1 files changed, 524 insertions, 197 deletions

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 3151acf5ec13..fa32899006a2 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -29,6 +29,9 @@
 #include <linux/if_vlan.h>
 #include <net/tcp.h>
 #include <net/udp.h>
+#include <net/addrconf.h>
+#include <net/ndisc.h>
+#include <net/ip6_checksum.h>
 #include <asm/unaligned.h>
 #include <trace/events/napi.h>
 
@@ -44,6 +47,8 @@ static struct sk_buff_head skb_pool;
 
 static atomic_t trapped;
 
+static struct srcu_struct netpoll_srcu;
+
 #define USEC_PER_POLL	50
 #define NETPOLL_RX_ENABLED  1
 #define NETPOLL_RX_DROP     2
@@ -55,7 +60,8 @@ static atomic_t trapped;
 	 MAX_UDP_CHUNK)
 
 static void zap_completion_queue(void);
-static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo);
+static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo);
+static void netpoll_async_cleanup(struct work_struct *work);
 
 static unsigned int carrier_timeout = 4;
 module_param(carrier_timeout, uint, 0644);
@@ -181,13 +187,13 @@ static void poll_napi(struct net_device *dev)
 	}
 }
 
-static void service_arp_queue(struct netpoll_info *npi)
+static void service_neigh_queue(struct netpoll_info *npi)
 {
 	if (npi) {
 		struct sk_buff *skb;
 
-		while ((skb = skb_dequeue(&npi->arp_tx)))
-			netpoll_arp_reply(skb, npi);
+		while ((skb = skb_dequeue(&npi->neigh_tx)))
+			netpoll_neigh_reply(skb, npi);
 	}
 }
 
@@ -196,35 +202,76 @@ static void netpoll_poll_dev(struct net_device *dev)
 	const struct net_device_ops *ops;
 	struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
 
-	if (!dev || !netif_running(dev))
+	/* Don't do any rx activity if the dev_lock mutex is held
+	 * the dev_open/close paths use this to block netpoll activity
+	 * while changing device state
+	 */
+	if (!mutex_trylock(&ni->dev_lock))
 		return;
 
+	if (!netif_running(dev)) {
+		mutex_unlock(&ni->dev_lock);
+		return;
+	}
+
 	ops = dev->netdev_ops;
-	if (!ops->ndo_poll_controller)
+	if (!ops->ndo_poll_controller) {
+		mutex_unlock(&ni->dev_lock);
 		return;
+	}
 
 	/* Process pending work on NIC */
 	ops->ndo_poll_controller(dev);
 
 	poll_napi(dev);
 
+	mutex_unlock(&ni->dev_lock);
+
 	if (dev->flags & IFF_SLAVE) {
 		if (ni) {
-			struct net_device *bond_dev = dev->master;
+			struct net_device *bond_dev;
 			struct sk_buff *skb;
-			struct netpoll_info *bond_ni = rcu_dereference_bh(bond_dev->npinfo);
-			while ((skb = skb_dequeue(&ni->arp_tx))) {
+			struct netpoll_info *bond_ni;
+
+			bond_dev = netdev_master_upper_dev_get_rcu(dev);
+			bond_ni = rcu_dereference_bh(bond_dev->npinfo);
+			while ((skb = skb_dequeue(&ni->neigh_tx))) {
 				skb->dev = bond_dev;
-				skb_queue_tail(&bond_ni->arp_tx, skb);
+				skb_queue_tail(&bond_ni->neigh_tx, skb);
 			}
 		}
 	}
 
-	service_arp_queue(ni);
+	service_neigh_queue(ni);
 
 	zap_completion_queue();
 }
 
+int netpoll_rx_disable(struct net_device *dev)
+{
+	struct netpoll_info *ni;
+	int idx;
+	might_sleep();
+	idx = srcu_read_lock(&netpoll_srcu);
+	ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
+	if (ni)
+		mutex_lock(&ni->dev_lock);
+	srcu_read_unlock(&netpoll_srcu, idx);
+	return 0;
+}
+EXPORT_SYMBOL(netpoll_rx_disable);
+
+void netpoll_rx_enable(struct net_device *dev)
+{
+	struct netpoll_info *ni;
+	rcu_read_lock();
+	ni = rcu_dereference(dev->npinfo);
+	if (ni)
+		mutex_unlock(&ni->dev_lock);
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL(netpoll_rx_enable);
+
 static void refill_skbs(void)
 {
 	struct sk_buff *skb;
@@ -381,9 +428,14 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 	struct iphdr *iph;
 	struct ethhdr *eth;
 	static atomic_t ip_ident;
+	struct ipv6hdr *ip6h;
 
