Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1265 insertions, 0 deletions

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
new file mode 100644
index 000000000..ea999a663
--- /dev/null
+++ b/drivers/net/veth.c
@@ -0,0 +1,1265 @@
+/*
+ *  drivers/net/veth.c
+ *
+ *  Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
+ *
+ * Author: Pavel Emelianov <xemul@openvz.org>
+ * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
+ *
+ */
+
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <linux/ethtool.h>
+#include <linux/etherdevice.h>
+#include <linux/u64_stats_sync.h>
+
+#include <net/rtnetlink.h>
+#include <net/dst.h>
+#include <net/xfrm.h>
+#include <net/xdp.h>
+#include <linux/veth.h>
+#include <linux/module.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/ptr_ring.h>
+#include <linux/bpf_trace.h>
+
+#define DRV_NAME	"veth"
+#define DRV_VERSION	"1.0"
+
+#define VETH_XDP_FLAG		BIT(0)
+#define VETH_RING_SIZE		256
+#define VETH_XDP_HEADROOM	(XDP_PACKET_HEADROOM + NET_IP_ALIGN)
+
+/* Separating two types of XDP xmit */
+#define VETH_XDP_TX		BIT(0)
+#define VETH_XDP_REDIR		BIT(1)
+
+struct pcpu_vstats {
+	u64			packets;
+	u64			bytes;
+	struct u64_stats_sync	syncp;
+};
+
+struct veth_rq {
+	struct napi_struct	xdp_napi;
+	struct net_device	*dev;
+	struct bpf_prog __rcu	*xdp_prog;
+	struct xdp_mem_info	xdp_mem;
+	bool			rx_notify_masked;
+	struct ptr_ring		xdp_ring;
+	struct xdp_rxq_info	xdp_rxq;
+};
+
+struct veth_priv {
+	struct net_device __rcu	*peer;
+	atomic64_t		dropped;
+	struct bpf_prog		*_xdp_prog;
+	struct veth_rq		*rq;
+	unsigned int		requested_headroom;
+};
+
+/*
+ * ethtool interface
+ */
+
+static struct {
+	const char string[ETH_GSTRING_LEN];
+} ethtool_stats_keys[] = {
+	{ "peer_ifindex" },
+};
+
+static int veth_get_link_ksettings(struct net_device *dev,
+				   struct ethtool_link_ksettings *cmd)
+{
+	cmd->base.speed		= SPEED_10000;
+	cmd->base.duplex	= DUPLEX_FULL;
+	cmd->base.port		= PORT_TP;
+	cmd->base.autoneg	= AUTONEG_DISABLE;
+	return 0;
+}
+
+static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
+{
+	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
+	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
+}
+
+static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
+{
+	switch(stringset) {
+	case ETH_SS_STATS:
+		memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
+		break;
+	}
+}
+
+static int veth_get_sset_count(struct net_device *dev, int sset)
+{
+	switch (sset) {
+	case ETH_SS_STATS:
+		return ARRAY_SIZE(ethtool_stats_keys);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static void veth_get_ethtool_stats(struct net_device *dev,
+		struct ethtool_stats *stats, u64 *data)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer = rtnl_dereference(priv->peer);
+
+	data[0] = peer ? peer->ifindex : 0;
+}
+
+static const struct ethtool_ops veth_ethtool_ops = {
+	.get_drvinfo		= veth_get_drvinfo,
+	.get_link		= ethtool_op_get_link,
+	.get_strings		= veth_get_strings,
+	.get_sset_count		= veth_get_sset_count,
+	.get_ethtool_stats	= veth_get_ethtool_stats,
+	.get_link_ksettings	= veth_get_link_ksettings,
+};
+
+/* general routines */
+
+static bool veth_is_xdp_frame(void *ptr)
+{
+	return (unsigned long)ptr & VETH_XDP_FLAG;
+}
+
+static void *veth_ptr_to_xdp(void *ptr)
+{
+	return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
+}
+
+static void *veth_xdp_to_ptr(void *ptr)
+{
+	return (void *)((unsigned long)ptr | VETH_XDP_FLAG);
+}
+
+static void veth_ptr_free(void *ptr)
+{
+	if (veth_is_xdp_frame(ptr))
+		xdp_return_frame(veth_ptr_to_xdp(ptr));
+	else
+		kfree_skb(ptr);
+}
+
+static void __veth_xdp_flush(struct veth_rq *rq)
+{
+	/* Write ptr_ring before reading rx_notify_masked */
+	smp_mb();
+	if (!READ_ONCE(rq->rx_notify_masked) &&
+	    napi_schedule_prep(&rq->xdp_napi)) {
+		WRITE_ONCE(rq->rx_notify_masked, true);
+		__napi_schedule(&rq->xdp_napi);
+	}
+}
+
+static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
+{
+	if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
+		dev_kfree_skb_any(skb);
+		return NET_RX_DROP;
+	}
+
+	return NET_RX_SUCCESS;
+}
+
+static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
+			    struct veth_rq *rq, bool xdp)
+{
+	return __dev_forward_skb(dev, skb) ?: xdp ?
