xref: /openbmc/linux/drivers/net/ipvlan/ipvlan_core.c (revision 8730046c)
1 /* Copyright (c) 2014 Mahesh Bandewar <maheshb@google.com>
2  *
3  * This program is free software; you can redistribute it and/or
4  * modify it under the terms of the GNU General Public License as
5  * published by the Free Software Foundation; either version 2 of
6  * the License, or (at your option) any later version.
7  *
8  */
9 
10 #include "ipvlan.h"
11 
12 static u32 ipvlan_jhash_secret __read_mostly;
13 
14 void ipvlan_init_secret(void)
15 {
16 	net_get_random_once(&ipvlan_jhash_secret, sizeof(ipvlan_jhash_secret));
17 }
18 
19 static void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
20 			    unsigned int len, bool success, bool mcast)
21 {
22 	if (!ipvlan)
23 		return;
24 
25 	if (likely(success)) {
26 		struct ipvl_pcpu_stats *pcptr;
27 
28 		pcptr = this_cpu_ptr(ipvlan->pcpu_stats);
29 		u64_stats_update_begin(&pcptr->syncp);
30 		pcptr->rx_pkts++;
31 		pcptr->rx_bytes += len;
32 		if (mcast)
33 			pcptr->rx_mcast++;
34 		u64_stats_update_end(&pcptr->syncp);
35 	} else {
36 		this_cpu_inc(ipvlan->pcpu_stats->rx_errs);
37 	}
38 }
39 
40 static u8 ipvlan_get_v6_hash(const void *iaddr)
41 {
42 	const struct in6_addr *ip6_addr = iaddr;
43 
44 	return __ipv6_addr_jhash(ip6_addr, ipvlan_jhash_secret) &
45 	       IPVLAN_HASH_MASK;
46 }
47 
48 static u8 ipvlan_get_v4_hash(const void *iaddr)
49 {
50 	const struct in_addr *ip4_addr = iaddr;
51 
52 	return jhash_1word(ip4_addr->s_addr, ipvlan_jhash_secret) &
53 	       IPVLAN_HASH_MASK;
54 }
55 
56 static struct ipvl_addr *ipvlan_ht_addr_lookup(const struct ipvl_port *port,
57 					       const void *iaddr, bool is_v6)
58 {
59 	struct ipvl_addr *addr;
60 	u8 hash;
61 
62 	hash = is_v6 ? ipvlan_get_v6_hash(iaddr) :
63 	       ipvlan_get_v4_hash(iaddr);
64 	hlist_for_each_entry_rcu(addr, &port->hlhead[hash], hlnode) {
65 		if (is_v6 && addr->atype == IPVL_IPV6 &&
66 		    ipv6_addr_equal(&addr->ip6addr, iaddr))
67 			return addr;
68 		else if (!is_v6 && addr->atype == IPVL_IPV4 &&
69 			 addr->ip4addr.s_addr ==
70 				((struct in_addr *)iaddr)->s_addr)
71 			return addr;
72 	}
73 	return NULL;
74 }
75 
76 void ipvlan_ht_addr_add(struct ipvl_dev *ipvlan, struct ipvl_addr *addr)
77 {
78 	struct ipvl_port *port = ipvlan->port;
79 	u8 hash;
80 
81 	hash = (addr->atype == IPVL_IPV6) ?
