drivers/net/ipvlan/ipvlan_core.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /* Copyright (c) 2014 Mahesh Bandewar <maheshb@google.com>
  */

 #include "ipvlan.h"

 static u32 ipvlan_jhash_secret __read_mostly;

 void ipvlan_init_secret(void)
 {
 	net_get_random_once(&ipvlan_jhash_secret, sizeof(ipvlan_jhash_secret));
 }

 void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
 			    unsigned int len, bool success, bool mcast)
 {
 	if (likely(success)) {
 		struct ipvl_pcpu_stats *pcptr;

 		pcptr = this_cpu_ptr(ipvlan->pcpu_stats);
 		u64_stats_update_begin(&pcptr->syncp);
 		pcptr->rx_pkts++;
 		pcptr->rx_bytes += len;
 		if (mcast)
 			pcptr->rx_mcast++;
 		u64_stats_update_end(&pcptr->syncp);
 	} else {
 		this_cpu_inc(ipvlan->pcpu_stats->rx_errs);
 	}
 }
 EXPORT_SYMBOL_GPL(ipvlan_count_rx);

 #if IS_ENABLED(CONFIG_IPV6)
 static u8 ipvlan_get_v6_hash(const void *iaddr)
 {
 	const struct in6_addr *ip6_addr = iaddr;

 	return __ipv6_addr_jhash(ip6_addr, ipvlan_jhash_secret) &
 	       IPVLAN_HASH_MASK;
 }
 #else
 static u8 ipvlan_get_v6_hash(const void *iaddr)
 {
 	return 0;
 }
 #endif

 static u8 ipvlan_get_v4_hash(const void *iaddr)
 {
 	const struct in_addr *ip4_addr = iaddr;

 	return jhash_1word(ip4_addr->s_addr, ipvlan_jhash_secret) &
 	       IPVLAN_HASH_MASK;
 }

 static bool addr_equal(bool is_v6, struct ipvl_addr *addr, const void *iaddr)
 {
 	if (!is_v6 && addr->atype == IPVL_IPV4) {
 		struct in_addr *i4addr = (struct in_addr *)iaddr;

 		return addr->ip4addr.s_addr == i4addr->s_addr;
 #if IS_ENABLED(CONFIG_IPV6)
 	} else if (is_v6 && addr->atype == IPVL_IPV6) {
 		struct in6_addr *i6addr = (struct in6_addr *)iaddr;

 		return ipv6_addr_equal(&addr->ip6addr, i6addr);
 #endif
 	}

 	return false;
 }

 static struct ipvl_addr *ipvlan_ht_addr_lookup(const struct ipvl_port *port,
 					       const void *iaddr, bool is_v6)
 {
 	struct ipvl_addr *addr;
 	u8 hash;

 	hash = is_v6 ? ipvlan_get_v6_hash(iaddr) :
 	       ipvlan_get_v4_hash(iaddr);
 	hlist_for_each_entry_rcu(addr, &port->hlhead[hash], hlnode)
 		if (addr_equal(is_v6, addr, iaddr))
 			return addr;
 	return NULL;
 }

 void ipvlan_ht_addr_add(struct ipvl_dev *ipvlan, struct ipvl_addr *addr)
 {
 	struct ipvl_port *port = ipvlan->port;
 	u8 hash;

 	hash = (addr->atype == IPVL_IPV6) ?
 	       ipvlan_get_v6_hash(&addr->ip6addr) :
 	       ipvlan_get_v4_hash(&addr->ip4addr);
 	if (hlist_unhashed(&addr->hlnode))
 		hlist_add_head_rcu(&addr->hlnode, &port->hlhead[hash]);
 }

 void ipvlan_ht_addr_del(struct ipvl_addr *addr)
 {
 	hlist_del_init_rcu(&addr->hlnode);
 }

 struct ipvl_addr *ipvlan_find_addr(const struct ipvl_dev *ipvlan,
 				   const void *iaddr, bool is_v6)
 {
 	struct ipvl_addr *addr, *ret = NULL;

 	rcu_read_lock();
 	list_for_each_entry_rcu(addr, &ipvlan->addrs, anode) {
 		if (addr_equal(is_v6, addr, iaddr)) {
 			ret = addr;
 			break;
 		}
 	}
 	rcu_read_unlock();
 	return ret;
 }

 bool ipvlan_addr_busy(struct ipvl_port *port, void *iaddr, bool is_v6)
 {
 	struct ipvl_dev *ipvlan;
 	bool ret = false;

 	rcu_read_lock();
 	list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
 		if (ipvlan_find_addr(ipvlan, iaddr, is_v6)) {
 			ret = true;
 			break;
 		}
 	}
 	rcu_read_unlock();
 	return ret;
 }

 void *ipvlan_get_L3_hdr(struct ipvl_port *port, struct sk_buff *skb, int *type)
 {
 	void *lyr3h = NULL;

 	switch (skb->protocol) {
 	case htons(ETH_P_ARP): {
 		struct arphdr *arph;

 		if (unlikely(!pskb_may_pull(skb, arp_hdr_len(port->dev))))
 			return NULL;

 		arph = arp_hdr(skb);
 		*type = IPVL_ARP;
 		lyr3h = arph;
 		break;
 	}
 	case htons(ETH_P_IP): {
 		u32 pktlen;
 		struct iphdr *ip4h;

 		if (unlikely(!pskb_may_pull(skb, sizeof(*ip4h))))
 			return NULL;

 		ip4h = ip_hdr(skb);
 		pktlen = ntohs(ip4h->tot_len);
 		if (ip4h->ihl < 5 || ip4h->version != 4)
 			return NULL;
 		if (skb->len < pktlen || pktlen < (ip4h->ihl * 4))
 			return NULL;

 		*type = IPVL_IPV4;
 		lyr3h = ip4h;
 		break;
 	}
 #if IS_ENABLED(CONFIG_IPV6)
 	case htons(ETH_P_IPV6): {
 		struct ipv6hdr *ip6h;

 		if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h))))
 			return NULL;

 		ip6h = ipv6_hdr(skb);
 		if (ip6h->version != 6)
 			return NULL;

