xref: /linux/drivers/net/ipvlan/ipvlan_core.c (revision 06a130e42a5bfc84795464bff023bff4c16f58c5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Copyright (c) 2014 Mahesh Bandewar <maheshb@google.com>
3  */
4 
5 #include <net/inet_dscp.h>
6 
7 #include "ipvlan.h"
8 
9 static u32 ipvlan_jhash_secret __read_mostly;
10 
11 void ipvlan_init_secret(void)
12 {
13 	net_get_random_once(&ipvlan_jhash_secret, sizeof(ipvlan_jhash_secret));
14 }
15 
16 void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
17 			    unsigned int len, bool success, bool mcast)
18 {
19 	if (likely(success)) {
20 		struct ipvl_pcpu_stats *pcptr;
21 
22 		pcptr = this_cpu_ptr(ipvlan->pcpu_stats);
23 		u64_stats_update_begin(&pcptr->syncp);
24 		u64_stats_inc(&pcptr->rx_pkts);
25 		u64_stats_add(&pcptr->rx_bytes, len);
26 		if (mcast)
27 			u64_stats_inc(&pcptr->rx_mcast);
28 		u64_stats_update_end(&pcptr->syncp);
29 	} else {
30 		this_cpu_inc(ipvlan->pcpu_stats->rx_errs);
31 	}
32 }
33 EXPORT_SYMBOL_GPL(ipvlan_count_rx);
34 
35 #if IS_ENABLED(CONFIG_IPV6)
36 static u8 ipvlan_get_v6_hash(const void *iaddr)
37 {
38 	const struct in6_addr *ip6_addr = iaddr;
39 
40 	return __ipv6_addr_jhash(ip6_addr, ipvlan_jhash_secret) &
41 	       IPVLAN_HASH_MASK;
42 }
43 #else
44 static u8 ipvlan_get_v6_hash(const void *iaddr)
45 {
46 	return 0;
47 }
48 #endif
49 
50 static u8 ipvlan_get_v4_hash(const void *iaddr)
51 {
52 	const struct in_addr *ip4_addr = iaddr;
53 
54 	return jhash_1word(ip4_addr->s_addr, ipvlan_jhash_secret) &
55 	       IPVLAN_HASH_MASK;
56 }
57 
58 static bool addr_equal(bool is_v6, struct ipvl_addr *addr, const void *iaddr)
59 {
60 	if (!is_v6 && addr->atype == IPVL_IPV4) {
61 		struct in_addr *i4addr = (struct in_addr *)iaddr;
62 
63 		return addr->ip4addr.s_addr == i4addr->s_addr;
64 #if IS_ENABLED(CONFIG_IPV6)
65 	} else if (is_v6 && addr->atype == IPVL_IPV6) {
66 		struct in6_addr *i6addr = (struct in6_addr *)iaddr;
67 
68 		return ipv6_addr_equal(&addr->ip6addr, i6addr);
69 #endif
70 	}
71 
72 	return false;
73 }
74 
75 static struct ipvl_addr *ipvlan_ht_addr_lookup(const struct ipvl_port *port,
76 					       const void *iaddr, bool is_v6)
77 {
78 	struct ipvl_addr *addr;
79 	u8 hash;
80 
81 	hash = is_v6 ? ipvlan_get_v6_hash(iaddr) :
82 	       ipvlan_get_v4_hash(iaddr);
83 	hlist_for_each_entry_rcu(addr, &port->hlhead[hash], hlnode)
84 		if (addr_equal(is_v6, addr, iaddr))
85 			return addr;
86 	return NULL;
87 }
88 
89 void ipvlan_ht_addr_add(struct ipvl_dev *ipvlan, struct ipvl_addr *addr)
90 {
91 	struct ipvl_port *port = ipvlan->port;
92 	u8 hash;
93 
94 	hash = (addr->atype == IPVL_IPV6) ?