82 	       ipvlan_get_v6_hash(&addr->ip6addr) :
83 	       ipvlan_get_v4_hash(&addr->ip4addr);
84 	if (hlist_unhashed(&addr->hlnode))
85 		hlist_add_head_rcu(&addr->hlnode, &port->hlhead[hash]);
86 }
87 
88 void ipvlan_ht_addr_del(struct ipvl_addr *addr)
89 {
90 	hlist_del_init_rcu(&addr->hlnode);
91 }
92 
93 struct ipvl_addr *ipvlan_find_addr(const struct ipvl_dev *ipvlan,
94 				   const void *iaddr, bool is_v6)
95 {
96 	struct ipvl_addr *addr;
97 
98 	list_for_each_entry(addr, &ipvlan->addrs, anode) {
99 		if ((is_v6 && addr->atype == IPVL_IPV6 &&
100 		    ipv6_addr_equal(&addr->ip6addr, iaddr)) ||
101 		    (!is_v6 && addr->atype == IPVL_IPV4 &&
102 		    addr->ip4addr.s_addr == ((struct in_addr *)iaddr)->s_addr))
103 			return addr;
104 	}
105 	return NULL;
106 }
107 
108 bool ipvlan_addr_busy(struct ipvl_port *port, void *iaddr, bool is_v6)
109 {
110 	struct ipvl_dev *ipvlan;
111 
112 	ASSERT_RTNL();
113 
114 	list_for_each_entry(ipvlan, &port->ipvlans, pnode) {
115 		if (ipvlan_find_addr(ipvlan, iaddr, is_v6))
116 			return true;
117 	}
118 	return false;
119 }
120 
121 static void *ipvlan_get_L3_hdr(struct sk_buff *skb, int *type)
122 {
123 	void *lyr3h = NULL;
124 
125 	switch (skb->protocol) {
126 	case htons(ETH_P_ARP): {
127 		struct arphdr *arph;
128 
129 		if (unlikely(!pskb_may_pull(skb, sizeof(*arph))))
130 			return NULL;
131 
132 		arph = arp_hdr(skb);
133 		*type = IPVL_ARP;
134 		lyr3h = arph;
135 		break;
136 	}
137 	case htons(ETH_P_IP): {
138 		u32 pktlen;
139 		struct iphdr *ip4h;
140 
141 		if (unlikely(!pskb_may_pull(skb, sizeof(*ip4h))))
142 			return NULL;
143 
144 		ip4h = ip_hdr(skb);
145 		pktlen = ntohs(ip4h->tot_len);
146 		if (ip4h->ihl < 5 || ip4h->version != 4)
147 			return NULL;
148 		if (skb->len < pktlen || pktlen < (ip4h->ihl * 4))
149 			return NULL;
150 
151 		*type = IPVL_IPV4;
152 		lyr3h = ip4h;
153 		break;
154 	}
155 	case htons(ETH_P_IPV6): {
156 		struct ipv6hdr *ip6h;
157 
158 		if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h))))
159 			return NULL;
160 
161 		ip6h = ipv6_hdr(skb);
162 		if (ip6h->version != 6)
163 			return NULL;
164 
165 		*type = IPVL_IPV6;
166 		lyr3h = ip6h;
167 		/* Only Neighbour Solicitation pkts need different treatment */
168 		if (ipv6_addr_any(&ip6h->saddr) &&
169 		    ip6h->nexthdr == NEXTHDR_ICMP) {
170 			*type = IPVL_ICMPV6;
171 			lyr3h = ip6h + 1;
172 		}
173 		break;
174 	}
175 	default:
176 		return NULL;
177 	}
178 
179 	return lyr3h;
180 }
181 
182 unsigned int ipvlan_mac_hash(const unsigned char *addr)
183 {
184 	u32 hash = jhash_1word(__get_unaligned_cpu32(addr+2),
185 			       ipvlan_jhash_secret);
186 
187 	return hash & IPVLAN_MAC_FILTER_MASK;
188 }
189 
190 void ipvlan_process_multicast(struct work_struct *work)
191 {
192 	struct ipvl_port *port = container_of(work, struct ipvl_port, wq);
193 	struct ethhdr *ethh;
194 	struct ipvl_dev *ipvlan;
195 	struct sk_buff *skb, *nskb;
196 	struct sk_buff_head list;
197 	unsigned int len;
198 	unsigned int mac_hash;
199 	int ret;
200 	u8 pkt_type;
201 	bool tx_pkt;
202 
203 	__skb_queue_head_init(&list);
204 
205 	spin_lock_bh(&port->backlog.lock);
206 	skb_queue_splice_tail_init(&port->backlog, &list);
207 	spin_unlock_bh(&port->backlog.lock);
208 
209 	while ((skb = __skb_dequeue(&list)) != NULL) {
210 		struct net_device *dev = skb->dev;
211 		bool consumed = false;