+		veth_xdp_rx(rq, skb) :
+		netif_rx(skb);
+}
+
+static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
+	struct veth_rq *rq = NULL;
+	struct net_device *rcv;
+	int length = skb->len;
+	bool rcv_xdp = false;
+	int rxq;
+
+	rcu_read_lock();
+	rcv = rcu_dereference(priv->peer);
+	if (unlikely(!rcv) || !pskb_may_pull(skb, ETH_HLEN)) {
+		kfree_skb(skb);
+		goto drop;
+	}
+
+	rcv_priv = netdev_priv(rcv);
+	rxq = skb_get_queue_mapping(skb);
+	if (rxq < rcv->real_num_rx_queues) {
+		rq = &rcv_priv->rq[rxq];
+		rcv_xdp = rcu_access_pointer(rq->xdp_prog);
+	}
+
+	if (likely(veth_forward_skb(rcv, skb, rq, rcv_xdp) == NET_RX_SUCCESS)) {
+		struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
+
+		u64_stats_update_begin(&stats->syncp);
+		stats->bytes += length;
+		stats->packets++;
+		u64_stats_update_end(&stats->syncp);
+	} else {
+drop:
+		atomic64_inc(&priv->dropped);
+	}
+
+	if (rcv_xdp)
+		__veth_xdp_flush(rq);
+
+	rcu_read_unlock();
+
+	return NETDEV_TX_OK;
+}
+
+static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int cpu;
+
+	result->packets = 0;
+	result->bytes = 0;
+	for_each_possible_cpu(cpu) {
+		struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
+		u64 packets, bytes;
+		unsigned int start;
+
+		do {
+			start = u64_stats_fetch_begin_irq(&stats->syncp);
+			packets = stats->packets;
+			bytes = stats->bytes;
+		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
+		result->packets += packets;
+		result->bytes += bytes;
+	}
+	return atomic64_read(&priv->dropped);
+}
+
+static void veth_get_stats64(struct net_device *dev,
+			     struct rtnl_link_stats64 *tot)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer;
+	struct pcpu_vstats one;
+
+	tot->tx_dropped = veth_stats_one(&one, dev);
+	tot->tx_bytes = one.bytes;
+	tot->tx_packets = one.packets;
+
+	rcu_read_lock();
+	peer = rcu_dereference(priv->peer);
+	if (peer) {
+		tot->rx_dropped = veth_stats_one(&one, peer);
+		tot->rx_bytes = one.bytes;
+		tot->rx_packets = one.packets;
+	}
+	rcu_read_unlock();
+}
+
+/* fake multicast ability */
+static void veth_set_multicast_list(struct net_device *dev)
+{
+}
+
+static struct sk_buff *veth_build_skb(void *head, int headroom, int len,
+				      int buflen)
+{
+	struct sk_buff *skb;
+
+	if (!buflen) {
+		buflen = SKB_DATA_ALIGN(headroom + len) +
+			 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+	}
+	skb = build_skb(head, buflen);
+	if (!skb)
+		return NULL;
+
+	skb_reserve(skb, headroom);
+	skb_put(skb, len);
+
+	return skb;
+}
+
+static int veth_select_rxq(struct net_device *dev)
+{
+	return smp_processor_id() % dev->real_num_rx_queues;
+}
+
+static int veth_xdp_xmit(struct net_device *dev, int n,
+			 struct xdp_frame **frames, u32 flags)
+{
+	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
+	struct net_device *rcv;
+	unsigned int max_len;
+	struct veth_rq *rq;
+	int i, drops = 0;
+
+	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
+		return -EINVAL;
+
+	rcv = rcu_dereference(priv->peer);
+	if (unlikely(!rcv))
+		return -ENXIO;
+
+	rcv_priv = netdev_priv(rcv);
+	rq = &rcv_priv->rq[veth_select_rxq(rcv)];
+	/* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive
+	 * side. This means an XDP program is loaded on the peer and the peer
+	 * device is up.