95 	       ipvlan_get_v6_hash(&addr->ip6addr) :
96 	       ipvlan_get_v4_hash(&addr->ip4addr);
97 	if (hlist_unhashed(&addr->hlnode))
98 		hlist_add_head_rcu(&addr->hlnode, &port->hlhead[hash]);
99 }
100 
101 void ipvlan_ht_addr_del(struct ipvl_addr *addr)
102 {
103 	hlist_del_init_rcu(&addr->hlnode);
104 }
105 
106 struct ipvl_addr *ipvlan_find_addr(const struct ipvl_dev *ipvlan,
107 				   const void *iaddr, bool is_v6)
108 {
109 	struct ipvl_addr *addr, *ret = NULL;
110 
111 	rcu_read_lock();
112 	list_for_each_entry_rcu(addr, &ipvlan->addrs, anode) {
113 		if (addr_equal(is_v6, addr, iaddr)) {
114 			ret = addr;
115 			break;
116 		}
117 	}
118 	rcu_read_unlock();
119 	return ret;
120 }
121 
122 bool ipvlan_addr_busy(struct ipvl_port *port, void *iaddr, bool is_v6)
123 {
124 	struct ipvl_dev *ipvlan;
125 	bool ret = false;
126 
127 	rcu_read_lock();
128 	list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
129 		if (ipvlan_find_addr(ipvlan, iaddr, is_v6)) {
130 			ret = true;
131 			break;
132 		}
133 	}
134 	rcu_read_unlock();
135 	return ret;
136 }
137 
138 void *ipvlan_get_L3_hdr(struct ipvl_port *port, struct sk_buff *skb, int *type)
139 {
140 	void *lyr3h = NULL;
141 
142 	switch (skb->protocol) {
143 	case htons(ETH_P_ARP): {
144 		struct arphdr *arph;
145 
146 		if (unlikely(!pskb_may_pull(skb, arp_hdr_len(port->dev))))
147 			return NULL;
148 
149 		arph = arp_hdr(skb);
150 		*type = IPVL_ARP;
151 		lyr3h = arph;
152 		break;
153 	}
154 	case htons(ETH_P_IP): {
155 		u32 pktlen;
156 		struct iphdr *ip4h;
157 
158 		if (unlikely(!pskb_may_pull(skb, sizeof(*ip4h))))
159 			return NULL;
160 
161 		ip4h = ip_hdr(skb);
162 		pktlen = skb_ip_totlen(skb);
163 		if (ip4h->ihl < 5 || ip4h->version != 4)
164 			return NULL;
165 		if (skb->len < pktlen || pktlen < (ip4h->ihl * 4))
166 			return NULL;
167 
168 		*type = IPVL_IPV4;
169 		lyr3h = ip4h;
170 		break;
171 	}
172 #if IS_ENABLED(CONFIG_IPV6)
173 	case htons(ETH_P_IPV6): {
174 		struct ipv6hdr *ip6h;
175 
176 		if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h))))
177 			return NULL;
178 
179 		ip6h = ipv6_hdr(skb);
180 		if (ip6h->version != 6)
181 			return NULL;
182 
183 		*type = IPVL_IPV6;
184 		lyr3h = ip6h;
185 		/* Only Neighbour Solicitation pkts need different treatment */
186 		if (ipv6_addr_any(&ip6h->saddr) &&
187 		    ip6h->nexthdr == NEXTHDR_ICMP) {
188 			struct icmp6hdr	*icmph;
189 
190 			if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h) + sizeof(*icmph))))
191 				return NULL;
192 
193 			ip6h = ipv6_hdr(skb);
194 			icmph = (struct icmp6hdr *)(ip6h + 1);
195 
196 			if (icmph->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
197 				/* Need to access the ipv6 address in body */
198 				if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h) + sizeof(*icmph)
199 						+ sizeof(struct in6_addr))))
200 					return NULL;
201 
202 				ip6h = ipv6_hdr(skb);
203 				icmph = (struct icmp6hdr *)(ip6h + 1);
204 			}
205 
206 			*type = IPVL_ICMPV6;
207 			lyr3h = icmph;
208 		}
209 		break;
210 	}
211 #endif
212 	default:
213 		return NULL;
