward_skb(rcv, skb, rq, use_napi) == NET_RX_SUCCESS)) {
 376		if (!use_napi)
 377			dev_sw_netstats_tx_add(dev, 1, length);
 378		else
 379			__veth_xdp_flush(rq);
 380	} else {
 381drop:
 382		atomic64_inc(&priv->dropped);
 383		ret = NET_XMIT_DROP;
 384	}
 385
 386	rcu_read_unlock();
 
 
 387
 388	return ret;
 389}
 
 390
 391static void veth_stats_rx(struct veth_stats *result, struct net_device *dev)
 392{
 393	struct veth_priv *priv = netdev_priv(dev);
 394	int i;
 395
 396	result->peer_tq_xdp_xmit_err = 0;
 397	result->xdp_packets = 0;
 398	result->xdp_tx_err = 0;
 399	result->xdp_bytes = 0;
 400	result->rx_drops = 0;
 401	for (i = 0; i < dev->num_rx_queues; i++) {
 402		u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err;
 403		struct veth_rq_stats *stats = &priv->rq[i].stats;
 404		unsigned int start;
 405
 406		do {
 407			start = u64_stats_fetch_begin(&stats->syncp);
 408			peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err;
 409			xdp_tx_err = stats->vs.xdp_tx_err;
 410			packets = stats->vs.xdp_packets;
 411			bytes = stats->vs.xdp_bytes;
 412			drops = stats->vs.rx_drops;
 413		} while (u64_stats_fetch_retry(&stats->syncp, start));
 414		result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err;
 415		result->xdp_tx_err += xdp_tx_err;
 416		result->xdp_packets += packets;
 417		result->xdp_bytes += bytes;
 418		result->rx_drops += drops;
 419	}
 
