xref: /openbmc/linux/drivers/net/ipvlan/ipvlan_core.c (revision 612a462a)
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 void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
20 			    unsigned int len, bool success, bool mcast)
21 {
22 	if (likely(success)) {
23 		struct ipvl_pcpu_stats *pcptr;
24 
25 		pcptr = this_cpu_ptr(ipvlan->pcpu_stats);
26 		u64_stats_update_begin(&pcptr->syncp);
27 		pcptr->rx_pkts++;
28 		pcptr->rx_bytes += len;
29 		if (mcast)
30 			pcptr->rx_mcast++;
31 		u64_stats_update_end(&pcptr->syncp);
32 	} else {
33 		this_cpu_inc(ipvlan->pcpu_stats->rx_errs);
34 	}
35 }
36 EXPORT_SYMBOL_GPL(ipvlan_count_rx);
37 
38 static u8 ipvlan_get_v6_hash(const void *iaddr)
39 {
40 	const struct in6_addr *ip6_addr = iaddr;
41 
42 	return __ipv6_addr_jhash(ip6_addr, ipvlan_jhash_secret) &
43 	       IPVLAN_HASH_MASK;
44 }
45 
46 static u8 ipvlan_get_v4_hash(const void *iaddr)
47 {
48 	const struct in_addr *ip4_addr = iaddr;
49 
50 	return jhash_1word(ip4_addr->s_addr, ipvlan_jhash_secret) &
51 	       IPVLAN_HASH_MASK;
52 }
53 
54 static struct ipvl_addr *ipvlan_ht_addr_lookup(const struct ipvl_port *port,
55 					       const void *iaddr, bool is_v6)
56 {
57 	struct ipvl_addr *addr;
58 	u8 hash;
59 
60 	hash = is_v6 ? ipvlan_get_v6_hash(iaddr) :
61 	       ipvlan_get_v4_hash(iaddr);
62 	hlist_for_each_entry_rcu(addr, &port->hlhead[hash], hlnode) {
63 		if (is_v6 && addr->atype == IPVL_IPV6 &&
64 		    ipv6_addr_equal(&addr->ip6addr, iaddr))
65 			return addr;
66 		else if (!is_v6 && addr->atype == IPVL_IPV4 &&
67 			 addr->ip4addr.s_addr ==
68 				((struct in_addr *)iaddr)->s_addr)
69 			return addr;
70 	}
71 	return NULL;
72 }
73 
74 void ipvlan_ht_addr_add(struct ipvl_dev *ipvlan, struct ipvl_addr *addr)
75 {
76 	struct ipvl_port *port = ipvlan->port;
77 	u8 hash;
78 
79 	hash = (addr->atype == IPVL_IPV6) ?
80 	       ipvlan_get_v6_hash(&addr->ip6addr) :
81 	       ipvlan_get_v4_hash(&addr->ip4addr);
82 	if (hlist_unhashed(&addr->hlnode))
83 		hlist_add_head_rcu(&addr->hlnode, &port->hlhead[hash]);
84 }
85 
86 void ipvlan_ht_addr_del(struct ipvl_addr *addr)
87 {
88 	hlist_del_init_rcu(&addr->hlnode);
89 }
90 
91 struct ipvl_addr *ipvlan_find_addr(const struct ipvl_dev *ipvlan,
92 				   const void *iaddr, bool is_v6)
93 {
94 	struct ipvl_addr *addr;
95 
96 	list_for_each_entry(addr, &ipvlan->addrs, anode) {
97 		if ((is_v6 && addr->atype == IPVL_IPV6 &&
98 		    ipv6_addr_equal(&addr->ip6addr, iaddr)) ||
99 		    (!is_v6 && addr->atype == IPVL_IPV4 &&
100 		    addr->ip4addr.s_addr == ((struct in_addr *)iaddr)->s_addr))
101 			return addr;
102 	}
103 	return NULL;
104 }
105 
106 bool ipvlan_addr_busy(struct ipvl_port *port, void *iaddr, bool is_v6)
107 {
108 	struct ipvl_dev *ipvlan;
109 
110 	ASSERT_RTNL();
111 
112 	list_for_each_entry(ipvlan, &port->ipvlans, pnode) {
113 		if (ipvlan_find_addr(ipvlan, iaddr, is_v6))