+	 */
+	if (!rcu_access_pointer(rq->xdp_prog))
+		return -ENXIO;
+
+	max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
+
+	spin_lock(&rq->xdp_ring.producer_lock);
+	for (i = 0; i < n; i++) {
+		struct xdp_frame *frame = frames[i];
+		void *ptr = veth_xdp_to_ptr(frame);
+
+		if (unlikely(frame->len > max_len ||
+			     __ptr_ring_produce(&rq->xdp_ring, ptr))) {
+			xdp_return_frame_rx_napi(frame);
+			drops++;
+		}
+	}
+	spin_unlock(&rq->xdp_ring.producer_lock);
+
+	if (flags & XDP_XMIT_FLUSH)
+		__veth_xdp_flush(rq);
+
+	return n - drops;
+}
+
+static void veth_xdp_flush(struct net_device *dev)
+{
+	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
+	struct net_device *rcv;
+	struct veth_rq *rq;
+
+	rcu_read_lock();
+	rcv = rcu_dereference(priv->peer);
+	if (unlikely(!rcv))
+		goto out;
+
+	rcv_priv = netdev_priv(rcv);
+	rq = &rcv_priv->rq[veth_select_rxq(rcv)];
+	/* xdp_ring is initialized on receive side? */
+	if (unlikely(!rcu_access_pointer(rq->xdp_prog)))
+		goto out;
+
+	__veth_xdp_flush(rq);
+out:
+	rcu_read_unlock();
+}
+
+static int veth_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
+{
+	struct xdp_frame *frame = convert_to_xdp_frame(xdp);
+
+	if (unlikely(!frame))
+		return -EOVERFLOW;
+
+	return veth_xdp_xmit(dev, 1, &frame, 0);
+}
+
+static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
+					struct xdp_frame *frame,
+					unsigned int *xdp_xmit)
+{
+	void *hard_start = frame->data - frame->headroom;
+	int len = frame->len, delta = 0;
+	struct xdp_frame orig_frame;
+	struct bpf_prog *xdp_prog;
+	unsigned int headroom;
+	struct sk_buff *skb;
+
+	/* bpf_xdp_adjust_head() assures BPF cannot access xdp_frame area */
+	hard_start -= sizeof(struct xdp_frame);
+
+	rcu_read_lock();
+	xdp_prog = rcu_dereference(rq->xdp_prog);
+	if (likely(xdp_prog)) {
+		struct xdp_buff xdp;
+		u32 act;
+
+		xdp.data_hard_start = hard_start;
+		xdp.data = frame->data;
+		xdp.data_end = frame->data + frame->len;
+		xdp.data_meta = frame->data - frame->metasize;
+		xdp.rxq = &rq->xdp_rxq;
+
+		act = bpf_prog_run_xdp(xdp_prog, &xdp);
+
+		switch (act) {
+		case XDP_PASS:
+			delta = frame->data - xdp.data;
+			len = xdp.data_end - xdp.data;
+			break;
+		case XDP_TX:
+			orig_frame = *frame;
+			xdp.rxq->mem = frame->mem;
+			if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
+				trace_xdp_exception(rq->dev, xdp_prog, act);
+				frame = &orig_frame;
+				goto err_xdp;
+			}
+			*xdp_xmit |= VETH_XDP_TX;
+			rcu_read_unlock();
+			goto xdp_xmit;
+		case XDP_REDIRECT:
+			orig_frame = *frame;
+			xdp.rxq->mem = frame->mem;
+			if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
+				frame = &orig_frame;
+				goto err_xdp;
+			}
+			*xdp_xmit |= VETH_XDP_REDIR;
+			rcu_read_unlock();
+			goto xdp_xmit;
+		default:
+			bpf_warn_invalid_xdp_action(act);
+		case XDP_ABORTED:
+			trace_xdp_exception(rq->dev, xdp_prog, act);
+		case XDP_DROP:
+			goto err_xdp;
+		}
+	}
+	rcu_read_unlock();
+
+	headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
+	skb = veth_build_skb(hard_start, headroom, len, 0);
+	if (!skb) {
+		xdp_return_frame(frame);
+		goto err;
+	}
+
+	xdp_scrub_frame(frame);
+	skb->protocol = eth_type_trans(skb, rq->dev);
+err:
+	return skb;
+err_xdp:
+	rcu_read_unlock();
+	xdp_return_frame(frame);
+xdp_xmit:
+	return NULL;
+}
+
+static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, struct sk_buff *skb,
+					unsigned int *xdp_xmit)
+{
+	u32 pktlen, headroom, act, metalen;
+	void *orig_data, *orig_data_end;
+	struct bpf_prog *xdp_prog;
+	int mac_len, delta, off;
+	struct xdp_buff xdp;
+
+	skb_orphan(skb);
+
+	rcu_read_lock();