 420}
 421
 422static void veth_get_stats64(struct net_device *dev,
 423			     struct rtnl_link_stats64 *tot)
 424{
 425	struct veth_priv *priv = netdev_priv(dev);
 426	struct net_device *peer;
 427	struct veth_stats rx;
 428
 429	tot->tx_dropped = atomic64_read(&priv->dropped);
 430	dev_fetch_sw_netstats(tot, dev->tstats);
 431
 432	veth_stats_rx(&rx, dev);
 433	tot->tx_dropped += rx.xdp_tx_err;
 434	tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err;
 435	tot->rx_bytes += rx.xdp_bytes;
 436	tot->rx_packets += rx.xdp_packets;
 437
 438	rcu_read_lock();
 439	peer = rcu_dereference(priv->peer);
 440	if (peer) {
 441		struct rtnl_link_stats64 tot_peer = {};
 442
 443		dev_fetch_sw_netstats(&tot_peer, peer->tstats);
 444		tot->rx_bytes += tot_peer.tx_bytes;
 445		tot->rx_packets += tot_peer.tx_packets;
 446
 447		veth_stats_rx(&rx, peer);
 448		tot->tx_dropped += rx.peer_tq_xdp_xmit_err;
 449		tot->rx_dropped += rx.xdp_tx_err;
 450		tot->tx_bytes += rx.xdp_bytes;
 451		tot->tx_packets += rx.xdp_packets;
 452	}
 453	rcu_read_unlock();
 454}
 455
 456/* fake multicast ability */
 457static void veth_set_multicast_list(struct net_device *dev)
 458{
 459}
 460
 461static int veth_select_rxq(struct net_device *dev)
 462{
 463	return smp_processor_id() % dev->real_num_rx_queues;
 464}
 465
 466static struct net_device *veth_peer_dev(struct net_device *dev)
 467{
 468	struct veth_priv *priv = netdev_priv(dev);
 469
 470	/* Callers must be under RCU read side. */
 471	return rcu_dereference(priv->peer);
 472}
 473
 474static int veth_xdp_xmit(struct net_device *dev, int n,
 475			 struct xdp_frame **frames,
 476			 u32 flags, bool ndo_xmit)
 477{
 478	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 479	int i, ret = -ENXIO, nxmit = 0;
 480	struct net_device *rcv;
 481	unsigned int max_len;
 482	struct veth_rq *rq;
 483
 484	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
 485		return -EINVAL;
 486
 487	rcu_read_lock();
 488	rcv = rcu_dereference(priv->peer);
 489	if (unlikely(!rcv))
 490		goto out;
 491
 492	rcv_priv = netdev_priv(rcv);
 493	rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 494	/* The napi pointer is set if NAPI is enabled, which ensures that
 495	 * xdp_ring is initialized on receive side and the peer device is up.
 496	 */
 497	if (!rcu_access_pointer(rq->napi))
 498		goto out;
 499
 500	max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
 501
 502	spin_lock(&rq->xdp_ring.producer_lock);
 503	for (i = 0; i < n; i++) {
 504		struct xdp_frame *frame = frames[i];
 505		void *ptr = veth_xdp_to_ptr(frame);
 506
 507		if (unlikely(xdp_get_frame_len(frame) > max_len ||
 508			     __ptr_ring_produce(&rq->xdp_ring, ptr)))
 509			break;
 510		nxmit++;
 511	}
 512	spin_unlock(&rq->xdp_ring.producer_lock);
 513
 514	if (flags & XDP_XMIT_FLUSH)
 515		__veth_xdp_flush(rq);
 516
 517	ret = nxmit;
 518	if (ndo_xmit) {
 519		u64_stats_update_begin(&rq->stats.syncp);
 520		rq->stats.vs.peer_tq_xdp_xmit += nxmit;
 521		rq->stats.vs.peer_tq_xdp_xmit_err += n - nxmit;
 522		u64_stats_update_end(&rq->stats.syncp);
 523	}
 524
 525out:
 526	rcu_read_unlock();
 527
 528	return ret;
 529}
 530
 531static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
 532			     struct xdp_frame **frames, u32 flags)
 533{
 534	int err;
 535
 536	err = veth_xdp_xmit(dev, n, frames, flags, true);
 537	if (err < 0) {
 538		struct veth_priv *priv = netdev_priv(dev);
 539
 540		atomic64_add(n, &priv->dropped);
 541	}
 542
 543	return err;
 544}
 545
 546static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 547{
 548	int sent, i, err = 0, drops;
 549
 550	sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false);
 551	if (sent < 0) {
 552		err = sent;
 553		sent = 0;
 554	}
 555
 556	for (i = sent; unlikely(i < bq->count); i++)
 557		xdp_return_frame(bq->q[i]);
 558
 559	drops = bq->count - sent;
 560	trace_xdp_bulk_tx(rq->dev, sent, drops, err);
 561
 562	u64_stats_update_begin(&rq->stats.syncp);
 563	rq->stats.vs.xdp_tx += sent;
 564	rq->stats.vs.xdp_tx_err += drops;
 565	u64_stats_update_end(&rq->stats.syncp);
 566
 567	bq->count = 0;
 568}
 569
 570static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 571{
 572	struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev);
 573	struct net_device *rcv;
 574	struct veth_rq *rcv_rq;
 575
 576	rcu_read_lock();
 577	veth_xdp_flush_bq(rq, bq);
 578	rcv = rcu_dereference(priv->peer);
 579	if (unlikely(!rcv))
 580		goto out;
 581
 582	rcv_priv = netdev_priv(rcv);
 583	rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 584	/* xdp_ring is initialized on receive side? */
 585	if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
 586		goto out;
 587
 588	__veth_xdp_flush(rcv_rq);
 589out:
 590	rcu_read_unlock();
 591}
 592
 593static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
 594		       struct veth_xdp_tx_bq *bq)
 595{
 596	struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
 597
 598	if (unlikely(!frame))
 599		return -EOVERFLOW;
 600
 601	if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
 602		veth_xdp_flush_bq(rq, bq);
 603
 604	bq->q[bq->count++] = frame;
 605
 606	return 0;
 607}
 608
 609static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
 610					  struct xdp_frame *frame,
 611					  struct veth_xdp_tx_bq *bq,
 612					  struct veth_stats *stats)
 613{
 614	struct xdp_frame orig_frame;
 615	struct bpf_prog *xdp_prog;
 616
 617	rcu_read_lock();
 618	xdp_prog = rcu_dereference(rq->xdp_prog);
 619	if (likely(xdp_prog)) {
 620		struct veth_xdp_buff vxbuf;
 621		struct xdp_buff *xdp = &vxbuf.xdp;
 622		u32 act;
 623
 624		xdp_convert_frame_to_buff(frame, xdp);
 625		xdp->rxq = &rq->xdp_rxq;
 626		vxbuf.skb = NULL;
 627
 628		act = bpf_prog_run_xdp(xdp_prog, xdp);
 629
 630		switch (act) {
 631		case XDP_PASS:
 632			if (xdp_update_frame_from_buff(xdp, frame))
 633				goto err_xdp;
 634			break;
 635		case XDP_TX:
 636			orig_frame = *frame;
 637			xdp->rxq->mem = frame->mem;
 638			if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
 639				trace_xdp_exception(rq->dev, xdp_prog, act);
 640				frame = &orig_frame;
 641				stats->rx_drops++;
 642				goto err_xdp;
 643			}
 644			stats->xdp_tx++;
 645			rcu_read_unlock();
 646			goto xdp_xmit;
 647		case XDP_REDIRECT:
 648			orig_frame = *frame;
 649			xdp->rxq->mem = frame->mem;
 650			if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
 651				frame = &orig_frame;
 652				stats->rx_drops++;
 653				goto err_xdp;
 654			}
 655			stats->xdp_redirect++;
 656			rcu_read_unlock();
 657			goto xdp_xmit;
 658		default:
 659			bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 660			fallthrough;
 661		case XDP_ABORTED:
 662			trace_xdp_exception(rq->dev, xdp_prog, act);
 663			fallthrough;
 664		case XDP_DROP:
 665			stats->xdp_drops++;
 666			goto err_xdp;
 667		}
 668	}
 669	rcu_read_unlock();
 670
 671	return frame;
 672err_xdp:
 673	rcu_read_unlock();
 674	xdp_return_frame(frame);
 675xdp_xmit:
 676	return NULL;