214 	}
215 
216 	return lyr3h;
217 }
218 
219 unsigned int ipvlan_mac_hash(const unsigned char *addr)
220 {
221 	u32 hash = jhash_1word(__get_unaligned_cpu32(addr+2),
222 			       ipvlan_jhash_secret);
223 
224 	return hash & IPVLAN_MAC_FILTER_MASK;
225 }
226 
227 void ipvlan_process_multicast(struct work_struct *work)
228 {
229 	struct ipvl_port *port = container_of(work, struct ipvl_port, wq);
230 	struct ethhdr *ethh;
231 	struct ipvl_dev *ipvlan;
232 	struct sk_buff *skb, *nskb;
233 	struct sk_buff_head list;
234 	unsigned int len;
235 	unsigned int mac_hash;
236 	int ret;
237 	u8 pkt_type;
238 	bool tx_pkt;
239 
240 	__skb_queue_head_init(&list);
241 
242 	spin_lock_bh(&port->backlog.lock);
243 	skb_queue_splice_tail_init(&port->backlog, &list);
244 	spin_unlock_bh(&port->backlog.lock);
245 
246 	while ((skb = __skb_dequeue(&list)) != NULL) {
247 		struct net_device *dev = skb->dev;
248 		bool consumed = false;
249 
250 		ethh = eth_hdr(skb);
251 		tx_pkt = IPVL_SKB_CB(skb)->tx_pkt;
252 		mac_hash = ipvlan_mac_hash(ethh->h_dest);
253 
254 		if (ether_addr_equal(ethh->h_dest, port->dev->broadcast))
255 			pkt_type = PACKET_BROADCAST;
256 		else
257 			pkt_type = PACKET_MULTICAST;
258 
259 		rcu_read_lock();
260 		list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
261 			if (tx_pkt && (ipvlan->dev == skb->dev))
262 				continue;
263 			if (!test_bit(mac_hash, ipvlan->mac_filters))
264 				continue;
265 			if (!(ipvlan->dev->flags & IFF_UP))
266 				continue;
267 			ret = NET_RX_DROP;
268 			len = skb->len + ETH_HLEN;
269 			nskb = skb_clone(skb, GFP_ATOMIC);
270 			local_bh_disable();
271 			if (nskb) {
272 				consumed = true;
273 				nskb->pkt_type = pkt_type;
274 				nskb->dev = ipvlan->dev;
275 				if (tx_pkt)
276 					ret = dev_forward_skb(ipvlan->dev, nskb);
277 				else
278 					ret = netif_rx(nskb);
279 			}
280 			ipvlan_count_rx(ipvlan, len, ret == NET_RX_SUCCESS, true);
281 			local_bh_enable();
282 		}
283 		rcu_read_unlock();
284 
285 		if (tx_pkt) {
286 			/* If the packet originated here, send it out. */
287 			skb->dev = port->dev;
288 			skb->pkt_type = pkt_type;
289 			dev_queue_xmit(skb);
290 		} else {
291 			if (consumed)
292 				consume_skb(skb);
293 			else
294 				kfree_skb(skb);
295 		}
296 		dev_put(dev);
297 		cond_resched();
298 	}
299 }
300 
301 static void ipvlan_skb_crossing_ns(struct sk_buff *skb, struct net_device *dev)
302 {
303 	bool xnet = true;
304 
305 	if (dev)
306 		xnet = !net_eq(dev_net(skb->dev), dev_net(dev));
307 
308 	skb_scrub_packet(skb, xnet);
309 	if (dev)
310 		skb->dev = dev;
311 }
312 
313 static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff **pskb,
314 			    bool local)
315 {
316 	struct ipvl_dev *ipvlan = addr->master;
317 	struct net_device *dev = ipvlan->dev;
318 	unsigned int len;
319 	rx_handler_result_t ret = RX_HANDLER_CONSUMED;
320 	bool success = false;
321 	struct sk_buff *skb = *pskb;
322 
323 	len = skb->len + ETH_HLEN;
324 	/* Only packets exchanged between two local slaves need to have
325 	 * device-up check as well as skb-share check.
