xref: /openbmc/linux/drivers/net/veth.c (revision cb1aaebe) 
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 <net/xdp.h>
21 #include <linux/veth.h>
22 #include <linux/module.h>
23 #include <linux/bpf.h>
24 #include <linux/filter.h>
25 #include <linux/ptr_ring.h>
26 #include <linux/bpf_trace.h>
27 #include <linux/net_tstamp.h>
28 
29 #define DRV_NAME	"veth"
30 #define DRV_VERSION	"1.0"
31 
32 #define VETH_XDP_FLAG		BIT(0)
33 #define VETH_RING_SIZE		256
34 #define VETH_XDP_HEADROOM	(XDP_PACKET_HEADROOM + NET_IP_ALIGN)
35 
36 /* Separating two types of XDP xmit */
37 #define VETH_XDP_TX		BIT(0)
38 #define VETH_XDP_REDIR		BIT(1)
39 
40 struct veth_rq_stats {
41 	u64			xdp_packets;
42 	u64			xdp_bytes;
43 	u64			xdp_drops;
44 	struct u64_stats_sync	syncp;
45 };
46 
47 struct veth_rq {
48 	struct napi_struct	xdp_napi;
49 	struct net_device	*dev;
50 	struct bpf_prog __rcu	*xdp_prog;
51 	struct xdp_mem_info	xdp_mem;
52 	struct veth_rq_stats	stats;
53 	bool			rx_notify_masked;
54 	struct ptr_ring		xdp_ring;
55 	struct xdp_rxq_info	xdp_rxq;
56 };
57 
58 struct veth_priv {
59 	struct net_device __rcu	*peer;
60 	atomic64_t		dropped;
61 	struct bpf_prog		*_xdp_prog;
62 	struct veth_rq		*rq;
63 	unsigned int		requested_headroom;
64 };
65 
66 /*
67  * ethtool interface
68  */
69 
70 struct veth_q_stat_desc {
71 	char	desc[ETH_GSTRING_LEN];
72 	size_t	offset;
73 };
74 
75 #define VETH_RQ_STAT(m)	offsetof(struct veth_rq_stats, m)
76 
77 static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
78 	{ "xdp_packets",	VETH_RQ_STAT(xdp_packets) },
79 	{ "xdp_bytes",		VETH_RQ_STAT(xdp_bytes) },
80 	{ "xdp_drops",		VETH_RQ_STAT(xdp_drops) },
81 };
82 
83 #define VETH_RQ_STATS_LEN	ARRAY_SIZE(veth_rq_stats_desc)
84 
85 static struct {
86 	const char string[ETH_GSTRING_LEN];
87 } ethtool_stats_keys[] = {
88 	{ "peer_ifindex" },
89 };
90 
91 static int veth_get_link_ksettings(struct net_device *dev,
92 				   struct ethtool_link_ksettings *cmd)
93 {
94 	cmd->base.speed		= SPEED_10000;
95 	cmd->base.duplex	= DUPLEX_FULL;
96 	cmd->base.port		= PORT_TP;
97 	cmd->base.autoneg	= AUTONEG_DISABLE;
98 	return 0;
99 }
100 
101 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
102 {
103 	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
104 	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
105 }
106 
107 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
108 {
109 	char *p = (char *)buf;
110 	int i, j;
111 
112 	switch(stringset) {
113 	case ETH_SS_STATS:
114 		memcpy(p, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
115 		p += sizeof(ethtool_stats_keys);
116 		for (i = 0; i < dev->real_num_rx_queues; i++) {
117 			for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
118 				snprintf(p, ETH_GSTRING_LEN,
119 					 "rx_queue_%u_%.11s",
120 					 i, veth_rq_stats_desc[j].desc);
121 				p += ETH_GSTRING_LEN;
122 			}
123 		}
124 		break;
125 	}
126 }
127 
128 static int veth_get_sset_count(struct net_device *dev, int sset)
129 {
130 	switch (sset) {
131 	case ETH_SS_STATS:
132 		return ARRAY_SIZE(ethtool_stats_keys) +
133 		       VETH_RQ_STATS_LEN * dev->real_num_rx_queues;
134 	default:
135 		return -EOPNOTSUPP;
136 	}
137 }
138 
139 static void veth_get_ethtool_stats(struct net_device *dev,
140 		struct ethtool_stats *stats, u64 *data)
141 {
142 	struct veth_priv *priv = netdev_priv(dev);
143 	struct net_device *peer = rtnl_dereference(priv->peer);
144 	int i, j, idx;
145 
146 	data[0] = peer ? peer->ifindex : 0;
147 	idx = 1;
148 	for (i = 0; i < dev->real_num_rx_queues; i++) {
149 		const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
150 		const void *stats_base = (void *)rq_stats;
151 		unsigned int start;
152 		size_t offset;
153 
154 		do {
155 			start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
156 			for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
157 				offset = veth_rq_stats_desc[j].offset;
158 				data[idx + j] = *(u64 *)(stats_base + offset);
159 			}
160 		} while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
161 		idx += VETH_RQ_STATS_LEN;
162 	}
163 }
164 
165 static const struct ethtool_ops veth_ethtool_ops = {
166 	.get_drvinfo		= veth_get_drvinfo,
167 	.get_link		= ethtool_op_get_link,
168 	.get_strings		= veth_get_strings,
169 	.get_sset_count		= veth_get_sset_count,
170 	.get_ethtool_stats	= veth_get_ethtool_stats,
171 	.get_link_ksettings	= veth_get_link_ksettings,
172 	.get_ts_info		= ethtool_op_get_ts_info,
173 };
174 
175 /* general routines */
176 
177 static bool veth_is_xdp_frame(void *ptr)
178 {
179 	return (unsigned long)ptr & VETH_XDP_FLAG;
180 }
181 
182 static void *veth_ptr_to_xdp(void *ptr)
183 {
184 	return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
185 }
186 
187 static void *veth_xdp_to_ptr(void *ptr)
188 {
189 	return (void *)((unsigned long)ptr | VETH_XDP_FLAG);
190 }
191 
192 static void veth_ptr_free(void *ptr)
193 {
194 	if (veth_is_xdp_frame(ptr))
195 		xdp_return_frame(veth_ptr_to_xdp(ptr));
196 	else
197 		kfree_skb(ptr);
198 }
199 
200 static void __veth_xdp_flush(struct veth_rq *rq)
201 {
202 	/* Write ptr_ring before reading rx_notify_masked */
203 	smp_mb();
204 	if (!rq->rx_notify_masked) {
205 		rq->rx_notify_masked = true;
206 		napi_schedule(&rq->xdp_napi);
207 	}
208 }
209 
210 static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
211 {
212 	if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
213 		dev_kfree_skb_any(skb);
214 		return NET_RX_DROP;
215 	}
216 
217 	return NET_RX_SUCCESS;
218 }
219 
220 static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
221 			    struct veth_rq *rq, bool xdp)
222 {
223 	return __dev_forward_skb(dev, skb) ?: xdp ?