 677}
 678
 679/* frames array contains VETH_XDP_BATCH at most */
 680static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames,
 681				  int n_xdpf, struct veth_xdp_tx_bq *bq,
 682				  struct veth_stats *stats)
 683{
 684	void *skbs[VETH_XDP_BATCH];
 685	int i;
 686
 687	if (xdp_alloc_skb_bulk(skbs, n_xdpf,
 688			       GFP_ATOMIC | __GFP_ZERO) < 0) {
 689		for (i = 0; i < n_xdpf; i++)
 690			xdp_return_frame(frames[i]);
 691		stats->rx_drops += n_xdpf;
 692
 693		return;
 694	}
 695
 696	for (i = 0; i < n_xdpf; i++) {
 697		struct sk_buff *skb = skbs[i];
 698
 699		skb = __xdp_build_skb_from_frame(frames[i], skb,
 700						 rq->dev);
 701		if (!skb) {
 702			xdp_return_frame(frames[i]);
 703			stats->rx_drops++;
 704			continue;
 705		}
 706		napi_gro_receive(&rq->xdp_napi, skb);
 707	}
 708}
 709
 710static void veth_xdp_get(struct xdp_buff *xdp)
 711{
 712	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
 713	int i;
 714
 715	get_page(virt_to_page(xdp->data));
 716	if (likely(!xdp_buff_has_frags(xdp)))
 717		return;
 718
 719	for (i = 0; i < sinfo->nr_frags; i++)
 720		__skb_frag_ref(&sinfo->frags[i]);
 721}
 722
 723static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
 724					struct xdp_buff *xdp,
 725					struct sk_buff **pskb)
 726{
 727	struct sk_buff *skb = *pskb;
 728	u32 frame_sz;
 729
 730	if (skb_shared(skb) || skb_head_is_locked(skb) ||
 731	    skb_shinfo(skb)->nr_frags ||
 732	    skb_headroom(skb) < XDP_PACKET_HEADROOM) {
 733		if (skb_pp_cow_data(rq->page_pool, pskb, XDP_PACKET_HEADROOM))
 734			goto drop;
 735
 736		skb = *pskb;
 737	}
 738
 739	/* SKB "head" area always have tailroom for skb_shared_info */
 740	frame_sz = skb_end_pointer(skb) - skb->head;
 741	frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 742	xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq);
 743	xdp_prepare_buff(xdp, skb->head, skb_headroom(skb),
 744			 skb_headlen(skb), true);
 745
 746	if (skb_is_nonlinear(skb)) {
 747		skb_shinfo(skb)->xdp_frags_size = skb->data_len;
 748		xdp_buff_set_frags_flag(xdp);
 749	} else {
 750		xdp_buff_clear_frags_flag(xdp);
 751	}
 752	*pskb = skb;
 753
 754	return 0;
 755drop:
 756	consume_skb(skb);
 757	*pskb = NULL;
 758
 759	return -ENOMEM;
 760}
 761
 762static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 763					struct sk_buff *skb,
 764					struct veth_xdp_tx_bq *bq,
 765					struct veth_stats *stats)
 766{
 767	void *orig_data, *orig_data_end;
 768	struct bpf_prog *xdp_prog;
 769	struct veth_xdp_buff vxbuf;
 770	struct xdp_buff *xdp = &vxbuf.xdp;
 771	u32 act, metalen;
 772	int off;
 773
 774	skb_prepare_for_gro(skb);
 775
 776	rcu_read_lock();
 777	xdp_prog = rcu_dereference(rq->xdp_prog);
 778	if (unlikely(!xdp_prog)) {
 779		rcu_read_unlock();
 780		goto out;
 781	}
 782
 783	__skb_push(skb, skb->data - skb_mac_header(skb));
 784	if (veth_convert_skb_to_xdp_buff(rq, xdp, &skb))
 785		goto drop;
 786	vxbuf.skb = skb;
 787
 788	orig_data = xdp->data;
 789	orig_data_end = xdp->data_end;
 790
 791	act = bpf_prog_run_xdp(xdp_prog, xdp);
 792
 793	switch (act) {
 794	case XDP_PASS:
 795		break;
 796	case XDP_TX:
 797		veth_xdp_get(xdp);
 798		consume_skb(skb);
 799		xdp->rxq->mem = rq->xdp_mem;
 800		if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
 801			trace_xdp_exception(rq->dev, xdp_prog, act);
 802			stats->rx_drops++;
 803			goto err_xdp;
 804		}
 805		stats->xdp_tx++;
 806		rcu_read_unlock();
 807		goto xdp_xmit;
 808	case XDP_REDIRECT:
 809		veth_xdp_get(xdp);
 810		consume_skb(skb);
 811		xdp->rxq->mem = rq->xdp_mem;
 812		if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
 813			stats->rx_drops++;
 814			goto err_xdp;
 815		}
 816		stats->xdp_redirect++;
 817		rcu_read_unlock();
 818		goto xdp_xmit;
 819	default:
 820		bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 821		fallthrough;
 822	case XDP_ABORTED:
 823		trace_xdp_exception(rq->dev, xdp_prog, act);
 824		fallthrough;
 825	case XDP_DROP:
 826		stats->xdp_drops++;
 827		goto xdp_drop;
 828	}
 829	rcu_read_unlock();
 830
 831	/* check if bpf_xdp_adjust_head was used */
 832	off = orig_data - xdp->data;
 833	if (off > 0)
 834		__skb_push(skb, off);
 835	else if (off < 0)
 836		__skb_pull(skb, -off);
 837
 838	skb_reset_mac_header(skb);
 839
 840	/* check if bpf_xdp_adjust_tail was used */
 841	off = xdp->data_end - orig_data_end;
 842	if (off != 0)
 843		__skb_put(skb, off); /* positive on grow, negative on shrink */
 844
 845	/* XDP frag metadata (e.g. nr_frags) are updated in eBPF helpers
 846	 * (e.g. bpf_xdp_adjust_tail), we need to update data_len here.
 847	 */
 848	if (xdp_buff_has_frags(xdp))
 849		skb->data_len = skb_shinfo(skb)->xdp_frags_size;
 850	else
 851		skb->data_len = 0;
 852
 853	skb->protocol = eth_type_trans(skb, rq->dev);
 854
 855	metalen = xdp->data - xdp->data_meta;
 856	if (metalen)
 857		skb_metadata_set(skb, metalen);
 858out:
 859	return skb;
 860drop:
 861	stats->rx_drops++;
 862xdp_drop:
 863	rcu_read_unlock();
 864	kfree_skb(skb);
 865	return NULL;
 866err_xdp:
 867	rcu_read_unlock();
 868	xdp_return_buff(xdp);
 869xdp_xmit:
 870	return NULL;
 871}
 872
 873static int veth_xdp_rcv(struct veth_rq *rq, int budget,
 874			struct veth_xdp_tx_bq *bq,
 875			struct veth_stats *stats)
 876{
 877	int i, done = 0, n_xdpf = 0;
 878	void *xdpf[VETH_XDP_BATCH];
 879
 880	for (i = 0; i < budget; i++) {
 881		void *ptr = __ptr_ring_consume(&rq->xdp_ring);
 882
 883		if (!ptr)
 884			break;
 885
 886		if (veth_is_xdp_frame(ptr)) {
 887			/* ndo_xdp_xmit */
 888			struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
 889
 890			stats->xdp_bytes += xdp_get_frame_len(frame);
 891			frame = veth_xdp_rcv_one(rq, frame, bq, stats);
 892			if (frame) {
 893				/* XDP_PASS */
 894				xdpf[n_xdpf++] = frame;
 895				if (n_xdpf == VETH_XDP_BATCH) {
 896					veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf,
 897							      bq, stats);
 898					n_xdpf = 0;
 899				}
 900			}
 901		} else {
 902			/* ndo_start_xmit */
 903			struct sk_buff *skb = ptr;
 904
 905			stats->xdp_bytes += skb->len;
 906			skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
 907			if (skb) {
 908				if (skb_shared(skb) || skb_unclone(skb, GFP_ATOMIC))
 909					netif_receive_skb(skb);
 910				else
 911					napi_gro_receive(&rq->xdp_napi, skb);
 912			}
 913		}
 914		done++;
 915	}
 916
 917	if (n_xdpf)
 918		veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats);
 919
 920	u64_stats_update_begin(&rq->stats.syncp);
 921	rq->stats.vs.xdp_redirect += stats->xdp_redirect;
 922	rq->stats.vs.xdp_bytes += stats->xdp_bytes;
 923	rq->stats.vs.xdp_drops += stats->xdp_drops;
 924	rq->stats.vs.rx_drops += stats->rx_drops;
 925	rq->stats.vs.xdp_packets += done;
 926	u64_stats_update_end(&rq->stats.syncp);
 927
 928	return done;
 929}
 930
 931static int veth_poll(struct napi_struct *napi, int budget)
 932{
 933	struct veth_rq *rq =
 934		container_of(napi, struct veth_rq, xdp_napi);