+	xdp_prog = rcu_dereference(rq->xdp_prog);
+	if (unlikely(!xdp_prog)) {
+		rcu_read_unlock();
+		goto out;
+	}
+
+	mac_len = skb->data - skb_mac_header(skb);
+	pktlen = skb->len + mac_len;
+	headroom = skb_headroom(skb) - mac_len;
+
+	if (skb_shared(skb) || skb_head_is_locked(skb) ||
+	    skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) {
+		struct sk_buff *nskb;
+		int size, head_off;
+		void *head, *start;
+		struct page *page;
+
+		size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) +
+		       SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+		if (size > PAGE_SIZE)
+			goto drop;
+
+		page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
+		if (!page)
+			goto drop;
+
+		head = page_address(page);
+		start = head + VETH_XDP_HEADROOM;
+		if (skb_copy_bits(skb, -mac_len, start, pktlen)) {
+			page_frag_free(head);
+			goto drop;
+		}
+
+		nskb = veth_build_skb(head,
+				      VETH_XDP_HEADROOM + mac_len, skb->len,
+				      PAGE_SIZE);
+		if (!nskb) {
+			page_frag_free(head);
+			goto drop;
+		}
+
+		skb_copy_header(nskb, skb);
+		head_off = skb_headroom(nskb) - skb_headroom(skb);
+		skb_headers_offset_update(nskb, head_off);
+		consume_skb(skb);
+		skb = nskb;
+	}
+
+	xdp.data_hard_start = skb->head;
+	xdp.data = skb_mac_header(skb);
+	xdp.data_end = xdp.data + pktlen;
+	xdp.data_meta = xdp.data;
+	xdp.rxq = &rq->xdp_rxq;
+	orig_data = xdp.data;
+	orig_data_end = xdp.data_end;
+
+	act = bpf_prog_run_xdp(xdp_prog, &xdp);
+
+	switch (act) {
+	case XDP_PASS:
+		break;
+	case XDP_TX:
+		get_page(virt_to_page(xdp.data));
+		consume_skb(skb);
+		xdp.rxq->mem = rq->xdp_mem;
+		if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
+			trace_xdp_exception(rq->dev, xdp_prog, act);
+			goto err_xdp;
+		}
+		*xdp_xmit |= VETH_XDP_TX;
+		rcu_read_unlock();
+		goto xdp_xmit;
+	case XDP_REDIRECT:
+		get_page(virt_to_page(xdp.data));
+		consume_skb(skb);
+		xdp.rxq->mem = rq->xdp_mem;
+		if (xdp_do_redirect(rq->dev, &xdp, xdp_prog))
+			goto err_xdp;
+		*xdp_xmit |= VETH_XDP_REDIR;
+		rcu_read_unlock();
+		goto xdp_xmit;
+	default:
+		bpf_warn_invalid_xdp_action(act);
+	case XDP_ABORTED:
+		trace_xdp_exception(rq->dev, xdp_prog, act);
+	case XDP_DROP:
+		goto drop;
+	}
+	rcu_read_unlock();
+
+	delta = orig_data - xdp.data;
+	off = mac_len + delta;
+	if (off > 0)
+		__skb_push(skb, off);
+	else if (off < 0)
+		__skb_pull(skb, -off);
+	skb->mac_header -= delta;
+	off = xdp.data_end - orig_data_end;
+	if (off != 0)
+		__skb_put(skb, off);
+	skb->protocol = eth_type_trans(skb, rq->dev);
+
+	metalen = xdp.data - xdp.data_meta;
+	if (metalen)
+		skb_metadata_set(skb, metalen);
+out:
+	return skb;
+drop:
+	rcu_read_unlock();
+	kfree_skb(skb);
+	return NULL;
+err_xdp:
+	rcu_read_unlock();
+	page_frag_free(xdp.data);
+xdp_xmit:
+	return NULL;
+}
+
+static int veth_xdp_rcv(struct veth_rq *rq, int budget, unsigned int *xdp_xmit)
+{
+	int i, done = 0;
+
+	for (i = 0; i < budget; i++) {
+		void *ptr = __ptr_ring_consume(&rq->xdp_ring);
+		struct sk_buff *skb;
+
+		if (!ptr)
+			break;
+
+		if (veth_is_xdp_frame(ptr)) {
+			skb = veth_xdp_rcv_one(rq, veth_ptr_to_xdp(ptr),
+					       xdp_xmit);
+		} else {
+			skb = veth_xdp_rcv_skb(rq, ptr, xdp_xmit);
+		}
+
+		if (skb)
+			napi_gro_receive(&rq->xdp_napi, skb);
+
+		done++;
+	}
+
+	return done;
+}
+
+static int veth_poll(struct napi_struct *napi, int budget)
+{
+	struct veth_rq *rq =
+		container_of(napi, struct veth_rq, xdp_napi);
+	unsigned int xdp_xmit = 0;
+	int done;
+
+	xdp_set_return_frame_no_direct();
+	done = veth_xdp_rcv(rq, budget, &xdp_xmit);
+
+	if (done < budget && napi_complete_done(napi, done)) {