114 			return true;
115 	}
116 	return false;
117 }
118 
119 static void *ipvlan_get_L3_hdr(struct sk_buff *skb, int *type)
120 {
121 	void *lyr3h = NULL;
122 
123 	switch (skb->protocol) {
124 	case htons(ETH_P_ARP): {
125 		struct arphdr *arph;
126 
127 		if (unlikely(!pskb_may_pull(skb, sizeof(*arph))))
128 			return NULL;
129 
130 		arph = arp_hdr(skb);
131 		*type = IPVL_ARP;
132 		lyr3h = arph;
133 		break;
134 	}
135 	case htons(ETH_P_IP): {
136 		u32 pktlen;
137 		struct iphdr *ip4h;
138 
139 		if (unlikely(!pskb_may_pull(skb, sizeof(*ip4h))))
140 			return NULL;
141 
142 		ip4h = ip_hdr(skb);
143 		pktlen = ntohs(ip4h->tot_len);
144 		if (ip4h->ihl < 5 || ip4h->version != 4)
145 			return NULL;
146 		if (skb->len < pktlen || pktlen < (ip4h->ihl * 4))
147 			return NULL;
148 
149 		*type = IPVL_IPV4;
150 		lyr3h = ip4h;
151 		break;
152 	}
153 	case htons(ETH_P_IPV6): {
154 		struct ipv6hdr *ip6h;
155 
156 		if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h))))
157 			return NULL;
158 
159 		ip6h = ipv6_hdr(skb);
160 		if (ip6h->version != 6)
161 			return NULL;
162 
163 		*type = IPVL_IPV6;
164 		lyr3h = ip6h;
165 		/* Only Neighbour Solicitation pkts need different treatment */
166 		if (ipv6_addr_any(&ip6h->saddr) &&
167 		    ip6h->nexthdr == NEXTHDR_ICMP) {
168 			*type = IPVL_ICMPV6;
169 			lyr3h = ip6h + 1;
170 		}
171 		break;
172 	}
173 	default:
174 		return NULL;
175 	}
176 
177 	return lyr3h;
178 }
179 
180 unsigned int ipvlan_mac_hash(const unsigned char *addr)
181 {
182 	u32 hash = jhash_1word(__get_unaligned_cpu32(addr+2),
183 			       ipvlan_jhash_secret);
184 
185 	return hash & IPVLAN_MAC_FILTER_MASK;
186 }
187 
188 void ipvlan_process_multicast(struct work_struct *work)
189 {
190 	struct ipvl_port *port = container_of(work, struct ipvl_port, wq);
191 	struct ethhdr *ethh;
192 	struct ipvl_dev *ipvlan;
193 	struct sk_buff *skb, *nskb;
194 	struct sk_buff_head list;
195 	unsigned int len;
196 	unsigned int mac_hash;
197 	int ret;
198 	u8 pkt_type;
199 	bool tx_pkt;
200 
201 	__skb_queue_head_init(&list);
202 
203 	spin_lock_bh(&port->backlog.lock);
204 	skb_queue_splice_tail_init(&port->backlog, &list);
205 	spin_unlock_bh(&port->backlog.lock);
206 
207 	while ((skb = __skb_dequeue(&list)) != NULL) {
208 		struct net_device *dev = skb->dev;
209 		bool consumed = false;
210 
211 		ethh = eth_hdr(skb);
212 		tx_pkt = IPVL_SKB_CB(skb)->tx_pkt;
213 		mac_hash = ipvlan_mac_hash(ethh->h_dest);
214 
215 		if (ether_addr_equal(ethh->h_dest, port->dev->broadcast))
216 			pkt_type = PACKET_BROADCAST;
217 		else
218 			pkt_type = PACKET_MULTICAST;
219 
220 		rcu_read_lock();
221 		list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
222 			if (tx_pkt && (ipvlan->dev == skb->dev))
223 				continue;
224 			if (!test_bit(mac_hash, ipvlan->mac_filters))
225 				continue;