 		*type = IPVL_IPV6;
 		lyr3h = ip6h;
 		/* Only Neighbour Solicitation pkts need different treatment */
 		if (ipv6_addr_any(&ip6h->saddr) &&
 		    ip6h->nexthdr == NEXTHDR_ICMP) {
 			struct icmp6hdr	*icmph;

 			if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h) + sizeof(*icmph))))
 				return NULL;

 			ip6h = ipv6_hdr(skb);
 			icmph = (struct icmp6hdr *)(ip6h + 1);

 			if (icmph->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
 				/* Need to access the ipv6 address in body */
 				if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h) + sizeof(*icmph)
 						+ sizeof(struct in6_addr))))
 					return NULL;

 				ip6h = ipv6_hdr(skb);
 				icmph = (struct icmp6hdr *)(ip6h + 1);
 			}

 			*type = IPVL_ICMPV6;
 			lyr3h = icmph;
 		}
 		break;
 	}
 #endif
 	default:
 		return NULL;
 	}

 	return lyr3h;
 }

 unsigned int ipvlan_mac_hash(const unsigned char *addr)
 {
 	u32 hash = jhash_1word(__get_unaligned_cpu32(addr+2),
 			       ipvlan_jhash_secret);

 	return hash & IPVLAN_MAC_FILTER_MASK;
 }

 void ipvlan_process_multicast(struct work_struct *work)
 {
 	struct ipvl_port *port = container_of(work, struct ipvl_port, wq);
 	struct ethhdr *ethh;
 	struct ipvl_dev *ipvlan;
 	struct sk_buff *skb, *nskb;
 	struct sk_buff_head list;
 	unsigned int len;
 	unsigned int mac_hash;
 	int ret;
 	u8 pkt_type;
 	bool tx_pkt;

 	__skb_queue_head_init(&list);

 	spin_lock_bh(&port->backlog.lock);
 	skb_queue_splice_tail_init(&port->backlog, &list);
 	spin_unlock_bh(&port->backlog.lock);

 	while ((skb = __skb_dequeue(&list)) != NULL) {
 		struct net_device *dev = skb->dev;
 		bool consumed = false;

 		ethh = eth_hdr(skb);
 		tx_pkt = IPVL_SKB_CB(skb)->tx_pkt;
 		mac_hash = ipvlan_mac_hash(ethh->h_dest);

 		if (ether_addr_equal(ethh->h_dest, port->dev->broadcast))
 			pkt_type = PACKET_BROADCAST;
 		else
 			pkt_type = PACKET_MULTICAST;

 		rcu_read_lock();
 		list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
 			if (tx_pkt && (ipvlan->dev == skb->dev))
 				continue;
 			if (!test_bit(mac_hash, ipvlan->mac_filters))
 				continue;
 			if (!(ipvlan->dev->flags & IFF_UP))
 				continue;
 			ret = NET_RX_DROP;
 			len = skb->len + ETH_HLEN;
 			nskb = skb_clone(skb, GFP_ATOMIC);
 			local_bh_disable();
 			if (nskb) {
 				consumed = true;
 				nskb->pkt_type = pkt_type;
 				nskb->dev = ipvlan->dev;
 				if (tx_pkt)
 					ret = dev_forward_skb(ipvlan->dev, nskb);
 				else
 					ret = netif_rx(nskb);
 			}
 			ipvlan_count_rx(ipvlan, len, ret == NET_RX_SUCCESS, true);
 			local_bh_enable();
 		}
 		rcu_read_unlock();

 		if (tx_pkt) {
 			/* If the packet originated here, send it out. */
 			skb->dev = port->dev;
 			skb->pkt_type = pkt_type;
 			dev_queue_xmit(skb);
 		} else {
 			if (consumed)
 				consume_skb(skb);
 			else
 				kfree_skb(skb);
 		}
 		if (dev)
 			dev_put(dev);
 	}
 }

 static void ipvlan_skb_crossing_ns(struct sk_buff *skb, struct net_device *dev)
 {
 	bool xnet = true;

 	if (dev)
 		xnet = !net_eq(dev_net(skb->dev), dev_net(dev));

 	skb_scrub_packet(skb, xnet);
 	if (dev)
 		skb->dev = dev;
 }

 static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff **pskb,
 			    bool local)
 {
 	struct ipvl_dev *ipvlan = addr->master;
 	struct net_device *dev = ipvlan->dev;
 	unsigned int len;
 	rx_handler_result_t ret = RX_HANDLER_CONSUMED;
 	bool success = false;
 	struct sk_buff *skb = *pskb;

 	len = skb->len + ETH_HLEN;
 	/* Only packets exchanged between two local slaves need to have
 	 * device-up check as well as skb-share check.
 	 */
 	if (local) {
 		if (unlikely(!(dev->flags & IFF_UP))) {
 			kfree_skb(skb);
 			goto out;
 		}

 		skb = skb_share_check(skb, GFP_ATOMIC);
 		if (!skb)
 			goto out;

 		*pskb = skb;
 	}

 	if (local) {
 		skb->pkt_type = PACKET_HOST;
 		if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)
 			success = true;
 	} else {
 		skb->dev = dev;
 		ret = RX_HANDLER_ANOTHER;
 		success = true;
 	}

 out:
 	ipvlan_count_rx(ipvlan, len, success, false);
 	return ret;
 }

 struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port, void *lyr3h,
 				     int addr_type, bool use_dest)
 {
 	struct ipvl_addr *addr = NULL;

 	switch (addr_type) {
 #if IS_ENABLED(CONFIG_IPV6)
 	case IPVL_IPV6: {
 		struct ipv6hdr *ip6h;
 		struct in6_addr *i6addr;

 		ip6h = (struct ipv6hdr *)lyr3h;
 		i6addr = use_dest ? &ip6h->daddr : &ip6h->saddr;
 		addr = ipvlan_ht_addr_lookup(port, i6addr, true);
 		break;
 	}
 	case IPVL_ICMPV6: {
 		struct nd_msg *ndmh;
 		struct in6_addr *i6addr;

