xref: /openbmc/linux/drivers/net/ipvlan/ipvlan_core.c (revision e2f1cf25)
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 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 hlocal, dlocal;
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 		ethh = eth_hdr(skb);
211 		hlocal = ether_addr_equal(ethh->h_source, port->dev->dev_addr);
212 		mac_hash = ipvlan_mac_hash(ethh->h_dest);
213 
214 		if (ether_addr_equal(ethh->h_dest, port->dev->broadcast))
215 			pkt_type = PACKET_BROADCAST;
216 		else
217 			pkt_type = PACKET_MULTICAST;
218 
219 		dlocal = false;
220 		rcu_read_lock();
221 		list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
222 			if (hlocal && (ipvlan->dev == skb->dev)) {
223 				dlocal = true;
224 				continue;
225 			}
226 			if (!test_bit(mac_hash, ipvlan->mac_filters))
227 				continue;
228 
229 			ret = NET_RX_DROP;
230 			len = skb->len + ETH_HLEN;
231 			nskb = skb_clone(skb, GFP_ATOMIC);
232 			if (!nskb)
233 				goto acct;
234 
235 			nskb->pkt_type = pkt_type;
236 			nskb->dev = ipvlan->dev;
237 			if (hlocal)
238 				ret = dev_forward_skb(ipvlan->dev, nskb);
239 			else
240 				ret = netif_rx(nskb);
241 acct:
242 			ipvlan_count_rx(ipvlan, len, ret == NET_RX_SUCCESS, true);
243 		}
244 		rcu_read_unlock();
245 
246 		if (dlocal) {
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 			kfree_skb(skb);
253 		}
254 	}
255 }
256 
257 static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff *skb,
258 			    bool local)
259 {
260 	struct ipvl_dev *ipvlan = addr->master;
261 	struct net_device *dev = ipvlan->dev;
262 	unsigned int len;
263 	rx_handler_result_t ret = RX_HANDLER_CONSUMED;
264 	bool success = false;
265 
266 	len = skb->len + ETH_HLEN;
267 	if (unlikely(!(dev->flags & IFF_UP))) {
268 		kfree_skb(skb);
269 		goto out;
270 	}
271 
272 	skb = skb_share_check(skb, GFP_ATOMIC);
273 	if (!skb)
274 		goto out;
275 
276 	skb->dev = dev;
277 	skb->pkt_type = PACKET_HOST;
278 
279 	if (local) {
280 		if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)
281 			success = true;
282 	} else {
283 		ret = RX_HANDLER_ANOTHER;
284 		success = true;
285 	}
286 
287 out:
288 	ipvlan_count_rx(ipvlan, len, success, false);
289 	return ret;
290 }
291 
292 static struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port,
293 					    void *lyr3h, int addr_type,
294 					    bool use_dest)
295 {
296 	struct ipvl_addr *addr = NULL;
297 
298 	if (addr_type == IPVL_IPV6) {
299 		struct ipv6hdr *ip6h;
300 		struct in6_addr *i6addr;
301 
302 		ip6h = (struct ipv6hdr *)lyr3h;
303 		i6addr = use_dest ? &ip6h->daddr : &ip6h->saddr;
304 		addr = ipvlan_ht_addr_lookup(port, i6addr, true);
305 	} else if (addr_type == IPVL_ICMPV6) {
306 		struct nd_msg *ndmh;
307 		struct in6_addr *i6addr;
308 
309 		/* Make sure that the NeighborSolicitation ICMPv6 packets
310 		 * are handled to avoid DAD issue.