224 		veth_xdp_rx(rq, skb) :
225 		netif_rx(skb);
226 }
227 
228 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
229 {
230 	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
231 	struct veth_rq *rq = NULL;
232 	struct net_device *rcv;
233 	int length = skb->len;
234 	bool rcv_xdp = false;
235 	int rxq;
236 
237 	rcu_read_lock();
238 	rcv = rcu_dereference(priv->peer);
239 	if (unlikely(!rcv)) {
240 		kfree_skb(skb);
241 		goto drop;
242 	}
243 
244 	rcv_priv = netdev_priv(rcv);
245 	rxq = skb_get_queue_mapping(skb);
246 	if (rxq < rcv->real_num_rx_queues) {
247 		rq = &rcv_priv->rq[rxq];
248 		rcv_xdp = rcu_access_pointer(rq->xdp_prog);
249 		if (rcv_xdp)
250 			skb_record_rx_queue(skb, rxq);
251 	}
252 
253 	skb_tx_timestamp(skb);
254 	if (likely(veth_forward_skb(rcv, skb, rq, rcv_xdp) == NET_RX_SUCCESS)) {
255 		if (!rcv_xdp) {
256 			struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);
257 
258 			u64_stats_update_begin(&stats->syncp);
259 			stats->bytes += length;
260 			stats->packets++;
261 			u64_stats_update_end(&stats->syncp);
262 		}
263 	} else {
264 drop:
265 		atomic64_inc(&priv->dropped);
266 	}
267 
268 	if (rcv_xdp)
269 		__veth_xdp_flush(rq);
270 
271 	rcu_read_unlock();
272 
273 	return NETDEV_TX_OK;
274 }
275 
276 static u64 veth_stats_tx(struct pcpu_lstats *result, struct net_device *dev)
277 {
278 	struct veth_priv *priv = netdev_priv(dev);
279 	int cpu;
280 
281 	result->packets = 0;
282 	result->bytes = 0;
283 	for_each_possible_cpu(cpu) {
284 		struct pcpu_lstats *stats = per_cpu_ptr(dev->lstats, cpu);
285 		u64 packets, bytes;
286 		unsigned int start;
287 
288 		do {
289 			start = u64_stats_fetch_begin_irq(&stats->syncp);
290 			packets = stats->packets;
291 			bytes = stats->bytes;
292 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
293 		result->packets += packets;
294 		result->bytes += bytes;
295 	}
296 	return atomic64_read(&priv->dropped);
297 }
298 
299 static void veth_stats_rx(struct veth_rq_stats *result, struct net_device *dev)
300 {
301 	struct veth_priv *priv = netdev_priv(dev);
302 	int i;
303 
304 	result->xdp_packets = 0;
305 	result->xdp_bytes = 0;
306 	result->xdp_drops = 0;
307 	for (i = 0; i < dev->num_rx_queues; i++) {
308 		struct veth_rq_stats *stats = &priv->rq[i].stats;
309 		u64 packets, bytes, drops;
310 		unsigned int start;
311 
312 		do {
313 			start = u64_stats_fetch_begin_irq(&stats->syncp);
314 			packets = stats->xdp_packets;
315 			bytes = stats->xdp_bytes;
316 			drops = stats->xdp_drops;
317 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
318 		result->xdp_packets += packets;
319 		result->xdp_bytes += bytes;
320 		result->xdp_drops += drops;
321 	}
322 }
323 
324 static void veth_get_stats64(struct net_device *dev,
325 			     struct rtnl_link_stats64 *tot)
326 {
327 	struct veth_priv *priv = netdev_priv(dev);
328 	struct net_device *peer;
329 	struct veth_rq_stats rx;
330 	struct pcpu_lstats tx;
331 
332 	tot->tx_dropped = veth_stats_tx(&tx, dev);
333 	tot->tx_bytes = tx.bytes;
334 	tot->tx_packets = tx.packets;
335 
336 	veth_stats_rx(&rx, dev);
337 	tot->rx_dropped = rx.xdp_drops;
338 	tot->rx_bytes = rx.xdp_bytes;
339 	tot->rx_packets = rx.xdp_packets;
340 
341 	rcu_read_lock();
342 	peer = rcu_dereference(priv->peer);
343 	if (peer) {
344 		tot->rx_dropped += veth_stats_tx(&tx, peer);
345 		tot->rx_bytes += tx.bytes;
346 		tot->rx_packets += tx.packets;
347 
348 		veth_stats_rx(&rx, peer);
349 		tot->tx_bytes += rx.xdp_bytes;
350 		tot->tx_packets += rx.xdp_packets;
351 	}
352 	rcu_read_unlock();
353 }
354 
355 /* fake multicast ability */
356 static void veth_set_multicast_list(struct net_device *dev)
357 {
358 }
359 
360 static struct sk_buff *veth_build_skb(void *head, int headroom, int len,
361 				      int buflen)
362 {
363 	struct sk_buff *skb;
364 
365 	if (!buflen) {
366 		buflen = SKB_DATA_ALIGN(headroom + len) +
367 			 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
368 	}
369 	skb = build_skb(head, buflen);
370 	if (!skb)
371 		return NULL;
372 
373 	skb_reserve(skb, headroom);
374 	skb_put(skb, len);
375 
376 	return skb;
377 }
378 
379 static int veth_select_rxq(struct net_device *dev)
380 {
381 	return smp_processor_id() % dev->real_num_rx_queues;
382 }
383 
384 static int veth_xdp_xmit(struct net_device *dev, int n,
385 			 struct xdp_frame **frames, u32 flags)
386 {
387 	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
388 	struct net_device *rcv;