 		/* Make sure that the NeighborSolicitation ICMPv6 packets
 		 * are handled to avoid DAD issue.
 		 */
 		ndmh = (struct nd_msg *)lyr3h;
 		if (ndmh->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
 			i6addr = &ndmh->target;
 			addr = ipvlan_ht_addr_lookup(port, i6addr, true);
 		}
 		break;
 	}
 #endif
 	case IPVL_IPV4: {
 		struct iphdr *ip4h;
 		__be32 *i4addr;

 		ip4h = (struct iphdr *)lyr3h;
 		i4addr = use_dest ? &ip4h->daddr : &ip4h->saddr;
 		addr = ipvlan_ht_addr_lookup(port, i4addr, false);
 		break;
 	}
 	case IPVL_ARP: {
 		struct arphdr *arph;
 		unsigned char *arp_ptr;
 		__be32 dip;

 		arph = (struct arphdr *)lyr3h;
 		arp_ptr = (unsigned char *)(arph + 1);
 		if (use_dest)
 			arp_ptr += (2 * port->dev->addr_len) + 4;
 		else
 			arp_ptr += port->dev->addr_len;

 		memcpy(&dip, arp_ptr, 4);
 		addr = ipvlan_ht_addr_lookup(port, &dip, false);
 		break;
 	}
 	}

 	return addr;
 }

 static int ipvlan_process_v4_outbound(struct sk_buff *skb)
 {
 	const struct iphdr *ip4h = ip_hdr(skb);
 	struct net_device *dev = skb->dev;
 	struct net *net = dev_net(dev);
 	struct rtable *rt;
 	int err, ret = NET_XMIT_DROP;
 	struct flowi4 fl4 = {
 		.flowi4_oif = dev->ifindex,
 		.flowi4_tos = RT_TOS(ip4h->tos),
 		.flowi4_flags = FLOWI_FLAG_ANYSRC,
 		.flowi4_mark = skb->mark,
 		.daddr = ip4h->daddr,
 		.saddr = ip4h->saddr,
 	};

 	rt = ip_route_output_flow(net, &fl4, NULL);
 	if (IS_ERR(rt))
 		goto err;

 	if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
 		ip_rt_put(rt);
 		goto err;
 	}
 	skb_dst_set(skb, &rt->dst);
 	err = ip_local_out(net, skb->sk, skb);
 	if (unlikely(net_xmit_eval(err)))
 		dev->stats.tx_errors++;
 	else
 		ret = NET_XMIT_SUCCESS;
 	goto out;
 err:
 	dev->stats.tx_errors++;
 	kfree_skb(skb);
 out:
 	return ret;
 }

 #if IS_ENABLED(CONFIG_IPV6)
 static int ipvlan_process_v6_outbound(struct sk_buff *skb)
 {
 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 	struct net_device *dev = skb->dev;
 	struct net *net = dev_net(dev);
 	struct dst_entry *dst;
 	int err, ret = NET_XMIT_DROP;
 	struct flowi6 fl6 = {
 		.flowi6_oif = dev->ifindex,
 		.daddr = ip6h->daddr,
 		.saddr = ip6h->saddr,
 		.flowi6_flags = FLOWI_FLAG_ANYSRC,
 		.flowlabel = ip6_flowinfo(ip6h),
 		.flowi6_mark = skb->mark,
 		.flowi6_proto = ip6h->nexthdr,
 	};

 	dst = ip6_route_output(net, NULL, &fl6);
 	if (dst->error) {
 		ret = dst->error;
 		dst_release(dst);
 		goto err;
 	}
 	skb_dst_set(skb, dst);
 	err = ip6_local_out(net, skb->sk, skb);
 	if (unlikely(net_xmit_eval(err)))
 		dev->stats.tx_errors++;
 	else
 		ret = NET_XMIT_SUCCESS;
 	goto out;
 err:
 	dev->stats.tx_errors++;
 	kfree_skb(skb);
 out:
 	return ret;
 }
 #else
 static int ipvlan_process_v6_outbound(struct sk_buff *skb)
 {
 	return NET_XMIT_DROP;
 }
 #endif

 static int ipvlan_process_outbound(struct sk_buff *skb)
 {
 	struct ethhdr *ethh = eth_hdr(skb);
 	int ret = NET_XMIT_DROP;

 	/* In this mode we dont care about multicast and broadcast traffic */
 	if (is_multicast_ether_addr(ethh->h_dest)) {
 		pr_debug_ratelimited("Dropped {multi|broad}cast of type=[%x]\n",
 				     ntohs(skb->protocol));
 		kfree_skb(skb);
 		goto out;
 	}

 	/* The ipvlan is a pseudo-L2 device, so the packets that we receive
 	 * will have L2; which need to discarded and processed further
 	 * in the net-ns of the main-device.
 	 */
 	if (skb_mac_header_was_set(skb)) {
 		skb_pull(skb, sizeof(*ethh));
 		skb->mac_header = (typeof(skb->mac_header))~0U;
 		skb_reset_network_header(skb);
 	}

 	if (skb->protocol == htons(ETH_P_IPV6))
 		ret = ipvlan_process_v6_outbound(skb);
 	else if (skb->protocol == htons(ETH_P_IP))
 		ret = ipvlan_process_v4_outbound(skb);
 	else {
 		pr_warn_ratelimited("Dropped outbound packet type=%x\n",
 				    ntohs(skb->protocol));
 		kfree_skb(skb);
 	}
 out:
 	return ret;
 }

 static void ipvlan_multicast_enqueue(struct ipvl_port *port,
 				     struct sk_buff *skb, bool tx_pkt)
 {
 	if (skb->protocol == htons(ETH_P_PAUSE)) {
 		kfree_skb(skb);
 		return;
 	}

