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 <net/page_pool/helpers.h>
  30
  31#define DRV_NAME	"veth"
  32#define DRV_VERSION	"1.0"
  33
  34#define VETH_XDP_FLAG		BIT(0)
  35#define VETH_RING_SIZE		256
  36#define VETH_XDP_HEADROOM	(XDP_PACKET_HEADROOM + NET_IP_ALIGN)
  37
  38#define VETH_XDP_TX_BULK_SIZE	16
  39#define VETH_XDP_BATCH		16
  40
  41struct veth_stats {
  42	u64	rx_drops;
  43	/* xdp */
  44	u64	xdp_packets;
  45	u64	xdp_bytes;
  46	u64	xdp_redirect;
  47	u64	xdp_drops;
  48	u64	xdp_tx;
  49	u64	xdp_tx_err;
  50	u64	peer_tq_xdp_xmit;
  51	u64	peer_tq_xdp_xmit_err;
  52};
  53
  54struct veth_rq_stats {
  55	struct veth_stats	vs;
 
  56	struct u64_stats_sync	syncp;
  57};
  58
  59struct veth_rq {
  60	struct napi_struct	xdp_napi;
  61	struct napi_struct __rcu *napi; /* points to xdp_napi when the latter is initialized */
  62	struct net_device	*dev;
  63	struct bpf_prog __rcu	*xdp_prog;
  64	struct xdp_mem_info	xdp_mem;
  65	struct veth_rq_stats	stats;
  66	bool			rx_notify_masked;
  67	struct ptr_ring		xdp_ring;
  68	struct xdp_rxq_info	xdp_rxq;
  69	struct page_pool	*page_pool;
  70};
  71
  72struct veth_priv {
  73	struct net_device __rcu	*peer;
  74	atomic64_t		dropped;
  75	struct bpf_prog		*_xdp_prog;
  76	struct veth_rq		*rq;
  77	unsigned int		requested_headroom;
  78};
  79
  80struct veth_xdp_tx_bq {
  81	struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
  82	unsigned int count;
  83};
  84
  85/*
  86 * ethtool interface
  87 */
  88
  89struct veth_q_stat_desc {
  90	char	desc[ETH_GSTRING_LEN];
  91	size_t	offset;
  92};
  93
  94#define VETH_RQ_STAT(m)	offsetof(struct veth_stats, m)
  95
  96static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
  97	{ "xdp_packets",	VETH_RQ_STAT(xdp_packets) },
  98	{ "xdp_bytes",		VETH_RQ_STAT(xdp_bytes) },
  99	{ "drops",		VETH_RQ_STAT(rx_drops) },
 100	{ "xdp_redirect",	VETH_RQ_STAT(xdp_redirect) },
 101	{ "xdp_drops",		VETH_RQ_STAT(xdp_drops) },
 102	{ "xdp_tx",		VETH_RQ_STAT(xdp_tx) },
 103	{ "xdp_tx_errors",	VETH_RQ_STAT(xdp_tx_err) },
 104};
 105
 106#define VETH_RQ_STATS_LEN	ARRAY_SIZE(veth_rq_stats_desc)
 107
 108static const struct veth_q_stat_desc veth_tq_stats_desc[] = {
 109	{ "xdp_xmit",		VETH_RQ_STAT(peer_tq_xdp_xmit) },
 110	{ "xdp_xmit_errors",	VETH_RQ_STAT(peer_tq_xdp_xmit_err) },
 111};
 112
 113#define VETH_TQ_STATS_LEN	ARRAY_SIZE(veth_tq_stats_desc)
 114
 115static struct {
 116	const char string[ETH_GSTRING_LEN];
 117} ethtool_stats_keys[] = {
 118	{ "peer_ifindex" },
 119};
 120
 121struct veth_xdp_buff {
 122	struct xdp_buff xdp;
 123	struct sk_buff *skb;
 124};
 125
 126static int veth_get_link_ksettings(struct net_device *dev,
 127				   struct ethtool_link_ksettings *cmd)
 128{
 129	cmd->base.speed		= SPEED_10000;
 130	cmd->base.duplex	= DUPLEX_FULL;
 131	cmd->base.port		= PORT_TP;
 132	cmd->base.autoneg	= AUTONEG_DISABLE;
 
 
 
 
 
 
 133	return 0;
 134}
 135
 136static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 137{
 138	strscpy(info->driver, DRV_NAME, sizeof(info->driver));
 139	strscpy(info->version, DRV_VERSION, sizeof(info->version));
 140}
 141
 142static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
 143{
 144	u8 *p = buf;
 145	int i, j;
 146
 147	switch(stringset) {
 148	case ETH_SS_STATS:
 149		memcpy(p, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
 150		p += sizeof(ethtool_stats_keys);
 151		for (i = 0; i < dev->real_num_rx_queues; i++)
 152			for (j = 0; j < VETH_RQ_STATS_LEN; j++)
 153				ethtool_sprintf(&p, "rx_queue_%u_%.18s",
 154						i, veth_rq_stats_desc[j].desc);
 155
 156		for (i = 0; i < dev->real_num_tx_queues; i++)
 157			for (j = 0; j < VETH_TQ_STATS_LEN; j++)
 158				ethtool_sprintf(&p, "tx_queue_%u_%.18s",
 159						i, veth_tq_stats_desc[j].desc);
 160
 161		page_pool_ethtool_stats_get_strings(p);
 162		break;
 163	}
 164}
 165
 166static int veth_get_sset_count(struct net_device *dev, int sset)
 167{
 168	switch (sset) {
 169	case ETH_SS_STATS:
 170		return ARRAY_SIZE(ethtool_stats_keys) +
 171		       VETH_RQ_STATS_LEN * dev->real_num_rx_queues +
 172		       VETH_TQ_STATS_LEN * dev->real_num_tx_queues +
 173		       page_pool_ethtool_stats_get_count();
 174	default:
 175		return -EOPNOTSUPP;
 176	}
 177}
 178
 179static void veth_get_page_pool_stats(struct net_device *dev, u64 *data)
 180{
 181#ifdef CONFIG_PAGE_POOL_STATS
 182	struct veth_priv *priv = netdev_priv(dev);
 183	struct page_pool_stats pp_stats = {};
 184	int i;
 185
 186	for (i = 0; i < dev->real_num_rx_queues; i++) {
 187		if (!priv->rq[i].page_pool)
 188			continue;
 189		page_pool_get_stats(priv->rq[i].page_pool, &pp_stats);
 190	}
 191	page_pool_ethtool_stats_get(data, &pp_stats);
 192#endif /* CONFIG_PAGE_POOL_STATS */
 193}
 194
 195static void veth_get_ethtool_stats(struct net_device *dev,
 196		struct ethtool_stats *stats, u64 *data)
 197{
 198	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 199	struct net_device *peer = rtnl_dereference(priv->peer);
 200	int i, j, idx, pp_idx;
 201
 202	data[0] = peer ? peer->ifindex : 0;
 203	idx = 1;
 204	for (i = 0; i < dev->real_num_rx_queues; i++) {
 205		const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
 206		const void *stats_base = (void *)&rq_stats->vs;
 207		unsigned int start;
 208		size_t offset;
 209
 210		do {
 211			start = u64_stats_fetch_begin(&rq_stats->syncp);
 212			for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
 213				offset = veth_rq_stats_desc[j].offset;
 214				data[idx + j] = *(u64 *)(stats_base + offset);
 215			}
 216		} while (u64_stats_fetch_retry(&rq_stats->syncp, start));
 217		idx += VETH_RQ_STATS_LEN;
 218	}
 219	pp_idx = idx;
 220
 221	if (!peer)
 222		goto page_pool_stats;
 223
 224	rcv_priv = netdev_priv(peer);
 225	for (i = 0; i < peer->real_num_rx_queues; i++) {
 226		const struct veth_rq_stats *rq_stats = &rcv_priv->rq[i].stats;
 227		const void *base = (void *)&rq_stats->vs;
 228		unsigned int start, tx_idx = idx;
 229		size_t offset;
 230
 231		tx_idx += (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN;
 232		do {
 233			start = u64_stats_fetch_begin(&rq_stats->syncp);
 234			for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
 235				offset = veth_tq_stats_desc[j].offset;
 236				data[tx_idx + j] += *(u64 *)(base + offset);
 237			}
 238		} while (u64_stats_fetch_retry(&rq_stats->syncp, start));
 239	}
 240	pp_idx = idx + dev->real_num_tx_queues * VETH_TQ_STATS_LEN;
 241
 242page_pool_stats:
 243	veth_get_page_pool_stats(dev, &data[pp_idx]);
 244}
 245
 246static void veth_get_channels(struct net_device *dev,
 247			      struct ethtool_channels *channels)
 248{
 249	channels->tx_count = dev->real_num_tx_queues;
 250	channels->rx_count = dev->real_num_rx_queues;
 251	channels->max_tx = dev->num_tx_queues;
 252	channels->max_rx = dev->num_rx_queues;
 253}
 254
 255static int veth_set_channels(struct net_device *dev,
 256			     struct ethtool_channels *ch);
 257
 258static const struct ethtool_ops veth_ethtool_ops = {
 
 259	.get_drvinfo		= veth_get_drvinfo,
 260	.get_link		= ethtool_op_get_link,
 261	.get_strings		= veth_get_strings,
 262	.get_sset_count		= veth_get_sset_count,