 	udp_len = len + sizeof(*udph);
-	ip_len = udp_len + sizeof(*iph);
+	if (np->ipv6)
+		ip_len = udp_len + sizeof(*ip6h);
+	else
+		ip_len = udp_len + sizeof(*iph);
+
 	total_len = ip_len + LL_RESERVED_SPACE(np->dev);
 
 	skb = find_skb(np, total_len + np->dev->needed_tailroom,
@@ -400,34 +452,66 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 	udph->source = htons(np->local_port);
 	udph->dest = htons(np->remote_port);
 	udph->len = htons(udp_len);
-	udph->check = 0;
-	udph->check = csum_tcpudp_magic(np->local_ip,
-					np->remote_ip,
-					udp_len, IPPROTO_UDP,
-					csum_partial(udph, udp_len, 0));
-	if (udph->check == 0)
-		udph->check = CSUM_MANGLED_0;
-
-	skb_push(skb, sizeof(*iph));
-	skb_reset_network_header(skb);
-	iph = ip_hdr(skb);
-
-	/* iph->version = 4; iph->ihl = 5; */
-	put_unaligned(0x45, (unsigned char *)iph);
-	iph->tos      = 0;
-	put_unaligned(htons(ip_len), &(iph->tot_len));
-	iph->id       = htons(atomic_inc_return(&ip_ident));
-	iph->frag_off = 0;
-	iph->ttl      = 64;
-	iph->protocol = IPPROTO_UDP;
-	iph->check    = 0;
-	put_unaligned(np->local_ip, &(iph->saddr));
-	put_unaligned(np->remote_ip, &(iph->daddr));
-	iph->check    = ip_fast_csum((unsigned char *)iph, iph->ihl);
-
-	eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
-	skb_reset_mac_header(skb);
-	skb->protocol = eth->h_proto = htons(ETH_P_IP);
+
+	if (np->ipv6) {
+		udph->check = 0;
+		udph->check = csum_ipv6_magic(&np->local_ip.in6,
+					      &np->remote_ip.in6,
+					      udp_len, IPPROTO_UDP,
+					      csum_partial(udph, udp_len, 0));
+		if (udph->check == 0)
+			udph->check = CSUM_MANGLED_0;
+
+		skb_push(skb, sizeof(*ip6h));
+		skb_reset_network_header(skb);
+		ip6h = ipv6_hdr(skb);
+
+		/* ip6h->version = 6; ip6h->priority = 0; */
+		put_unaligned(0x60, (unsigned char *)ip6h);
+		ip6h->flow_lbl[0] = 0;
+		ip6h->flow_lbl[1] = 0;
+		ip6h->flow_lbl[2] = 0;
+
+		ip6h->payload_len = htons(sizeof(struct udphdr) + len);
+		ip6h->nexthdr = IPPROTO_UDP;
+		ip6h->hop_limit = 32;
+		ip6h->saddr = np->local_ip.in6;
+		ip6h->daddr = np->remote_ip.in6;
+
+		eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
+		skb_reset_mac_header(skb);
+		skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
+	} else {
+		udph->check = 0;
+		udph->check = csum_tcpudp_magic(np->local_ip.ip,
+						np->remote_ip.ip,
+						udp_len, IPPROTO_UDP,
+						csum_partial(udph, udp_len, 0));
+		if (udph->check == 0)
+			udph->check = CSUM_MANGLED_0;
+
+		skb_push(skb, sizeof(*iph));
+		skb_reset_network_header(skb);
+		iph = ip_hdr(skb);
+
+		/* iph->version = 4; iph->ihl = 5; */
+		put_unaligned(0x45, (unsigned char *)iph);
+		iph->tos      = 0;
+		put_unaligned(htons(ip_len), &(iph->tot_len));
+		iph->id       = htons(atomic_inc_return(&ip_ident));
+		iph->frag_off = 0;
+		iph->ttl      = 64;
+		iph->protocol = IPPROTO_UDP;
+		iph->check    = 0;
+		put_unaligned(np->local_ip.ip, &(iph->saddr));
+		put_unaligned(np->remote_ip.ip, &(iph->daddr));
+		iph->check    = ip_fast_csum((unsigned char *)iph, iph->ihl);
+
+		eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
+		skb_reset_mac_header(skb);
+		skb->protocol = eth->h_proto = htons(ETH_P_IP);
+	}
+
 	memcpy(eth->h_source, np->dev->dev_addr, ETH_ALEN);
 	memcpy(eth->h_dest, np->remote_mac, ETH_ALEN);
 