212 
213 		ethh = eth_hdr(skb);
214 		tx_pkt = IPVL_SKB_CB(skb)->tx_pkt;
215 		mac_hash = ipvlan_mac_hash(ethh->h_dest);
216 
217 		if (ether_addr_equal(ethh->h_dest, port->dev->broadcast))
218 			pkt_type = PACKET_BROADCAST;
219 		else
220 			pkt_type = PACKET_MULTICAST;
221 
222 		rcu_read_lock();
223 		list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
224 			if (tx_pkt && (ipvlan->dev == skb->dev))
225 				continue;
226 			if (!test_bit(mac_hash, ipvlan->mac_filters))
227 				continue;
228 			if (!(ipvlan->dev->flags & IFF_UP))
229 				continue;
230 			ret = NET_RX_DROP;
231 			len = skb->len + ETH_HLEN;
232 			nskb = skb_clone(skb, GFP_ATOMIC);
233 			local_bh_disable();
234 			if (nskb) {
235 				consumed = true;
236 				nskb->pkt_type = pkt_type;
237 				nskb->dev = ipvlan->dev;
238 				if (tx_pkt)
239 					ret = dev_forward_skb(ipvlan->dev, nskb);
240 				else
241 					ret = netif_rx(nskb);
242 			}
243 			ipvlan_count_rx(ipvlan, len, ret == NET_RX_SUCCESS, true);
244 			local_bh_enable();
245 		}
246 		rcu_read_unlock();
247 
248 		if (tx_pkt) {
249 			/* If the packet originated here, send it out. */
250 			skb->dev = port->dev;
251 			skb->pkt_type = pkt_type;
252 			dev_queue_xmit(skb);
253 		} else {
254 			if (consumed)
255 				consume_skb(skb);
256 			else
257 				kfree_skb(skb);
258 		}
259 		if (dev)
260 			dev_put(dev);
261 	}
262 }
263 
264 static void ipvlan_skb_crossing_ns(struct sk_buff *skb, struct net_device *dev)
265 {
266 	bool xnet = true;
267 
268 	if (dev)
269 		xnet = !net_eq(dev_net(skb->dev), dev_net(dev));
270 
271 	skb_scrub_packet(skb, xnet);
272 	if (dev)
273 		skb->dev = dev;
274 }
275 
276 static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff **pskb,
277 			    bool local)
278 {
279 	struct ipvl_dev *ipvlan = addr->master;
280 	struct net_device *dev = ipvlan->dev;
281 	unsigned int len;
282 	rx_handler_result_t ret = RX_HANDLER_CONSUMED;
283 	bool success = false;
284 	struct sk_buff *skb = *pskb;
285 
286 	len = skb->len + ETH_HLEN;
287 	/* Only packets exchanged between two local slaves need to have
288 	 * device-up check as well as skb-share check.
289 	 */
290 	if (local) {
291 		if (unlikely(!(dev->flags & IFF_UP))) {
292 			kfree_skb(skb);
293 			goto out;
294 		}
295 
296 		skb = skb_share_check(skb, GFP_ATOMIC);
297 		if (!skb)
298 			goto out;
299 
300 		*pskb = skb;
301 	}
302 	ipvlan_skb_crossing_ns(skb, dev);
303 
304 	if (local) {
305 		skb->pkt_type = PACKET_HOST;
306 		if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)
307 			success = true;
308 	} else {
309 		ret = RX_HANDLER_ANOTHER;
310 		success = true;
311 	}
312 
313 out:
314 	ipvlan_count_rx(ipvlan, len, success, false);
315 	return ret;
316 }
317 
318 static struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port,
319 					    void *lyr3h, int addr_type,
320 					    bool use_dest)
321 {
322 	struct ipvl_addr *addr = NULL;
323 
324 	if (addr_type == IPVL_IPV6) {
325 		struct ipv6hdr *ip6h;
326 		struct in6_addr *i6addr;
327 
328 		ip6h = (struct ipv6hdr *)lyr3h;
329 		i6addr = use_dest ? &ip6h->daddr : &ip6h->saddr;
330 		addr = ipvlan_ht_addr_lookup(port, i6addr, true);
331 	} else if (addr_type == IPVL_ICMPV6) {
332 		struct nd_msg *ndmh;
333 		struct in6_addr *i6addr;
334 
335 		/* Make sure that the NeighborSolicitation ICMPv6 packets
336 		 * are handled to avoid DAD issue.