 	/* Record that the deferred packet is from TX or RX path. By
 	 * looking at mac-addresses on packet will lead to erronus decisions.
 	 * (This would be true for a loopback-mode on master device or a
 	 * hair-pin mode of the switch.)
 	 */
 	IPVL_SKB_CB(skb)->tx_pkt = tx_pkt;

 	spin_lock(&port->backlog.lock);
 	if (skb_queue_len(&port->backlog) < IPVLAN_QBACKLOG_LIMIT) {
 		if (skb->dev)
 			dev_hold(skb->dev);
 		__skb_queue_tail(&port->backlog, skb);
 		spin_unlock(&port->backlog.lock);
 		schedule_work(&port->wq);
 	} else {
 		spin_unlock(&port->backlog.lock);
 		atomic_long_inc(&skb->dev->rx_dropped);
 		kfree_skb(skb);
 	}
 }

 static int ipvlan_xmit_mode_l3(struct sk_buff *skb, struct net_device *dev)
 {
 	const struct ipvl_dev *ipvlan = netdev_priv(dev);
 	void *lyr3h;
 	struct ipvl_addr *addr;
 	int addr_type;

 	lyr3h = ipvlan_get_L3_hdr(ipvlan->port, skb, &addr_type);
 	if (!lyr3h)
 		goto out;

 	if (!ipvlan_is_vepa(ipvlan->port)) {
 		addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
 		if (addr) {
 			if (ipvlan_is_private(ipvlan->port)) {
 				consume_skb(skb);
 				return NET_XMIT_DROP;
 			}
 			return ipvlan_rcv_frame(addr, &skb, true);
 		}
 	}
 out:
 	ipvlan_skb_crossing_ns(skb, ipvlan->phy_dev);
 	return ipvlan_process_outbound(skb);
 }

 static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
 {
 	const struct ipvl_dev *ipvlan = netdev_priv(dev);
 	struct ethhdr *eth = eth_hdr(skb);
 	struct ipvl_addr *addr;
 	void *lyr3h;
 	int addr_type;

 	if (!ipvlan_is_vepa(ipvlan->port) &&
 	    ether_addr_equal(eth->h_dest, eth->h_source)) {
 		lyr3h = ipvlan_get_L3_hdr(ipvlan->port, skb, &addr_type);
 		if (lyr3h) {
 			addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
 			if (addr) {
 				if (ipvlan_is_private(ipvlan->port)) {
 					consume_skb(skb);
 					return NET_XMIT_DROP;
 				}
 				return ipvlan_rcv_frame(addr, &skb, true);
 			}
 		}
 		skb = skb_share_check(skb, GFP_ATOMIC);
 		if (!skb)
 			return NET_XMIT_DROP;

 		/* Packet definitely does not belong to any of the
 		 * virtual devices, but the dest is local. So forward
 		 * the skb for the main-dev. At the RX side we just return
 		 * RX_PASS for it to be processed further on the stack.
 		 */
 		return dev_forward_skb(ipvlan->phy_dev, skb);

 	} else if (is_multicast_ether_addr(eth->h_dest)) {
 		ipvlan_skb_crossing_ns(skb, NULL);
 		ipvlan_multicast_enqueue(ipvlan->port, skb, true);
 		return NET_XMIT_SUCCESS;
 	}

 	skb->dev = ipvlan->phy_dev;
 	return dev_queue_xmit(skb);
 }

 int ipvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct ipvl_dev *ipvlan = netdev_priv(dev);
 	struct ipvl_port *port = ipvlan_port_get_rcu_bh(ipvlan->phy_dev);

 	if (!port)
 		goto out;

 	if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
 		goto out;

 	switch(port->mode) {
 	case IPVLAN_MODE_L2:
 		return ipvlan_xmit_mode_l2(skb, dev);
 	case IPVLAN_MODE_L3:
 #ifdef CONFIG_IPVLAN_L3S
 	case IPVLAN_MODE_L3S:
 #endif
 		return ipvlan_xmit_mode_l3(skb, dev);
 	}

 	/* Should not reach here */
 	WARN_ONCE(true, "ipvlan_queue_xmit() called for mode = [%hx]\n",
 			  port->mode);
 out:
 	kfree_skb(skb);
 	return NET_XMIT_DROP;
 }

 static bool ipvlan_external_frame(struct sk_buff *skb, struct ipvl_port *port)
 {
 	struct ethhdr *eth = eth_hdr(skb);
 	struct ipvl_addr *addr;
 	void *lyr3h;
 	int addr_type;

 	if (ether_addr_equal(eth->h_source, skb->dev->dev_addr)) {
 		lyr3h = ipvlan_get_L3_hdr(port, skb, &addr_type);
 		if (!lyr3h)
 			return true;

 		addr = ipvlan_addr_lookup(port, lyr3h, addr_type, false);
 		if (addr)
 			return false;
 	}

 	return true;
 }

 static rx_handler_result_t ipvlan_handle_mode_l3(struct sk_buff **pskb,
 						 struct ipvl_port *port)
 {
 	void *lyr3h;
 	int addr_type;
 	struct ipvl_addr *addr;
 	struct sk_buff *skb = *pskb;
 	rx_handler_result_t ret = RX_HANDLER_PASS;

 	lyr3h = ipvlan_get_L3_hdr(port, skb, &addr_type);
 	if (!lyr3h)
 		goto out;

 	addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
 	if (addr)
 		ret = ipvlan_rcv_frame(addr, pskb, false);

 out:
 	return ret;
 }

 static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
 						 struct ipvl_port *port)
 {
 	struct sk_buff *skb = *pskb;
 	struct ethhdr *eth = eth_hdr(skb);
 	rx_handler_result_t ret = RX_HANDLER_PASS;

 	if (is_multicast_ether_addr(eth->h_dest)) {
 		if (ipvlan_external_frame(skb, port)) {
 			struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);

 			/* External frames are queued for device local
 			 * distribution, but a copy is given to master
 			 * straight away to avoid sending duplicates later
 			 * when work-queue processes this frame. This is
 			 * achieved by returning RX_HANDLER_PASS.
 			 */
 			if (nskb) {
 				ipvlan_skb_crossing_ns(nskb, NULL);
 				ipvlan_multicast_enqueue(port, nskb, false);
 			}
 		}
 	} else {
 		/* Perform like l3 mode for non-multicast packet */
 		ret = ipvlan_handle_mode_l3(pskb, port);
 	}

 	return ret;
 }

 rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
 {
 	struct sk_buff *skb = *pskb;
 	struct ipvl_port *port = ipvlan_port_get_rcu(skb->dev);

 	if (!port)
 		return RX_HANDLER_PASS;

 	switch (port->mode) {
 	case IPVLAN_MODE_L2:
 		return ipvlan_handle_mode_l2(pskb, port);
 	case IPVLAN_MODE_L3:
 		return ipvlan_handle_mode_l3(pskb, port);
 #ifdef CONFIG_IPVLAN_L3S
 	case IPVLAN_MODE_L3S:
 		return RX_HANDLER_PASS;
 #endif
 	}