 935	struct veth_stats stats = {};
 936	struct veth_xdp_tx_bq bq;
 937	int done;
 938
 939	bq.count = 0;
 940
 941	xdp_set_return_frame_no_direct();
 942	done = veth_xdp_rcv(rq, budget, &bq, &stats);
 943
 944	if (stats.xdp_redirect > 0)
 945		xdp_do_flush();
 946
 947	if (done < budget && napi_complete_done(napi, done)) {
 948		/* Write rx_notify_masked before reading ptr_ring */
 949		smp_store_mb(rq->rx_notify_masked, false);
 950		if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
 951			if (napi_schedule_prep(&rq->xdp_napi)) {
 952				WRITE_ONCE(rq->rx_notify_masked, true);
 953				__napi_schedule(&rq->xdp_napi);
 954			}
 955		}
 956	}
 957
 958	if (stats.xdp_tx > 0)
 959		veth_xdp_flush(rq, &bq);
 960	xdp_clear_return_frame_no_direct();
 961
 962	return done;
 963}
 964
 965static int veth_create_page_pool(struct veth_rq *rq)
 966{
 967	struct page_pool_params pp_params = {
 968		.order = 0,
 969		.pool_size = VETH_RING_SIZE,
 970		.nid = NUMA_NO_NODE,
 971		.dev = &rq->dev->dev,
 972	};
 973
 974	rq->page_pool = page_pool_create(&pp_params);
 975	if (IS_ERR(rq->page_pool)) {
 976		int err = PTR_ERR(rq->page_pool);
 977
 978		rq->page_pool = NULL;
 979		return err;
 980	}
 981
 982	return 0;
 983}
 984
 985static int __veth_napi_enable_range(struct net_device *dev, int start, int end)
 986{
 987	struct veth_priv *priv = netdev_priv(dev);
 988	int err, i;
 989
 990	for (i = start; i < end; i++) {
 991		err = veth_create_page_pool(&priv->rq[i]);
 992		if (err)
 993			goto err_page_pool;
 994	}
 995
 996	for (i = start; i < end; i++) {
 997		struct veth_rq *rq = &priv->rq[i];
 998
 999		err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
1000		if (err)
1001			goto err_xdp_ring;
1002	}
1003
1004	for (i = start; i < end; i++) {
1005		struct veth_rq *rq = &priv->rq[i];
1006
1007		napi_enable(&rq->xdp_napi);
1008		rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1009	}
1010
1011	return 0;
1012
1013err_xdp_ring:
1014	for (i--; i >= start; i--)
1015		ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
1016	i = end;
1017err_page_pool:
1018	for (i--; i >= start; i--) {
1019		page_pool_destroy(priv->rq[i].page_pool);
1020		priv->rq[i].page_pool = NULL;
1021	}
1022
1023	return err;
1024}
1025
1026static int __veth_napi_enable(struct net_device *dev)
1027{
1028	return __veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1029}
1030
1031static void veth_napi_del_range(struct net_device *dev, int start, int end)
1032{
1033	struct veth_priv *priv = netdev_priv(dev);
1034	int i;
1035
1036	for (i = start; i < end; i++) {
1037		struct veth_rq *rq = &priv->rq[i];
1038
1039		rcu_assign_pointer(priv->rq[i].napi, NULL);
1040		napi_disable(&rq->xdp_napi);
1041		__netif_napi_del(&rq->xdp_napi);
1042	}
1043	synchronize_net();
1044
1045	for (i = start; i < end; i++) {
1046		struct veth_rq *rq = &priv->rq[i];
1047
1048		rq->rx_notify_masked = false;
1049		ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
1050	}
1051
1052	for (i = start; i < end; i++) {
1053		page_pool_destroy(priv->rq[i].page_pool);
1054		priv->rq[i].page_pool = NULL;
1055	}
1056}
1057
1058static void veth_napi_del(struct net_device *dev)
1059{
1060	veth_napi_del_range(dev, 0, dev->real_num_rx_queues);
1061}
1062
1063static bool veth_gro_requested(const struct net_device *dev)
1064{
1065	return !!(dev->wanted_features & NETIF_F_GRO);
1066}
1067
1068static int veth_enable_xdp_range(struct net_device *dev, int start, int end,
1069				 bool napi_already_on)
1070{
1071	struct veth_priv *priv = netdev_priv(dev);
1072	int err, i;
1073
1074	for (i = start; i < end; i++) {
1075		struct veth_rq *rq = &priv->rq[i];
1076
1077		if (!napi_already_on)
1078			netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1079		err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id);
1080		if (err < 0)
1081			goto err_rxq_reg;
1082
1083		err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
1084						 MEM_TYPE_PAGE_SHARED,
1085						 NULL);
1086		if (err < 0)
1087			goto err_reg_mem;
1088
1089		/* Save original mem info as it can be overwritten */
1090		rq->xdp_mem = rq->xdp_rxq.mem;
1091	}
1092	return 0;
1093
1094err_reg_mem:
1095	xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
1096err_rxq_reg:
1097	for (i--; i >= start; i--) {
1098		struct veth_rq *rq = &priv->rq[i];
1099
1100		xdp_rxq_info_unreg(&rq->xdp_rxq);
1101		if (!napi_already_on)
1102			netif_napi_del(&rq->xdp_napi);
1103	}
1104
1105	return err;
1106}
1107
1108static void veth_disable_xdp_range(struct net_device *dev, int start, int end,
1109				   bool delete_napi)
1110{
1111	struct veth_priv *priv = netdev_priv(dev);
1112	int i;
1113
1114	for (i = start; i < end; i++) {
1115		struct veth_rq *rq = &priv->rq[i];
1116
1117		rq->xdp_rxq.mem = rq->xdp_mem;
1118		xdp_rxq_info_unreg(&rq->xdp_rxq);
1119
1120		if (delete_napi)
1121			netif_napi_del(&rq->xdp_napi);
1122	}
1123}
1124
1125static int veth_enable_xdp(struct net_device *dev)
1126{
1127	bool napi_already_on = veth_gro_requested(dev) && (dev->flags & IFF_UP);
1128	struct veth_priv *priv = netdev_priv(dev);
1129	int err, i;
1130
1131	if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
1132		err = veth_enable_xdp_range(dev, 0, dev->real_num_rx_queues, napi_already_on);
1133		if (err)
1134			return err;
1135
1136		if (!napi_already_on) {
1137			err = __veth_napi_enable(dev);
1138			if (err) {
1139				veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, true);
1140				return err;
1141			}
1142		}
1143	}
1144
1145	for (i = 0; i < dev->real_num_rx_queues; i++) {
1146		rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
1147		rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1148	}
1149
1150	return 0;
1151}
1152
1153static void veth_disable_xdp(struct net_device *dev)
1154{
1155	struct veth_priv *priv = netdev_priv(dev);
1156	int i;
1157
1158	for (i = 0; i < dev->real_num_rx_queues; i++)
1159		rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
1160
1161	if (!netif_running(dev) || !veth_gro_requested(dev))
1162		veth_napi_del(dev);
1163
1164	veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, false);
1165}
1166
1167static int veth_napi_enable_range(struct net_device *dev, int start, int end)
1168{
1169	struct veth_priv *priv = netdev_priv(dev);
1170	int err, i;
1171
1172	for (i = start; i < end; i++) {
1173		struct veth_rq *rq = &priv->rq[i];
1174
1175		netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1176	}
1177
1178	err = __veth_napi_enable_range(dev, start, end);
1179	if (err) {
1180		for (i = start; i < end; i++) {
1181			struct veth_rq *rq = &priv->rq[i];
1182
1183			netif_napi_del(&rq->xdp_napi);
1184		}
1185		return err;
1186	}
1187	return err;
1188}
1189
1190static int veth_napi_enable(struct net_device *dev)
1191{
1192	return veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1193}
1194
1195static void veth_disable_range_safe(struct net_device *dev, int start, int end)
1196{
1197	struct veth_priv *priv = netdev_priv(dev);
1198
1199	if (start >= end)
1200		return;