@@ -437,18 +521,16 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 }
 EXPORT_SYMBOL(netpoll_send_udp);
 
-static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
+static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
 {
-	struct arphdr *arp;
-	unsigned char *arp_ptr;
-	int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
+	int size, type = ARPOP_REPLY;
 	__be32 sip, tip;
 	unsigned char *sha;
 	struct sk_buff *send_skb;
 	struct netpoll *np, *tmp;
 	unsigned long flags;
 	int hlen, tlen;
-	int hits = 0;
+	int hits = 0, proto;
 
 	if (list_empty(&npinfo->rx_np))
 		return;
@@ -466,94 +548,214 @@ static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
 	if (!hits)
 		return;
 
-	/* No arp on this interface */
-	if (skb->dev->flags & IFF_NOARP)
-		return;
-
-	if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
-		return;
+	proto = ntohs(eth_hdr(skb)->h_proto);
+	if (proto == ETH_P_IP) {
+		struct arphdr *arp;
+		unsigned char *arp_ptr;
+		/* No arp on this interface */
+		if (skb->dev->flags & IFF_NOARP)
+			return;
 
-	skb_reset_network_header(skb);
-	skb_reset_transport_header(skb);
-	arp = arp_hdr(skb);
+		if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
+			return;
 
-	if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
-	     arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
-	    arp->ar_pro != htons(ETH_P_IP) ||
-	    arp->ar_op != htons(ARPOP_REQUEST))
-		return;
+		skb_reset_network_header(skb);
+		skb_reset_transport_header(skb);
+		arp = arp_hdr(skb);
 
-	arp_ptr = (unsigned char *)(arp+1);
-	/* save the location of the src hw addr */
-	sha = arp_ptr;
-	arp_ptr += skb->dev->addr_len;
-	memcpy(&sip, arp_ptr, 4);
-	arp_ptr += 4;
-	/* If we actually cared about dst hw addr,
-	   it would get copied here */
-	arp_ptr += skb->dev->addr_len;
-	memcpy(&tip, arp_ptr, 4);
-
-	/* Should we ignore arp? */
-	if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
-		return;
+		if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
+		     arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
+		    arp->ar_pro != htons(ETH_P_IP) ||
+		    arp->ar_op != htons(ARPOP_REQUEST))
+			return;
 
-	size = arp_hdr_len(skb->dev);
+		arp_ptr = (unsigned char *)(arp+1);
+		/* save the location of the src hw addr */
+		sha = arp_ptr;
+		arp_ptr += skb->dev->addr_len;
+		memcpy(&sip, arp_ptr, 4);
+		arp_ptr += 4;
+		/* If we actually cared about dst hw addr,
+		   it would get copied here */
+		arp_ptr += skb->dev->addr_len;
+		memcpy(&tip, arp_ptr, 4);
 
-	spin_lock_irqsave(&npinfo->rx_lock, flags);
-	list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
-		if (tip != np->local_ip)
-			continue;
+		/* Should we ignore arp? */
+		if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
+			return;
 
-		hlen = LL_RESERVED_SPACE(np->dev);
-		tlen = np->dev->needed_tailroom;
-		send_skb = find_skb(np, size + hlen + tlen, hlen);
-		if (!send_skb)
-			continue;
+		size = arp_hdr_len(skb->dev);
 