+		/* Write rx_notify_masked before reading ptr_ring */
+		smp_store_mb(rq->rx_notify_masked, false);
+		if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
+			if (napi_schedule_prep(&rq->xdp_napi)) {
+				WRITE_ONCE(rq->rx_notify_masked, true);
+				__napi_schedule(&rq->xdp_napi);
+			}
+		}
+	}
+
+	if (xdp_xmit & VETH_XDP_TX)
+		veth_xdp_flush(rq->dev);
+	if (xdp_xmit & VETH_XDP_REDIR)
+		xdp_do_flush_map();
+	xdp_clear_return_frame_no_direct();
+
+	return done;
+}
+
+static int veth_napi_add(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int err, i;
+
+	for (i = 0; i < dev->real_num_rx_queues; i++) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
+		if (err)
+			goto err_xdp_ring;
+	}
+
+	for (i = 0; i < dev->real_num_rx_queues; i++) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
+		napi_enable(&rq->xdp_napi);
+	}
+
+	return 0;
+err_xdp_ring:
+	for (i--; i >= 0; i--)
+		ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
+
+	return err;
+}
+
+static void veth_napi_del(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int i;
+
+	for (i = 0; i < dev->real_num_rx_queues; i++) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		napi_disable(&rq->xdp_napi);
+		napi_hash_del(&rq->xdp_napi);
+	}
+	synchronize_net();
+
+	for (i = 0; i < dev->real_num_rx_queues; i++) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		netif_napi_del(&rq->xdp_napi);
+		rq->rx_notify_masked = false;
+		ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
+	}
+}
+
+static int veth_enable_xdp(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int err, i;
+
+	if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
+		for (i = 0; i < dev->real_num_rx_queues; i++) {
+			struct veth_rq *rq = &priv->rq[i];
+
+			err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i);
+			if (err < 0)
+				goto err_rxq_reg;
+
+			err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
+							 MEM_TYPE_PAGE_SHARED,
+							 NULL);
+			if (err < 0)
+				goto err_reg_mem;
+
+			/* Save original mem info as it can be overwritten */
+			rq->xdp_mem = rq->xdp_rxq.mem;
+		}
+
+		err = veth_napi_add(dev);
+		if (err)
+			goto err_rxq_reg;
+	}
+
+	for (i = 0; i < dev->real_num_rx_queues; i++)
+		rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
+
+	return 0;
+err_reg_mem:
+	xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
+err_rxq_reg:
+	for (i--; i >= 0; i--)
+		xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
+
+	return err;
+}
+
+static void veth_disable_xdp(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int i;
+
+	for (i = 0; i < dev->real_num_rx_queues; i++)
+		rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
+	veth_napi_del(dev);
+	for (i = 0; i < dev->real_num_rx_queues; i++) {
+		struct veth_rq *rq = &priv->rq[i];
+
+		rq->xdp_rxq.mem = rq->xdp_mem;
+		xdp_rxq_info_unreg(&rq->xdp_rxq);
+	}
+}
+
+static int veth_open(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer = rtnl_dereference(priv->peer);
+	int err;
+
+	if (!peer)
+		return -ENOTCONN;
+
+	if (priv->_xdp_prog) {
+		err = veth_enable_xdp(dev);
+		if (err)
+			return err;
+	}
+
+	if (peer->flags & IFF_UP) {
+		netif_carrier_on(dev);
+		netif_carrier_on(peer);
+	}
+
+	return 0;
+}
+
+static int veth_close(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer = rtnl_dereference(priv->peer);
+
+	netif_carrier_off(dev);
+	if (peer)
+		netif_carrier_off(peer);
+
+	if (priv->_xdp_prog)
+		veth_disable_xdp(dev);
+
+	return 0;
+}
+
+static int is_valid_veth_mtu(int mtu)
+{
+	return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
+}
+
+static int veth_alloc_queues(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	int i;