326 	 */
327 	if (local) {
328 		if (unlikely(!(dev->flags & IFF_UP))) {
329 			kfree_skb(skb);
330 			goto out;
331 		}
332 
333 		skb = skb_share_check(skb, GFP_ATOMIC);
334 		if (!skb)
335 			goto out;
336 
337 		*pskb = skb;
338 	}
339 
340 	if (local) {
341 		skb->pkt_type = PACKET_HOST;
342 		if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)
343 			success = true;
344 	} else {
345 		skb->dev = dev;
346 		ret = RX_HANDLER_ANOTHER;
347 		success = true;
348 	}
349 
350 out:
351 	ipvlan_count_rx(ipvlan, len, success, false);
352 	return ret;
353 }
354 
355 struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port, void *lyr3h,
356 				     int addr_type, bool use_dest)
357 {
358 	struct ipvl_addr *addr = NULL;
359 
360 	switch (addr_type) {
361 #if IS_ENABLED(CONFIG_IPV6)
362 	case IPVL_IPV6: {
363 		struct ipv6hdr *ip6h;
364 		struct in6_addr *i6addr;
365 
366 		ip6h = (struct ipv6hdr *)lyr3h;
367 		i6addr = use_dest ? &ip6h->daddr : &ip6h->saddr;
368 		addr = ipvlan_ht_addr_lookup(port, i6addr, true);
369 		break;
370 	}
371 	case IPVL_ICMPV6: {
372 		struct nd_msg *ndmh;
373 		struct in6_addr *i6addr;
374 
375 		/* Make sure that the NeighborSolicitation ICMPv6 packets
376 		 * are handled to avoid DAD issue.
377 		 */
378 		ndmh = (struct nd_msg *)lyr3h;
379 		if (ndmh->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
380 			i6addr = &ndmh->target;
381 			addr = ipvlan_ht_addr_lookup(port, i6addr, true);
382 		}
383 		break;
384 	}
385 #endif
386 	case IPVL_IPV4: {
387 		struct iphdr *ip4h;
388 		__be32 *i4addr;
389 
390 		ip4h = (struct iphdr *)lyr3h;
391 		i4addr = use_dest ? &ip4h->daddr : &ip4h->saddr;
392 		addr = ipvlan_ht_addr_lookup(port, i4addr, false);
393 		break;
394 	}
395 	case IPVL_ARP: {
396 		struct arphdr *arph;
397 		unsigned char *arp_ptr;
398 		__be32 dip;
399 
400 		arph = (struct arphdr *)lyr3h;
401 		arp_ptr = (unsigned char *)(arph + 1);
402 		if (use_dest)
403 			arp_ptr += (2 * port->dev->addr_len) + 4;
404 		else
405 			arp_ptr += port->dev->addr_len;
406 
407 		memcpy(&dip, arp_ptr, 4);
408 		addr = ipvlan_ht_addr_lookup(port, &dip, false);
409 		break;
410 	}
411 	}
412 
413 	return addr;
414 }
415 
416 static noinline_for_stack int ipvlan_process_v4_outbound(struct sk_buff *skb)
417 {
418 	const struct iphdr *ip4h = ip_hdr(skb);
419 	struct net_device *dev = skb->dev;
420 	struct net *net = dev_net(dev);
421 	struct rtable *rt;
422 	int err, ret = NET_XMIT_DROP;
423 	struct flowi4 fl4 = {
424 		.flowi4_oif = dev->ifindex,
425 		.flowi4_tos = ip4h->tos & INET_DSCP_MASK,
426 		.flowi4_flags = FLOWI_FLAG_ANYSRC,
427 		.flowi4_mark = skb->mark,
428 		.daddr = ip4h->daddr,
429 		.saddr = ip4h->saddr,
430 	};
431 
432 	rt = ip_route_output_flow(net, &fl4, NULL);
433 	if (IS_ERR(rt))
434 		goto err;
435 
436 	if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
437 		ip_rt_put(rt);
438 		goto err;
439 	}
440 	skb_dst_set(skb, &rt->dst);
441 
442 	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
443 
444 	err = ip_local_out(net, NULL, skb);
445 	if (unlikely(net_xmit_eval(err)))
446 		DEV_STATS_INC(dev, tx_errors);