226 			if (!(ipvlan->dev->flags & IFF_UP))
227 				continue;
228 			ret = NET_RX_DROP;
229 			len = skb->len + ETH_HLEN;
230 			nskb = skb_clone(skb, GFP_ATOMIC);
231 			local_bh_disable();
232 			if (nskb) {
233 				consumed = true;
234 				nskb->pkt_type = pkt_type;
235 				nskb->dev = ipvlan->dev;
236 				if (tx_pkt)
237 					ret = dev_forward_skb(ipvlan->dev, nskb);
238 				else
239 					ret = netif_rx(nskb);
240 			}
241 			ipvlan_count_rx(ipvlan, len, ret == NET_RX_SUCCESS, true);
242 			local_bh_enable();
243 		}
244 		rcu_read_unlock();
245 
246 		if (tx_pkt) {
247 			/* If the packet originated here, send it out. */
248 			skb->dev = port->dev;
249 			skb->pkt_type = pkt_type;
250 			dev_queue_xmit(skb);
251 		} else {
252 			if (consumed)
253 				consume_skb(skb);
254 			else
255 				kfree_skb(skb);
256 		}
257 		if (dev)
258 			dev_put(dev);
259 	}
260 }
261 
262 static void ipvlan_skb_crossing_ns(struct sk_buff *skb, struct net_device *dev)
263 {
264 	bool xnet = true;
265 
266 	if (dev)
267 		xnet = !net_eq(dev_net(skb->dev), dev_net(dev));
268 
269 	skb_scrub_packet(skb, xnet);
270 	if (dev)
271 		skb->dev = dev;
272 }
273 
274 static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff **pskb,
275 			    bool local)
276 {
277 	struct ipvl_dev *ipvlan = addr->master;
278 	struct net_device *dev = ipvlan->dev;
279 	unsigned int len;
280 	rx_handler_result_t ret = RX_HANDLER_CONSUMED;
281 	bool success = false;
282 	struct sk_buff *skb = *pskb;
283 
284 	len = skb->len + ETH_HLEN;
285 	/* Only packets exchanged between two local slaves need to have
286 	 * device-up check as well as skb-share check.
287 	 */
288 	if (local) {
289 		if (unlikely(!(dev->flags & IFF_UP))) {
290 			kfree_skb(skb);
291 			goto out;
292 		}
293 
294 		skb = skb_share_check(skb, GFP_ATOMIC);
295 		if (!skb)
296 			goto out;
297 
298 		*pskb = skb;
299 	}
300 	ipvlan_skb_crossing_ns(skb, dev);
301 
302 	if (local) {
303 		skb->pkt_type = PACKET_HOST;
304 		if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)
305 			success = true;
306 	} else {
307 		ret = RX_HANDLER_ANOTHER;
308 		success = true;
309 	}
310 
311 out:
312 	ipvlan_count_rx(ipvlan, len, success, false);
313 	return ret;
314 }
315 
316 static struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port,
317 					    void *lyr3h, int addr_type,
318 					    bool use_dest)
319 {
320 	struct ipvl_addr *addr = NULL;
321 
322 	if (addr_type == IPVL_IPV6) {
323 		struct ipv6hdr *ip6h;
324 		struct in6_addr *i6addr;
325 
326 		ip6h = (struct ipv6hdr *)lyr3h;
327 		i6addr = use_dest ? &ip6h->daddr : &ip6h->saddr;
328 		addr = ipvlan_ht_addr_lookup(port, i6addr, true);
329 	} else if (addr_type == IPVL_ICMPV6) {
330 		struct nd_msg *ndmh;
331 		struct in6_addr *i6addr;
332 
333 		/* Make sure that the NeighborSolicitation ICMPv6 packets
334 		 * are handled to avoid DAD issue.