1201
1202	if (priv->_xdp_prog) {
1203		veth_napi_del_range(dev, start, end);
1204		veth_disable_xdp_range(dev, start, end, false);
1205	} else if (veth_gro_requested(dev)) {
1206		veth_napi_del_range(dev, start, end);
1207	}
1208}
1209
1210static int veth_enable_range_safe(struct net_device *dev, int start, int end)
1211{
1212	struct veth_priv *priv = netdev_priv(dev);
1213	int err;
1214
1215	if (start >= end)
1216		return 0;
1217
1218	if (priv->_xdp_prog) {
1219		/* these channels are freshly initialized, napi is not on there even
1220		 * when GRO is requeste
1221		 */
1222		err = veth_enable_xdp_range(dev, start, end, false);
1223		if (err)
1224			return err;
1225
1226		err = __veth_napi_enable_range(dev, start, end);
1227		if (err) {
1228			/* on error always delete the newly added napis */
1229			veth_disable_xdp_range(dev, start, end, true);
1230			return err;
1231		}
1232	} else if (veth_gro_requested(dev)) {
1233		return veth_napi_enable_range(dev, start, end);
1234	}
1235	return 0;
1236}
1237
1238static void veth_set_xdp_features(struct net_device *dev)
1239{
1240	struct veth_priv *priv = netdev_priv(dev);
1241	struct net_device *peer;
1242
1243	peer = rtnl_dereference(priv->peer);
1244	if (peer && peer->real_num_tx_queues <= dev->real_num_rx_queues) {
1245		struct veth_priv *priv_peer = netdev_priv(peer);
1246		xdp_features_t val = NETDEV_XDP_ACT_BASIC |
1247				     NETDEV_XDP_ACT_REDIRECT |
1248				     NETDEV_XDP_ACT_RX_SG;
1249
1250		if (priv_peer->_xdp_prog || veth_gro_requested(peer))
1251			val |= NETDEV_XDP_ACT_NDO_XMIT |
1252			       NETDEV_XDP_ACT_NDO_XMIT_SG;
1253		xdp_set_features_flag(dev, val);
1254	} else {
1255		xdp_clear_features_flag(dev);
1256	}
1257}
1258
1259static int veth_set_channels(struct net_device *dev,
1260			     struct ethtool_channels *ch)
1261{
1262	struct veth_priv *priv = netdev_priv(dev);
1263	unsigned int old_rx_count, new_rx_count;
1264	struct veth_priv *peer_priv;
1265	struct net_device *peer;
1266	int err;
1267
1268	/* sanity check. Upper bounds are already enforced by the caller */
1269	if (!ch->rx_count || !ch->tx_count)
1270		return -EINVAL;
1271
1272	/* avoid braking XDP, if that is enabled */
1273	peer = rtnl_dereference(priv->peer);
1274	peer_priv = peer ? netdev_priv(peer) : NULL;
1275	if (priv->_xdp_prog && peer && ch->rx_count < peer->real_num_tx_queues)
1276		return -EINVAL;
1277
1278	if (peer && peer_priv && peer_priv->_xdp_prog && ch->tx_count > peer->real_num_rx_queues)
1279		return -EINVAL;
1280
1281	old_rx_count = dev->real_num_rx_queues;
1282	new_rx_count = ch->rx_count;
1283	if (netif_running(dev)) {
1284		/* turn device off */
1285		netif_carrier_off(dev);
1286		if (peer)
1287			netif_carrier_off(peer);
1288
1289		/* try to allocate new resurces, as needed*/
1290		err = veth_enable_range_safe(dev, old_rx_count, new_rx_count);
1291		if (err)
1292			goto out;
1293	}
1294
1295	err = netif_set_real_num_rx_queues(dev, ch->rx_count);
1296	if (err)
1297		goto revert;
1298
1299	err = netif_set_real_num_tx_queues(dev, ch->tx_count);
1300	if (err) {
1301		int err2 = netif_set_real_num_rx_queues(dev, old_rx_count);
1302
1303		/* this error condition could happen only if rx and tx change
1304		 * in opposite directions (e.g. tx nr raises, rx nr decreases)
1305		 * and we can't do anything to fully restore the original
1306		 * status
1307		 */
1308		if (err2)
1309			pr_warn("Can't restore rx queues config %d -> %d %d",
1310				new_rx_count, old_rx_count, err2);
1311		else
1312			goto revert;
1313	}
1314
1315out:
1316	if (netif_running(dev)) {
1317		/* note that we need to swap the arguments WRT the enable part
1318		 * to identify the range we have to disable
1319		 */
1320		veth_disable_range_safe(dev, new_rx_count, old_rx_count);
1321		netif_carrier_on(dev);
1322		if (peer)
1323			netif_carrier_on(peer);
1324	}
1325
1326	/* update XDP supported features */
1327	veth_set_xdp_features(dev);
1328	if (peer)
1329		veth_set_xdp_features(peer);
1330
1331	return err;
1332
1333revert:
1334	new_rx_count = old_rx_count;
1335	old_rx_count = ch->rx_count;
1336	goto out;
1337}
1338
1339static int veth_open(struct net_device *dev)
1340{
1341	struct veth_priv *priv = netdev_priv(dev);
1342	struct net_device *peer = rtnl_dereference(priv->peer);
1343	int err;
1344
1345	if (!peer)
1346		return -ENOTCONN;
1347
1348	if (priv->_xdp_prog) {
1349		err = veth_enable_xdp(dev);
1350		if (err)
1351			return err;
1352	} else if (veth_gro_requested(dev)) {
1353		err = veth_napi_enable(dev);
1354		if (err)
1355			return err;
1356	}
1357
1358	if (peer->flags & IFF_UP) {
1359		netif_carrier_on(dev);
1360		netif_carrier_on(peer);
1361	}
1362
1363	veth_set_xdp_features(dev);
1364
1365	return 0;
1366}
1367
1368static int veth_close(struct net_device *dev)
1369{
1370	struct veth_priv *priv = netdev_priv(dev);
1371	struct net_device *peer = rtnl_dereference(priv->peer);
1372
1373	netif_carrier_off(dev);
1374	if (peer)
1375		netif_carrier_off(peer);
1376
1377	if (priv->_xdp_prog)
1378		veth_disable_xdp(dev);
1379	else if (veth_gro_requested(dev))
1380		veth_napi_del(dev);
1381
1382	return 0;
1383}
1384
1385static int is_valid_veth_mtu(int mtu)
1386{
1387	return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1388}
1389
1390static int veth_alloc_queues(struct net_device *dev)
1391{
1392	struct veth_priv *priv = netdev_priv(dev);
1393	int i;
1394
1395	priv->rq = kvcalloc(dev->num_rx_queues, sizeof(*priv->rq),
1396			    GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
1397	if (!priv->rq)
1398		return -ENOMEM;
1399
1400	for (i = 0; i < dev->num_rx_queues; i++) {
1401		priv->rq[i].dev = dev;
1402		u64_stats_init(&priv->rq[i].stats.syncp);
1403	}
1404
1405	return 0;
1406}
1407
1408static void veth_free_queues(struct net_device *dev)
1409{
1410	struct veth_priv *priv = netdev_priv(dev);
1411
1412	kvfree(priv->rq);
1413}
1414
1415static int veth_dev_init(struct net_device *dev)
1416{
1417	netdev_lockdep_set_classes(dev);
1418	return veth_alloc_queues(dev);
1419}
1420
1421static void veth_dev_free(struct net_device *dev)
1422{
1423	veth_free_queues(dev);
1424}
1425
1426#ifdef CONFIG_NET_POLL_CONTROLLER
1427static void veth_poll_controller(struct net_device *dev)
1428{
1429	/* veth only receives frames when its peer sends one
1430	 * Since it has nothing to do with disabling irqs, we are guaranteed
1431	 * never to have pending data when we poll for it so
1432	 * there is nothing to do here.
1433	 *
1434	 * We need this though so netpoll recognizes us as an interface that
1435	 * supports polling, which enables bridge devices in virt setups to
1436	 * still use netconsole
1437	 */
1438}
1439#endif	/* CONFIG_NET_POLL_CONTROLLER */
1440
1441static int veth_get_iflink(const struct net_device *dev)
1442{
1443	struct veth_priv *priv = netdev_priv(dev);
1444	struct net_device *peer;
1445	int iflink;
1446
1447	rcu_read_lock();
1448	peer = rcu_dereference(priv->peer);
1449	iflink = peer ? READ_ONCE(peer->ifindex) : 0;
1450	rcu_read_unlock();