447 	else
448 		ret = NET_XMIT_SUCCESS;
449 	goto out;
450 err:
451 	DEV_STATS_INC(dev, tx_errors);
452 	kfree_skb(skb);
453 out:
454 	return ret;
455 }
456 
457 #if IS_ENABLED(CONFIG_IPV6)
458 
459 static noinline_for_stack int
460 ipvlan_route_v6_outbound(struct net_device *dev, struct sk_buff *skb)
461 {
462 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
463 	struct flowi6 fl6 = {
464 		.flowi6_oif = dev->ifindex,
465 		.daddr = ip6h->daddr,
466 		.saddr = ip6h->saddr,
467 		.flowi6_flags = FLOWI_FLAG_ANYSRC,
468 		.flowlabel = ip6_flowinfo(ip6h),
469 		.flowi6_mark = skb->mark,
470 		.flowi6_proto = ip6h->nexthdr,
471 	};
472 	struct dst_entry *dst;
473 	int err;
474 
475 	dst = ip6_route_output(dev_net(dev), NULL, &fl6);
476 	err = dst->error;
477 	if (err) {
478 		dst_release(dst);
479 		return err;
480 	}
481 	skb_dst_set(skb, dst);
482 	return 0;
483 }
484 
485 static int ipvlan_process_v6_outbound(struct sk_buff *skb)
486 {
487 	struct net_device *dev = skb->dev;
488 	int err, ret = NET_XMIT_DROP;
489 
490 	err = ipvlan_route_v6_outbound(dev, skb);
491 	if (unlikely(err)) {
492 		DEV_STATS_INC(dev, tx_errors);
493 		kfree_skb(skb);
494 		return err;
495 	}
496 
497 	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
498 
499 	err = ip6_local_out(dev_net(dev), NULL, skb);
500 	if (unlikely(net_xmit_eval(err)))
501 		DEV_STATS_INC(dev, tx_errors);
502 	else
503 		ret = NET_XMIT_SUCCESS;
504 	return ret;
505 }
506 #else
507 static int ipvlan_process_v6_outbound(struct sk_buff *skb)
508 {
509 	return NET_XMIT_DROP;
510 }
511 #endif
512 
513 static int ipvlan_process_outbound(struct sk_buff *skb)
514 {
515 	int ret = NET_XMIT_DROP;
516 
517 	/* The ipvlan is a pseudo-L2 device, so the packets that we receive
518 	 * will have L2; which need to discarded and processed further
519 	 * in the net-ns of the main-device.
520 	 */
521 	if (skb_mac_header_was_set(skb)) {
522 		/* In this mode we dont care about
523 		 * multicast and broadcast traffic */
524 		struct ethhdr *ethh = eth_hdr(skb);
525 
526 		if (is_multicast_ether_addr(ethh->h_dest)) {
527 			pr_debug_ratelimited(
528 				"Dropped {multi|broad}cast of type=[%x]\n",
529 				ntohs(skb->protocol));
530 			kfree_skb(skb);
531 			goto out;
532 		}
533 
534 		skb_pull(skb, sizeof(*ethh));
535 		skb->mac_header = (typeof(skb->mac_header))~0U;
536 		skb_reset_network_header(skb);
537 	}
538 
539 	if (skb->protocol == htons(ETH_P_IPV6))
540 		ret = ipvlan_process_v6_outbound(skb);
541 	else if (skb->protocol == htons(ETH_P_IP))
542 		ret = ipvlan_process_v4_outbound(skb);
543 	else {
544 		pr_warn_ratelimited("Dropped outbound packet type=%x\n",
545 				    ntohs(skb->protocol));
546 		kfree_skb(skb);
547 	}
548 out:
549 	return ret;
550 }
551 
552 static void ipvlan_multicast_enqueue(struct ipvl_port *port,
553 				     struct sk_buff *skb, bool tx_pkt)
554 {
555 	if (skb->protocol == htons(ETH_P_PAUSE)) {
556 		kfree_skb(skb);
557 		return;
558 	}
559 
560 	/* Record that the deferred packet is from TX or RX path. By
561 	 * looking at mac-addresses on packet will lead to erronus decisions.