337 		 */
338 		ndmh = (struct nd_msg *)lyr3h;
339 		if (ndmh->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
340 			i6addr = &ndmh->target;
341 			addr = ipvlan_ht_addr_lookup(port, i6addr, true);
342 		}
343 	} else if (addr_type == IPVL_IPV4) {
344 		struct iphdr *ip4h;
345 		__be32 *i4addr;
346 
347 		ip4h = (struct iphdr *)lyr3h;
348 		i4addr = use_dest ? &ip4h->daddr : &ip4h->saddr;
349 		addr = ipvlan_ht_addr_lookup(port, i4addr, false);
350 	} else if (addr_type == IPVL_ARP) {
351 		struct arphdr *arph;
352 		unsigned char *arp_ptr;
353 		__be32 dip;
354 
355 		arph = (struct arphdr *)lyr3h;
356 		arp_ptr = (unsigned char *)(arph + 1);
357 		if (use_dest)
358 			arp_ptr += (2 * port->dev->addr_len) + 4;
359 		else
360 			arp_ptr += port->dev->addr_len;
361 
362 		memcpy(&dip, arp_ptr, 4);
363 		addr = ipvlan_ht_addr_lookup(port, &dip, false);
364 	}
365 
366 	return addr;
367 }
368 
369 static int ipvlan_process_v4_outbound(struct sk_buff *skb)
370 {
371 	const struct iphdr *ip4h = ip_hdr(skb);
372 	struct net_device *dev = skb->dev;
373 	struct net *net = dev_net(dev);
374 	struct rtable *rt;
375 	int err, ret = NET_XMIT_DROP;
376 	struct flowi4 fl4 = {
377 		.flowi4_oif = dev->ifindex,
378 		.flowi4_tos = RT_TOS(ip4h->tos),
379 		.flowi4_flags = FLOWI_FLAG_ANYSRC,
380 		.daddr = ip4h->daddr,
381 		.saddr = ip4h->saddr,
382 	};
383 
384 	rt = ip_route_output_flow(net, &fl4, NULL);
385 	if (IS_ERR(rt))
386 		goto err;
387 
388 	if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
389 		ip_rt_put(rt);
390 		goto err;
391 	}
392 	skb_dst_set(skb, &rt->dst);
393 	err = ip_local_out(net, skb->sk, skb);
394 	if (unlikely(net_xmit_eval(err)))
395 		dev->stats.tx_errors++;
396 	else
397 		ret = NET_XMIT_SUCCESS;
398 	goto out;
399 err:
400 	dev->stats.tx_errors++;
401 	kfree_skb(skb);
402 out:
403 	return ret;
404 }
405 
406 static int ipvlan_process_v6_outbound(struct sk_buff *skb)
407 {
408 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
409 	struct net_device *dev = skb->dev;
410 	struct net *net = dev_net(dev);
411 	struct dst_entry *dst;
412 	int err, ret = NET_XMIT_DROP;
413 	struct flowi6 fl6 = {
414 		.flowi6_iif = dev->ifindex,
415 		.daddr = ip6h->daddr,
416 		.saddr = ip6h->saddr,
417 		.flowi6_flags = FLOWI_FLAG_ANYSRC,
418 		.flowlabel = ip6_flowinfo(ip6h),
419 		.flowi6_mark = skb->mark,
420 		.flowi6_proto = ip6h->nexthdr,
421 	};
422 
423 	dst = ip6_route_output(net, NULL, &fl6);
424 	if (dst->error) {
425 		ret = dst->error;
426 		dst_release(dst);
427 		goto err;
428 	}
429 	skb_dst_set(skb, dst);
430 	err = ip6_local_out(net, skb->sk, skb);
431 	if (unlikely(net_xmit_eval(err)))
432 		dev->stats.tx_errors++;
433 	else
434 		ret = NET_XMIT_SUCCESS;
435 	goto out;
436 err:
437 	dev->stats.tx_errors++;
438 	kfree_skb(skb);
439 out:
440 	return ret;
441 }
442 
443 static int ipvlan_process_outbound(struct sk_buff *skb)
444 {
445 	struct ethhdr *ethh = eth_hdr(skb);
446 	int ret = NET_XMIT_DROP;
447 
448 	/* In this mode we dont care about multicast and broadcast traffic */
449 	if (is_multicast_ether_addr(ethh->h_dest)) {
450 		pr_warn_ratelimited("Dropped {multi|broad}cast of type= [%x]\n",
451 				    ntohs(skb->protocol));
452 		kfree_skb(skb);
453 		goto out;
454 	}
455 
456 	/* The ipvlan is a pseudo-L2 device, so the packets that we receive
457 	 * will have L2; which need to discarded and processed further
458 	 * in the net-ns of the main-device.