-		skb_reset_network_header(send_skb);
-		arp = (struct arphdr *) skb_put(send_skb, size);
-		send_skb->dev = skb->dev;
-		send_skb->protocol = htons(ETH_P_ARP);
+		spin_lock_irqsave(&npinfo->rx_lock, flags);
+		list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
+			if (tip != np->local_ip.ip)
+				continue;
+
+			hlen = LL_RESERVED_SPACE(np->dev);
+			tlen = np->dev->needed_tailroom;
+			send_skb = find_skb(np, size + hlen + tlen, hlen);
+			if (!send_skb)
+				continue;
+
+			skb_reset_network_header(send_skb);
+			arp = (struct arphdr *) skb_put(send_skb, size);
+			send_skb->dev = skb->dev;
+			send_skb->protocol = htons(ETH_P_ARP);
+
+			/* Fill the device header for the ARP frame */
+			if (dev_hard_header(send_skb, skb->dev, ETH_P_ARP,
+					    sha, np->dev->dev_addr,
+					    send_skb->len) < 0) {
+				kfree_skb(send_skb);
+				continue;
+			}
 
-		/* Fill the device header for the ARP frame */
-		if (dev_hard_header(send_skb, skb->dev, ptype,
-				    sha, np->dev->dev_addr,
-				    send_skb->len) < 0) {
-			kfree_skb(send_skb);
-			continue;
+			/*
+			 * Fill out the arp protocol part.
+			 *
+			 * we only support ethernet device type,
+			 * which (according to RFC 1390) should
+			 * always equal 1 (Ethernet).
+			 */
+
+			arp->ar_hrd = htons(np->dev->type);
+			arp->ar_pro = htons(ETH_P_IP);
+			arp->ar_hln = np->dev->addr_len;
+			arp->ar_pln = 4;
+			arp->ar_op = htons(type);
+
+			arp_ptr = (unsigned char *)(arp + 1);
+			memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
+			arp_ptr += np->dev->addr_len;
+			memcpy(arp_ptr, &tip, 4);
+			arp_ptr += 4;
+			memcpy(arp_ptr, sha, np->dev->addr_len);
+			arp_ptr += np->dev->addr_len;
+			memcpy(arp_ptr, &sip, 4);
+
+			netpoll_send_skb(np, send_skb);
+
+			/* If there are several rx_hooks for the same address,
+			   we're fine by sending a single reply */
+			break;
 		}
+		spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+	} else if( proto == ETH_P_IPV6) {
+#if IS_ENABLED(CONFIG_IPV6)
+		struct nd_msg *msg;
+		u8 *lladdr = NULL;
+		struct ipv6hdr *hdr;
+		struct icmp6hdr *icmp6h;
+		const struct in6_addr *saddr;
+		const struct in6_addr *daddr;
+		struct inet6_dev *in6_dev = NULL;
+		struct in6_addr *target;
+
+		in6_dev = in6_dev_get(skb->dev);
+		if (!in6_dev || !in6_dev->cnf.accept_ra)
+			return;
 
-		/*
-		 * Fill out the arp protocol part.
-		 *
-		 * we only support ethernet device type,
-		 * which (according to RFC 1390) should
-		 * always equal 1 (Ethernet).
-		 */
+		if (!pskb_may_pull(skb, skb->len))
+			return;
 
-		arp->ar_hrd = htons(np->dev->type);
-		arp->ar_pro = htons(ETH_P_IP);
-		arp->ar_hln = np->dev->addr_len;
-		arp->ar_pln = 4;
-		arp->ar_op = htons(type);
+		msg = (struct nd_msg *)skb_transport_header(skb);
 
-		arp_ptr = (unsigned char *)(arp + 1);
-		memcpy(arp_ptr, np->dev->dev_addr, np->dev->addr_len);
-		arp_ptr += np->dev->addr_len;
-		memcpy(arp_ptr, &tip, 4);
-		arp_ptr += 4;
-		memcpy(arp_ptr, sha, np->dev->addr_len);
-		arp_ptr += np->dev->addr_len;
-		memcpy(arp_ptr, &sip, 4);
+		__skb_push(skb, skb->data - skb_transport_header(skb));
 
-		netpoll_send_skb(np, send_skb);
+		if (ipv6_hdr(skb)->hop_limit != 255)
+			return;
+		if (msg->icmph.icmp6_code != 0)
+			return;
+		if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
+			return;
+
+		saddr = &ipv6_hdr(skb)->saddr;
+		daddr = &ipv6_hdr(skb)->daddr;
 