389 	int i, ret, drops = n;
390 	unsigned int max_len;
391 	struct veth_rq *rq;
392 
393 	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
394 		ret = -EINVAL;
395 		goto drop;
396 	}
397 
398 	rcv = rcu_dereference(priv->peer);
399 	if (unlikely(!rcv)) {
400 		ret = -ENXIO;
401 		goto drop;
402 	}
403 
404 	rcv_priv = netdev_priv(rcv);
405 	rq = &rcv_priv->rq[veth_select_rxq(rcv)];
406 	/* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive
407 	 * side. This means an XDP program is loaded on the peer and the peer
408 	 * device is up.
409 	 */
410 	if (!rcu_access_pointer(rq->xdp_prog)) {
411 		ret = -ENXIO;
412 		goto drop;
413 	}
414 
415 	drops = 0;
416 	max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
417 
418 	spin_lock(&rq->xdp_ring.producer_lock);
419 	for (i = 0; i < n; i++) {
420 		struct xdp_frame *frame = frames[i];
421 		void *ptr = veth_xdp_to_ptr(frame);
422 
423 		if (unlikely(frame->len > max_len ||
424 			     __ptr_ring_produce(&rq->xdp_ring, ptr))) {
425 			xdp_return_frame_rx_napi(frame);
426 			drops++;
427 		}
428 	}
429 	spin_unlock(&rq->xdp_ring.producer_lock);
430 
431 	if (flags & XDP_XMIT_FLUSH)
432 		__veth_xdp_flush(rq);
433 
434 	if (likely(!drops))
435 		return n;
436 
437 	ret = n - drops;
438 drop:
439 	atomic64_add(drops, &priv->dropped);
440 
441 	return ret;
442 }
443 
444 static void veth_xdp_flush(struct net_device *dev)
445 {
446 	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
447 	struct net_device *rcv;
448 	struct veth_rq *rq;
449 
450 	rcu_read_lock();
451 	rcv = rcu_dereference(priv->peer);
452 	if (unlikely(!rcv))
453 		goto out;
454 
455 	rcv_priv = netdev_priv(rcv);
456 	rq = &rcv_priv->rq[veth_select_rxq(rcv)];
457 	/* xdp_ring is initialized on receive side? */
458 	if (unlikely(!rcu_access_pointer(rq->xdp_prog)))
459 		goto out;
460 
461 	__veth_xdp_flush(rq);
462 out:
463 	rcu_read_unlock();
464 }
465 
466 static int veth_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
467 {
468 	struct xdp_frame *frame = convert_to_xdp_frame(xdp);
469 
470 	if (unlikely(!frame))
471 		return -EOVERFLOW;
472 
473 	return veth_xdp_xmit(dev, 1, &frame, 0);
474 }
475 
476 static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
477 					struct xdp_frame *frame,
478 					unsigned int *xdp_xmit)
479 {
480 	void *hard_start = frame->data - frame->headroom;
481 	void *head = hard_start - sizeof(struct xdp_frame);
482 	int len = frame->len, delta = 0;
483 	struct xdp_frame orig_frame;
484 	struct bpf_prog *xdp_prog;
485 	unsigned int headroom;
486 	struct sk_buff *skb;
487 
488 	rcu_read_lock();
489 	xdp_prog = rcu_dereference(rq->xdp_prog);
490 	if (likely(xdp_prog)) {
491 		struct xdp_buff xdp;
492 		u32 act;
493 
494 		xdp.data_hard_start = hard_start;
495 		xdp.data = frame->data;
496 		xdp.data_end = frame->data + frame->len;
497 		xdp.data_meta = frame->data - frame->metasize;
498 		xdp.rxq = &rq->xdp_rxq;
499 
500 		act = bpf_prog_run_xdp(xdp_prog, &xdp);
501 
502 		switch (act) {
503 		case XDP_PASS:
504 			delta = frame->data - xdp.data;
505 			len = xdp.data_end - xdp.data;
506 			break;
507 		case XDP_TX:
508 			orig_frame = *frame;
509 			xdp.data_hard_start = head;
510 			xdp.rxq->mem = frame->mem;
511 			if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
512 				trace_xdp_exception(rq->dev, xdp_prog, act);
513 				frame = &orig_frame;
514 				goto err_xdp;
515 			}
516 			*xdp_xmit |= VETH_XDP_TX;
517 			rcu_read_unlock();
518 			goto xdp_xmit;
519 		case XDP_REDIRECT:
520 			orig_frame = *frame;
521 			xdp.data_hard_start = head;
522 			xdp.rxq->mem = frame->mem;
523 			if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
524 				frame = &orig_frame;
525 				goto err_xdp;
526 			}
527 			*xdp_xmit |= VETH_XDP_REDIR;
528 			rcu_read_unlock();
529 			goto xdp_xmit;
530 		default:
531 			bpf_warn_invalid_xdp_action(act);
532 			/* fall through */
533 		case XDP_ABORTED:
534 			trace_xdp_exception(rq->dev, xdp_prog, act);
535 			/* fall through */
536 		case XDP_DROP:
537 			goto err_xdp;
538 		}
539 	}
540 	rcu_read_unlock();
541 
542 	headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
543 	skb = veth_build_skb(head, headroom, len, 0);
544 	if (!skb) {
545 		xdp_return_frame(frame);
546 		goto err;
547 	}
548 
549 	xdp_scrub_frame(frame);
550 	skb->protocol = eth_type_trans(skb, rq->dev);
551 err:
552 	return skb;
553 err_xdp:
554 	rcu_read_unlock();
555 	xdp_return_frame(frame);
556 xdp_xmit:
557 	return NULL;
558 }
559 
560 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, struct sk_buff *skb,
561 					unsigned int *xdp_xmit)
562 {
563 	u32 pktlen, headroom, act, metalen;
564 	void *orig_data, *orig_data_end;
565 	struct bpf_prog *xdp_prog;
566 	int mac_len, delta, off;
567 	struct xdp_buff xdp;
568 
569 	skb_orphan(skb);
570 
571 	rcu_read_lock();
572 	xdp_prog = rcu_dereference(rq->xdp_prog);
573 	if (unlikely(!xdp_prog)) {
574 		rcu_read_unlock();
575 		goto out;
576 	}
577 
578 	mac_len = skb->data - skb_mac_header(skb);
579 	pktlen = skb->len + mac_len;
580 	headroom = skb_headroom(skb) - mac_len;
581 
582 	if (skb_shared(skb) || skb_head_is_locked(skb) ||
583 	    skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) {
584 		struct sk_buff *nskb;
585 		int size, head_off;
586 		void *head, *start;
587 		struct page *page;
588 
589 		size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) +
590 		       SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
591 		if (size > PAGE_SIZE)
592 			goto drop;
593 
594 		page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
595 		if (!page)
596 			goto drop;
597 
598 		head = page_address(page);
599 		start = head + VETH_XDP_HEADROOM;
600 		if (skb_copy_bits(skb, -mac_len, start, pktlen)) {
601 			page_frag_free(head);
602 			goto drop;
603 		}
604 
605 		nskb = veth_build_skb(head,
606 				      VETH_XDP_HEADROOM + mac_len, skb->len,
607 				      PAGE_SIZE);
608 		if (!nskb) {
609 			page_frag_free(head);
610 			goto drop;
611 		}
612 
613 		skb_copy_header(nskb, skb);
614 		head_off = skb_headroom(nskb) - skb_headroom(skb);
615 		skb_headers_offset_update(nskb, head_off);
616 		consume_skb(skb);
617 		skb = nskb;
618 	}
619 
620 	xdp.data_hard_start = skb->head;
621 	xdp.data = skb_mac_header(skb);
622 	xdp.data_end = xdp.data + pktlen;
623 	xdp.data_meta = xdp.data;
624 	xdp.rxq = &rq->xdp_rxq;
625 	orig_data = xdp.data;
626 	orig_data_end = xdp.data_end;
627 
628 	act = bpf_prog_run_xdp(xdp_prog, &xdp);
629 
630 	switch (act) {
631 	case XDP_PASS:
632 		break;
633 	case XDP_TX:
634 		get_page(virt_to_page(xdp.data));
635 		consume_skb(skb);
636 		xdp.rxq->mem = rq->xdp_mem;
637 		if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
638 			trace_xdp_exception(rq->dev, xdp_prog, act);
639 			goto err_xdp;
640 		}
641 		*xdp_xmit |= VETH_XDP_TX;
642 		rcu_read_unlock();
643 		goto xdp_xmit;
644 	case XDP_REDIRECT:
645 		get_page(virt_to_page(xdp.data));
646 		consume_skb(skb);
647 		xdp.rxq->mem = rq->xdp_mem;
648 		if (xdp_do_redirect(rq->dev, &xdp, xdp_prog))
649 			goto err_xdp;
650 		*xdp_xmit |= VETH_XDP_REDIR;
651 		rcu_read_unlock();
652 		goto xdp_xmit;
653 	default:
654 		bpf_warn_invalid_xdp_action(act);
655 		/* fall through */
656 	case XDP_ABORTED:
657 		trace_xdp_exception(rq->dev, xdp_prog, act);
658 		/* fall through */
659 	case XDP_DROP:
660 		goto drop;
661 	}
662 	rcu_read_unlock();
663 
664 	delta = orig_data - xdp.data;
665 	off = mac_len + delta;
666 	if (off > 0)
667 		__skb_push(skb, off);
668 	else if (off < 0)
669 		__skb_pull(skb, -off);
670 	skb->mac_header -= delta;
671 	off = xdp.data_end - orig_data_end;
672 	if (off != 0)
673 		__skb_put(skb, off);
674 	skb->protocol = eth_type_trans(skb, rq->dev);
675 
676 	metalen = xdp.data - xdp.data_meta;
677 	if (metalen)
678 		skb_metadata_set(skb, metalen);
679 out:
680 	return skb;
681 drop:
682 	rcu_read_unlock();
683 	kfree_skb(skb);
684 	return NULL;
685 err_xdp:
686 	rcu_read_unlock();
687 	page_frag_free(xdp.data);
688 xdp_xmit:
689 	return NULL;
690 }
691 
692 static int veth_xdp_rcv(struct veth_rq *rq, int budget, unsigned int *xdp_xmit)
693 {
694 	int i, done = 0, drops = 0, bytes = 0;
695 
696 	for (i = 0; i < budget; i++) {
697 		void *ptr = __ptr_ring_consume(&rq->xdp_ring);
698 		unsigned int xdp_xmit_one = 0;
699 		struct sk_buff *skb;
700 
701 		if (!ptr)
702 			break;
703 
704 		if (veth_is_xdp_frame(ptr)) {
705 			struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
706 
707 			bytes += frame->len;
708 			skb = veth_xdp_rcv_one(rq, frame, &xdp_xmit_one);
709 		} else {
710 			skb = ptr;
711 			bytes += skb->len;
712 			skb = veth_xdp_rcv_skb(rq, skb, &xdp_xmit_one);
713 		}
714 		*xdp_xmit |= xdp_xmit_one;
715 
716 		if (skb)
717 			napi_gro_receive(&rq->xdp_napi, skb);
718 		else if (!xdp_xmit_one)
719 			drops++;
720 
721 		done++;
722 	}
723 
724 	u64_stats_update_begin(&rq->stats.syncp);