311 		 */
312 		ndmh = (struct nd_msg *)lyr3h;
313 		if (ndmh->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
314 			i6addr = &ndmh->target;
315 			addr = ipvlan_ht_addr_lookup(port, i6addr, true);
316 		}
317 	} else if (addr_type == IPVL_IPV4) {
318 		struct iphdr *ip4h;
319 		__be32 *i4addr;
320 
321 		ip4h = (struct iphdr *)lyr3h;
322 		i4addr = use_dest ? &ip4h->daddr : &ip4h->saddr;
323 		addr = ipvlan_ht_addr_lookup(port, i4addr, false);
324 	} else if (addr_type == IPVL_ARP) {
325 		struct arphdr *arph;
326 		unsigned char *arp_ptr;
327 		__be32 dip;
328 
329 		arph = (struct arphdr *)lyr3h;
330 		arp_ptr = (unsigned char *)(arph + 1);
331 		if (use_dest)
332 			arp_ptr += (2 * port->dev->addr_len) + 4;
333 		else
334 			arp_ptr += port->dev->addr_len;
335 
336 		memcpy(&dip, arp_ptr, 4);
337 		addr = ipvlan_ht_addr_lookup(port, &dip, false);
338 	}
339 
340 	return addr;
341 }
342 
343 static int ipvlan_process_v4_outbound(struct sk_buff *skb)
344 {
345 	const struct iphdr *ip4h = ip_hdr(skb);
346 	struct net_device *dev = skb->dev;
347 	struct rtable *rt;
348 	int err, ret = NET_XMIT_DROP;
349 	struct flowi4 fl4 = {
350 		.flowi4_oif = dev_get_iflink(dev),
351 		.flowi4_tos = RT_TOS(ip4h->tos),
352 		.flowi4_flags = FLOWI_FLAG_ANYSRC,
353 		.daddr = ip4h->daddr,
354 		.saddr = ip4h->saddr,
355 	};
356 
357 	rt = ip_route_output_flow(dev_net(dev), &fl4, NULL);
358 	if (IS_ERR(rt))
359 		goto err;
360 
361 	if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
362 		ip_rt_put(rt);
363 		goto err;
364 	}
365 	skb_dst_drop(skb);
366 	skb_dst_set(skb, &rt->dst);
367 	err = ip_local_out(skb);
368 	if (unlikely(net_xmit_eval(err)))
369 		dev->stats.tx_errors++;
370 	else
371 		ret = NET_XMIT_SUCCESS;
372 	goto out;
373 err:
374 	dev->stats.tx_errors++;
375 	kfree_skb(skb);
376 out:
377 	return ret;
378 }
379 
380 static int ipvlan_process_v6_outbound(struct sk_buff *skb)
381 {
382 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
383 	struct net_device *dev = skb->dev;
384 	struct dst_entry *dst;
385 	int err, ret = NET_XMIT_DROP;
386 	struct flowi6 fl6 = {
387 		.flowi6_iif = skb->dev->ifindex,
388 		.daddr = ip6h->daddr,
389 		.saddr = ip6h->saddr,
390 		.flowi6_flags = FLOWI_FLAG_ANYSRC,
391 		.flowlabel = ip6_flowinfo(ip6h),
392 		.flowi6_mark = skb->mark,
393 		.flowi6_proto = ip6h->nexthdr,
394 	};
395 
396 	dst = ip6_route_output(dev_net(dev), NULL, &fl6);
397 	if (dst->error) {
398 		ret = dst->error;
399 		dst_release(dst);
400 		goto err;
401 	}
402 	skb_dst_drop(skb);
403 	skb_dst_set(skb, dst);
404 	err = ip6_local_out(skb);
405 	if (unlikely(net_xmit_eval(err)))
406 		dev->stats.tx_errors++;
407 	else
408 		ret = NET_XMIT_SUCCESS;
409 	goto out;
410 err:
411 	dev->stats.tx_errors++;
412 	kfree_skb(skb);
413 out:
414 	return ret;
415 }
416 
417 static int ipvlan_process_outbound(struct sk_buff *skb,
418 				   const struct ipvl_dev *ipvlan)
419 {
420 	struct ethhdr *ethh = eth_hdr(skb);
421 	int ret = NET_XMIT_DROP;
422 
423 	/* In this mode we dont care about multicast and broadcast traffic */
424 	if (is_multicast_ether_addr(ethh->h_dest)) {
425 		pr_warn_ratelimited("Dropped {multi|broad}cast of type= [%x]\n",
426 				    ntohs(skb->protocol));
427 		kfree_skb(skb);
428 		goto out;
429 	}
430 
431 	/* The ipvlan is a pseudo-L2 device, so the packets that we receive
432 	 * will have L2; which need to discarded and processed further
433 	 * in the net-ns of the main-device.