 263	.get_ethtool_stats	= veth_get_ethtool_stats,
 264	.get_link_ksettings	= veth_get_link_ksettings,
 265	.get_ts_info		= ethtool_op_get_ts_info,
 266	.get_channels		= veth_get_channels,
 267	.set_channels		= veth_set_channels,
 268};
 269
 270/* general routines */
 271
 272static bool veth_is_xdp_frame(void *ptr)
 273{
 274	return (unsigned long)ptr & VETH_XDP_FLAG;
 275}
 276
 277static struct xdp_frame *veth_ptr_to_xdp(void *ptr)
 278{
 279	return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
 280}
 281
 282static void *veth_xdp_to_ptr(struct xdp_frame *xdp)
 283{
 284	return (void *)((unsigned long)xdp | VETH_XDP_FLAG);
 285}
 286
 287static void veth_ptr_free(void *ptr)
 288{
 289	if (veth_is_xdp_frame(ptr))
 290		xdp_return_frame(veth_ptr_to_xdp(ptr));
 291	else
 292		kfree_skb(ptr);
 293}
 294
 295static void __veth_xdp_flush(struct veth_rq *rq)
 296{
 297	/* Write ptr_ring before reading rx_notify_masked */
 298	smp_mb();
 299	if (!READ_ONCE(rq->rx_notify_masked) &&
 300	    napi_schedule_prep(&rq->xdp_napi)) {
 301		WRITE_ONCE(rq->rx_notify_masked, true);
 302		__napi_schedule(&rq->xdp_napi);
 303	}
 304}
 305
 306static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
 307{
 308	if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
 309		dev_kfree_skb_any(skb);
 310		return NET_RX_DROP;
 311	}
 312
 313	return NET_RX_SUCCESS;
 314}
 315
 316static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
 317			    struct veth_rq *rq, bool xdp)
 318{
 319	return __dev_forward_skb(dev, skb) ?: xdp ?
 320		veth_xdp_rx(rq, skb) :
 321		__netif_rx(skb);
 322}
 323
 324/* return true if the specified skb has chances of GRO aggregation
 325 * Don't strive for accuracy, but try to avoid GRO overhead in the most
 326 * common scenarios.
 327 * When XDP is enabled, all traffic is considered eligible, as the xmit
 328 * device has TSO off.
 329 * When TSO is enabled on the xmit device, we are likely interested only
 330 * in UDP aggregation, explicitly check for that if the skb is suspected
 331 * - the sock_wfree destructor is used by UDP, ICMP and XDP sockets -
 332 * to belong to locally generated UDP traffic.
 333 */
 334static bool veth_skb_is_eligible_for_gro(const struct net_device *dev,
 335					 const struct net_device *rcv,
 336					 const struct sk_buff *skb)
 337{
 338	return !(dev->features & NETIF_F_ALL_TSO) ||
 339		(skb->destructor == sock_wfree &&
 340		 rcv->features & (NETIF_F_GRO_FRAGLIST | NETIF_F_GRO_UDP_FWD));
 341}
 342
 343static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 344{
 345	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 346	struct veth_rq *rq = NULL;
 347	int ret = NETDEV_TX_OK;
 348	struct net_device *rcv;
 349	int length = skb->len;
 350	bool use_napi = false;
 351	int rxq;
 352
 353	rcu_read_lock();
 354	rcv = rcu_dereference(priv->peer);
 355	if (unlikely(!rcv) || !pskb_may_pull(skb, ETH_HLEN)) {
 356		kfree_skb(skb);
 357		goto drop;
 358	}
 359
 360	rcv_priv = netdev_priv(rcv);
 361	rxq = skb_get_queue_mapping(skb);
 362	if (rxq < rcv->real_num_rx_queues) {
 363		rq = &rcv_priv->rq[rxq];
 364
 365		/* The napi pointer is available when an XDP program is
 366		 * attached or when GRO is enabled
 367		 * Don't bother with napi/GRO if the skb can't be aggregated
 368		 */
 369		use_napi = rcu_access_pointer(rq->napi) &&
 370			   veth_skb_is_eligible_for_gro(dev, rcv, skb);
 371	}
 372
 373	skb_tx_timestamp(skb);
 374	if (likely(veth_forward_skb(rcv, skb, rq, use_napi) == NET_RX_SUCCESS)) {
 375		if (!use_napi)
 376			dev_sw_netstats_tx_add(dev, 1, length);
 377		else
 378			__veth_xdp_flush(rq);
 379	} else {
 380drop:
 381		atomic64_inc(&priv->dropped);
 382		ret = NET_XMIT_DROP;
 383	}
 384
 385	rcu_read_unlock();
 386
 387	return ret;
 388}
 389
 390static void veth_stats_rx(struct veth_stats *result, struct net_device *dev)
 
 
 
 
 391{
 392	struct veth_priv *priv = netdev_priv(dev);
 393	int i;
 394
 395	result->peer_tq_xdp_xmit_err = 0;
 396	result->xdp_packets = 0;
 397	result->xdp_tx_err = 0;
 398	result->xdp_bytes = 0;
 399	result->rx_drops = 0;
 400	for (i = 0; i < dev->num_rx_queues; i++) {
 401		u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err;
 402		struct veth_rq_stats *stats = &priv->rq[i].stats;
 403		unsigned int start;
 404
 405		do {
 406			start = u64_stats_fetch_begin(&stats->syncp);
 407			peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err;
 408			xdp_tx_err = stats->vs.xdp_tx_err;
 409			packets = stats->vs.xdp_packets;
 410			bytes = stats->vs.xdp_bytes;
 411			drops = stats->vs.rx_drops;
 412		} while (u64_stats_fetch_retry(&stats->syncp, start));
 413		result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err;
 414		result->xdp_tx_err += xdp_tx_err;
 415		result->xdp_packets += packets;
 416		result->xdp_bytes += bytes;
 417		result->rx_drops += drops;
 418	}
 
 419}
 420
 421static void veth_get_stats64(struct net_device *dev,
 422			     struct rtnl_link_stats64 *tot)
 423{
 424	struct veth_priv *priv = netdev_priv(dev);
 425	struct net_device *peer;
 426	struct veth_stats rx;
 427
 428	tot->tx_dropped = atomic64_read(&priv->dropped);
 429	dev_fetch_sw_netstats(tot, dev->tstats);
 430
 431	veth_stats_rx(&rx, dev);
 432	tot->tx_dropped += rx.xdp_tx_err;
 433	tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err;
 434	tot->rx_bytes += rx.xdp_bytes;
 435	tot->rx_packets += rx.xdp_packets;
 436
 437	rcu_read_lock();
 438	peer = rcu_dereference(priv->peer);
 439	if (peer) {
 440		struct rtnl_link_stats64 tot_peer = {};
 441
 442		dev_fetch_sw_netstats(&tot_peer, peer->tstats);
 443		tot->rx_bytes += tot_peer.tx_bytes;
 444		tot->rx_packets += tot_peer.tx_packets;
 445
 446		veth_stats_rx(&rx, peer);
 447		tot->tx_dropped += rx.peer_tq_xdp_xmit_err;
 448		tot->rx_dropped += rx.xdp_tx_err;
 449		tot->tx_bytes += rx.xdp_bytes;
 450		tot->tx_packets += rx.xdp_packets;
 451	}
 452	rcu_read_unlock();
 
 
 453}
 454
 455/* fake multicast ability */
 456static void veth_set_multicast_list(struct net_device *dev)
 457{
 458}
 459
 460static int veth_select_rxq(struct net_device *dev)
 461{
 462	return smp_processor_id() % dev->real_num_rx_queues;
 463}
 464
 465static struct net_device *veth_peer_dev(struct net_device *dev)
 466{
 467	struct veth_priv *priv = netdev_priv(dev);
 468
 469	/* Callers must be under RCU read side. */
 470	return rcu_dereference(priv->peer);
 471}
 472
 473static int veth_xdp_xmit(struct net_device *dev, int n,
 474			 struct xdp_frame **frames,
 475			 u32 flags, bool ndo_xmit)
 476{
 477	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 478	int i, ret = -ENXIO, nxmit = 0;
 479	struct net_device *rcv;
 480	unsigned int max_len;
 481	struct veth_rq *rq;
 482
 483	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
 484		return -EINVAL;
 485
 486	rcu_read_lock();
 487	rcv = rcu_dereference(priv->peer);
 488	if (unlikely(!rcv))
 489		goto out;
 490
 491	rcv_priv = netdev_priv(rcv);
 492	rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 493	/* The napi pointer is set if NAPI is enabled, which ensures that
 494	 * xdp_ring is initialized on receive side and the peer device is up.