+
+	priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
+	if (!priv->rq)
+		return -ENOMEM;
+
+	for (i = 0; i < dev->num_rx_queues; i++)
+		priv->rq[i].dev = dev;
+
+	return 0;
+}
+
+static void veth_free_queues(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+
+	kfree(priv->rq);
+}
+
+static int veth_dev_init(struct net_device *dev)
+{
+	int err;
+
+	dev->vstats = netdev_alloc_pcpu_stats(struct pcpu_vstats);
+	if (!dev->vstats)
+		return -ENOMEM;
+
+	err = veth_alloc_queues(dev);
+	if (err) {
+		free_percpu(dev->vstats);
+		return err;
+	}
+
+	return 0;
+}
+
+static void veth_dev_free(struct net_device *dev)
+{
+	veth_free_queues(dev);
+	free_percpu(dev->vstats);
+}
+
+#ifdef CONFIG_NET_POLL_CONTROLLER
+static void veth_poll_controller(struct net_device *dev)
+{
+	/* veth only receives frames when its peer sends one
+	 * Since it has nothing to do with disabling irqs, we are guaranteed
+	 * never to have pending data when we poll for it so
+	 * there is nothing to do here.
+	 *
+	 * We need this though so netpoll recognizes us as an interface that
+	 * supports polling, which enables bridge devices in virt setups to
+	 * still use netconsole
+	 */
+}
+#endif	/* CONFIG_NET_POLL_CONTROLLER */
+
+static int veth_get_iflink(const struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer;
+	int iflink;
+
+	rcu_read_lock();
+	peer = rcu_dereference(priv->peer);
+	iflink = peer ? peer->ifindex : 0;
+	rcu_read_unlock();
+
+	return iflink;
+}
+
+static netdev_features_t veth_fix_features(struct net_device *dev,
+					   netdev_features_t features)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer;
+
+	peer = rtnl_dereference(priv->peer);
+	if (peer) {
+		struct veth_priv *peer_priv = netdev_priv(peer);
+
+		if (peer_priv->_xdp_prog)
+			features &= ~NETIF_F_GSO_SOFTWARE;
+	}
+
+	return features;
+}
+
+static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
+{
+	struct veth_priv *peer_priv, *priv = netdev_priv(dev);
+	struct net_device *peer;
+
+	if (new_hr < 0)
+		new_hr = 0;
+
+	rcu_read_lock();
+	peer = rcu_dereference(priv->peer);
+	if (unlikely(!peer))
+		goto out;
+
+	peer_priv = netdev_priv(peer);
+	priv->requested_headroom = new_hr;
+	new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
+	dev->needed_headroom = new_hr;
+	peer->needed_headroom = new_hr;
+
+out:
+	rcu_read_unlock();
+}
+
+static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
+			struct netlink_ext_ack *extack)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct bpf_prog *old_prog;
+	struct net_device *peer;
+	unsigned int max_mtu;
+	int err;
+
+	old_prog = priv->_xdp_prog;
+	priv->_xdp_prog = prog;
+	peer = rtnl_dereference(priv->peer);
+
+	if (prog) {
+		if (!peer) {
+			NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
+			err = -ENOTCONN;
+			goto err;
+		}
+
+		max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
+			  peer->hard_header_len -
+			  SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+		if (peer->mtu > max_mtu) {
+			NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
+			err = -ERANGE;
+			goto err;
+		}
+
+		if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
+			NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
+			err = -ENOSPC;
+			goto err;
+		}
+
+		if (dev->flags & IFF_UP) {
+			err = veth_enable_xdp(dev);
+			if (err) {
+				NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
+				goto err;
+			}
+		}
+
+		if (!old_prog) {
+			peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
+			peer->max_mtu = max_mtu;
+		}
+	}
+
+	if (old_prog) {
+		if (!prog) {
+			if (dev->flags & IFF_UP)
+				veth_disable_xdp(dev);
+