562 	 * (This would be true for a loopback-mode on master device or a
563 	 * hair-pin mode of the switch.)
564 	 */
565 	IPVL_SKB_CB(skb)->tx_pkt = tx_pkt;
566 
567 	spin_lock(&port->backlog.lock);
568 	if (skb_queue_len(&port->backlog) < IPVLAN_QBACKLOG_LIMIT) {
569 		dev_hold(skb->dev);
570 		__skb_queue_tail(&port->backlog, skb);
571 		spin_unlock(&port->backlog.lock);
572 		schedule_work(&port->wq);
573 	} else {
574 		spin_unlock(&port->backlog.lock);
575 		dev_core_stats_rx_dropped_inc(skb->dev);
576 		kfree_skb(skb);
577 	}
578 }
579 
580 static int ipvlan_xmit_mode_l3(struct sk_buff *skb, struct net_device *dev)
581 {
582 	const struct ipvl_dev *ipvlan = netdev_priv(dev);
583 	void *lyr3h;
584 	struct ipvl_addr *addr;
585 	int addr_type;
586 
587 	lyr3h = ipvlan_get_L3_hdr(ipvlan->port, skb, &addr_type);
588 	if (!lyr3h)
589 		goto out;
590 
591 	if (!ipvlan_is_vepa(ipvlan->port)) {
592 		addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
593 		if (addr) {
594 			if (ipvlan_is_private(ipvlan->port)) {
595 				consume_skb(skb);
596 				return NET_XMIT_DROP;
597 			}
598 			ipvlan_rcv_frame(addr, &skb, true);
599 			return NET_XMIT_SUCCESS;
600 		}
601 	}
602 out:
603 	ipvlan_skb_crossing_ns(skb, ipvlan->phy_dev);
604 	return ipvlan_process_outbound(skb);
605 }
606 
607 static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
608 {
609 	const struct ipvl_dev *ipvlan = netdev_priv(dev);
610 	struct ethhdr *eth = skb_eth_hdr(skb);
611 	struct ipvl_addr *addr;
612 	void *lyr3h;
613 	int addr_type;
614 
615 	if (!ipvlan_is_vepa(ipvlan->port) &&
616 	    ether_addr_equal(eth->h_dest, eth->h_source)) {
617 		lyr3h = ipvlan_get_L3_hdr(ipvlan->port, skb, &addr_type);
618 		if (lyr3h) {
619 			addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
620 			if (addr) {
621 				if (ipvlan_is_private(ipvlan->port)) {
622 					consume_skb(skb);
623 					return NET_XMIT_DROP;
624 				}
625 				ipvlan_rcv_frame(addr, &skb, true);
626 				return NET_XMIT_SUCCESS;
627 			}
628 		}
629 		skb = skb_share_check(skb, GFP_ATOMIC);
630 		if (!skb)
631 			return NET_XMIT_DROP;
632 
633 		/* Packet definitely does not belong to any of the
634 		 * virtual devices, but the dest is local. So forward
635 		 * the skb for the main-dev. At the RX side we just return
636 		 * RX_PASS for it to be processed further on the stack.