 	/* Should not reach here */
 	WARN_ONCE(true, "ipvlan_handle_frame() called for mode = [%hx]\n",
 			  port->mode);
 	kfree_skb(skb);
 	return RX_HANDLER_CONSUMED;
 }
	// SPDX-License-Identifier: GPL-2.0-or-later
	/* Copyright (c) 2014 Mahesh Bandewar <maheshb@google.com>
	*/

	#include "ipvlan.h"

	static u32 ipvlan_jhash_secret __read_mostly;

	void ipvlan_init_secret(void)
	{
	net_get_random_once(&ipvlan_jhash_secret, sizeof(ipvlan_jhash_secret));
	}

	void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
	unsigned int len, bool success, bool mcast)
	{
	if (likely(success)) {
	struct ipvl_pcpu_stats *pcptr;

	pcptr = this_cpu_ptr(ipvlan->pcpu_stats);
	u64_stats_update_begin(&pcptr->syncp);
	pcptr->rx_pkts++;
	pcptr->rx_bytes += len;
	if (mcast)
	pcptr->rx_mcast++;
	u64_stats_update_end(&pcptr->syncp);
	} else {
	this_cpu_inc(ipvlan->pcpu_stats->rx_errs);
	}
	}
	EXPORT_SYMBOL_GPL(ipvlan_count_rx);

	#if IS_ENABLED(CONFIG_IPV6)
	static u8 ipvlan_get_v6_hash(const void *iaddr)
	{
	const struct in6_addr *ip6_addr = iaddr;

	return __ipv6_addr_jhash(ip6_addr, ipvlan_jhash_secret) &
	IPVLAN_HASH_MASK;
	}
	#else
	static u8 ipvlan_get_v6_hash(const void *iaddr)
	{
	return 0;
	}
	#endif

	static u8 ipvlan_get_v4_hash(const void *iaddr)
	{
	const struct in_addr *ip4_addr = iaddr;

	return jhash_1word(ip4_addr->s_addr, ipvlan_jhash_secret) &
	IPVLAN_HASH_MASK;
	}

	static bool addr_equal(bool is_v6, struct ipvl_addr addr, const void iaddr)
	{
	if (!is_v6 && addr->atype == IPVL_IPV4) {
	struct in_addr i4addr = (struct in_addr )iaddr;

	return addr->ip4addr.s_addr == i4addr->s_addr;
	#if IS_ENABLED(CONFIG_IPV6)
	} else if (is_v6 && addr->atype == IPVL_IPV6) {
	struct in6_addr i6addr = (struct in6_addr )iaddr;

	return ipv6_addr_equal(&addr->ip6addr, i6addr);
	#endif
	}

	return false;
	}

	static struct ipvl_addr ipvlan_ht_addr_lookup(const struct ipvl_port port,
	const void *iaddr, bool is_v6)
	{
	struct ipvl_addr *addr;
	u8 hash;

	hash = is_v6 ? ipvlan_get_v6_hash(iaddr) :
	ipvlan_get_v4_hash(iaddr);
	hlist_for_each_entry_rcu(addr, &port->hlhead[hash], hlnode)
	if (addr_equal(is_v6, addr, iaddr))
	return addr;
	return NULL;
	}

	void ipvlan_ht_addr_add(struct ipvl_dev ipvlan, struct ipvl_addr addr)
	{
	struct ipvl_port *port = ipvlan->port;
	u8 hash;

	hash = (addr->atype == IPVL_IPV6) ?
	ipvlan_get_v6_hash(&addr->ip6addr) :
	ipvlan_get_v4_hash(&addr->ip4addr);
	if (hlist_unhashed(&addr->hlnode))
	hlist_add_head_rcu(&addr->hlnode, &port->hlhead[hash]);
	}

	void ipvlan_ht_addr_del(struct ipvl_addr *addr)
	{
	hlist_del_init_rcu(&addr->hlnode);
	}

	struct ipvl_addr ipvlan_find_addr(const struct ipvl_dev ipvlan,
	const void *iaddr, bool is_v6)
	{
	struct ipvl_addr addr, ret = NULL;

	rcu_read_lock();
	list_for_each_entry_rcu(addr, &ipvlan->addrs, anode) {
	if (addr_equal(is_v6, addr, iaddr)) {
	ret = addr;
	break;
	}
	}
	rcu_read_unlock();
	return ret;
	}

	bool ipvlan_addr_busy(struct ipvl_port port, void iaddr, bool is_v6)
	{
	struct ipvl_dev *ipvlan;
	bool ret = false;

	rcu_read_lock();
	list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
	if (ipvlan_find_addr(ipvlan, iaddr, is_v6)) {
	ret = true;
	break;
	}
	}
	rcu_read_unlock();
	return ret;
	}

	void ipvlan_get_L3_hdr(struct ipvl_port port, struct sk_buff skb, int type)
	{
	void *lyr3h = NULL;

	switch (skb->protocol) {
	case htons(ETH_P_ARP): {
	struct arphdr *arph;

	if (unlikely(!pskb_may_pull(skb, arp_hdr_len(port->dev))))
	return NULL;

	arph = arp_hdr(skb);
	*type = IPVL_ARP;
	lyr3h = arph;
	break;
	}
	case htons(ETH_P_IP): {
	u32 pktlen;
	struct iphdr *ip4h;

	if (unlikely(!pskb_may_pull(skb, sizeof(*ip4h))))
	return NULL;

	ip4h = ip_hdr(skb);
	pktlen = ntohs(ip4h->tot_len);
	if (ip4h->ihl < 5 \|\| ip4h->version != 4)
	return NULL;
	if (skb->len < pktlen \|\| pktlen < (ip4h->ihl * 4))
	return NULL;

	*type = IPVL_IPV4;
	lyr3h = ip4h;
	break;
	}
	#if IS_ENABLED(CONFIG_IPV6)
	case htons(ETH_P_IPV6): {
	struct ipv6hdr *ip6h;

	if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h))))
	return NULL;

	ip6h = ipv6_hdr(skb);
	if (ip6h->version != 6)
	return NULL;