335 		 */
336 		ndmh = (struct nd_msg *)lyr3h;
337 		if (ndmh->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
338 			i6addr = &ndmh->target;
339 			addr = ipvlan_ht_addr_lookup(port, i6addr, true);
340 		}
341 	} else if (addr_type == IPVL_IPV4) {
342 		struct iphdr *ip4h;
343 		__be32 *i4addr;
344 
345 		ip4h = (struct iphdr *)lyr3h;
346 		i4addr = use_dest ? &ip4h->daddr : &ip4h->saddr;
347 		addr = ipvlan_ht_addr_lookup(port, i4addr, false);
348 	} else if (addr_type == IPVL_ARP) {
349 		struct arphdr *arph;
350 		unsigned char *arp_ptr;
351 		__be32 dip;
352 
353 		arph = (struct arphdr *)lyr3h;
354 		arp_ptr = (unsigned char *)(arph + 1);
355 		if (use_dest)
356 			arp_ptr += (2 * port->dev->addr_len) + 4;
357 		else
358 			arp_ptr += port->dev->addr_len;
359 
360 		memcpy(&dip, arp_ptr, 4);
361 		addr = ipvlan_ht_addr_lookup(port, &dip, false);
362 	}
363 
364 	return addr;
365 }
366 
367 static int ipvlan_process_v4_outbound(struct sk_buff *skb)
368 {
369 	const struct iphdr *ip4h = ip_hdr(skb);
370 	struct net_device *dev = skb->dev;
371 	struct net *net = dev_net(dev);
372 	struct rtable *rt;
373 	int err, ret = NET_XMIT_DROP;
374 	struct flowi4 fl4 = {
375 		.flowi4_oif = dev->ifindex,
376 		.flowi4_tos = RT_TOS(ip4h->tos),
377 		.flowi4_flags = FLOWI_FLAG_ANYSRC,
378 		.daddr = ip4h->daddr,
379 		.saddr = ip4h->saddr,
380 	};
381 
382 	rt = ip_route_output_flow(net, &fl4, NULL);
383 	if (IS_ERR(rt))
384 		goto err;
385 
386 	if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
387 		ip_rt_put(rt);
388 		goto err;
389 	}
390 	skb_dst_set(skb, &rt->dst);
391 	err = ip_local_out(net, skb->sk, skb);
392 	if (unlikely(net_xmit_eval(err)))
393 		dev->stats.tx_errors++;
394 	else
395 		ret = NET_XMIT_SUCCESS;
396 	goto out;
397 err:
398 	dev->stats.tx_errors++;
399 	kfree_skb(skb);
400 out:
401 	return ret;
402 }
403 
404 static int ipvlan_process_v6_outbound(struct sk_buff *skb)
405 {
406 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
407 	struct net_device *dev = skb->dev;
408 	struct net *net = dev_net(dev);
409 	struct dst_entry *dst;
410 	int err, ret = NET_XMIT_DROP;
411 	struct flowi6 fl6 = {
412 		.flowi6_iif = dev->ifindex,
413 		.daddr = ip6h->daddr,
414 		.saddr = ip6h->saddr,
415 		.flowi6_flags = FLOWI_FLAG_ANYSRC,
416 		.flowlabel = ip6_flowinfo(ip6h),
417 		.flowi6_mark = skb->mark,
418 		.flowi6_proto = ip6h->nexthdr,
419 	};
420 
421 	dst = ip6_route_output(net, NULL, &fl6);
422 	if (dst->error) {
423 		ret = dst->error;
424 		dst_release(dst);
425 		goto err;
426 	}
427 	skb_dst_set(skb, dst);
428 	err = ip6_local_out(net, skb->sk, skb);
429 	if (unlikely(net_xmit_eval(err)))
430 		dev->stats.tx_errors++;
431 	else
432 		ret = NET_XMIT_SUCCESS;
433 	goto out;
434 err:
435 	dev->stats.tx_errors++;
436 	kfree_skb(skb);
437 out:
438 	return ret;
439 }
440 
441 static int ipvlan_process_outbound(struct sk_buff *skb)
442 {
443 	struct ethhdr *ethh = eth_hdr(skb);
444 	int ret = NET_XMIT_DROP;
445 
446 	/* In this mode we dont care about multicast and broadcast traffic */
447 	if (is_multicast_ether_addr(ethh->h_dest)) {
448 		pr_warn_ratelimited("Dropped {multi|broad}cast of type= [%x]\n",
449 				    ntohs(skb->protocol));
450 		kfree_skb(skb);
451 		goto out;
452 	}
453 
454 	/* The ipvlan is a pseudo-L2 device, so the packets that we receive
455 	 * will have L2; which need to discarded and processed further
456 	 * in the net-ns of the main-device.