637 		 */
638 		dev_forward_skb(ipvlan->phy_dev, skb);
639 		return NET_XMIT_SUCCESS;
640 
641 	} else if (is_multicast_ether_addr(eth->h_dest)) {
642 		skb_reset_mac_header(skb);
643 		ipvlan_skb_crossing_ns(skb, NULL);
644 		ipvlan_multicast_enqueue(ipvlan->port, skb, true);
645 		return NET_XMIT_SUCCESS;
646 	}
647 
648 	skb->dev = ipvlan->phy_dev;
649 	return dev_queue_xmit(skb);
650 }
651 
652 int ipvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
653 {
654 	struct ipvl_dev *ipvlan = netdev_priv(dev);
655 	struct ipvl_port *port = ipvlan_port_get_rcu_bh(ipvlan->phy_dev);
656 
657 	if (!port)
658 		goto out;
659 
660 	if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
661 		goto out;
662 
663 	switch(port->mode) {
664 	case IPVLAN_MODE_L2:
665 		return ipvlan_xmit_mode_l2(skb, dev);
666 	case IPVLAN_MODE_L3:
667 #ifdef CONFIG_IPVLAN_L3S
668 	case IPVLAN_MODE_L3S:
669 #endif
670 		return ipvlan_xmit_mode_l3(skb, dev);
671 	}
672 
673 	/* Should not reach here */
674 	WARN_ONCE(true, "%s called for mode = [%x]\n", __func__, port->mode);
675 out:
676 	kfree_skb(skb);
677 	return NET_XMIT_DROP;
678 }
679 
680 static bool ipvlan_external_frame(struct sk_buff *skb, struct ipvl_port *port)
681 {
682 	struct ethhdr *eth = eth_hdr(skb);
683 	struct ipvl_addr *addr;
684 	void *lyr3h;
685 	int addr_type;
686 
687 	if (ether_addr_equal(eth->h_source, skb->dev->dev_addr)) {
688 		lyr3h = ipvlan_get_L3_hdr(port, skb, &addr_type);
689 		if (!lyr3h)
690 			return true;
691 
692 		addr = ipvlan_addr_lookup(port, lyr3h, addr_type, false);
693 		if (addr)
694 			return false;
695 	}
696 
697 	return true;
698 }
699 
700 static rx_handler_result_t ipvlan_handle_mode_l3(struct sk_buff **pskb,
701 						 struct ipvl_port *port)
702 {
703 	void *lyr3h;
704 	int addr_type;
705 	struct ipvl_addr *addr;
706 	struct sk_buff *skb = *pskb;
707 	rx_handler_result_t ret = RX_HANDLER_PASS;
708 
709 	lyr3h = ipvlan_get_L3_hdr(port, skb, &addr_type);
710 	if (!lyr3h)
711 		goto out;
712 
713 	addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
714 	if (addr)
715 		ret = ipvlan_rcv_frame(addr, pskb, false);
716 
717 out:
718 	return ret;
719 }
720 
721 static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
722 						 struct ipvl_port *port)
723 {
724 	struct sk_buff *skb = *pskb;
725 	struct ethhdr *eth = eth_hdr(skb);
726 	rx_handler_result_t ret = RX_HANDLER_PASS;
727 
728 	if (is_multicast_ether_addr(eth->h_dest)) {
729 		if (ipvlan_external_frame(skb, port)) {
730 			struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
731 
732 			/* External frames are queued for device local
733 			 * distribution, but a copy is given to master
734 			 * straight away to avoid sending duplicates later
735 			 * when work-queue processes this frame. This is
736 			 * achieved by returning RX_HANDLER_PASS.
737 			 */
738 			if (nskb) {
739 				ipvlan_skb_crossing_ns(nskb, NULL);
740 				ipvlan_multicast_enqueue(port, nskb, false);
741 			}
742 		}
743 	} else {
744 		/* Perform like l3 mode for non-multicast packet */
745 		ret = ipvlan_handle_mode_l3(pskb, port);
746 	}
747 
748 	return ret;
749 }
750 
751 rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
752 {
753 	struct sk_buff *skb = *pskb;
754 	struct ipvl_port *port = ipvlan_port_get_rcu(skb->dev);
755 
756 	if (!port)
757 		return RX_HANDLER_PASS;
758 
759 	switch (port->mode) {
760 	case IPVLAN_MODE_L2:
761 		return ipvlan_handle_mode_l2(pskb, port);
762 	case IPVLAN_MODE_L3:
763 		return ipvlan_handle_mode_l3(pskb, port);
764 #ifdef CONFIG_IPVLAN_L3S
765 	case IPVLAN_MODE_L3S:
766 		return RX_HANDLER_PASS;
767 #endif
768 	}
769 
770 	/* Should not reach here */
771 	WARN_ONCE(true, "%s called for mode = [%x]\n", __func__, port->mode);
772 	kfree_skb(skb);
773 	return RX_HANDLER_CONSUMED;
774 }
775