 495	 */
 496	if (!rcu_access_pointer(rq->napi))
 497		goto out;
 498
 499	max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
 500
 501	spin_lock(&rq->xdp_ring.producer_lock);
 502	for (i = 0; i < n; i++) {
 503		struct xdp_frame *frame = frames[i];
 504		void *ptr = veth_xdp_to_ptr(frame);
 505
 506		if (unlikely(xdp_get_frame_len(frame) > max_len ||
 507			     __ptr_ring_produce(&rq->xdp_ring, ptr)))
 508			break;
 509		nxmit++;
 510	}
 511	spin_unlock(&rq->xdp_ring.producer_lock);
 512
 513	if (flags & XDP_XMIT_FLUSH)
 514		__veth_xdp_flush(rq);
 515
 516	ret = nxmit;
 517	if (ndo_xmit) {
 518		u64_stats_update_begin(&rq->stats.syncp);
 519		rq->stats.vs.peer_tq_xdp_xmit += nxmit;
 520		rq->stats.vs.peer_tq_xdp_xmit_err += n - nxmit;
 521		u64_stats_update_end(&rq->stats.syncp);
 522	}
 523
 524out:
 525	rcu_read_unlock();
 526
 527	return ret;
 528}
 529
 530static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
 531			     struct xdp_frame **frames, u32 flags)
 532{
 533	int err;
 534
 535	err = veth_xdp_xmit(dev, n, frames, flags, true);
 536	if (err < 0) {
 537		struct veth_priv *priv = netdev_priv(dev);
 538
 539		atomic64_add(n, &priv->dropped);
 540	}
 541
 542	return err;
 543}
 544
 545static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 546{
 547	int sent, i, err = 0, drops;
 548
 549	sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false);
 550	if (sent < 0) {
 551		err = sent;
 552		sent = 0;
 553	}
 554
 555	for (i = sent; unlikely(i < bq->count); i++)
 556		xdp_return_frame(bq->q[i]);
 557
 558	drops = bq->count - sent;
 559	trace_xdp_bulk_tx(rq->dev, sent, drops, err);
 560
 561	u64_stats_update_begin(&rq->stats.syncp);
 562	rq->stats.vs.xdp_tx += sent;
 563	rq->stats.vs.xdp_tx_err += drops;
 564	u64_stats_update_end(&rq->stats.syncp);
 565
 566	bq->count = 0;
 567}
 568
 569static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 570{
 571	struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev);
 572	struct net_device *rcv;
 573	struct veth_rq *rcv_rq;
 574
 575	rcu_read_lock();
 576	veth_xdp_flush_bq(rq, bq);
 577	rcv = rcu_dereference(priv->peer);
 578	if (unlikely(!rcv))
 579		goto out;
 580
 581	rcv_priv = netdev_priv(rcv);
 582	rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 583	/* xdp_ring is initialized on receive side? */
 584	if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
 585		goto out;
 586
 587	__veth_xdp_flush(rcv_rq);
 588out:
 589	rcu_read_unlock();
 590}
 591
 592static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
 593		       struct veth_xdp_tx_bq *bq)
 594{
 595	struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
 596
 597	if (unlikely(!frame))
 598		return -EOVERFLOW;
 599
 600	if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
 601		veth_xdp_flush_bq(rq, bq);
 602
 603	bq->q[bq->count++] = frame;
 604
 605	return 0;
 606}
 607
 608static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
 609					  struct xdp_frame *frame,
 610					  struct veth_xdp_tx_bq *bq,
 611					  struct veth_stats *stats)
 612{
 613	struct xdp_frame orig_frame;
 614	struct bpf_prog *xdp_prog;
 615
 616	rcu_read_lock();
 617	xdp_prog = rcu_dereference(rq->xdp_prog);
 618	if (likely(xdp_prog)) {
 619		struct veth_xdp_buff vxbuf;
 620		struct xdp_buff *xdp = &vxbuf.xdp;
 621		u32 act;
 622
 623		xdp_convert_frame_to_buff(frame, xdp);
 624		xdp->rxq = &rq->xdp_rxq;
 625		vxbuf.skb = NULL;
 626
 627		act = bpf_prog_run_xdp(xdp_prog, xdp);
 628
 629		switch (act) {
 630		case XDP_PASS:
 631			if (xdp_update_frame_from_buff(xdp, frame))
 632				goto err_xdp;
 633			break;
 634		case XDP_TX:
 635			orig_frame = *frame;
 636			xdp->rxq->mem = frame->mem;
 637			if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
 638				trace_xdp_exception(rq->dev, xdp_prog, act);
 639				frame = &orig_frame;
 640				stats->rx_drops++;
 641				goto err_xdp;
 642			}
 643			stats->xdp_tx++;
 644			rcu_read_unlock();
 645			goto xdp_xmit;
 646		case XDP_REDIRECT:
 647			orig_frame = *frame;
 648			xdp->rxq->mem = frame->mem;
 649			if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
 650				frame = &orig_frame;
 651				stats->rx_drops++;
 652				goto err_xdp;
 653			}
 654			stats->xdp_redirect++;
 655			rcu_read_unlock();
 656			goto xdp_xmit;
 657		default:
 658			bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 659			fallthrough;
 660		case XDP_ABORTED:
 661			trace_xdp_exception(rq->dev, xdp_prog, act);
 662			fallthrough;
 663		case XDP_DROP:
 664			stats->xdp_drops++;
 665			goto err_xdp;
 666		}
 667	}
 668	rcu_read_unlock();
 669
 670	return frame;
 671err_xdp:
 672	rcu_read_unlock();
 673	xdp_return_frame(frame);
 674xdp_xmit:
 675	return NULL;
 676}
 677
 678/* frames array contains VETH_XDP_BATCH at most */
 679static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames,
 680				  int n_xdpf, struct veth_xdp_tx_bq *bq,
 681				  struct veth_stats *stats)
 682{
 683	void *skbs[VETH_XDP_BATCH];
 684	int i;
 685
 686	if (xdp_alloc_skb_bulk(skbs, n_xdpf,
 687			       GFP_ATOMIC | __GFP_ZERO) < 0) {
 688		for (i = 0; i < n_xdpf; i++)
 689			xdp_return_frame(frames[i]);
 690		stats->rx_drops += n_xdpf;
 691
 692		return;
 693	}
 694
 695	for (i = 0; i < n_xdpf; i++) {
 696		struct sk_buff *skb = skbs[i];
 697
 698		skb = __xdp_build_skb_from_frame(frames[i], skb,
 699						 rq->dev);
 700		if (!skb) {
 701			xdp_return_frame(frames[i]);
 702			stats->rx_drops++;
 703			continue;
 704		}
 705		napi_gro_receive(&rq->xdp_napi, skb);
 706	}
 707}
 708
 709static void veth_xdp_get(struct xdp_buff *xdp)
 710{
 711	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
 712	int i;
 713
 714	get_page(virt_to_page(xdp->data));
 715	if (likely(!xdp_buff_has_frags(xdp)))
 716		return;
 717
 718	for (i = 0; i < sinfo->nr_frags; i++)
 719		__skb_frag_ref(&sinfo->frags[i]);
 720}
 721
 722static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
 723					struct xdp_buff *xdp,
 724					struct sk_buff **pskb)
 725{
 726	struct sk_buff *skb = *pskb;
 727	u32 frame_sz;
 728
 729	if (skb_shared(skb) || skb_head_is_locked(skb) ||
 730	    skb_shinfo(skb)->nr_frags ||
 731	    skb_headroom(skb) < XDP_PACKET_HEADROOM) {
 732		u32 size, len, max_head_size, off, truesize, page_offset;
 733		struct sk_buff *nskb;
 734		struct page *page;
 735		int i, head_off;
 736		void *va;
 737
 738		/* We need a private copy of the skb and data buffers since
 739		 * the ebpf program can modify it. We segment the original skb
 740		 * into order-0 pages without linearize it.