-		/* If there are several rx_hooks for the same address,
-		   we're fine by sending a single reply */
-		break;
+		size = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
+
+		spin_lock_irqsave(&npinfo->rx_lock, flags);
+		list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
+			if (!ipv6_addr_equal(daddr, &np->local_ip.in6))
+				continue;
+
+			hlen = LL_RESERVED_SPACE(np->dev);
+			tlen = np->dev->needed_tailroom;
+			send_skb = find_skb(np, size + hlen + tlen, hlen);
+			if (!send_skb)
+				continue;
+
+			send_skb->protocol = htons(ETH_P_IPV6);
+			send_skb->dev = skb->dev;
+
+			skb_reset_network_header(send_skb);
+			skb_put(send_skb, sizeof(struct ipv6hdr));
+			hdr = ipv6_hdr(send_skb);
+
+			*(__be32*)hdr = htonl(0x60000000);
+
+			hdr->payload_len = htons(size);
+			hdr->nexthdr = IPPROTO_ICMPV6;
+			hdr->hop_limit = 255;
+			hdr->saddr = *saddr;
+			hdr->daddr = *daddr;
+
+			send_skb->transport_header = send_skb->tail;
+			skb_put(send_skb, size);
+
+			icmp6h = (struct icmp6hdr *)skb_transport_header(skb);
+			icmp6h->icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
+			icmp6h->icmp6_router = 0;
+			icmp6h->icmp6_solicited = 1;
+			target = (struct in6_addr *)(skb_transport_header(send_skb) + sizeof(struct icmp6hdr));
+			*target = msg->target;
+			icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, size,
+							      IPPROTO_ICMPV6,
+							      csum_partial(icmp6h,
+									   size, 0));
+
+			if (dev_hard_header(send_skb, skb->dev, ETH_P_IPV6,
+					    lladdr, np->dev->dev_addr,
+					    send_skb->len) < 0) {
+				kfree_skb(send_skb);
+				continue;
+			}
+
+			netpoll_send_skb(np, send_skb);
+
+			/* If there are several rx_hooks for the same address,
+			   we're fine by sending a single reply */
+			break;
+		}
+		spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+#endif
 	}
-	spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+}
+
+static bool pkt_is_ns(struct sk_buff *skb)
+{
+	struct nd_msg *msg;
+	struct ipv6hdr *hdr;
+
+	if (skb->protocol != htons(ETH_P_ARP))
+		return false;
+	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct nd_msg)))
+		return false;
+
+	msg = (struct nd_msg *)skb_transport_header(skb);
+	__skb_push(skb, skb->data - skb_transport_header(skb));
+	hdr = ipv6_hdr(skb);
+
+	if (hdr->nexthdr != IPPROTO_ICMPV6)
+		return false;
+	if (hdr->hop_limit != 255)
+		return false;
+	if (msg->icmph.icmp6_code != 0)
+		return false;
+	if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
+		return false;
+
+	return true;
 }
 
 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
@@ -571,9 +773,11 @@ int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
 		goto out;
 
 	/* check if netpoll clients need ARP */
-	if (skb->protocol == htons(ETH_P_ARP) &&
-	    atomic_read(&trapped)) {
-		skb_queue_tail(&npinfo->arp_tx, skb);
+	if (skb->protocol == htons(ETH_P_ARP) && atomic_read(&trapped)) {
+		skb_queue_tail(&npinfo->neigh_tx, skb);
+		return 1;
+	} else if (pkt_is_ns(skb) && atomic_read(&trapped)) {
+		skb_queue_tail(&npinfo->neigh_tx, skb);
 		return 1;
 	}
 
@@ -584,60 +788,100 @@ int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
 	}
 
 	proto = ntohs(eth_hdr(skb)->h_proto);
-	if (proto != ETH_P_IP)
+	if (proto != ETH_P_IP && proto != ETH_P_IPV6)
 		goto out;
 	if (skb->pkt_type == PACKET_OTHERHOST)
 		goto out;
 	if (skb_shared(skb))
 		goto out;
 