457 	 */
458 	if (skb_mac_header_was_set(skb)) {
459 		skb_pull(skb, sizeof(*ethh));
460 		skb->mac_header = (typeof(skb->mac_header))~0U;
461 		skb_reset_network_header(skb);
462 	}
463 
464 	if (skb->protocol == htons(ETH_P_IPV6))
465 		ret = ipvlan_process_v6_outbound(skb);
466 	else if (skb->protocol == htons(ETH_P_IP))
467 		ret = ipvlan_process_v4_outbound(skb);
468 	else {
469 		pr_warn_ratelimited("Dropped outbound packet type=%x\n",
470 				    ntohs(skb->protocol));
471 		kfree_skb(skb);
472 	}
473 out:
474 	return ret;
475 }
476 
477 static void ipvlan_multicast_enqueue(struct ipvl_port *port,
478 				     struct sk_buff *skb, bool tx_pkt)
479 {
480 	if (skb->protocol == htons(ETH_P_PAUSE)) {
481 		kfree_skb(skb);
482 		return;
483 	}
484 
485 	/* Record that the deferred packet is from TX or RX path. By
486 	 * looking at mac-addresses on packet will lead to erronus decisions.
487 	 * (This would be true for a loopback-mode on master device or a
488 	 * hair-pin mode of the switch.)
489 	 */
490 	IPVL_SKB_CB(skb)->tx_pkt = tx_pkt;
491 
492 	spin_lock(&port->backlog.lock);
493 	if (skb_queue_len(&port->backlog) < IPVLAN_QBACKLOG_LIMIT) {
494 		if (skb->dev)
495 			dev_hold(skb->dev);
496 		__skb_queue_tail(&port->backlog, skb);
497 		spin_unlock(&port->backlog.lock);
498 		schedule_work(&port->wq);
499 	} else {
500 		spin_unlock(&port->backlog.lock);
501 		atomic_long_inc(&skb->dev->rx_dropped);
502 		kfree_skb(skb);
503 	}
504 }
505 
506 static int ipvlan_xmit_mode_l3(struct sk_buff *skb, struct net_device *dev)
507 {
508 	const struct ipvl_dev *ipvlan = netdev_priv(dev);
509 	void *lyr3h;
510 	struct ipvl_addr *addr;
511 	int addr_type;
512 
513 	lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
514 	if (!lyr3h)
515 		goto out;
516 
517 	addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
518 	if (addr)
519 		return ipvlan_rcv_frame(addr, &skb, true);
520 
521 out:
522 	ipvlan_skb_crossing_ns(skb, ipvlan->phy_dev);
523 	return ipvlan_process_outbound(skb);
524 }
525 
526 static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
527 {
528 	const struct ipvl_dev *ipvlan = netdev_priv(dev);
529 	struct ethhdr *eth = eth_hdr(skb);
530 	struct ipvl_addr *addr;
531 	void *lyr3h;
532 	int addr_type;
533 
534 	if (ether_addr_equal(eth->h_dest, eth->h_source)) {
535 		lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
536 		if (lyr3h) {
537 			addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
538 			if (addr)
539 				return ipvlan_rcv_frame(addr, &skb, true);
540 		}
541 		skb = skb_share_check(skb, GFP_ATOMIC);
542 		if (!skb)
543 			return NET_XMIT_DROP;
544 
545 		/* Packet definitely does not belong to any of the
546 		 * virtual devices, but the dest is local. So forward
547 		 * the skb for the main-dev. At the RX side we just return
548 		 * RX_PASS for it to be processed further on the stack.