 741		 *
 742		 * Make sure we have enough space for linear and paged area
 743		 */
 744		max_head_size = SKB_WITH_OVERHEAD(PAGE_SIZE -
 745						  VETH_XDP_HEADROOM);
 746		if (skb->len > PAGE_SIZE * MAX_SKB_FRAGS + max_head_size)
 747			goto drop;
 748
 749		size = min_t(u32, skb->len, max_head_size);
 750		truesize = SKB_HEAD_ALIGN(size) + VETH_XDP_HEADROOM;
 751
 752		/* Allocate skb head */
 753		va = page_pool_dev_alloc_va(rq->page_pool, &truesize);
 754		if (!va)
 755			goto drop;
 756
 757		nskb = napi_build_skb(va, truesize);
 758		if (!nskb) {
 759			page_pool_free_va(rq->page_pool, va, true);
 760			goto drop;
 761		}
 762
 763		skb_reserve(nskb, VETH_XDP_HEADROOM);
 764		skb_copy_header(nskb, skb);
 765		skb_mark_for_recycle(nskb);
 766
 767		if (skb_copy_bits(skb, 0, nskb->data, size)) {
 768			consume_skb(nskb);
 769			goto drop;
 770		}
 771		skb_put(nskb, size);
 772
 773		head_off = skb_headroom(nskb) - skb_headroom(skb);
 774		skb_headers_offset_update(nskb, head_off);
 775
 776		/* Allocate paged area of new skb */
 777		off = size;
 778		len = skb->len - off;
 779
 780		for (i = 0; i < MAX_SKB_FRAGS && off < skb->len; i++) {
 781			size = min_t(u32, len, PAGE_SIZE);
 782			truesize = size;
 783
 784			page = page_pool_dev_alloc(rq->page_pool, &page_offset,
 785						   &truesize);
 786			if (!page) {
 787				consume_skb(nskb);
 788				goto drop;
 789			}
 790
 791			skb_add_rx_frag(nskb, i, page, page_offset, size,
 792					truesize);
 793			if (skb_copy_bits(skb, off,
 794					  page_address(page) + page_offset,
 795					  size)) {
 796				consume_skb(nskb);
 797				goto drop;
 798			}
 799
 800			len -= size;
 801			off += size;
 802		}
 803
 804		consume_skb(skb);
 805		skb = nskb;
 806	}
 807
 808	/* SKB "head" area always have tailroom for skb_shared_info */
 809	frame_sz = skb_end_pointer(skb) - skb->head;
 810	frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 811	xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq);
 812	xdp_prepare_buff(xdp, skb->head, skb_headroom(skb),
 813			 skb_headlen(skb), true);
 814
 815	if (skb_is_nonlinear(skb)) {
 816		skb_shinfo(skb)->xdp_frags_size = skb->data_len;
 817		xdp_buff_set_frags_flag(xdp);
 818	} else {
 819		xdp_buff_clear_frags_flag(xdp);
 820	}
 821	*pskb = skb;
 822
 823	return 0;
 824drop:
 825	consume_skb(skb);
 826	*pskb = NULL;
 827
 828	return -ENOMEM;
 829}
 830
 831static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 832					struct sk_buff *skb,
 833					struct veth_xdp_tx_bq *bq,
 834					struct veth_stats *stats)
 835{
 836	void *orig_data, *orig_data_end;
 837	struct bpf_prog *xdp_prog;
 838	struct veth_xdp_buff vxbuf;
 839	struct xdp_buff *xdp = &vxbuf.xdp;
 840	u32 act, metalen;
 841	int off;
 842
 843	skb_prepare_for_gro(skb);
 844
 845	rcu_read_lock();
 846	xdp_prog = rcu_dereference(rq->xdp_prog);
 847	if (unlikely(!xdp_prog)) {
 848		rcu_read_unlock();
 849		goto out;
 850	}
 851
 852	__skb_push(skb, skb->data - skb_mac_header(skb));
 853	if (veth_convert_skb_to_xdp_buff(rq, xdp, &skb))
 854		goto drop;
 855	vxbuf.skb = skb;
 856
 857	orig_data = xdp->data;
 858	orig_data_end = xdp->data_end;
 859
 860	act = bpf_prog_run_xdp(xdp_prog, xdp);
 861
 862	switch (act) {
 863	case XDP_PASS:
 864		break;
 865	case XDP_TX:
 866		veth_xdp_get(xdp);
 867		consume_skb(skb);
 868		xdp->rxq->mem = rq->xdp_mem;
 869		if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
 870			trace_xdp_exception(rq->dev, xdp_prog, act);
 871			stats->rx_drops++;
 872			goto err_xdp;
 873		}
 874		stats->xdp_tx++;
 875		rcu_read_unlock();
 876		goto xdp_xmit;
 877	case XDP_REDIRECT:
 878		veth_xdp_get(xdp);
 879		consume_skb(skb);
 880		xdp->rxq->mem = rq->xdp_mem;
 881		if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
 882			stats->rx_drops++;
 883			goto err_xdp;
 884		}
 885		stats->xdp_redirect++;
 886		rcu_read_unlock();
 887		goto xdp_xmit;
 888	default:
 889		bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 890		fallthrough;
 891	case XDP_ABORTED:
 892		trace_xdp_exception(rq->dev, xdp_prog, act);
 893		fallthrough;
 894	case XDP_DROP:
 895		stats->xdp_drops++;
 896		goto xdp_drop;
 897	}
 898	rcu_read_unlock();
 899
 900	/* check if bpf_xdp_adjust_head was used */
 901	off = orig_data - xdp->data;
 902	if (off > 0)
 903		__skb_push(skb, off);
 904	else if (off < 0)
 905		__skb_pull(skb, -off);
 906
 907	skb_reset_mac_header(skb);
 908
 909	/* check if bpf_xdp_adjust_tail was used */
 910	off = xdp->data_end - orig_data_end;
 911	if (off != 0)
 912		__skb_put(skb, off); /* positive on grow, negative on shrink */
 913
 914	/* XDP frag metadata (e.g. nr_frags) are updated in eBPF helpers
 915	 * (e.g. bpf_xdp_adjust_tail), we need to update data_len here.