	*type = IPVL_IPV6;
	lyr3h = ip6h;
	/* Only Neighbour Solicitation pkts need different treatment */
	if (ipv6_addr_any(&ip6h->saddr) &&
	ip6h->nexthdr == NEXTHDR_ICMP) {
	struct icmp6hdr *icmph;

	if (unlikely(!pskb_may_pull(skb, sizeof(ip6h) + sizeof(icmph))))
	return NULL;

	ip6h = ipv6_hdr(skb);
	icmph = (struct icmp6hdr *)(ip6h + 1);

	if (icmph->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
	/* Need to access the ipv6 address in body */
	if (unlikely(!pskb_may_pull(skb, sizeof(ip6h) + sizeof(icmph)
	+ sizeof(struct in6_addr))))
	return NULL;

	ip6h = ipv6_hdr(skb);
	icmph = (struct icmp6hdr *)(ip6h + 1);
	}

	*type = IPVL_ICMPV6;
	lyr3h = icmph;
	}
	break;
	}
	#endif
	default:
	return NULL;
	}

	return lyr3h;
	}

	unsigned int ipvlan_mac_hash(const unsigned char *addr)
	{
	u32 hash = jhash_1word(__get_unaligned_cpu32(addr+2),
	ipvlan_jhash_secret);

	return hash & IPVLAN_MAC_FILTER_MASK;
	}

	void ipvlan_process_multicast(struct work_struct *work)
	{
	struct ipvl_port *port = container_of(work, struct ipvl_port, wq);
	struct ethhdr *ethh;
	struct ipvl_dev *ipvlan;
	struct sk_buff skb, nskb;
	struct sk_buff_head list;
	unsigned int len;
	unsigned int mac_hash;
	int ret;
	u8 pkt_type;
	bool tx_pkt;

	__skb_queue_head_init(&list);

	spin_lock_bh(&port->backlog.lock);
	skb_queue_splice_tail_init(&port->backlog, &list);
	spin_unlock_bh(&port->backlog.lock);

	while ((skb = __skb_dequeue(&list)) != NULL) {
	struct net_device *dev = skb->dev;
	bool consumed = false;

	ethh = eth_hdr(skb);
	tx_pkt = IPVL_SKB_CB(skb)->tx_pkt;
	mac_hash = ipvlan_mac_hash(ethh->h_dest);

	if (ether_addr_equal(ethh->h_dest, port->dev->broadcast))
	pkt_type = PACKET_BROADCAST;
	else
	pkt_type = PACKET_MULTICAST;

	rcu_read_lock();
	list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
	if (tx_pkt && (ipvlan->dev == skb->dev))
	continue;
	if (!test_bit(mac_hash, ipvlan->mac_filters))
	continue;
	if (!(ipvlan->dev->flags & IFF_UP))
	continue;
	ret = NET_RX_DROP;
	len = skb->len + ETH_HLEN;
	nskb = skb_clone(skb, GFP_ATOMIC);
	local_bh_disable();
	if (nskb) {
	consumed = true;
	nskb->pkt_type = pkt_type;
	nskb->dev = ipvlan->dev;
	if (tx_pkt)
	ret = dev_forward_skb(ipvlan->dev, nskb);
	else
	ret = netif_rx(nskb);
	}
	ipvlan_count_rx(ipvlan, len, ret == NET_RX_SUCCESS, true);
	local_bh_enable();
	}
	rcu_read_unlock();

	if (tx_pkt) {
	/* If the packet originated here, send it out. */
	skb->dev = port->dev;
	skb->pkt_type = pkt_type;
	dev_queue_xmit(skb);
	} else {
	if (consumed)
	consume_skb(skb);
	else
	kfree_skb(skb);
	}
	if (dev)
	dev_put(dev);
	}
	}

	static void ipvlan_skb_crossing_ns(struct sk_buff skb, struct net_device dev)
	{
	bool xnet = true;

	if (dev)
	xnet = !net_eq(dev_net(skb->dev), dev_net(dev));

	skb_scrub_packet(skb, xnet);
	if (dev)
	skb->dev = dev;
	}

	static int ipvlan_rcv_frame(struct ipvl_addr addr, struct sk_buff *pskb,
	bool local)
	{
	struct ipvl_dev *ipvlan = addr->master;
	struct net_device *dev = ipvlan->dev;
	unsigned int len;
	rx_handler_result_t ret = RX_HANDLER_CONSUMED;
	bool success = false;
	struct sk_buff skb = pskb;

	len = skb->len + ETH_HLEN;
	/* Only packets exchanged between two local slaves need to have
	* device-up check as well as skb-share check.
	*/
	if (local) {
	if (unlikely(!(dev->flags & IFF_UP))) {
	kfree_skb(skb);
	goto out;
	}

	skb = skb_share_check(skb, GFP_ATOMIC);
	if (!skb)
	goto out;

	*pskb = skb;
	}

	if (local) {
	skb->pkt_type = PACKET_HOST;
	if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)
	success = true;
	} else {
	skb->dev = dev;
	ret = RX_HANDLER_ANOTHER;
	success = true;
	}

	out:
	ipvlan_count_rx(ipvlan, len, success, false);
	return ret;
	}

	struct ipvl_addr ipvlan_addr_lookup(struct ipvl_port port, void *lyr3h,
	int addr_type, bool use_dest)
	{
	struct ipvl_addr *addr = NULL;

	switch (addr_type) {
	#if IS_ENABLED(CONFIG_IPV6)
	case IPVL_IPV6: {
	struct ipv6hdr *ip6h;
	struct in6_addr *i6addr;

	ip6h = (struct ipv6hdr *)lyr3h;
	i6addr = use_dest ? &ip6h->daddr : &ip6h->saddr;
	addr = ipvlan_ht_addr_lookup(port, i6addr, true);
	break;
	}
	case IPVL_ICMPV6: {
	struct nd_msg *ndmh;
	struct in6_addr *i6addr;