725 	rq->stats.xdp_packets += done;
726 	rq->stats.xdp_bytes += bytes;
727 	rq->stats.xdp_drops += drops;
728 	u64_stats_update_end(&rq->stats.syncp);
729 
730 	return done;
731 }
732 
733 static int veth_poll(struct napi_struct *napi, int budget)
734 {
735 	struct veth_rq *rq =
736 		container_of(napi, struct veth_rq, xdp_napi);
737 	unsigned int xdp_xmit = 0;
738 	int done;
739 
740 	xdp_set_return_frame_no_direct();
741 	done = veth_xdp_rcv(rq, budget, &xdp_xmit);
742 
743 	if (done < budget && napi_complete_done(napi, done)) {
744 		/* Write rx_notify_masked before reading ptr_ring */
745 		smp_store_mb(rq->rx_notify_masked, false);
746 		if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
747 			rq->rx_notify_masked = true;
748 			napi_schedule(&rq->xdp_napi);
749 		}
750 	}
751 
752 	if (xdp_xmit & VETH_XDP_TX)
753 		veth_xdp_flush(rq->dev);
754 	if (xdp_xmit & VETH_XDP_REDIR)
755 		xdp_do_flush_map();
756 	xdp_clear_return_frame_no_direct();
757 
758 	return done;
759 }
760 
761 static int veth_napi_add(struct net_device *dev)
762 {
763 	struct veth_priv *priv = netdev_priv(dev);
764 	int err, i;
765 
766 	for (i = 0; i < dev->real_num_rx_queues; i++) {
767 		struct veth_rq *rq = &priv->rq[i];
768 
769 		err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
770 		if (err)
771 			goto err_xdp_ring;
772 	}
773 
774 	for (i = 0; i < dev->real_num_rx_queues; i++) {
775 		struct veth_rq *rq = &priv->rq[i];
776 
777 		netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
778 		napi_enable(&rq->xdp_napi);
779 	}
780 
781 	return 0;
782 err_xdp_ring:
783 	for (i--; i >= 0; i--)
784 		ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
785 
786 	return err;
787 }
788 
789 static void veth_napi_del(struct net_device *dev)
790 {
791 	struct veth_priv *priv = netdev_priv(dev);
792 	int i;
793 
794 	for (i = 0; i < dev->real_num_rx_queues; i++) {
795 		struct veth_rq *rq = &priv->rq[i];
796 
797 		napi_disable(&rq->xdp_napi);
798 		napi_hash_del(&rq->xdp_napi);
799 	}
800 	synchronize_net();
801 
802 	for (i = 0; i < dev->real_num_rx_queues; i++) {
803 		struct veth_rq *rq = &priv->rq[i];
804 
805 		netif_napi_del(&rq->xdp_napi);
806 		rq->rx_notify_masked = false;
807 		ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
808 	}
809 }
810 
811 static int veth_enable_xdp(struct net_device *dev)
812 {
813 	struct veth_priv *priv = netdev_priv(dev);
814 	int err, i;
815 
816 	if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
817 		for (i = 0; i < dev->real_num_rx_queues; i++) {
818 			struct veth_rq *rq = &priv->rq[i];
819 
820 			err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i);
821 			if (err < 0)
822 				goto err_rxq_reg;
823 
824 			err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
825 							 MEM_TYPE_PAGE_SHARED,
826 							 NULL);
827 			if (err < 0)
828 				goto err_reg_mem;
829 
830 			/* Save original mem info as it can be overwritten */
831 			rq->xdp_mem = rq->xdp_rxq.mem;
832 		}
833 
834 		err = veth_napi_add(dev);
835 		if (err)
836 			goto err_rxq_reg;
837 	}
838 
839 	for (i = 0; i < dev->real_num_rx_queues; i++)
840 		rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
841 
842 	return 0;
843 err_reg_mem:
844 	xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
845 err_rxq_reg:
846 	for (i--; i >= 0; i--)
847 		xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
848 
849 	return err;
850 }
851 
852 static void veth_disable_xdp(struct net_device *dev)
853 {
854 	struct veth_priv *priv = netdev_priv(dev);
855 	int i;
856 
857 	for (i = 0; i < dev->real_num_rx_queues; i++)
858 		rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
859 	veth_napi_del(dev);
860 	for (i = 0; i < dev->real_num_rx_queues; i++) {
861 		struct veth_rq *rq = &priv->rq[i];
862 
863 		rq->xdp_rxq.mem = rq->xdp_mem;
864 		xdp_rxq_info_unreg(&rq->xdp_rxq);
865 	}
866 }
867 
868 static int veth_open(struct net_device *dev)
869 {
870 	struct veth_priv *priv = netdev_priv(dev);
871 	struct net_device *peer = rtnl_dereference(priv->peer);
872 	int err;
873 
874 	if (!peer)
875 		return -ENOTCONN;
876 
877 	if (priv->_xdp_prog) {
878 		err = veth_enable_xdp(dev);
879 		if (err)
880 			return err;
881 	}
882 
883 	if (peer->flags & IFF_UP) {
884 		netif_carrier_on(dev);
885 		netif_carrier_on(peer);
886 	}
887 
888 	return 0;
889 }
890 
891 static int veth_close(struct net_device *dev)
892 {
893 	struct veth_priv *priv = netdev_priv(dev);
894 	struct net_device *peer = rtnl_dereference(priv->peer);