459 	 */
460 	if (skb_mac_header_was_set(skb)) {
461 		skb_pull(skb, sizeof(*ethh));
462 		skb->mac_header = (typeof(skb->mac_header))~0U;
463 		skb_reset_network_header(skb);
464 	}
465 
466 	if (skb->protocol == htons(ETH_P_IPV6))
467 		ret = ipvlan_process_v6_outbound(skb);
468 	else if (skb->protocol == htons(ETH_P_IP))
469 		ret = ipvlan_process_v4_outbound(skb);
470 	else {
471 		pr_warn_ratelimited("Dropped outbound packet type=%x\n",
472 				    ntohs(skb->protocol));
473 		kfree_skb(skb);
474 	}
475 out:
476 	return ret;
477 }
478 
479 static void ipvlan_multicast_enqueue(struct ipvl_port *port,
480 				     struct sk_buff *skb, bool tx_pkt)
481 {
482 	if (skb->protocol == htons(ETH_P_PAUSE)) {
483 		kfree_skb(skb);
484 		return;
485 	}
486 
487 	/* Record that the deferred packet is from TX or RX path. By
488 	 * looking at mac-addresses on packet will lead to erronus decisions.
489 	 * (This would be true for a loopback-mode on master device or a
490 	 * hair-pin mode of the switch.)
491 	 */
492 	IPVL_SKB_CB(skb)->tx_pkt = tx_pkt;
493 
494 	spin_lock(&port->backlog.lock);
495 	if (skb_queue_len(&port->backlog) < IPVLAN_QBACKLOG_LIMIT) {
496 		if (skb->dev)
497 			dev_hold(skb->dev);
498 		__skb_queue_tail(&port->backlog, skb);
499 		spin_unlock(&port->backlog.lock);
500 		schedule_work(&port->wq);
501 	} else {
502 		spin_unlock(&port->backlog.lock);
503 		atomic_long_inc(&skb->dev->rx_dropped);
504 		kfree_skb(skb);
505 	}
506 }
507 
508 static int ipvlan_xmit_mode_l3(struct sk_buff *skb, struct net_device *dev)
509 {
510 	const struct ipvl_dev *ipvlan = netdev_priv(dev);
511 	void *lyr3h;
512 	struct ipvl_addr *addr;
513 	int addr_type;
514 
515 	lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
516 	if (!lyr3h)
517 		goto out;
518 
519 	addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
520 	if (addr)
521 		return ipvlan_rcv_frame(addr, &skb, true);
522 
523 out:
524 	ipvlan_skb_crossing_ns(skb, ipvlan->phy_dev);
525 	return ipvlan_process_outbound(skb);
526 }
527 
528 static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
529 {
530 	const struct ipvl_dev *ipvlan = netdev_priv(dev);
531 	struct ethhdr *eth = eth_hdr(skb);
532 	struct ipvl_addr *addr;
533 	void *lyr3h;
534 	int addr_type;
535 
536 	if (ether_addr_equal(eth->h_dest, eth->h_source)) {
537 		lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
538 		if (lyr3h) {
539 			addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
540 			if (addr)
541 				return ipvlan_rcv_frame(addr, &skb, true);
542 		}
543 		skb = skb_share_check(skb, GFP_ATOMIC);
544 		if (!skb)
545 			return NET_XMIT_DROP;
546 
547 		/* Packet definitely does not belong to any of the
548 		 * virtual devices, but the dest is local. So forward
549 		 * the skb for the main-dev. At the RX side we just return
550 		 * RX_PASS for it to be processed further on the stack.