434 	 */
435 	if (skb_mac_header_was_set(skb)) {
436 		skb_pull(skb, sizeof(*ethh));
437 		skb->mac_header = (typeof(skb->mac_header))~0U;
438 		skb_reset_network_header(skb);
439 	}
440 
441 	if (skb->protocol == htons(ETH_P_IPV6))
442 		ret = ipvlan_process_v6_outbound(skb);
443 	else if (skb->protocol == htons(ETH_P_IP))
444 		ret = ipvlan_process_v4_outbound(skb);
445 	else {
446 		pr_warn_ratelimited("Dropped outbound packet type=%x\n",
447 				    ntohs(skb->protocol));
448 		kfree_skb(skb);
449 	}
450 out:
451 	return ret;
452 }
453 
454 static void ipvlan_multicast_enqueue(struct ipvl_port *port,
455 				     struct sk_buff *skb)
456 {
457 	if (skb->protocol == htons(ETH_P_PAUSE)) {
458 		kfree_skb(skb);
459 		return;
460 	}
461 
462 	spin_lock(&port->backlog.lock);
463 	if (skb_queue_len(&port->backlog) < IPVLAN_QBACKLOG_LIMIT) {
464 		__skb_queue_tail(&port->backlog, skb);
465 		spin_unlock(&port->backlog.lock);
466 		schedule_work(&port->wq);
467 	} else {
468 		spin_unlock(&port->backlog.lock);
469 		atomic_long_inc(&skb->dev->rx_dropped);
470 		kfree_skb(skb);
471 	}
472 }
473 
474 static int ipvlan_xmit_mode_l3(struct sk_buff *skb, struct net_device *dev)
475 {
476 	const struct ipvl_dev *ipvlan = netdev_priv(dev);
477 	void *lyr3h;
478 	struct ipvl_addr *addr;
479 	int addr_type;
480 
481 	lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
482 	if (!lyr3h)
483 		goto out;
484 
485 	addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
486 	if (addr)
487 		return ipvlan_rcv_frame(addr, skb, true);
488 
489 out:
490 	skb->dev = ipvlan->phy_dev;
491 	return ipvlan_process_outbound(skb, ipvlan);
492 }
493 
494 static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
495 {
496 	const struct ipvl_dev *ipvlan = netdev_priv(dev);
497 	struct ethhdr *eth = eth_hdr(skb);
498 	struct ipvl_addr *addr;
499 	void *lyr3h;
500 	int addr_type;
501 
502 	if (ether_addr_equal(eth->h_dest, eth->h_source)) {
503 		lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
504 		if (lyr3h) {
505 			addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
506 			if (addr)
507 				return ipvlan_rcv_frame(addr, skb, true);
508 		}
509 		skb = skb_share_check(skb, GFP_ATOMIC);
510 		if (!skb)
511 			return NET_XMIT_DROP;
512 
513 		/* Packet definitely does not belong to any of the
514 		 * virtual devices, but the dest is local. So forward
515 		 * the skb for the main-dev. At the RX side we just return
516 		 * RX_PASS for it to be processed further on the stack.