-	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
-		goto out;
-	iph = (struct iphdr *)skb->data;
-	if (iph->ihl < 5 || iph->version != 4)
-		goto out;
-	if (!pskb_may_pull(skb, iph->ihl*4))
-		goto out;
-	iph = (struct iphdr *)skb->data;
-	if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
-		goto out;
-
-	len = ntohs(iph->tot_len);
-	if (skb->len < len || len < iph->ihl*4)
-		goto out;
+	if (proto == ETH_P_IP) {
+		if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+			goto out;
+		iph = (struct iphdr *)skb->data;
+		if (iph->ihl < 5 || iph->version != 4)
+			goto out;
+		if (!pskb_may_pull(skb, iph->ihl*4))
+			goto out;
+		iph = (struct iphdr *)skb->data;
+		if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
+			goto out;
 
-	/*
-	 * Our transport medium may have padded the buffer out.
-	 * Now We trim to the true length of the frame.
-	 */
-	if (pskb_trim_rcsum(skb, len))
-		goto out;
+		len = ntohs(iph->tot_len);
+		if (skb->len < len || len < iph->ihl*4)
+			goto out;
 
-	iph = (struct iphdr *)skb->data;
-	if (iph->protocol != IPPROTO_UDP)
-		goto out;
+		/*
+		 * Our transport medium may have padded the buffer out.
+		 * Now We trim to the true length of the frame.
+		 */
+		if (pskb_trim_rcsum(skb, len))
+			goto out;
 
-	len -= iph->ihl*4;
-	uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
-	ulen = ntohs(uh->len);
+		iph = (struct iphdr *)skb->data;
+		if (iph->protocol != IPPROTO_UDP)
+			goto out;
 
-	if (ulen != len)
-		goto out;
-	if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
-		goto out;
+		len -= iph->ihl*4;
+		uh = (struct udphdr *)(((char *)iph) + iph->ihl*4);
+		ulen = ntohs(uh->len);
 
-	list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
-		if (np->local_ip && np->local_ip != iph->daddr)
-			continue;
-		if (np->remote_ip && np->remote_ip != iph->saddr)
-			continue;
-		if (np->local_port && np->local_port != ntohs(uh->dest))
-			continue;
+		if (ulen != len)
+			goto out;
+		if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
+			goto out;
+		list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
+			if (np->local_ip.ip && np->local_ip.ip != iph->daddr)
+				continue;
+			if (np->remote_ip.ip && np->remote_ip.ip != iph->saddr)
+				continue;
+			if (np->local_port && np->local_port != ntohs(uh->dest))
+				continue;
+
+			np->rx_hook(np, ntohs(uh->source),
+				       (char *)(uh+1),
+				       ulen - sizeof(struct udphdr));
+			hits++;
+		}
+	} else {
+#if IS_ENABLED(CONFIG_IPV6)
+		const struct ipv6hdr *ip6h;
 
-		np->rx_hook(np, ntohs(uh->source),
-			       (char *)(uh+1),
-			       ulen - sizeof(struct udphdr));
-		hits++;
+		if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
+			goto out;
+		ip6h = (struct ipv6hdr *)skb->data;
+		if (ip6h->version != 6)
+			goto out;
+		len = ntohs(ip6h->payload_len);
+		if (!len)
+			goto out;
+		if (len + sizeof(struct ipv6hdr) > skb->len)
+			goto out;
+		if (pskb_trim_rcsum(skb, len + sizeof(struct ipv6hdr)))
+			goto out;
+		ip6h = ipv6_hdr(skb);
+		if (!pskb_may_pull(skb, sizeof(struct udphdr)))
+			goto out;
+		uh = udp_hdr(skb);
+		ulen = ntohs(uh->len);
+		if (ulen != skb->len)
+			goto out;
+		if (udp6_csum_init(skb, uh, IPPROTO_UDP))
+			goto out;
+		list_for_each_entry_safe(np, tmp, &npinfo->rx_np, rx) {
+			if (!ipv6_addr_equal(&np->local_ip.in6, &ip6h->daddr))
+				continue;
+			if (!ipv6_addr_equal(&np->remote_ip.in6, &ip6h->saddr))
+				continue;
+			if (np->local_port && np->local_port != ntohs(uh->dest))
+				continue;
+
+			np->rx_hook(np, ntohs(uh->source),
+				       (char *)(uh+1),
+				       ulen - sizeof(struct udphdr));
+			hits++;
+		}
+#endif
 	}
 