895 
896 	netif_carrier_off(dev);
897 	if (peer)
898 		netif_carrier_off(peer);
899 
900 	if (priv->_xdp_prog)
901 		veth_disable_xdp(dev);
902 
903 	return 0;
904 }
905 
906 static int is_valid_veth_mtu(int mtu)
907 {
908 	return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
909 }
910 
911 static int veth_alloc_queues(struct net_device *dev)
912 {
913 	struct veth_priv *priv = netdev_priv(dev);
914 	int i;
915 
916 	priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
917 	if (!priv->rq)
918 		return -ENOMEM;
919 
920 	for (i = 0; i < dev->num_rx_queues; i++) {
921 		priv->rq[i].dev = dev;
922 		u64_stats_init(&priv->rq[i].stats.syncp);
923 	}
924 
925 	return 0;
926 }
927 
928 static void veth_free_queues(struct net_device *dev)
929 {
930 	struct veth_priv *priv = netdev_priv(dev);
931 
932 	kfree(priv->rq);
933 }
934 
935 static int veth_dev_init(struct net_device *dev)
936 {
937 	int err;
938 
939 	dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
940 	if (!dev->lstats)
941 		return -ENOMEM;
942 
943 	err = veth_alloc_queues(dev);
944 	if (err) {
945 		free_percpu(dev->lstats);
946 		return err;
947 	}
948 
949 	return 0;
950 }
951 
952 static void veth_dev_free(struct net_device *dev)
953 {
954 	veth_free_queues(dev);
955 	free_percpu(dev->lstats);
956 }
957 
958 #ifdef CONFIG_NET_POLL_CONTROLLER
959 static void veth_poll_controller(struct net_device *dev)
960 {
961 	/* veth only receives frames when its peer sends one
962 	 * Since it has nothing to do with disabling irqs, we are guaranteed
963 	 * never to have pending data when we poll for it so
964 	 * there is nothing to do here.
965 	 *
966 	 * We need this though so netpoll recognizes us as an interface that
967 	 * supports polling, which enables bridge devices in virt setups to
968 	 * still use netconsole
969 	 */
970 }
971 #endif	/* CONFIG_NET_POLL_CONTROLLER */
972 
973 static int veth_get_iflink(const struct net_device *dev)
974 {
975 	struct veth_priv *priv = netdev_priv(dev);
976 	struct net_device *peer;
977 	int iflink;
978 
979 	rcu_read_lock();
980 	peer = rcu_dereference(priv->peer);
981 	iflink = peer ? peer->ifindex : 0;
982 	rcu_read_unlock();
983 
984 	return iflink;
985 }
986 
987 static netdev_features_t veth_fix_features(struct net_device *dev,
988 					   netdev_features_t features)
989 {
990 	struct veth_priv *priv = netdev_priv(dev);
991 	struct net_device *peer;
992 
993 	peer = rtnl_dereference(priv->peer);
994 	if (peer) {
995 		struct veth_priv *peer_priv = netdev_priv(peer);
996 
997 		if (peer_priv->_xdp_prog)
998 			features &= ~NETIF_F_GSO_SOFTWARE;
999 	}
1000 
1001 	return features;
1002 }
1003 
1004 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1005 {
1006 	struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1007 	struct net_device *peer;
1008 
1009 	if (new_hr < 0)
1010 		new_hr = 0;
1011 
1012 	rcu_read_lock();
1013 	peer = rcu_dereference(priv->peer);
1014 	if (unlikely(!peer))
1015 		goto out;
1016 
1017 	peer_priv = netdev_priv(peer);
1018 	priv->requested_headroom = new_hr;
1019 	new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1020 	dev->needed_headroom = new_hr;
1021 	peer->needed_headroom = new_hr;
1022 
1023 out:
1024 	rcu_read_unlock();
1025 }
1026 
1027 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1028 			struct netlink_ext_ack *extack)
1029 {
1030 	struct veth_priv *priv = netdev_priv(dev);
1031 	struct bpf_prog *old_prog;
1032 	struct net_device *peer;
1033 	unsigned int max_mtu;
1034 	int err;
1035 
1036 	old_prog = priv->_xdp_prog;
1037 	priv->_xdp_prog = prog;
1038 	peer = rtnl_dereference(priv->peer);
1039 
1040 	if (prog) {
1041 		if (!peer) {
1042 			NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1043 			err = -ENOTCONN;
1044 			goto err;
1045 		}
1046 
1047 		max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
1048 			  peer->hard_header_len -
1049 			  SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1050 		if (peer->mtu > max_mtu) {
1051 			NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1052 			err = -ERANGE;
1053 			goto err;
1054 		}
1055 
1056 		if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1057 			NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1058 			err = -ENOSPC;
1059 			goto err;
1060 		}
1061 
1062 		if (dev->flags & IFF_UP) {
1063 			err = veth_enable_xdp(dev);
1064 			if (err) {
1065 				NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1066 				goto err;