 916	 */
 917	if (xdp_buff_has_frags(xdp))
 918		skb->data_len = skb_shinfo(skb)->xdp_frags_size;
 919	else
 920		skb->data_len = 0;
 921
 922	skb->protocol = eth_type_trans(skb, rq->dev);
 923
 924	metalen = xdp->data - xdp->data_meta;
 925	if (metalen)
 926		skb_metadata_set(skb, metalen);
 927out:
 928	return skb;
 929drop:
 930	stats->rx_drops++;
 931xdp_drop:
 932	rcu_read_unlock();
 933	kfree_skb(skb);
 934	return NULL;
 935err_xdp:
 936	rcu_read_unlock();
 937	xdp_return_buff(xdp);
 938xdp_xmit:
 939	return NULL;
 940}
 941
 942static int veth_xdp_rcv(struct veth_rq *rq, int budget,
 943			struct veth_xdp_tx_bq *bq,
 944			struct veth_stats *stats)
 945{
 946	int i, done = 0, n_xdpf = 0;
 947	void *xdpf[VETH_XDP_BATCH];
 948
 949	for (i = 0; i < budget; i++) {
 950		void *ptr = __ptr_ring_consume(&rq->xdp_ring);
 951
 952		if (!ptr)
 953			break;
 954
 955		if (veth_is_xdp_frame(ptr)) {
 956			/* ndo_xdp_xmit */
 957			struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
 958
 959			stats->xdp_bytes += xdp_get_frame_len(frame);
 960			frame = veth_xdp_rcv_one(rq, frame, bq, stats);
 961			if (frame) {
 962				/* XDP_PASS */
 963				xdpf[n_xdpf++] = frame;
 964				if (n_xdpf == VETH_XDP_BATCH) {
 965					veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf,
 966							      bq, stats);
 967					n_xdpf = 0;
 968				}
 969			}
 970		} else {
 971			/* ndo_start_xmit */
 972			struct sk_buff *skb = ptr;
 973
 974			stats->xdp_bytes += skb->len;
 975			skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
 976			if (skb) {
 977				if (skb_shared(skb) || skb_unclone(skb, GFP_ATOMIC))
 978					netif_receive_skb(skb);
 979				else
 980					napi_gro_receive(&rq->xdp_napi, skb);
 981			}
 982		}
 983		done++;
 984	}
 985
 986	if (n_xdpf)
 987		veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats);
 988
 989	u64_stats_update_begin(&rq->stats.syncp);
 990	rq->stats.vs.xdp_redirect += stats->xdp_redirect;
 991	rq->stats.vs.xdp_bytes += stats->xdp_bytes;
 992	rq->stats.vs.xdp_drops += stats->xdp_drops;
 993	rq->stats.vs.rx_drops += stats->rx_drops;
 994	rq->stats.vs.xdp_packets += done;
 995	u64_stats_update_end(&rq->stats.syncp);
 996
 997	return done;
 998}
 999
1000static int veth_poll(struct napi_struct *napi, int budget)
1001{
1002	struct veth_rq *rq =
1003		container_of(napi, struct veth_rq, xdp_napi);
1004	struct veth_stats stats = {};
1005	struct veth_xdp_tx_bq bq;
1006	int done;
1007
1008	bq.count = 0;
1009
1010	xdp_set_return_frame_no_direct();
1011	done = veth_xdp_rcv(rq, budget, &bq, &stats);
1012
1013	if (stats.xdp_redirect > 0)
1014		xdp_do_flush();
1015
1016	if (done < budget && napi_complete_done(napi, done)) {
1017		/* Write rx_notify_masked before reading ptr_ring */
1018		smp_store_mb(rq->rx_notify_masked, false);
1019		if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
1020			if (napi_schedule_prep(&rq->xdp_napi)) {
1021				WRITE_ONCE(rq->rx_notify_masked, true);
1022				__napi_schedule(&rq->xdp_napi);
1023			}
1024		}
1025	}
1026
1027	if (stats.xdp_tx > 0)
1028		veth_xdp_flush(rq, &bq);
1029	xdp_clear_return_frame_no_direct();
1030
1031	return done;
1032}
1033
1034static int veth_create_page_pool(struct veth_rq *rq)
1035{
1036	struct page_pool_params pp_params = {
1037		.order = 0,
1038		.pool_size = VETH_RING_SIZE,
1039		.nid = NUMA_NO_NODE,
1040		.dev = &rq->dev->dev,
1041	};
1042
1043	rq->page_pool = page_pool_create(&pp_params);
1044	if (IS_ERR(rq->page_pool)) {
1045		int err = PTR_ERR(rq->page_pool);
1046
1047		rq->page_pool = NULL;
1048		return err;
1049	}
1050
1051	return 0;
1052}
1053
1054static int __veth_napi_enable_range(struct net_device *dev, int start, int end)
1055{
1056	struct veth_priv *priv = netdev_priv(dev);
1057	int err, i;
1058
1059	for (i = start; i < end; i++) {
1060		err = veth_create_page_pool(&priv->rq[i]);
1061		if (err)
1062			goto err_page_pool;
1063	}
1064
1065	for (i = start; i < end; i++) {
1066		struct veth_rq *rq = &priv->rq[i];
1067
1068		err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
1069		if (err)
1070			goto err_xdp_ring;
1071	}
1072
1073	for (i = start; i < end; i++) {
1074		struct veth_rq *rq = &priv->rq[i];
1075
1076		napi_enable(&rq->xdp_napi);
1077		rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1078	}
1079
1080	return 0;
1081
1082err_xdp_ring:
1083	for (i--; i >= start; i--)
1084		ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
1085	i = end;
1086err_page_pool:
1087	for (i--; i >= start; i--) {
1088		page_pool_destroy(priv->rq[i].page_pool);
1089		priv->rq[i].page_pool = NULL;
1090	}
1091
1092	return err;
1093}
1094
1095static int __veth_napi_enable(struct net_device *dev)
1096{
1097	return __veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1098}
1099
1100static void veth_napi_del_range(struct net_device *dev, int start, int end)
1101{
1102	struct veth_priv *priv = netdev_priv(dev);
1103	int i;
1104
1105	for (i = start; i < end; i++) {
1106		struct veth_rq *rq = &priv->rq[i];
1107
1108		rcu_assign_pointer(priv->rq[i].napi, NULL);
1109		napi_disable(&rq->xdp_napi);
1110		__netif_napi_del(&rq->xdp_napi);
1111	}
1112	synchronize_net();
1113
1114	for (i = start; i < end; i++) {
1115		struct veth_rq *rq = &priv->rq[i];
1116
1117		rq->rx_notify_masked = false;
1118		ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
1119	}
1120
1121	for (i = start; i < end; i++) {
1122		page_pool_destroy(priv->rq[i].page_pool);
1123		priv->rq[i].page_pool = NULL;
1124	}
1125}
1126
1127static void veth_napi_del(struct net_device *dev)
1128{
1129	veth_napi_del_range(dev, 0, dev->real_num_rx_queues);
1130}
1131
1132static bool veth_gro_requested(const struct net_device *dev)
1133{
1134	return !!(dev->wanted_features & NETIF_F_GRO);
1135}
1136
1137static int veth_enable_xdp_range(struct net_device *dev, int start, int end,
1138				 bool napi_already_on)
1139{
1140	struct veth_priv *priv = netdev_priv(dev);
1141	int err, i;
1142
1143	for (i = start; i < end; i++) {
1144		struct veth_rq *rq = &priv->rq[i];
1145
1146		if (!napi_already_on)
1147			netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1148		err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id);
1149		if (err < 0)
1150			goto err_rxq_reg;
1151
1152		err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
1153						 MEM_TYPE_PAGE_SHARED,
1154						 NULL);
1155		if (err < 0)
1156			goto err_reg_mem;
1157
1158		/* Save original mem info as it can be overwritten */
1159		rq->xdp_mem = rq->xdp_rxq.mem;
1160	}
1161	return 0;
1162
1163err_reg_mem:
1164	xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
1165err_rxq_reg:
1166	for (i--; i >= start; i--) {
1167		struct veth_rq *rq = &priv->rq[i];
1168
1169		xdp_rxq_info_unreg(&rq->xdp_rxq);
1170		if (!napi_already_on)
1171			netif_napi_del(&rq->xdp_napi);
1172	}
1173
1174	return err;
1175}
1176
1177static void veth_disable_xdp_range(struct net_device *dev, int start, int end,
1178				   bool delete_napi)
1179{
1180	struct veth_priv *priv = netdev_priv(dev);
1181	int i;
1182
1183	for (i = start; i < end; i++) {
1184		struct veth_rq *rq = &priv->rq[i];
1185
1186		rq->xdp_rxq.mem = rq->xdp_mem;
1187		xdp_rxq_info_unreg(&rq->xdp_rxq);
1188
1189		if (delete_napi)
1190			netif_napi_del(&rq->xdp_napi);
1191	}
1192}
1193
1194static int veth_enable_xdp(struct net_device *dev)
1195{
1196	bool napi_already_on = veth_gro_requested(dev) && (dev->flags & IFF_UP);
1197	struct veth_priv *priv = netdev_priv(dev);
1198	int err, i;
1199
1200	if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
1201		err = veth_enable_xdp_range(dev, 0, dev->real_num_rx_queues, napi_already_on);
1202		if (err)
1203			return err;
1204
1205		if (!napi_already_on) {
1206			err = __veth_napi_enable(dev);
1207			if (err) {
1208				veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, true);
1209				return err;
1210			}
1211		}
1212	}
1213
1214	for (i = 0; i < dev->real_num_rx_queues; i++) {