 	if (!hits)
@@ -658,17 +902,44 @@ out:
 void netpoll_print_options(struct netpoll *np)
 {
 	np_info(np, "local port %d\n", np->local_port);
-	np_info(np, "local IP %pI4\n", &np->local_ip);
+	if (np->ipv6)
+		np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
+	else
+		np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
 	np_info(np, "interface '%s'\n", np->dev_name);
 	np_info(np, "remote port %d\n", np->remote_port);
-	np_info(np, "remote IP %pI4\n", &np->remote_ip);
+	if (np->ipv6)
+		np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
+	else
+		np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
 	np_info(np, "remote ethernet address %pM\n", np->remote_mac);
 }
 EXPORT_SYMBOL(netpoll_print_options);
 
+static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
+{
+	const char *end;
+
+	if (!strchr(str, ':') &&
+	    in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
+		if (!*end)
+			return 0;
+	}
+	if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
+#if IS_ENABLED(CONFIG_IPV6)
+		if (!*end)
+			return 1;
+#else
+		return -1;
+#endif
+	}
+	return -1;
+}
+
 int netpoll_parse_options(struct netpoll *np, char *opt)
 {
 	char *cur=opt, *delim;
+	int ipv6;
 
 	if (*cur != '@') {
 		if ((delim = strchr(cur, '@')) == NULL)
@@ -684,7 +955,11 @@ int netpoll_parse_options(struct netpoll *np, char *opt)
 		if ((delim = strchr(cur, '/')) == NULL)
 			goto parse_failed;
 		*delim = 0;
-		np->local_ip = in_aton(cur);
+		ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
+		if (ipv6 < 0)
+			goto parse_failed;
+		else
+			np->ipv6 = (bool)ipv6;
 		cur = delim;
 	}
 	cur++;
@@ -716,7 +991,13 @@ int netpoll_parse_options(struct netpoll *np, char *opt)
 	if ((delim = strchr(cur, '/')) == NULL)
 		goto parse_failed;
 	*delim = 0;
-	np->remote_ip = in_aton(cur);
+	ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
+	if (ipv6 < 0)
+		goto parse_failed;
+	else if (np->ipv6 != (bool)ipv6)
+		goto parse_failed;
+	else
+		np->ipv6 = (bool)ipv6;
 	cur = delim + 1;
 
 	if (*cur != 0) {
@@ -744,6 +1025,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
 
 	np->dev = ndev;
 	strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
+	INIT_WORK(&np->cleanup_work, netpoll_async_cleanup);
 
 	if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
 	    !ndev->netdev_ops->ndo_poll_controller) {
@@ -764,7 +1046,8 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
 		INIT_LIST_HEAD(&npinfo->rx_np);
 
 		spin_lock_init(&npinfo->rx_lock);
-		skb_queue_head_init(&npinfo->arp_tx);
+		mutex_init(&npinfo->dev_lock);
+		skb_queue_head_init(&npinfo->neigh_tx);
 		skb_queue_head_init(&npinfo->txq);
 		INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
 
@@ -777,7 +1060,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
 				goto free_npinfo;
 		}
 	} else {
-		npinfo = ndev->npinfo;
+		npinfo = rtnl_dereference(ndev->npinfo);
 		atomic_inc(&npinfo->refcnt);
 	}
 
@@ -808,14 +1091,19 @@ int netpoll_setup(struct netpoll *np)
 	struct in_device *in_dev;
 	int err;
 
-	if (np->dev_name)
-		ndev = dev_get_by_name(&init_net, np->dev_name);
+	rtnl_lock();
+	if (np->dev_name) {
+		struct net *net = current->nsproxy->net_ns;
+		ndev = __dev_get_by_name(net, np->dev_name);
+	}
 	if (!ndev) {
 		np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
-		return -ENODEV;
+		err = -ENODEV;
+		goto unlock;
 	}
+	dev_hold(ndev);
 
-	if (ndev->master) {
+	if (netdev_master_upper_dev_get(ndev)) {
 		np_err(np, "%s is a slave device, aborting\n", np->dev_name);
 		err = -EBUSY;
 		goto put;
@@ -826,15 +1114,14 @@ int netpoll_setup(struct netpoll *np)
 
 		np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
 
-		rtnl_lock();
 		err = dev_open(ndev);
-		rtnl_unlock();
 
 		if (err) {
 			np_err(np, "failed to open %s\n", ndev->name);
 			goto put;
 		}
 
+		rtnl_unlock();
 		atleast = jiffies + HZ/10;
 		atmost = jiffies + carrier_timeout * HZ;
 		while (!netif_carrier_ok(ndev)) {
@@ -854,39 +1141,70 @@ int netpoll_setup(struct netpoll *np)
 			np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
 			msleep(4000);
 		}
+		rtnl_lock();
 	}
 