1451
1452	return iflink;
1453}
1454
1455static netdev_features_t veth_fix_features(struct net_device *dev,
1456					   netdev_features_t features)
1457{
1458	struct veth_priv *priv = netdev_priv(dev);
1459	struct net_device *peer;
1460
1461	peer = rtnl_dereference(priv->peer);
1462	if (peer) {
1463		struct veth_priv *peer_priv = netdev_priv(peer);
1464
1465		if (peer_priv->_xdp_prog)
1466			features &= ~NETIF_F_GSO_SOFTWARE;
1467	}
1468
1469	return features;
1470}
1471
1472static int veth_set_features(struct net_device *dev,
1473			     netdev_features_t features)
1474{
1475	netdev_features_t changed = features ^ dev->features;
1476	struct veth_priv *priv = netdev_priv(dev);
1477	struct net_device *peer;
1478	int err;
1479
1480	if (!(changed & NETIF_F_GRO) || !(dev->flags & IFF_UP) || priv->_xdp_prog)
1481		return 0;
1482
1483	peer = rtnl_dereference(priv->peer);
1484	if (features & NETIF_F_GRO) {
1485		err = veth_napi_enable(dev);
1486		if (err)
1487			return err;
1488
1489		if (peer)
1490			xdp_features_set_redirect_target(peer, true);
1491	} else {
1492		if (peer)
1493			xdp_features_clear_redirect_target(peer);
1494		veth_napi_del(dev);
1495	}
1496	return 0;
1497}
1498
1499static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1500{
1501	struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1502	struct net_device *peer;
1503
1504	if (new_hr < 0)
1505		new_hr = 0;
1506
1507	rcu_read_lock();
1508	peer = rcu_dereference(priv->peer);
1509	if (unlikely(!peer))
1510		goto out;
1511
1512	peer_priv = netdev_priv(peer);
1513	priv->requested_headroom = new_hr;
1514	new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1515	dev->needed_headroom = new_hr;
1516	peer->needed_headroom = new_hr;
1517
1518out:
1519	rcu_read_unlock();
1520}
1521
1522static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1523			struct netlink_ext_ack *extack)
1524{
1525	struct veth_priv *priv = netdev_priv(dev);
1526	struct bpf_prog *old_prog;
1527	struct net_device *peer;
1528	unsigned int max_mtu;
1529	int err;
1530
1531	old_prog = priv->_xdp_prog;
1532	priv->_xdp_prog = prog;
1533	peer = rtnl_dereference(priv->peer);
1534
1535	if (prog) {
1536		if (!peer) {
1537			NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1538			err = -ENOTCONN;
1539			goto err;
1540		}
1541
1542		max_mtu = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) -
1543			  peer->hard_header_len;
1544		/* Allow increasing the max_mtu if the program supports
1545		 * XDP fragments.
1546		 */
1547		if (prog->aux->xdp_has_frags)
1548			max_mtu += PAGE_SIZE * MAX_SKB_FRAGS;
1549
1550		if (peer->mtu > max_mtu) {
1551			NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1552			err = -ERANGE;
1553			goto err;
1554		}
1555
1556		if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1557			NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1558			err = -ENOSPC;
1559			goto err;
1560		}
1561
1562		if (dev->flags & IFF_UP) {
1563			err = veth_enable_xdp(dev);
1564			if (err) {
1565				NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1566				goto err;
1567			}
1568		}
1569
1570		if (!old_prog) {
1571			peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1572			peer->max_mtu = max_mtu;
1573		}
1574
1575		xdp_features_set_redirect_target(peer, true);
1576	}
1577
1578	if (old_prog) {
1579		if (!prog) {
1580			if (peer && !veth_gro_requested(dev))
1581				xdp_features_clear_redirect_target(peer);
1582
1583			if (dev->flags & IFF_UP)
1584				veth_disable_xdp(dev);
1585
1586			if (peer) {
1587				peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1588				peer->max_mtu = ETH_MAX_MTU;
1589			}
1590		}
1591		bpf_prog_put(old_prog);
1592	}
1593
1594	if ((!!old_prog ^ !!prog) && peer)
1595		netdev_update_features(peer);
1596
1597	return 0;
1598err:
1599	priv->_xdp_prog = old_prog;
1600
1601	return err;
1602}
1603
1604static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1605{
1606	switch (xdp->command) {
1607	case XDP_SETUP_PROG:
1608		return veth_xdp_set(dev, xdp->prog, xdp->extack);
1609	default:
1610		return -EINVAL;
1611	}
1612}
1613
1614static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
1615{
1616	struct veth_xdp_buff *_ctx = (void *)ctx;
1617
1618	if (!_ctx->skb)
1619		return -ENODATA;
1620
1621	*timestamp = skb_hwtstamps(_ctx->skb)->hwtstamp;
1622	return 0;
1623}
1624
1625static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
1626			    enum xdp_rss_hash_type *rss_type)
1627{
1628	struct veth_xdp_buff *_ctx = (void *)ctx;
1629	struct sk_buff *skb = _ctx->skb;
1630
1631	if (!skb)
1632		return -ENODATA;
1633
1634	*hash = skb_get_hash(skb);
1635	*rss_type = skb->l4_hash ? XDP_RSS_TYPE_L4_ANY : XDP_RSS_TYPE_NONE;
1636
1637	return 0;
1638}
1639
1640static int veth_xdp_rx_vlan_tag(const struct xdp_md *ctx, __be16 *vlan_proto,
1641				u16 *vlan_tci)
1642{
1643	const struct veth_xdp_buff *_ctx = (void *)ctx;
1644	const struct sk_buff *skb = _ctx->skb;
1645	int err;
1646
1647	if (!skb)
1648		return -ENODATA;
1649
1650	err = __vlan_hwaccel_get_tag(skb, vlan_tci);
1651	if (err)
1652		return err;
1653
1654	*vlan_proto = skb->vlan_proto;
1655	return err;
1656}
1657
1658static const struct net_device_ops veth_netdev_ops = {
1659	.ndo_init            = veth_dev_init,
1660	.ndo_open            = veth_open,
1661	.ndo_stop            = veth_close,
1662	.ndo_start_xmit      = veth_xmit,
1663	.ndo_get_stats64     = veth_get_stats64,
1664	.ndo_set_rx_mode     = veth_set_multicast_list,
1665	.ndo_set_mac_address = eth_mac_addr,
1666#ifdef CONFIG_NET_POLL_CONTROLLER
1667	.ndo_poll_controller	= veth_poll_controller,
1668#endif
1669	.ndo_get_iflink		= veth_get_iflink,
1670	.ndo_fix_features	= veth_fix_features,
1671	.ndo_set_features	= veth_set_features,
1672	.ndo_features_check	= passthru_features_check,
1673	.ndo_set_rx_headroom	= veth_set_rx_headroom,
1674	.ndo_bpf		= veth_xdp,
1675	.ndo_xdp_xmit		= veth_ndo_xdp_xmit,
1676	.ndo_get_peer_dev	= veth_peer_dev,
1677};
1678
1679static const struct xdp_metadata_ops veth_xdp_metadata_ops = {
1680	.xmo_rx_timestamp		= veth_xdp_rx_timestamp,
1681	.xmo_rx_hash			= veth_xdp_rx_hash,
1682	.xmo_rx_vlan_tag		= veth_xdp_rx_vlan_tag,
1683};
1684
1685#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1686		       NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1687		       NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1688		       NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1689		       NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1690
1691static void veth_setup(struct net_device *dev)
1692{
1693	ether_setup(dev);
1694
1695	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1696	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1697	dev->priv_flags |= IFF_NO_QUEUE;
1698	dev->priv_flags |= IFF_PHONY_HEADROOM;
1699	dev->priv_flags |= IFF_DISABLE_NETPOLL;
1700	dev->lltx = true;
1701
1702	dev->netdev_ops = &veth_netdev_ops;
1703	dev->xdp_metadata_ops = &veth_xdp_metadata_ops;
1704	dev->ethtool_ops = &veth_ethtool_ops;
 