1215		rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
1216		rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1217	}
1218
1219	return 0;
1220}
1221
1222static void veth_disable_xdp(struct net_device *dev)
1223{
1224	struct veth_priv *priv = netdev_priv(dev);
1225	int i;
1226
1227	for (i = 0; i < dev->real_num_rx_queues; i++)
1228		rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
1229
1230	if (!netif_running(dev) || !veth_gro_requested(dev))
1231		veth_napi_del(dev);
1232
1233	veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, false);
1234}
1235
1236static int veth_napi_enable_range(struct net_device *dev, int start, int end)
1237{
1238	struct veth_priv *priv = netdev_priv(dev);
1239	int err, i;
1240
1241	for (i = start; i < end; i++) {
1242		struct veth_rq *rq = &priv->rq[i];
1243
1244		netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1245	}
1246
1247	err = __veth_napi_enable_range(dev, start, end);
1248	if (err) {
1249		for (i = start; i < end; i++) {
1250			struct veth_rq *rq = &priv->rq[i];
1251
1252			netif_napi_del(&rq->xdp_napi);
1253		}
1254		return err;
1255	}
1256	return err;
1257}
1258
1259static int veth_napi_enable(struct net_device *dev)
1260{
1261	return veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1262}
1263
1264static void veth_disable_range_safe(struct net_device *dev, int start, int end)
1265{
1266	struct veth_priv *priv = netdev_priv(dev);
1267
1268	if (start >= end)
1269		return;
1270
1271	if (priv->_xdp_prog) {
1272		veth_napi_del_range(dev, start, end);
1273		veth_disable_xdp_range(dev, start, end, false);
1274	} else if (veth_gro_requested(dev)) {
1275		veth_napi_del_range(dev, start, end);
1276	}
1277}
1278
1279static int veth_enable_range_safe(struct net_device *dev, int start, int end)
1280{
1281	struct veth_priv *priv = netdev_priv(dev);
1282	int err;
1283
1284	if (start >= end)
1285		return 0;
1286
1287	if (priv->_xdp_prog) {
1288		/* these channels are freshly initialized, napi is not on there even
1289		 * when GRO is requeste
1290		 */
1291		err = veth_enable_xdp_range(dev, start, end, false);
1292		if (err)
1293			return err;
1294
1295		err = __veth_napi_enable_range(dev, start, end);
1296		if (err) {
1297			/* on error always delete the newly added napis */
1298			veth_disable_xdp_range(dev, start, end, true);
1299			return err;
1300		}
1301	} else if (veth_gro_requested(dev)) {
1302		return veth_napi_enable_range(dev, start, end);
1303	}
1304	return 0;
1305}
1306
1307static void veth_set_xdp_features(struct net_device *dev)
1308{
1309	struct veth_priv *priv = netdev_priv(dev);
1310	struct net_device *peer;
1311
1312	peer = rtnl_dereference(priv->peer);
1313	if (peer && peer->real_num_tx_queues <= dev->real_num_rx_queues) {
1314		struct veth_priv *priv_peer = netdev_priv(peer);
1315		xdp_features_t val = NETDEV_XDP_ACT_BASIC |
1316				     NETDEV_XDP_ACT_REDIRECT |
1317				     NETDEV_XDP_ACT_RX_SG;
1318
1319		if (priv_peer->_xdp_prog || veth_gro_requested(peer))
1320			val |= NETDEV_XDP_ACT_NDO_XMIT |
1321			       NETDEV_XDP_ACT_NDO_XMIT_SG;
1322		xdp_set_features_flag(dev, val);
1323	} else {
1324		xdp_clear_features_flag(dev);
1325	}
1326}
1327
1328static int veth_set_channels(struct net_device *dev,
1329			     struct ethtool_channels *ch)
1330{
1331	struct veth_priv *priv = netdev_priv(dev);
1332	unsigned int old_rx_count, new_rx_count;
1333	struct veth_priv *peer_priv;
1334	struct net_device *peer;
1335	int err;
1336
1337	/* sanity check. Upper bounds are already enforced by the caller */
1338	if (!ch->rx_count || !ch->tx_count)
1339		return -EINVAL;
1340
1341	/* avoid braking XDP, if that is enabled */
1342	peer = rtnl_dereference(priv->peer);
1343	peer_priv = peer ? netdev_priv(peer) : NULL;
1344	if (priv->_xdp_prog && peer && ch->rx_count < peer->real_num_tx_queues)
1345		return -EINVAL;
1346
1347	if (peer && peer_priv && peer_priv->_xdp_prog && ch->tx_count > peer->real_num_rx_queues)
1348		return -EINVAL;
1349
1350	old_rx_count = dev->real_num_rx_queues;
1351	new_rx_count = ch->rx_count;
1352	if (netif_running(dev)) {
1353		/* turn device off */
1354		netif_carrier_off(dev);
1355		if (peer)
1356			netif_carrier_off(peer);
1357
1358		/* try to allocate new resurces, as needed*/
1359		err = veth_enable_range_safe(dev, old_rx_count, new_rx_count);
1360		if (err)
1361			goto out;
1362	}
1363
1364	err = netif_set_real_num_rx_queues(dev, ch->rx_count);
1365	if (err)
1366		goto revert;
1367
1368	err = netif_set_real_num_tx_queues(dev, ch->tx_count);
1369	if (err) {
1370		int err2 = netif_set_real_num_rx_queues(dev, old_rx_count);
1371
1372		/* this error condition could happen only if rx and tx change
1373		 * in opposite directions (e.g. tx nr raises, rx nr decreases)
1374		 * and we can't do anything to fully restore the original
1375		 * status
1376		 */
1377		if (err2)
1378			pr_warn("Can't restore rx queues config %d -> %d %d",
1379				new_rx_count, old_rx_count, err2);
1380		else
1381			goto revert;
1382	}
1383
1384out:
1385	if (netif_running(dev)) {
1386		/* note that we need to swap the arguments WRT the enable part
1387		 * to identify the range we have to disable
1388		 */
1389		veth_disable_range_safe(dev, new_rx_count, old_rx_count);
1390		netif_carrier_on(dev);
1391		if (peer)
1392			netif_carrier_on(peer);
1393	}
1394
1395	/* update XDP supported features */
1396	veth_set_xdp_features(dev);
1397	if (peer)
1398		veth_set_xdp_features(peer);
1399
1400	return err;
1401
1402revert:
1403	new_rx_count = old_rx_count;
1404	old_rx_count = ch->rx_count;
1405	goto out;
1406}
1407
1408static int veth_open(struct net_device *dev)
1409{
1410	struct veth_priv *priv = netdev_priv(dev);
1411	struct net_device *peer = rtnl_dereference(priv->peer);
1412	int err;
1413
1414	if (!peer)
1415		return -ENOTCONN;
1416
1417	if (priv->_xdp_prog) {
1418		err = veth_enable_xdp(dev);
1419		if (err)
1420			return err;
1421	} else if (veth_gro_requested(dev)) {
1422		err = veth_napi_enable(dev);
1423		if (err)
1424			return err;
1425	}
1426
1427	if (peer->flags & IFF_UP) {
1428		netif_carrier_on(dev);
1429		netif_carrier_on(peer);
1430	}
1431
1432	veth_set_xdp_features(dev);
1433
1434	return 0;
1435}
1436
1437static int veth_close(struct net_device *dev)
1438{
1439	struct veth_priv *priv = netdev_priv(dev);
1440	struct net_device *peer = rtnl_dereference(priv->peer);
1441
1442	netif_carrier_off(dev);
1443	if (peer)
1444		netif_carrier_off(peer);
1445
1446	if (priv->_xdp_prog)
1447		veth_disable_xdp(dev);
1448	else if (veth_gro_requested(dev))
1449		veth_napi_del(dev);
1450
1451	return 0;
1452}
1453
1454static int is_valid_veth_mtu(int mtu)
1455{
1456	return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1457}
1458
1459static int veth_alloc_queues(struct net_device *dev)
1460{
1461	struct veth_priv *priv = netdev_priv(dev);
1462	int i;
1463
1464	priv->rq = kvcalloc(dev->num_rx_queues, sizeof(*priv->rq),
1465			    GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
1466	if (!priv->rq)
1467		return -ENOMEM;
1468
1469	for (i = 0; i < dev->num_rx_queues; i++) {
1470		priv->rq[i].dev = dev;
1471		u64_stats_init(&priv->rq[i].stats.syncp);
1472	}
1473
1474	return 0;
1475}
1476
1477static void veth_free_queues(struct net_device *dev)
1478{
1479	struct veth_priv *priv = netdev_priv(dev);
1480
1481	kvfree(priv->rq);
1482}
1483
1484static int veth_dev_init(struct net_device *dev)
1485{
1486	return veth_alloc_queues(dev);
 
 
 
1487}
1488
1489static void veth_dev_free(struct net_device *dev)
1490{
1491	veth_free_queues(dev);
 
1492}
1493
1494#ifdef CONFIG_NET_POLL_CONTROLLER
1495static void veth_poll_controller(struct net_device *dev)
1496{
1497	/* veth only receives frames when its peer sends one
1498	 * Since it has nothing to do with disabling irqs, we are guaranteed
1499	 * never to have pending data when we poll for it so
1500	 * there is nothing to do here.