	/* Make sure that the NeighborSolicitation ICMPv6 packets
	* are handled to avoid DAD issue.
	*/
	ndmh = (struct nd_msg *)lyr3h;
	if (ndmh->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
	i6addr = &ndmh->target;
	addr = ipvlan_ht_addr_lookup(port, i6addr, true);
	}
	break;
	}
	#endif
	case IPVL_IPV4: {
	struct iphdr *ip4h;
	__be32 *i4addr;

	ip4h = (struct iphdr *)lyr3h;
	i4addr = use_dest ? &ip4h->daddr : &ip4h->saddr;
	addr = ipvlan_ht_addr_lookup(port, i4addr, false);
	break;
	}
	case IPVL_ARP: {
	struct arphdr *arph;
	unsigned char *arp_ptr;
	__be32 dip;

	arph = (struct arphdr *)lyr3h;
	arp_ptr = (unsigned char *)(arph + 1);
	if (use_dest)
	arp_ptr += (2 * port->dev->addr_len) + 4;
	else
	arp_ptr += port->dev->addr_len;

	memcpy(&dip, arp_ptr, 4);
	addr = ipvlan_ht_addr_lookup(port, &dip, false);
	break;
	}
	}

	return addr;
	}

	static int ipvlan_process_v4_outbound(struct sk_buff *skb)
	{
	const struct iphdr *ip4h = ip_hdr(skb);
	struct net_device *dev = skb->dev;
	struct net *net = dev_net(dev);
	struct rtable *rt;
	int err, ret = NET_XMIT_DROP;
	struct flowi4 fl4 = {
	.flowi4_oif = dev->ifindex,
	.flowi4_tos = RT_TOS(ip4h->tos),
	.flowi4_flags = FLOWI_FLAG_ANYSRC,
	.flowi4_mark = skb->mark,
	.daddr = ip4h->daddr,
	.saddr = ip4h->saddr,
	};

	rt = ip_route_output_flow(net, &fl4, NULL);
	if (IS_ERR(rt))
	goto err;

	if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
	ip_rt_put(rt);
	goto err;
	}
	skb_dst_set(skb, &rt->dst);
	err = ip_local_out(net, skb->sk, skb);
	if (unlikely(net_xmit_eval(err)))
	dev->stats.tx_errors++;
	else
	ret = NET_XMIT_SUCCESS;
	goto out;
	err:
	dev->stats.tx_errors++;
	kfree_skb(skb);
	out:
	return ret;
	}

	#if IS_ENABLED(CONFIG_IPV6)
	static int ipvlan_process_v6_outbound(struct sk_buff *skb)
	{
	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
	struct net_device *dev = skb->dev;
	struct net *net = dev_net(dev);
	struct dst_entry *dst;
	int err, ret = NET_XMIT_DROP;
	struct flowi6 fl6 = {
	.flowi6_oif = dev->ifindex,
	.daddr = ip6h->daddr,
	.saddr = ip6h->saddr,
	.flowi6_flags = FLOWI_FLAG_ANYSRC,
	.flowlabel = ip6_flowinfo(ip6h),
	.flowi6_mark = skb->mark,
	.flowi6_proto = ip6h->nexthdr,
	};

	dst = ip6_route_output(net, NULL, &fl6);
	if (dst->error) {
	ret = dst->error;
	dst_release(dst);
	goto err;
	}
	skb_dst_set(skb, dst);
	err = ip6_local_out(net, skb->sk, skb);
	if (unlikely(net_xmit_eval(err)))
	dev->stats.tx_errors++;
	else
	ret = NET_XMIT_SUCCESS;
	goto out;
	err:
	dev->stats.tx_errors++;
	kfree_skb(skb);
	out:
	return ret;
	}
	#else
	static int ipvlan_process_v6_outbound(struct sk_buff *skb)
	{
	return NET_XMIT_DROP;
	}
	#endif

	static int ipvlan_process_outbound(struct sk_buff *skb)
	{
	struct ethhdr *ethh = eth_hdr(skb);
	int ret = NET_XMIT_DROP;

	/* In this mode we dont care about multicast and broadcast traffic */
	if (is_multicast_ether_addr(ethh->h_dest)) {
	pr_debug_ratelimited("Dropped {multi\|broad}cast of type=[%x]\n",
	ntohs(skb->protocol));
	kfree_skb(skb);
	goto out;
	}

	/* The ipvlan is a pseudo-L2 device, so the packets that we receive
	* will have L2; which need to discarded and processed further
	* in the net-ns of the main-device.
	*/
	if (skb_mac_header_was_set(skb)) {
	skb_pull(skb, sizeof(*ethh));
	skb->mac_header = (typeof(skb->mac_header))~0U;
	skb_reset_network_header(skb);
	}

	if (skb->protocol == htons(ETH_P_IPV6))
	ret = ipvlan_process_v6_outbound(skb);
	else if (skb->protocol == htons(ETH_P_IP))
	ret = ipvlan_process_v4_outbound(skb);
	else {
	pr_warn_ratelimited("Dropped outbound packet type=%x\n",
	ntohs(skb->protocol));
	kfree_skb(skb);
	}
	out:
	return ret;
	}

	static void ipvlan_multicast_enqueue(struct ipvl_port *port,
	struct sk_buff *skb, bool tx_pkt)
	{
	if (skb->protocol == htons(ETH_P_PAUSE)) {
	kfree_skb(skb);
	return;
	}