1705	dev->features |= VETH_FEATURES;
1706	dev->vlan_features = dev->features &
1707			     ~(NETIF_F_HW_VLAN_CTAG_TX |
1708			       NETIF_F_HW_VLAN_STAG_TX |
1709			       NETIF_F_HW_VLAN_CTAG_RX |
1710			       NETIF_F_HW_VLAN_STAG_RX);
1711	dev->needs_free_netdev = true;
1712	dev->priv_destructor = veth_dev_free;
1713	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1714	dev->max_mtu = ETH_MAX_MTU;
1715
1716	dev->hw_features = VETH_FEATURES;
1717	dev->hw_enc_features = VETH_FEATURES;
1718	dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1719	netif_set_tso_max_size(dev, GSO_MAX_SIZE);
1720}
1721
1722/*
1723 * netlink interface
1724 */
1725
1726static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1727			 struct netlink_ext_ack *extack)
1728{
1729	if (tb[IFLA_ADDRESS]) {
1730		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1731			return -EINVAL;
1732		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1733			return -EADDRNOTAVAIL;
1734	}
1735	if (tb[IFLA_MTU]) {
1736		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1737			return -EINVAL;
1738	}
1739	return 0;
1740}
1741
1742static struct rtnl_link_ops veth_link_ops;
1743
1744static void veth_disable_gro(struct net_device *dev)
1745{
1746	dev->features &= ~NETIF_F_GRO;
1747	dev->wanted_features &= ~NETIF_F_GRO;
1748	netdev_update_features(dev);
1749}
1750
1751static int veth_init_queues(struct net_device *dev, struct nlattr *tb[])
1752{
1753	int err;
1754
1755	if (!tb[IFLA_NUM_TX_QUEUES] && dev->num_tx_queues > 1) {
1756		err = netif_set_real_num_tx_queues(dev, 1);
1757		if (err)
1758			return err;
1759	}
1760	if (!tb[IFLA_NUM_RX_QUEUES] && dev->num_rx_queues > 1) {
1761		err = netif_set_real_num_rx_queues(dev, 1);
1762		if (err)
1763			return err;
1764	}
1765	return 0;
1766}
1767
1768static int veth_newlink(struct net *peer_net, struct net_device *dev,
1769			struct nlattr *tb[], struct nlattr *data[],
1770			struct netlink_ext_ack *extack)
1771{
1772	int err;
1773	struct net_device *peer;
1774	struct veth_priv *priv;
1775	char ifname[IFNAMSIZ];
1776	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1777	unsigned char name_assign_type;
1778	struct ifinfomsg *ifmp;
 