1067 			}
1068 		}
1069 
1070 		if (!old_prog) {
1071 			peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1072 			peer->max_mtu = max_mtu;
1073 		}
1074 	}
1075 
1076 	if (old_prog) {
1077 		if (!prog) {
1078 			if (dev->flags & IFF_UP)
1079 				veth_disable_xdp(dev);
1080 
1081 			if (peer) {
1082 				peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1083 				peer->max_mtu = ETH_MAX_MTU;
1084 			}
1085 		}
1086 		bpf_prog_put(old_prog);
1087 	}
1088 
1089 	if ((!!old_prog ^ !!prog) && peer)
1090 		netdev_update_features(peer);
1091 
1092 	return 0;
1093 err:
1094 	priv->_xdp_prog = old_prog;
1095 
1096 	return err;
1097 }
1098 
1099 static u32 veth_xdp_query(struct net_device *dev)
1100 {
1101 	struct veth_priv *priv = netdev_priv(dev);
1102 	const struct bpf_prog *xdp_prog;
1103 
1104 	xdp_prog = priv->_xdp_prog;
1105 	if (xdp_prog)
1106 		return xdp_prog->aux->id;
1107 
1108 	return 0;
1109 }
1110 
1111 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1112 {
1113 	switch (xdp->command) {
1114 	case XDP_SETUP_PROG:
1115 		return veth_xdp_set(dev, xdp->prog, xdp->extack);
1116 	case XDP_QUERY_PROG:
1117 		xdp->prog_id = veth_xdp_query(dev);
1118 		return 0;
1119 	default:
1120 		return -EINVAL;
1121 	}
1122 }
1123 
1124 static const struct net_device_ops veth_netdev_ops = {
1125 	.ndo_init            = veth_dev_init,
1126 	.ndo_open            = veth_open,
1127 	.ndo_stop            = veth_close,
1128 	.ndo_start_xmit      = veth_xmit,
1129 	.ndo_get_stats64     = veth_get_stats64,
1130 	.ndo_set_rx_mode     = veth_set_multicast_list,
1131 	.ndo_set_mac_address = eth_mac_addr,
1132 #ifdef CONFIG_NET_POLL_CONTROLLER
1133 	.ndo_poll_controller	= veth_poll_controller,
1134 #endif
1135 	.ndo_get_iflink		= veth_get_iflink,
1136 	.ndo_fix_features	= veth_fix_features,
1137 	.ndo_features_check	= passthru_features_check,
1138 	.ndo_set_rx_headroom	= veth_set_rx_headroom,
1139 	.ndo_bpf		= veth_xdp,
1140 	.ndo_xdp_xmit		= veth_xdp_xmit,
1141 };
1142 
1143 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1144 		       NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1145 		       NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1146 		       NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1147 		       NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1148 
1149 static void veth_setup(struct net_device *dev)
1150 {
1151 	ether_setup(dev);
1152 
1153 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1154 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1155 	dev->priv_flags |= IFF_NO_QUEUE;
1156 	dev->priv_flags |= IFF_PHONY_HEADROOM;
1157 
1158 	dev->netdev_ops = &veth_netdev_ops;
1159 	dev->ethtool_ops = &veth_ethtool_ops;
1160 	dev->features |= NETIF_F_LLTX;
1161 	dev->features |= VETH_FEATURES;
1162 	dev->vlan_features = dev->features &
1163 			     ~(NETIF_F_HW_VLAN_CTAG_TX |
1164 			       NETIF_F_HW_VLAN_STAG_TX |
1165 			       NETIF_F_HW_VLAN_CTAG_RX |
1166 			       NETIF_F_HW_VLAN_STAG_RX);
1167 	dev->needs_free_netdev = true;
1168 	dev->priv_destructor = veth_dev_free;
1169 	dev->max_mtu = ETH_MAX_MTU;
1170 
1171 	dev->hw_features = VETH_FEATURES;
1172 	dev->hw_enc_features = VETH_FEATURES;
1173 	dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1174 }
1175 
1176 /*
1177  * netlink interface
1178  */
1179 
1180 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1181 			 struct netlink_ext_ack *extack)
1182 {
1183 	if (tb[IFLA_ADDRESS]) {
1184 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1185 			return -EINVAL;
1186 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1187 			return -EADDRNOTAVAIL;
1188 	}
1189 	if (tb[IFLA_MTU]) {
1190 		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1191 			return -EINVAL;
1192 	}
1193 	return 0;
1194 }
1195 
1196 static struct rtnl_link_ops veth_link_ops;
1197 
1198 static int veth_newlink(struct net *src_net, struct net_device *dev,
1199 			struct nlattr *tb[], struct nlattr *data[],
1200 			struct netlink_ext_ack *extack)
1201 {
1202 	int err;
1203 	struct net_device *peer;
1204 	struct veth_priv *priv;
1205 	char ifname[IFNAMSIZ];
1206 	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1207 	unsigned char name_assign_type;
1208 	struct ifinfomsg *ifmp;
1209 	struct net *net;
1210 
1211 	/*
1212 	 * create and register peer first
1213 	 */
1214 	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1215 		struct nlattr *nla_peer;
1216 