517 		 */
518 		return dev_forward_skb(ipvlan->phy_dev, skb);
519 
520 	} else if (is_multicast_ether_addr(eth->h_dest)) {
521 		ipvlan_multicast_enqueue(ipvlan->port, skb);
522 		return NET_XMIT_SUCCESS;
523 	}
524 
525 	skb->dev = ipvlan->phy_dev;
526 	return dev_queue_xmit(skb);
527 }
528 
529 int ipvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
530 {
531 	struct ipvl_dev *ipvlan = netdev_priv(dev);
532 	struct ipvl_port *port = ipvlan_port_get_rcu_bh(ipvlan->phy_dev);
533 
534 	if (!port)
535 		goto out;
536 
537 	if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
538 		goto out;
539 
540 	switch(port->mode) {
541 	case IPVLAN_MODE_L2:
542 		return ipvlan_xmit_mode_l2(skb, dev);
543 	case IPVLAN_MODE_L3:
544 		return ipvlan_xmit_mode_l3(skb, dev);
545 	}
546 
547 	/* Should not reach here */
548 	WARN_ONCE(true, "ipvlan_queue_xmit() called for mode = [%hx]\n",
549 			  port->mode);
550 out:
551 	kfree_skb(skb);
552 	return NET_XMIT_DROP;
553 }
554 
555 static bool ipvlan_external_frame(struct sk_buff *skb, struct ipvl_port *port)
556 {
557 	struct ethhdr *eth = eth_hdr(skb);
558 	struct ipvl_addr *addr;
559 	void *lyr3h;
560 	int addr_type;
561 
562 	if (ether_addr_equal(eth->h_source, skb->dev->dev_addr)) {
563 		lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
564 		if (!lyr3h)
565 			return true;
566 
567 		addr = ipvlan_addr_lookup(port, lyr3h, addr_type, false);
568 		if (addr)
569 			return false;
570 	}
571 
572 	return true;
573 }
574 
575 static rx_handler_result_t ipvlan_handle_mode_l3(struct sk_buff **pskb,
576 						 struct ipvl_port *port)
577 {
578 	void *lyr3h;
579 	int addr_type;
580 	struct ipvl_addr *addr;
581 	struct sk_buff *skb = *pskb;
582 	rx_handler_result_t ret = RX_HANDLER_PASS;
583 
584 	lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
585 	if (!lyr3h)
586 		goto out;
587 
588 	addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
589 	if (addr)
590 		ret = ipvlan_rcv_frame(addr, skb, false);
591 
592 out:
593 	return ret;
594 }
595 
596 static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
597 						 struct ipvl_port *port)
598 {
599 	struct sk_buff *skb = *pskb;
600 	struct ethhdr *eth = eth_hdr(skb);
601 	rx_handler_result_t ret = RX_HANDLER_PASS;
602 	void *lyr3h;
603 	int addr_type;
604 
605 	if (is_multicast_ether_addr(eth->h_dest)) {
606 		if (ipvlan_external_frame(skb, port)) {
607 			struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
608 
609 			/* External frames are queued for device local
610 			 * distribution, but a copy is given to master
611 			 * straight away to avoid sending duplicates later
612 			 * when work-queue processes this frame. This is
613 			 * achieved by returning RX_HANDLER_PASS.
614 			 */
615 			if (nskb)
616 				ipvlan_multicast_enqueue(port, nskb);
617 		}
618 	} else {
619 		struct ipvl_addr *addr;
620 
621 		lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
622 		if (!lyr3h)
623 			return ret;
624 
625 		addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
626 		if (addr)
627 			ret = ipvlan_rcv_frame(addr, skb, false);
628 	}
629 
630 	return ret;
631 }
632 
633 rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
634 {
635 	struct sk_buff *skb = *pskb;
636 	struct ipvl_port *port = ipvlan_port_get_rcu(skb->dev);
637 
638 	if (!port)
639 		return RX_HANDLER_PASS;
640 
641 	switch (port->mode) {
642 	case IPVLAN_MODE_L2:
643 		return ipvlan_handle_mode_l2(pskb, port);
644 	case IPVLAN_MODE_L3:
645 		return ipvlan_handle_mode_l3(pskb, port);
646 	}
647 
648 	/* Should not reach here */
649 	WARN_ONCE(true, "ipvlan_handle_frame() called for mode = [%hx]\n",
650 			  port->mode);
651 	kfree_skb(skb);
652 	return NET_RX_DROP;
653 }
654