+			if (peer) {
+				peer->hw_features |= NETIF_F_GSO_SOFTWARE;
+				peer->max_mtu = ETH_MAX_MTU;
+			}
+		}
+		bpf_prog_put(old_prog);
+	}
+
+	if ((!!old_prog ^ !!prog) && peer)
+		netdev_update_features(peer);
+
+	return 0;
+err:
+	priv->_xdp_prog = old_prog;
+
+	return err;
+}
+
+static u32 veth_xdp_query(struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	const struct bpf_prog *xdp_prog;
+
+	xdp_prog = priv->_xdp_prog;
+	if (xdp_prog)
+		return xdp_prog->aux->id;
+
+	return 0;
+}
+
+static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
+{
+	switch (xdp->command) {
+	case XDP_SETUP_PROG:
+		return veth_xdp_set(dev, xdp->prog, xdp->extack);
+	case XDP_QUERY_PROG:
+		xdp->prog_id = veth_xdp_query(dev);
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct net_device_ops veth_netdev_ops = {
+	.ndo_init            = veth_dev_init,
+	.ndo_open            = veth_open,
+	.ndo_stop            = veth_close,
+	.ndo_start_xmit      = veth_xmit,
+	.ndo_get_stats64     = veth_get_stats64,
+	.ndo_set_rx_mode     = veth_set_multicast_list,
+	.ndo_set_mac_address = eth_mac_addr,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	.ndo_poll_controller	= veth_poll_controller,
+#endif
+	.ndo_get_iflink		= veth_get_iflink,
+	.ndo_fix_features	= veth_fix_features,
+	.ndo_features_check	= passthru_features_check,
+	.ndo_set_rx_headroom	= veth_set_rx_headroom,
+	.ndo_bpf		= veth_xdp,
+	.ndo_xdp_xmit		= veth_xdp_xmit,
+};
+
+#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
+		       NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
+		       NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
+		       NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
+		       NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
+
+static void veth_setup(struct net_device *dev)
+{
+	ether_setup(dev);
+
+	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+	dev->priv_flags |= IFF_NO_QUEUE;
+	dev->priv_flags |= IFF_PHONY_HEADROOM;
+
+	dev->netdev_ops = &veth_netdev_ops;
+	dev->ethtool_ops = &veth_ethtool_ops;
+	dev->features |= NETIF_F_LLTX;
+	dev->features |= VETH_FEATURES;
+	dev->vlan_features = dev->features &
+			     ~(NETIF_F_HW_VLAN_CTAG_TX |
+			       NETIF_F_HW_VLAN_STAG_TX |
+			       NETIF_F_HW_VLAN_CTAG_RX |
+			       NETIF_F_HW_VLAN_STAG_RX);
+	dev->needs_free_netdev = true;
+	dev->priv_destructor = veth_dev_free;
+	dev->max_mtu = ETH_MAX_MTU;
+
+	dev->hw_features = VETH_FEATURES;
+	dev->hw_enc_features = VETH_FEATURES;
+	dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
+}
+
+/*
+ * netlink interface
+ */
+
+static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
+			 struct netlink_ext_ack *extack)
+{
+	if (tb[IFLA_ADDRESS]) {
+		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
+			return -EINVAL;
+		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
+			return -EADDRNOTAVAIL;
+	}
+	if (tb[IFLA_MTU]) {
+		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
+			return -EINVAL;
+	}
+	return 0;
+}
+
+static struct rtnl_link_ops veth_link_ops;
+
+static int veth_newlink(struct net *src_net, struct net_device *dev,
+			struct nlattr *tb[], struct nlattr *data[],
+			struct netlink_ext_ack *extack)
+{
+	int err;
+	struct net_device *peer;
+	struct veth_priv *priv;
+	char ifname[IFNAMSIZ];
+	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
+	unsigned char name_assign_type;
+	struct ifinfomsg *ifmp;
+	struct net *net;
+
+	/*
+	 * create and register peer first
+	 */
+	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
+		struct nlattr *nla_peer;
+
+		nla_peer = data[VETH_INFO_PEER];
+		ifmp = nla_data(nla_peer);
+		err = rtnl_nla_parse_ifla(peer_tb,