551 		 */
552 		return dev_forward_skb(ipvlan->phy_dev, skb);
553 
554 	} else if (is_multicast_ether_addr(eth->h_dest)) {
555 		ipvlan_skb_crossing_ns(skb, NULL);
556 		ipvlan_multicast_enqueue(ipvlan->port, skb, true);
557 		return NET_XMIT_SUCCESS;
558 	}
559 
560 	ipvlan_skb_crossing_ns(skb, ipvlan->phy_dev);
561 	return dev_queue_xmit(skb);
562 }
563 
564 int ipvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
565 {
566 	struct ipvl_dev *ipvlan = netdev_priv(dev);
567 	struct ipvl_port *port = ipvlan_port_get_rcu_bh(ipvlan->phy_dev);
568 
569 	if (!port)
570 		goto out;
571 
572 	if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
573 		goto out;
574 
575 	switch(port->mode) {
576 	case IPVLAN_MODE_L2:
577 		return ipvlan_xmit_mode_l2(skb, dev);
578 	case IPVLAN_MODE_L3:
579 	case IPVLAN_MODE_L3S:
580 		return ipvlan_xmit_mode_l3(skb, dev);
581 	}
582 
583 	/* Should not reach here */
584 	WARN_ONCE(true, "ipvlan_queue_xmit() called for mode = [%hx]\n",
585 			  port->mode);
586 out:
587 	kfree_skb(skb);
588 	return NET_XMIT_DROP;
589 }
590 
591 static bool ipvlan_external_frame(struct sk_buff *skb, struct ipvl_port *port)
592 {
593 	struct ethhdr *eth = eth_hdr(skb);
594 	struct ipvl_addr *addr;
595 	void *lyr3h;
596 	int addr_type;
597 
598 	if (ether_addr_equal(eth->h_source, skb->dev->dev_addr)) {
599 		lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
600 		if (!lyr3h)
601 			return true;
602 
603 		addr = ipvlan_addr_lookup(port, lyr3h, addr_type, false);
604 		if (addr)
605 			return false;
606 	}
607 
608 	return true;
609 }
610 
611 static rx_handler_result_t ipvlan_handle_mode_l3(struct sk_buff **pskb,
612 						 struct ipvl_port *port)
613 {
614 	void *lyr3h;
615 	int addr_type;
616 	struct ipvl_addr *addr;
617 	struct sk_buff *skb = *pskb;
618 	rx_handler_result_t ret = RX_HANDLER_PASS;
619 
620 	lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
621 	if (!lyr3h)
622 		goto out;
623 
624 	addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
625 	if (addr)
626 		ret = ipvlan_rcv_frame(addr, pskb, false);
627 
628 out:
629 	return ret;
630 }
631 
632 static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
633 						 struct ipvl_port *port)
634 {
635 	struct sk_buff *skb = *pskb;
636 	struct ethhdr *eth = eth_hdr(skb);
637 	rx_handler_result_t ret = RX_HANDLER_PASS;
638 	void *lyr3h;
639 	int addr_type;
640 
641 	if (is_multicast_ether_addr(eth->h_dest)) {
642 		if (ipvlan_external_frame(skb, port)) {
643 			struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
644 
645 			/* External frames are queued for device local
646 			 * distribution, but a copy is given to master
647 			 * straight away to avoid sending duplicates later
648 			 * when work-queue processes this frame. This is
649 			 * achieved by returning RX_HANDLER_PASS.