1779
1780	/*
1781	 * create and register peer first
1782	 */
1783	if (data && data[VETH_INFO_PEER]) {
1784		struct nlattr *nla_peer = data[VETH_INFO_PEER];
1785
 
1786		ifmp = nla_data(nla_peer);
1787		rtnl_nla_parse_ifinfomsg(peer_tb, nla_peer, extack);
 
 
 
 
 
 
 
 
 
 
1788		tbp = peer_tb;
1789	} else {
1790		ifmp = NULL;
1791		tbp = tb;
1792	}
1793
1794	if (ifmp && tbp[IFLA_IFNAME]) {
1795		nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1796		name_assign_type = NET_NAME_USER;
1797	} else {
1798		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1799		name_assign_type = NET_NAME_ENUM;
1800	}
1801
1802	peer = rtnl_create_link(peer_net, ifname, name_assign_type,
1803				&veth_link_ops, tbp, extack);
1804	if (IS_ERR(peer))
 
 
 
 
 
1805		return PTR_ERR(peer);
 
1806
1807	if (!ifmp || !tbp[IFLA_ADDRESS])
1808		eth_hw_addr_random(peer);
1809
1810	if (ifmp && (dev->ifindex != 0))
1811		peer->ifindex = ifmp->ifi_index;
1812
1813	netif_inherit_tso_max(peer, dev);
 
1814
1815	err = register_netdevice(peer);
 
 
1816	if (err < 0)
1817		goto err_register_peer;
1818
1819	/* keep GRO disabled by default to be consistent with the established
1820	 * veth behavior
1821	 */
1822	veth_disable_gro(peer);
1823	netif_carrier_off(peer);
1824
1825	err = rtnl_configure_link(peer, ifmp, 0, NULL);
1826	if (err < 0)
1827		goto err_configure_peer;
1828
1829	/*
1830	 * register dev last
1831	 *
1832	 * note, that since we've registered new device the dev's name
1833	 * should be re-allocated
1834	 */
1835
1836	if (tb[IFLA_ADDRESS] == NULL)
1837		eth_hw_addr_random(dev);
1838
1839	if (tb[IFLA_IFNAME])
1840		nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1841	else
1842		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1843
1844	err = register_netdevice(dev);
1845	if (err < 0)
1846		goto err_register_dev;
1847
1848	netif_carrier_off(dev);
1849
1850	/*
1851	 * tie the deviced together
1852	 */
1853
1854	priv = netdev_priv(dev);
1855	rcu_assign_pointer(priv->peer, peer);
1856	err = veth_init_queues(dev, tb);
1857	if (err)
1858		goto err_queues;
1859
1860	priv = netdev_priv(peer);
1861	rcu_assign_pointer(priv->peer, dev);
1862	err = veth_init_queues(peer, tb);
1863	if (err)
1864		goto err_queues;
1865
1866	veth_disable_gro(dev);
1867	/* update XDP supported features */
1868	veth_set_xdp_features(dev);
1869	veth_set_xdp_features(peer);
1870
1871	return 0;
1872
1873err_queues:
1874	unregister_netdevice(dev);
1875err_register_dev:
1876	/* nothing to do */
1877err_configure_peer:
1878	unregister_netdevice(peer);
1879	return err;
1880
1881err_register_peer:
1882	free_netdev(peer);
1883	return err;
1884}
1885
1886static void veth_dellink(struct net_device *dev, struct list_head *head)
1887{
1888	struct veth_priv *priv;
1889	struct net_device *peer;
1890
1891	priv = netdev_priv(dev);
1892	peer = rtnl_dereference(priv->peer);
1893
1894	/* Note : dellink() is called from default_device_exit_batch(),
1895	 * before a rcu_synchronize() point. The devices are guaranteed
1896	 * not being freed before one RCU grace period.
1897	 */
1898	RCU_INIT_POINTER(priv->peer, NULL);
1899	unregister_netdevice_queue(dev, head);
1900
1901	if (peer) {
1902		priv = netdev_priv(peer);
1903		RCU_INIT_POINTER(priv->peer, NULL);
1904		unregister_netdevice_queue(peer, head);
1905	}
1906}
1907
1908static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1909	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },
1910};
1911
1912static struct net *veth_get_link_net(const struct net_device *dev)
1913{
1914	struct veth_priv *priv = netdev_priv(dev);
1915	struct net_device *peer = rtnl_dereference(priv->peer);
1916
1917	return peer ? dev_net(peer) : dev_net(dev);
1918}
1919
1920static unsigned int veth_get_num_queues(void)
1921{
1922	/* enforce the same queue limit as rtnl_create_link */
1923	int queues = num_possible_cpus();
1924
1925	if (queues > 4096)
1926		queues = 4096;
1927	return queues;
1928}
1929
1930static struct rtnl_link_ops veth_link_ops = {
1931	.kind		= DRV_NAME,
1932	.priv_size	= sizeof(struct veth_priv),
1933	.setup		= veth_setup,
1934	.validate	= veth_validate,
1935	.newlink	= veth_newlink,
1936	.dellink	= veth_dellink,
1937	.policy		= veth_policy,
1938	.peer_type	= VETH_INFO_PEER,
1939	.maxtype	= VETH_INFO_MAX,
1940	.get_link_net	= veth_get_link_net,
1941	.get_num_tx_queues	= veth_get_num_queues,
1942	.get_num_rx_queues	= veth_get_num_queues,
1943};
1944
1945/*
1946 * init/fini
1947 */
1948
1949static __init int veth_init(void)
1950{
1951	return rtnl_link_register(&veth_link_ops);
1952}
1953
1954static __exit void veth_exit(void)
1955{
1956	rtnl_link_unregister(&veth_link_ops);
1957}
1958
1959module_init(veth_init);
1960module_exit(veth_exit);
1961
1962MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1963MODULE_LICENSE("GPL v2");
1964MODULE_ALIAS_RTNL_LINK(DRV_NAME);