1501	 *
1502	 * We need this though so netpoll recognizes us as an interface that
1503	 * supports polling, which enables bridge devices in virt setups to
1504	 * still use netconsole
1505	 */
1506}
1507#endif	/* CONFIG_NET_POLL_CONTROLLER */
1508
1509static int veth_get_iflink(const struct net_device *dev)
1510{
1511	struct veth_priv *priv = netdev_priv(dev);
1512	struct net_device *peer;
1513	int iflink;
1514
1515	rcu_read_lock();
1516	peer = rcu_dereference(priv->peer);
1517	iflink = peer ? peer->ifindex : 0;
1518	rcu_read_unlock();
1519
1520	return iflink;
1521}
1522
1523static netdev_features_t veth_fix_features(struct net_device *dev,
1524					   netdev_features_t features)
1525{
1526	struct veth_priv *priv = netdev_priv(dev);
1527	struct net_device *peer;
1528
1529	peer = rtnl_dereference(priv->peer);
1530	if (peer) {
1531		struct veth_priv *peer_priv = netdev_priv(peer);
1532
1533		if (peer_priv->_xdp_prog)
1534			features &= ~NETIF_F_GSO_SOFTWARE;
1535	}
1536	if (priv->_xdp_prog)
1537		features |= NETIF_F_GRO;
1538
1539	return features;
1540}
1541
1542static int veth_set_features(struct net_device *dev,
1543			     netdev_features_t features)
1544{
1545	netdev_features_t changed = features ^ dev->features;
1546	struct veth_priv *priv = netdev_priv(dev);
1547	struct net_device *peer;
1548	int err;
1549
1550	if (!(changed & NETIF_F_GRO) || !(dev->flags & IFF_UP) || priv->_xdp_prog)
1551		return 0;
1552
1553	peer = rtnl_dereference(priv->peer);
1554	if (features & NETIF_F_GRO) {
1555		err = veth_napi_enable(dev);
1556		if (err)
1557			return err;
1558
1559		if (peer)
1560			xdp_features_set_redirect_target(peer, true);
1561	} else {
1562		if (peer)
1563			xdp_features_clear_redirect_target(peer);
1564		veth_napi_del(dev);
1565	}
1566	return 0;
1567}
1568
1569static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1570{
1571	struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1572	struct net_device *peer;
1573
1574	if (new_hr < 0)
1575		new_hr = 0;
1576
1577	rcu_read_lock();
1578	peer = rcu_dereference(priv->peer);
1579	if (unlikely(!peer))
1580		goto out;
1581
1582	peer_priv = netdev_priv(peer);
1583	priv->requested_headroom = new_hr;
1584	new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1585	dev->needed_headroom = new_hr;
1586	peer->needed_headroom = new_hr;
1587
1588out:
1589	rcu_read_unlock();
1590}
1591
1592static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1593			struct netlink_ext_ack *extack)
1594{
1595	struct veth_priv *priv = netdev_priv(dev);
1596	struct bpf_prog *old_prog;
1597	struct net_device *peer;
1598	unsigned int max_mtu;
1599	int err;
1600
1601	old_prog = priv->_xdp_prog;
1602	priv->_xdp_prog = prog;
1603	peer = rtnl_dereference(priv->peer);
1604
1605	if (prog) {
1606		if (!peer) {
1607			NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1608			err = -ENOTCONN;
1609			goto err;
1610		}
1611
1612		max_mtu = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) -
1613			  peer->hard_header_len;
1614		/* Allow increasing the max_mtu if the program supports
1615		 * XDP fragments.
1616		 */
1617		if (prog->aux->xdp_has_frags)
1618			max_mtu += PAGE_SIZE * MAX_SKB_FRAGS;
1619
1620		if (peer->mtu > max_mtu) {
1621			NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1622			err = -ERANGE;
1623			goto err;
1624		}
1625
1626		if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1627			NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1628			err = -ENOSPC;
1629			goto err;
1630		}
1631
1632		if (dev->flags & IFF_UP) {
1633			err = veth_enable_xdp(dev);
1634			if (err) {
1635				NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1636				goto err;
1637			}
1638		}
1639
1640		if (!old_prog) {
1641			if (!veth_gro_requested(dev)) {
1642				/* user-space did not require GRO, but adding
1643				 * XDP is supposed to get GRO working
1644				 */
1645				dev->features |= NETIF_F_GRO;
1646				netdev_features_change(dev);
1647			}
1648
1649			peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1650			peer->max_mtu = max_mtu;
1651		}
1652
1653		xdp_features_set_redirect_target(peer, true);
1654	}
1655
1656	if (old_prog) {
1657		if (!prog) {
1658			if (peer && !veth_gro_requested(dev))
1659				xdp_features_clear_redirect_target(peer);
1660
1661			if (dev->flags & IFF_UP)
1662				veth_disable_xdp(dev);
1663
1664			/* if user-space did not require GRO, since adding XDP
1665			 * enabled it, clear it now
1666			 */
1667			if (!veth_gro_requested(dev)) {
1668				dev->features &= ~NETIF_F_GRO;
1669				netdev_features_change(dev);
1670			}
1671
1672			if (peer) {
1673				peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1674				peer->max_mtu = ETH_MAX_MTU;
1675			}
1676		}
1677		bpf_prog_put(old_prog);
1678	}
1679
1680	if ((!!old_prog ^ !!prog) && peer)
1681		netdev_update_features(peer);
1682
1683	return 0;
1684err:
1685	priv->_xdp_prog = old_prog;
1686
1687	return err;
1688}
1689
1690static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1691{
1692	switch (xdp->command) {
1693	case XDP_SETUP_PROG:
1694		return veth_xdp_set(dev, xdp->prog, xdp->extack);
1695	default:
1696		return -EINVAL;
1697	}
1698}
1699
1700static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
1701{
1702	struct veth_xdp_buff *_ctx = (void *)ctx;
1703
1704	if (!_ctx->skb)
1705		return -ENODATA;
1706
1707	*timestamp = skb_hwtstamps(_ctx->skb)->hwtstamp;
1708	return 0;
1709}
1710
1711static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
1712			    enum xdp_rss_hash_type *rss_type)
1713{
1714	struct veth_xdp_buff *_ctx = (void *)ctx;
1715	struct sk_buff *skb = _ctx->skb;
1716
1717	if (!skb)
1718		return -ENODATA;
1719
1720	*hash = skb_get_hash(skb);
1721	*rss_type = skb->l4_hash ? XDP_RSS_TYPE_L4_ANY : XDP_RSS_TYPE_NONE;
1722
1723	return 0;
1724}
1725
1726static int veth_xdp_rx_vlan_tag(const struct xdp_md *ctx, __be16 *vlan_proto,
1727				u16 *vlan_tci)
1728{
1729	const struct veth_xdp_buff *_ctx = (void *)ctx;
1730	const struct sk_buff *skb = _ctx->skb;
1731	int err;
1732
1733	if (!skb)
1734		return -ENODATA;
1735
1736	err = __vlan_hwaccel_get_tag(skb, vlan_tci);
1737	if (err)
1738		return err;
1739
1740	*vlan_proto = skb->vlan_proto;
1741	return err;
1742}
1743
1744static const struct net_device_ops veth_netdev_ops = {
1745	.ndo_init            = veth_dev_init,
1746	.ndo_open            = veth_open,
1747	.ndo_stop            = veth_close,
1748	.ndo_start_xmit      = veth_xmit,
 
1749	.ndo_get_stats64     = veth_get_stats64,
1750	.ndo_set_rx_mode     = veth_set_multicast_list,
1751	.ndo_set_mac_address = eth_mac_addr,
1752#ifdef CONFIG_NET_POLL_CONTROLLER
1753	.ndo_poll_controller	= veth_poll_controller,
1754#endif
1755	.ndo_get_iflink		= veth_get_iflink,
1756	.ndo_fix_features	= veth_fix_features,
1757	.ndo_set_features	= veth_set_features,
1758	.ndo_features_check	= passthru_features_check,
1759	.ndo_set_rx_headroom	= veth_set_rx_headroom,
1760	.ndo_bpf		= veth_xdp,
1761	.ndo_xdp_xmit		= veth_ndo_xdp_xmit,
1762	.ndo_get_peer_dev	= veth_peer_dev,
1763};
1764
1765static const struct xdp_metadata_ops veth_xdp_metadata_ops = {
1766	.xmo_rx_timestamp		= veth_xdp_rx_timestamp,
1767	.xmo_rx_hash			= veth_xdp_rx_hash,
1768	.xmo_rx_vlan_tag		= veth_xdp_rx_vlan_tag,
1769};
1770
1771#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1772		       NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1773		       NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1774		       NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1775		       NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1776
1777static void veth_setup(struct net_device *dev)
1778{
1779	ether_setup(dev);
1780