650 			 */
651 			if (nskb) {
652 				ipvlan_skb_crossing_ns(nskb, NULL);
653 				ipvlan_multicast_enqueue(port, nskb, false);
654 			}
655 		}
656 	} else {
657 		struct ipvl_addr *addr;
658 
659 		lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
660 		if (!lyr3h)
661 			return ret;
662 
663 		addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
664 		if (addr)
665 			ret = ipvlan_rcv_frame(addr, pskb, false);
666 	}
667 
668 	return ret;
669 }
670 
671 rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
672 {
673 	struct sk_buff *skb = *pskb;
674 	struct ipvl_port *port = ipvlan_port_get_rcu(skb->dev);
675 
676 	if (!port)
677 		return RX_HANDLER_PASS;
678 
679 	switch (port->mode) {
680 	case IPVLAN_MODE_L2:
681 		return ipvlan_handle_mode_l2(pskb, port);
682 	case IPVLAN_MODE_L3:
683 		return ipvlan_handle_mode_l3(pskb, port);
684 	case IPVLAN_MODE_L3S:
685 		return RX_HANDLER_PASS;
686 	}
687 
688 	/* Should not reach here */
689 	WARN_ONCE(true, "ipvlan_handle_frame() called for mode = [%hx]\n",
690 			  port->mode);
691 	kfree_skb(skb);
692 	return RX_HANDLER_CONSUMED;
693 }
694 
695 static struct ipvl_addr *ipvlan_skb_to_addr(struct sk_buff *skb,
696 					    struct net_device *dev)
697 {
698 	struct ipvl_addr *addr = NULL;
699 	struct ipvl_port *port;
700 	void *lyr3h;
701 	int addr_type;
702 
703 	if (!dev || !netif_is_ipvlan_port(dev))
704 		goto out;
705 
706 	port = ipvlan_port_get_rcu(dev);
707 	if (!port || port->mode != IPVLAN_MODE_L3S)
708 		goto out;
709 
710 	lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
711 	if (!lyr3h)
712 		goto out;
713 
714 	addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
715 out:
716 	return addr;
717 }
718 
719 struct sk_buff *ipvlan_l3_rcv(struct net_device *dev, struct sk_buff *skb,
720 			      u16 proto)
721 {
722 	struct ipvl_addr *addr;
723 	struct net_device *sdev;
724 
725 	addr = ipvlan_skb_to_addr(skb, dev);
726 	if (!addr)
727 		goto out;
728 
729 	sdev = addr->master->dev;
730 	switch (proto) {
731 	case AF_INET:
732 	{
733 		int err;
734 		struct iphdr *ip4h = ip_hdr(skb);
735 
736 		err = ip_route_input_noref(skb, ip4h->daddr, ip4h->saddr,
737 					   ip4h->tos, sdev);
738 		if (unlikely(err))
739 			goto out;
740 		break;
741 	}
742 	case AF_INET6:
743 	{
744 		struct dst_entry *dst;
745 		struct ipv6hdr *ip6h = ipv6_hdr(skb);
746 		int flags = RT6_LOOKUP_F_HAS_SADDR;
747 		struct flowi6 fl6 = {
748 			.flowi6_iif   = sdev->ifindex,
749 			.daddr        = ip6h->daddr,
750 			.saddr        = ip6h->saddr,
751 			.flowlabel    = ip6_flowinfo(ip6h),
752 			.flowi6_mark  = skb->mark,
753 			.flowi6_proto = ip6h->nexthdr,
754 		};
755 
756 		skb_dst_drop(skb);
757 		dst = ip6_route_input_lookup(dev_net(sdev), sdev, &fl6, flags);
758 		skb_dst_set(skb, dst);
759 		break;
760 	}
761 	default:
762 		break;
763 	}
764 
765 out:
766 	return skb;
767 }
768 
769 unsigned int ipvlan_nf_input(void *priv, struct sk_buff *skb,
770 			     const struct nf_hook_state *state)
771 {
772 	struct ipvl_addr *addr;
773 	unsigned int len;
774 
775 	addr = ipvlan_skb_to_addr(skb, skb->dev);
776 	if (!addr)
777 		goto out;
778 
779 	skb->dev = addr->master->dev;
780 	len = skb->len + ETH_HLEN;
781 	ipvlan_count_rx(addr->master, len, true, false);
782 out:
783 	return NF_ACCEPT;
784 }
785