	/* Record that the deferred packet is from TX or RX path. By
	* looking at mac-addresses on packet will lead to erronus decisions.
	* (This would be true for a loopback-mode on master device or a
	* hair-pin mode of the switch.)
	*/
	IPVL_SKB_CB(skb)->tx_pkt = tx_pkt;

	spin_lock(&port->backlog.lock);
	if (skb_queue_len(&port->backlog) < IPVLAN_QBACKLOG_LIMIT) {
	if (skb->dev)
	dev_hold(skb->dev);
	__skb_queue_tail(&port->backlog, skb);
	spin_unlock(&port->backlog.lock);
	schedule_work(&port->wq);
	} else {
	spin_unlock(&port->backlog.lock);
	atomic_long_inc(&skb->dev->rx_dropped);
	kfree_skb(skb);
	}
	}

	static int ipvlan_xmit_mode_l3(struct sk_buff skb, struct net_device dev)
	{
	const struct ipvl_dev *ipvlan = netdev_priv(dev);
	void *lyr3h;
	struct ipvl_addr *addr;
	int addr_type;

	lyr3h = ipvlan_get_L3_hdr(ipvlan->port, skb, &addr_type);
	if (!lyr3h)
	goto out;

	if (!ipvlan_is_vepa(ipvlan->port)) {
	addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
	if (addr) {
	if (ipvlan_is_private(ipvlan->port)) {
	consume_skb(skb);
	return NET_XMIT_DROP;
	}
	return ipvlan_rcv_frame(addr, &skb, true);
	}
	}
	out:
	ipvlan_skb_crossing_ns(skb, ipvlan->phy_dev);
	return ipvlan_process_outbound(skb);
	}

	static int ipvlan_xmit_mode_l2(struct sk_buff skb, struct net_device dev)
	{
	const struct ipvl_dev *ipvlan = netdev_priv(dev);
	struct ethhdr *eth = eth_hdr(skb);
	struct ipvl_addr *addr;
	void *lyr3h;
	int addr_type;

	if (!ipvlan_is_vepa(ipvlan->port) &&
	ether_addr_equal(eth->h_dest, eth->h_source)) {
	lyr3h = ipvlan_get_L3_hdr(ipvlan->port, skb, &addr_type);
	if (lyr3h) {
	addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
	if (addr) {
	if (ipvlan_is_private(ipvlan->port)) {
	consume_skb(skb);
	return NET_XMIT_DROP;
	}
	return ipvlan_rcv_frame(addr, &skb, true);
	}
	}
	skb = skb_share_check(skb, GFP_ATOMIC);
	if (!skb)
	return NET_XMIT_DROP;

	/* Packet definitely does not belong to any of the
	* virtual devices, but the dest is local. So forward
	* the skb for the main-dev. At the RX side we just return
	* RX_PASS for it to be processed further on the stack.
	*/
	return dev_forward_skb(ipvlan->phy_dev, skb);

	} else if (is_multicast_ether_addr(eth->h_dest)) {
	ipvlan_skb_crossing_ns(skb, NULL);
	ipvlan_multicast_enqueue(ipvlan->port, skb, true);
	return NET_XMIT_SUCCESS;
	}

	skb->dev = ipvlan->phy_dev;
	return dev_queue_xmit(skb);
	}

	int ipvlan_queue_xmit(struct sk_buff skb, struct net_device dev)
	{
	struct ipvl_dev *ipvlan = netdev_priv(dev);
	struct ipvl_port *port = ipvlan_port_get_rcu_bh(ipvlan->phy_dev);

	if (!port)
	goto out;

	if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
	goto out;

	switch(port->mode) {
	case IPVLAN_MODE_L2:
	return ipvlan_xmit_mode_l2(skb, dev);
	case IPVLAN_MODE_L3:
	#ifdef CONFIG_IPVLAN_L3S
	case IPVLAN_MODE_L3S:
	#endif
	return ipvlan_xmit_mode_l3(skb, dev);
	}

	/* Should not reach here */
	WARN_ONCE(true, "ipvlan_queue_xmit() called for mode = [%hx]\n",
	port->mode);
	out:
	kfree_skb(skb);
	return NET_XMIT_DROP;
	}

	static bool ipvlan_external_frame(struct sk_buff skb, struct ipvl_port port)
	{
	struct ethhdr *eth = eth_hdr(skb);
	struct ipvl_addr *addr;
	void *lyr3h;
	int addr_type;

	if (ether_addr_equal(eth->h_source, skb->dev->dev_addr)) {
	lyr3h = ipvlan_get_L3_hdr(port, skb, &addr_type);
	if (!lyr3h)
	return true;

	addr = ipvlan_addr_lookup(port, lyr3h, addr_type, false);
	if (addr)
	return false;
	}

	return true;
	}

	static rx_handler_result_t ipvlan_handle_mode_l3(struct sk_buff **pskb,
	struct ipvl_port *port)
	{
	void *lyr3h;
	int addr_type;
	struct ipvl_addr *addr;
	struct sk_buff skb = pskb;
	rx_handler_result_t ret = RX_HANDLER_PASS;

	lyr3h = ipvlan_get_L3_hdr(port, skb, &addr_type);
	if (!lyr3h)
	goto out;

	addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
	if (addr)
	ret = ipvlan_rcv_frame(addr, pskb, false);

	out:
	return ret;
	}

	static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
	struct ipvl_port *port)
	{
	struct sk_buff skb = pskb;
	struct ethhdr *eth = eth_hdr(skb);
	rx_handler_result_t ret = RX_HANDLER_PASS;

	if (is_multicast_ether_addr(eth->h_dest)) {
	if (ipvlan_external_frame(skb, port)) {
	struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);

	/* External frames are queued for device local
	* distribution, but a copy is given to master
	* straight away to avoid sending duplicates later
	* when work-queue processes this frame. This is
	* achieved by returning RX_HANDLER_PASS.
	*/
	if (nskb) {
	ipvlan_skb_crossing_ns(nskb, NULL);
	ipvlan_multicast_enqueue(port, nskb, false);
	}
	}
	} else {
	/* Perform like l3 mode for non-multicast packet */
	ret = ipvlan_handle_mode_l3(pskb, port);
	}

	return ret;
	}

	rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
	{
	struct sk_buff skb = pskb;
	struct ipvl_port *port = ipvlan_port_get_rcu(skb->dev);

	if (!port)
	return RX_HANDLER_PASS;

	switch (port->mode) {
	case IPVLAN_MODE_L2:
	return ipvlan_handle_mode_l2(pskb, port);
	case IPVLAN_MODE_L3:
	return ipvlan_handle_mode_l3(pskb, port);
	#ifdef CONFIG_IPVLAN_L3S
	case IPVLAN_MODE_L3S:
	return RX_HANDLER_PASS;
	#endif
	}

	/* Should not reach here */
	WARN_ONCE(true, "ipvlan_handle_frame() called for mode = [%hx]\n",
	port->mode);
	kfree_skb(skb);
	return RX_HANDLER_CONSUMED;
	}