1781	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1782	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1783	dev->priv_flags |= IFF_NO_QUEUE;
1784	dev->priv_flags |= IFF_PHONY_HEADROOM;
1785
1786	dev->netdev_ops = &veth_netdev_ops;
1787	dev->xdp_metadata_ops = &veth_xdp_metadata_ops;
1788	dev->ethtool_ops = &veth_ethtool_ops;
1789	dev->features |= NETIF_F_LLTX;
1790	dev->features |= VETH_FEATURES;
1791	dev->vlan_features = dev->features &
1792			     ~(NETIF_F_HW_VLAN_CTAG_TX |
1793			       NETIF_F_HW_VLAN_STAG_TX |
1794			       NETIF_F_HW_VLAN_CTAG_RX |
1795			       NETIF_F_HW_VLAN_STAG_RX);
1796	dev->needs_free_netdev = true;
1797	dev->priv_destructor = veth_dev_free;
1798	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1799	dev->max_mtu = ETH_MAX_MTU;
1800
1801	dev->hw_features = VETH_FEATURES;
1802	dev->hw_enc_features = VETH_FEATURES;
1803	dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1804	netif_set_tso_max_size(dev, GSO_MAX_SIZE);
1805}
1806
1807/*
1808 * netlink interface
1809 */
1810
1811static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1812			 struct netlink_ext_ack *extack)
1813{
1814	if (tb[IFLA_ADDRESS]) {
1815		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1816			return -EINVAL;
1817		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1818			return -EADDRNOTAVAIL;
1819	}
1820	if (tb[IFLA_MTU]) {
1821		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1822			return -EINVAL;
1823	}
1824	return 0;
1825}
1826
1827static struct rtnl_link_ops veth_link_ops;
1828
1829static void veth_disable_gro(struct net_device *dev)
1830{
1831	dev->features &= ~NETIF_F_GRO;
1832	dev->wanted_features &= ~NETIF_F_GRO;
1833	netdev_update_features(dev);
1834}
1835
1836static int veth_init_queues(struct net_device *dev, struct nlattr *tb[])
1837{
1838	int err;
1839
1840	if (!tb[IFLA_NUM_TX_QUEUES] && dev->num_tx_queues > 1) {
1841		err = netif_set_real_num_tx_queues(dev, 1);
1842		if (err)
1843			return err;
1844	}
1845	if (!tb[IFLA_NUM_RX_QUEUES] && dev->num_rx_queues > 1) {
1846		err = netif_set_real_num_rx_queues(dev, 1);
1847		if (err)
1848			return err;
1849	}
1850	return 0;
1851}
1852
1853static int veth_newlink(struct net *src_net, struct net_device *dev,
1854			struct nlattr *tb[], struct nlattr *data[],
1855			struct netlink_ext_ack *extack)
1856{
1857	int err;
1858	struct net_device *peer;
1859	struct veth_priv *priv;
1860	char ifname[IFNAMSIZ];
1861	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1862	unsigned char name_assign_type;
1863	struct ifinfomsg *ifmp;
1864	struct net *net;
1865
1866	/*
1867	 * create and register peer first
1868	 */
1869	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1870		struct nlattr *nla_peer;
1871
1872		nla_peer = data[VETH_INFO_PEER];
1873		ifmp = nla_data(nla_peer);
1874		err = rtnl_nla_parse_ifinfomsg(peer_tb, nla_peer, extack);
 
 
1875		if (err < 0)
1876			return err;
1877
1878		err = veth_validate(peer_tb, NULL, extack);
1879		if (err < 0)
1880			return err;
1881
1882		tbp = peer_tb;
1883	} else {
1884		ifmp = NULL;
1885		tbp = tb;
1886	}
1887
1888	if (ifmp && tbp[IFLA_IFNAME]) {
1889		nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1890		name_assign_type = NET_NAME_USER;
1891	} else {
1892		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1893		name_assign_type = NET_NAME_ENUM;
1894	}
1895
1896	net = rtnl_link_get_net(src_net, tbp);
1897	if (IS_ERR(net))
1898		return PTR_ERR(net);
1899
1900	peer = rtnl_create_link(net, ifname, name_assign_type,
1901				&veth_link_ops, tbp, extack);
1902	if (IS_ERR(peer)) {
1903		put_net(net);
1904		return PTR_ERR(peer);
1905	}
1906
1907	if (!ifmp || !tbp[IFLA_ADDRESS])
1908		eth_hw_addr_random(peer);
1909
1910	if (ifmp && (dev->ifindex != 0))
1911		peer->ifindex = ifmp->ifi_index;
1912
1913	netif_inherit_tso_max(peer, dev);
1914
1915	err = register_netdevice(peer);
1916	put_net(net);
1917	net = NULL;
1918	if (err < 0)
1919		goto err_register_peer;
1920
1921	/* keep GRO disabled by default to be consistent with the established
1922	 * veth behavior
1923	 */
1924	veth_disable_gro(peer);
1925	netif_carrier_off(peer);
1926
1927	err = rtnl_configure_link(peer, ifmp, 0, NULL);
1928	if (err < 0)
1929		goto err_configure_peer;
1930
1931	/*
1932	 * register dev last
1933	 *
1934	 * note, that since we've registered new device the dev's name
1935	 * should be re-allocated
1936	 */
1937
1938	if (tb[IFLA_ADDRESS] == NULL)
1939		eth_hw_addr_random(dev);
1940
1941	if (tb[IFLA_IFNAME])
1942		nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1943	else
1944		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1945
1946	err = register_netdevice(dev);
1947	if (err < 0)
1948		goto err_register_dev;
1949
1950	netif_carrier_off(dev);
1951
1952	/*
1953	 * tie the deviced together
1954	 */
1955
1956	priv = netdev_priv(dev);
1957	rcu_assign_pointer(priv->peer, peer);
1958	err = veth_init_queues(dev, tb);
1959	if (err)
1960		goto err_queues;
1961
1962	priv = netdev_priv(peer);
1963	rcu_assign_pointer(priv->peer, dev);
1964	err = veth_init_queues(peer, tb);
1965	if (err)
1966		goto err_queues;
1967
1968	veth_disable_gro(dev);
1969	/* update XDP supported features */
1970	veth_set_xdp_features(dev);
1971	veth_set_xdp_features(peer);
1972
1973	return 0;
1974
1975err_queues:
1976	unregister_netdevice(dev);
1977err_register_dev:
1978	/* nothing to do */
1979err_configure_peer:
1980	unregister_netdevice(peer);
1981	return err;
1982
1983err_register_peer:
1984	free_netdev(peer);
1985	return err;
1986}
1987
1988static void veth_dellink(struct net_device *dev, struct list_head *head)
1989{
1990	struct veth_priv *priv;
1991	struct net_device *peer;
1992
1993	priv = netdev_priv(dev);
1994	peer = rtnl_dereference(priv->peer);
1995
1996	/* Note : dellink() is called from default_device_exit_batch(),
1997	 * before a rcu_synchronize() point. The devices are guaranteed
1998	 * not being freed before one RCU grace period.
1999	 */
2000	RCU_INIT_POINTER(priv->peer, NULL);
2001	unregister_netdevice_queue(dev, head);
2002
2003	if (peer) {
2004		priv = netdev_priv(peer);
2005		RCU_INIT_POINTER(priv->peer, NULL);
2006		unregister_netdevice_queue(peer, head);
2007	}
2008}
2009
2010static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
2011	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },
2012};
2013
2014static struct net *veth_get_link_net(const struct net_device *dev)
2015{
2016	struct veth_priv *priv = netdev_priv(dev);
2017	struct net_device *peer = rtnl_dereference(priv->peer);
2018
2019	return peer ? dev_net(peer) : dev_net(dev);
2020}
2021
2022static unsigned int veth_get_num_queues(void)
2023{
2024	/* enforce the same queue limit as rtnl_create_link */
2025	int queues = num_possible_cpus();
2026
2027	if (queues > 4096)
2028		queues = 4096;
2029	return queues;
2030}
2031
2032static struct rtnl_link_ops veth_link_ops = {
2033	.kind		= DRV_NAME,
2034	.priv_size	= sizeof(struct veth_priv),
2035	.setup		= veth_setup,
2036	.validate	= veth_validate,
2037	.newlink	= veth_newlink,
2038	.dellink	= veth_dellink,
2039	.policy		= veth_policy,
2040	.maxtype	= VETH_INFO_MAX,
2041	.get_link_net	= veth_get_link_net,
2042	.get_num_tx_queues	= veth_get_num_queues,
2043	.get_num_rx_queues	= veth_get_num_queues,
2044};
2045
2046/*
2047 * init/fini
2048 */
2049
2050static __init int veth_init(void)
2051{
2052	return rtnl_link_register(&veth_link_ops);
2053}
2054
2055static __exit void veth_exit(void)
2056{
2057	rtnl_link_unregister(&veth_link_ops);
2058}
2059
2060module_init(veth_init);
2061module_exit(veth_exit);
2062
2063MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
2064MODULE_LICENSE("GPL v2");
2065MODULE_ALIAS_RTNL_LINK(DRV_NAME);