+					  nla_data(nla_peer) + sizeof(struct ifinfomsg),
+					  nla_len(nla_peer) - sizeof(struct ifinfomsg),
+					  NULL);
+		if (err < 0)
+			return err;
+
+		err = veth_validate(peer_tb, NULL, extack);
+		if (err < 0)
+			return err;
+
+		tbp = peer_tb;
+	} else {
+		ifmp = NULL;
+		tbp = tb;
+	}
+
+	if (ifmp && tbp[IFLA_IFNAME]) {
+		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
+		name_assign_type = NET_NAME_USER;
+	} else {
+		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
+		name_assign_type = NET_NAME_ENUM;
+	}
+
+	net = rtnl_link_get_net(src_net, tbp);
+	if (IS_ERR(net))
+		return PTR_ERR(net);
+
+	peer = rtnl_create_link(net, ifname, name_assign_type,
+				&veth_link_ops, tbp);
+	if (IS_ERR(peer)) {
+		put_net(net);
+		return PTR_ERR(peer);
+	}
+
+	if (!ifmp || !tbp[IFLA_ADDRESS])
+		eth_hw_addr_random(peer);
+
+	if (ifmp && (dev->ifindex != 0))
+		peer->ifindex = ifmp->ifi_index;
+
+	peer->gso_max_size = dev->gso_max_size;
+	peer->gso_max_segs = dev->gso_max_segs;
+
+	err = register_netdevice(peer);
+	put_net(net);
+	net = NULL;
+	if (err < 0)
+		goto err_register_peer;
+
+	netif_carrier_off(peer);
+
+	err = rtnl_configure_link(peer, ifmp);
+	if (err < 0)
+		goto err_configure_peer;
+
+	/*
+	 * register dev last
+	 *
+	 * note, that since we've registered new device the dev's name
+	 * should be re-allocated
+	 */
+
+	if (tb[IFLA_ADDRESS] == NULL)
+		eth_hw_addr_random(dev);
+
+	if (tb[IFLA_IFNAME])
+		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
+	else
+		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
+
+	err = register_netdevice(dev);
+	if (err < 0)
+		goto err_register_dev;
+
+	netif_carrier_off(dev);
+
+	/*
+	 * tie the deviced together
+	 */
+
+	priv = netdev_priv(dev);
+	rcu_assign_pointer(priv->peer, peer);
+
+	priv = netdev_priv(peer);
+	rcu_assign_pointer(priv->peer, dev);
+
+	return 0;
+
+err_register_dev:
+	/* nothing to do */
+err_configure_peer:
+	unregister_netdevice(peer);
+	return err;
+
+err_register_peer:
+	free_netdev(peer);
+	return err;
+}
+
+static void veth_dellink(struct net_device *dev, struct list_head *head)
+{
+	struct veth_priv *priv;
+	struct net_device *peer;
+
+	priv = netdev_priv(dev);
+	peer = rtnl_dereference(priv->peer);
+
+	/* Note : dellink() is called from default_device_exit_batch(),
+	 * before a rcu_synchronize() point. The devices are guaranteed
+	 * not being freed before one RCU grace period.
+	 */
+	RCU_INIT_POINTER(priv->peer, NULL);
+	unregister_netdevice_queue(dev, head);
+
+	if (peer) {
+		priv = netdev_priv(peer);
+		RCU_INIT_POINTER(priv->peer, NULL);
+		unregister_netdevice_queue(peer, head);
+	}
+}
+
+static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
+	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },
+};
+
+static struct net *veth_get_link_net(const struct net_device *dev)
+{
+	struct veth_priv *priv = netdev_priv(dev);
+	struct net_device *peer = rtnl_dereference(priv->peer);
+
+	return peer ? dev_net(peer) : dev_net(dev);
+}
+
+static struct rtnl_link_ops veth_link_ops = {
+	.kind		= DRV_NAME,
+	.priv_size	= sizeof(struct veth_priv),
+	.setup		= veth_setup,
+	.validate	= veth_validate,
+	.newlink	= veth_newlink,
+	.dellink	= veth_dellink,
+	.policy		= veth_policy,
+	.maxtype	= VETH_INFO_MAX,
+	.get_link_net	= veth_get_link_net,
+};
+
+/*
+ * init/fini
+ */
+
+static __init int veth_init(void)
+{
+	return rtnl_link_register(&veth_link_ops);
+}
+
+static __exit void veth_exit(void)
+{
+	rtnl_link_unregister(&veth_link_ops);
+}
+
+module_init(veth_init);
+module_exit(veth_exit);
+
+MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_RTNL_LINK(DRV_NAME);