549 		 */
550 		return dev_forward_skb(ipvlan->phy_dev, skb);
551 
552 	} else if (is_multicast_ether_addr(eth->h_dest)) {
553 		ipvlan_skb_crossing_ns(skb, NULL);
554 		ipvlan_multicast_enqueue(ipvlan->port, skb, true);
555 		return NET_XMIT_SUCCESS;
556 	}
557 
558 	ipvlan_skb_crossing_ns(skb, ipvlan->phy_dev);
559 	return dev_queue_xmit(skb);
560 }
561 
562 int ipvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
563 {
564 	struct ipvl_dev *ipvlan = netdev_priv(dev);
565 	struct ipvl_port *port = ipvlan_port_get_rcu_bh(ipvlan->phy_dev);
566 
567 	if (!port)
568 		goto out;
569 
570 	if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
571 		goto out;
572 
573 	switch(port->mode) {
574 	case IPVLAN_MODE_L2:
575 		return ipvlan_xmit_mode_l2(skb, dev);
576 	case IPVLAN_MODE_L3:
577 	case IPVLAN_MODE_L3S:
578 		return ipvlan_xmit_mode_l3(skb, dev);
579 	}
580 
581 	/* Should not reach here */
582 	WARN_ONCE(true, "ipvlan_queue_xmit() called for mode = [%hx]\n",
583 			  port->mode);
584 out:
585 	kfree_skb(skb);
586 	return NET_XMIT_DROP;
587 }
588 
589 static bool ipvlan_external_frame(struct sk_buff *skb, struct ipvl_port *port)
590 {
591 	struct ethhdr *eth = eth_hdr(skb);
592 	struct ipvl_addr *addr;
593 	void *lyr3h;
594 	int addr_type;
595 
596 	if (ether_addr_equal(eth->h_source, skb->dev->dev_addr)) {
597 		lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
598 		if (!lyr3h)
599 			return true;
600 
601 		addr = ipvlan_addr_lookup(port, lyr3h, addr_type, false);
602 		if (addr)
603 			return false;
604 	}
605 
606 	return true;
607 }
608 
609 static rx_handler_result_t ipvlan_handle_mode_l3(struct sk_buff **pskb,
610 						 struct ipvl_port *port)
611 {
612 	void *lyr3h;
613 	int addr_type;
614 	struct ipvl_addr *addr;
615 	struct sk_buff *skb = *pskb;
616 	rx_handler_result_t ret = RX_HANDLER_PASS;
617 
618 	lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
619 	if (!lyr3h)
620 		goto out;
621 
622 	addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
623 	if (addr)
624 		ret = ipvlan_rcv_frame(addr, pskb, false);
625 
626 out:
627 	return ret;
628 }
629 
630 static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
631 						 struct ipvl_port *port)
632 {
633 	struct sk_buff *skb = *pskb;
634 	struct ethhdr *eth = eth_hdr(skb);
635 	rx_handler_result_t ret = RX_HANDLER_PASS;
636 	void *lyr3h;
637 	int addr_type;
638 
639 	if (is_multicast_ether_addr(eth->h_dest)) {
640 		if (ipvlan_external_frame(skb, port)) {
641 			struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
642 
643 			/* External frames are queued for device local
644 			 * distribution, but a copy is given to master
645 			 * straight away to avoid sending duplicates later
646 			 * when work-queue processes this frame. This is
647 			 * achieved by returning RX_HANDLER_PASS.