1217 		nla_peer = data[VETH_INFO_PEER];
1218 		ifmp = nla_data(nla_peer);
1219 		err = rtnl_nla_parse_ifla(peer_tb,
1220 					  nla_data(nla_peer) + sizeof(struct ifinfomsg),
1221 					  nla_len(nla_peer) - sizeof(struct ifinfomsg),
1222 					  NULL);
1223 		if (err < 0)
1224 			return err;
1225 
1226 		err = veth_validate(peer_tb, NULL, extack);
1227 		if (err < 0)
1228 			return err;
1229 
1230 		tbp = peer_tb;
1231 	} else {
1232 		ifmp = NULL;
1233 		tbp = tb;
1234 	}
1235 
1236 	if (ifmp && tbp[IFLA_IFNAME]) {
1237 		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1238 		name_assign_type = NET_NAME_USER;
1239 	} else {
1240 		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1241 		name_assign_type = NET_NAME_ENUM;
1242 	}
1243 
1244 	net = rtnl_link_get_net(src_net, tbp);
1245 	if (IS_ERR(net))
1246 		return PTR_ERR(net);
1247 
1248 	peer = rtnl_create_link(net, ifname, name_assign_type,
1249 				&veth_link_ops, tbp, extack);
1250 	if (IS_ERR(peer)) {
1251 		put_net(net);
1252 		return PTR_ERR(peer);
1253 	}
1254 
1255 	if (!ifmp || !tbp[IFLA_ADDRESS])
1256 		eth_hw_addr_random(peer);
1257 
1258 	if (ifmp && (dev->ifindex != 0))
1259 		peer->ifindex = ifmp->ifi_index;
1260 
1261 	peer->gso_max_size = dev->gso_max_size;
1262 	peer->gso_max_segs = dev->gso_max_segs;
1263 
1264 	err = register_netdevice(peer);
1265 	put_net(net);
1266 	net = NULL;
1267 	if (err < 0)
1268 		goto err_register_peer;
1269 
1270 	netif_carrier_off(peer);
1271 
1272 	err = rtnl_configure_link(peer, ifmp);
1273 	if (err < 0)
1274 		goto err_configure_peer;
1275 
1276 	/*
1277 	 * register dev last
1278 	 *
1279 	 * note, that since we've registered new device the dev's name
1280 	 * should be re-allocated
1281 	 */
1282 
1283 	if (tb[IFLA_ADDRESS] == NULL)
1284 		eth_hw_addr_random(dev);
1285 
1286 	if (tb[IFLA_IFNAME])
1287 		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1288 	else
1289 		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1290 
1291 	err = register_netdevice(dev);
1292 	if (err < 0)
1293 		goto err_register_dev;
1294 
1295 	netif_carrier_off(dev);
1296 
1297 	/*
1298 	 * tie the deviced together
1299 	 */
1300 
1301 	priv = netdev_priv(dev);
1302 	rcu_assign_pointer(priv->peer, peer);
1303 
1304 	priv = netdev_priv(peer);
1305 	rcu_assign_pointer(priv->peer, dev);
1306 
1307 	return 0;
1308 
1309 err_register_dev:
1310 	/* nothing to do */
1311 err_configure_peer:
1312 	unregister_netdevice(peer);
1313 	return err;
1314 
1315 err_register_peer:
1316 	free_netdev(peer);
1317 	return err;
1318 }
1319 
1320 static void veth_dellink(struct net_device *dev, struct list_head *head)
1321 {
1322 	struct veth_priv *priv;
1323 	struct net_device *peer;
1324 
1325 	priv = netdev_priv(dev);
1326 	peer = rtnl_dereference(priv->peer);
1327 
1328 	/* Note : dellink() is called from default_device_exit_batch(),
1329 	 * before a rcu_synchronize() point. The devices are guaranteed
1330 	 * not being freed before one RCU grace period.
1331 	 */
1332 	RCU_INIT_POINTER(priv->peer, NULL);
1333 	unregister_netdevice_queue(dev, head);
1334 
1335 	if (peer) {
1336 		priv = netdev_priv(peer);
1337 		RCU_INIT_POINTER(priv->peer, NULL);
1338 		unregister_netdevice_queue(peer, head);
1339 	}
1340 }
1341 
1342 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1343 	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },
1344 };
1345 
1346 static struct net *veth_get_link_net(const struct net_device *dev)
1347 {
1348 	struct veth_priv *priv = netdev_priv(dev);
1349 	struct net_device *peer = rtnl_dereference(priv->peer);
1350 
1351 	return peer ? dev_net(peer) : dev_net(dev);
1352 }
1353 
1354 static struct rtnl_link_ops veth_link_ops = {
1355 	.kind		= DRV_NAME,
1356 	.priv_size	= sizeof(struct veth_priv),
1357 	.setup		= veth_setup,
1358 	.validate	= veth_validate,
1359 	.newlink	= veth_newlink,
1360 	.dellink	= veth_dellink,
1361 	.policy		= veth_policy,
1362 	.maxtype	= VETH_INFO_MAX,
1363 	.get_link_net	= veth_get_link_net,
1364 };
1365 
1366 /*
1367  * init/fini
1368  */
1369 
1370 static __init int veth_init(void)
1371 {
1372 	return rtnl_link_register(&veth_link_ops);
1373 }
1374 
1375 static __exit void veth_exit(void)
1376 {
1377 	rtnl_link_unregister(&veth_link_ops);
1378 }
1379 
1380 module_init(veth_init);
1381 module_exit(veth_exit);
1382 
1383 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1384 MODULE_LICENSE("GPL v2");
1385 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
1386