648 			 */
649 			if (nskb) {
650 				ipvlan_skb_crossing_ns(nskb, NULL);
651 				ipvlan_multicast_enqueue(port, nskb, false);
652 			}
653 		}
654 	} else {
655 		struct ipvl_addr *addr;
656 
657 		lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
658 		if (!lyr3h)
659 			return ret;
660 
661 		addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
662 		if (addr)
663 			ret = ipvlan_rcv_frame(addr, pskb, false);
664 	}
665 
666 	return ret;
667 }
668 
669 rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
670 {
671 	struct sk_buff *skb = *pskb;
672 	struct ipvl_port *port = ipvlan_port_get_rcu(skb->dev);
673 
674 	if (!port)
675 		return RX_HANDLER_PASS;
676 
677 	switch (port->mode) {
678 	case IPVLAN_MODE_L2:
679 		return ipvlan_handle_mode_l2(pskb, port);
680 	case IPVLAN_MODE_L3:
681 		return ipvlan_handle_mode_l3(pskb, port);
682 	case IPVLAN_MODE_L3S:
683 		return RX_HANDLER_PASS;
684 	}
685 
686 	/* Should not reach here */
687 	WARN_ONCE(true, "ipvlan_handle_frame() called for mode = [%hx]\n",
688 			  port->mode);
689 	kfree_skb(skb);
690 	return RX_HANDLER_CONSUMED;
691 }
692 
693 static struct ipvl_addr *ipvlan_skb_to_addr(struct sk_buff *skb,
694 					    struct net_device *dev)
695 {
696 	struct ipvl_addr *addr = NULL;
697 	struct ipvl_port *port;
698 	void *lyr3h;
699 	int addr_type;
700 
701 	if (!dev || !netif_is_ipvlan_port(dev))
702 		goto out;
703 
704 	port = ipvlan_port_get_rcu(dev);
705 	if (!port || port->mode != IPVLAN_MODE_L3S)
706 		goto out;
707 
708 	lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
709 	if (!lyr3h)
710 		goto out;
711 
712 	addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
713 out:
714 	return addr;
715 }
716 
717 struct sk_buff *ipvlan_l3_rcv(struct net_device *dev, struct sk_buff *skb,
718 			      u16 proto)
719 {
720 	struct ipvl_addr *addr;
721 	struct net_device *sdev;
722 
723 	addr = ipvlan_skb_to_addr(skb, dev);
724 	if (!addr)
725 		goto out;
726 
727 	sdev = addr->master->dev;
728 	switch (proto) {
729 	case AF_INET:
730 	{
731 		int err;
732 		struct iphdr *ip4h = ip_hdr(skb);
733 
734 		err = ip_route_input_noref(skb, ip4h->daddr, ip4h->saddr,
735 					   ip4h->tos, sdev);
736 		if (unlikely(err))
737 			goto out;
738 		break;
739 	}
740 	case AF_INET6:
741 	{
742 		struct dst_entry *dst;
743 		struct ipv6hdr *ip6h = ipv6_hdr(skb);
744 		int flags = RT6_LOOKUP_F_HAS_SADDR;
745 		struct flowi6 fl6 = {
746 			.flowi6_iif   = sdev->ifindex,
747 			.daddr        = ip6h->daddr,
748 			.saddr        = ip6h->saddr,
749 			.flowlabel    = ip6_flowinfo(ip6h),
750 			.flowi6_mark  = skb->mark,
751 			.flowi6_proto = ip6h->nexthdr,
752 		};
753 
754 		skb_dst_drop(skb);
755 		dst = ip6_route_input_lookup(dev_net(sdev), sdev, &fl6, flags);
756 		skb_dst_set(skb, dst);
757 		break;
758 	}
759 	default:
760 		break;
761 	}
762 
763 out:
764 	return skb;
765 }
766 
767 unsigned int ipvlan_nf_input(void *priv, struct sk_buff *skb,
768 			     const struct nf_hook_state *state)
769 {
770 	struct ipvl_addr *addr;
771 	unsigned int len;
772 
773 	addr = ipvlan_skb_to_addr(skb, skb->dev);
774 	if (!addr)
775 		goto out;
776 
777 	skb->dev = addr->master->dev;
778 	len = skb->len + ETH_HLEN;
779 	ipvlan_count_rx(addr->master, len, true, false);
780 out:
781 	return NF_ACCEPT;
782 }
783