-	if (!np->local_ip) {
-		rcu_read_lock();
-		in_dev = __in_dev_get_rcu(ndev);
+	if (!np->local_ip.ip) {
+		if (!np->ipv6) {
+			in_dev = __in_dev_get_rtnl(ndev);
+
+			if (!in_dev || !in_dev->ifa_list) {
+				np_err(np, "no IP address for %s, aborting\n",
+				       np->dev_name);
+				err = -EDESTADDRREQ;
+				goto put;
+			}
+
+			np->local_ip.ip = in_dev->ifa_list->ifa_local;
+			np_info(np, "local IP %pI4\n", &np->local_ip.ip);
+		} else {
+#if IS_ENABLED(CONFIG_IPV6)
+			struct inet6_dev *idev;
 
-		if (!in_dev || !in_dev->ifa_list) {
-			rcu_read_unlock();
-			np_err(np, "no IP address for %s, aborting\n",
-			       np->dev_name);
 			err = -EDESTADDRREQ;
+			idev = __in6_dev_get(ndev);
+			if (idev) {
+				struct inet6_ifaddr *ifp;
+
+				read_lock_bh(&idev->lock);
+				list_for_each_entry(ifp, &idev->addr_list, if_list) {
+					if (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)
+						continue;
+					np->local_ip.in6 = ifp->addr;
+					err = 0;
+					break;
+				}
+				read_unlock_bh(&idev->lock);
+			}
+			if (err) {
+				np_err(np, "no IPv6 address for %s, aborting\n",
+				       np->dev_name);
+				goto put;
+			} else
+				np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
+#else
+			np_err(np, "IPv6 is not supported %s, aborting\n",
+			       np->dev_name);
+			err = -EINVAL;
 			goto put;
+#endif
 		}
-
-		np->local_ip = in_dev->ifa_list->ifa_local;
-		rcu_read_unlock();
-		np_info(np, "local IP %pI4\n", &np->local_ip);
 	}
 
 	/* fill up the skb queue */
 	refill_skbs();
 
-	rtnl_lock();
 	err = __netpoll_setup(np, ndev, GFP_KERNEL);
-	rtnl_unlock();
-
 	if (err)
 		goto put;
 
+	rtnl_unlock();
 	return 0;
 
 put:
 	dev_put(ndev);
+unlock:
+	rtnl_unlock();
 	return err;
 }
 EXPORT_SYMBOL(netpoll_setup);
@@ -894,6 +1212,7 @@ EXPORT_SYMBOL(netpoll_setup);
 static int __init netpoll_init(void)
 {
 	skb_queue_head_init(&skb_pool);
+	init_srcu_struct(&netpoll_srcu);
 	return 0;
 }
 core_initcall(netpoll_init);
@@ -903,7 +1222,7 @@ static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
 	struct netpoll_info *npinfo =
 			container_of(rcu_head, struct netpoll_info, rcu);
 
-	skb_queue_purge(&npinfo->arp_tx);
+	skb_queue_purge(&npinfo->neigh_tx);
 	skb_queue_purge(&npinfo->txq);
 
 	/* we can't call cancel_delayed_work_sync here, as we are in softirq */
@@ -921,7 +1240,11 @@ void __netpoll_cleanup(struct netpoll *np)
 	struct netpoll_info *npinfo;
 	unsigned long flags;
 
-	npinfo = np->dev->npinfo;
+	/* rtnl_dereference would be preferable here but
+	 * rcu_cleanup_netpoll path can put us in here safely without
+	 * holding the rtnl, so plain rcu_dereference it is
+	 */
+	npinfo = rtnl_dereference(np->dev->npinfo);
 	if (!npinfo)
 		return;
 
@@ -933,6 +1256,8 @@ void __netpoll_cleanup(struct netpoll *np)
 		spin_unlock_irqrestore(&npinfo->rx_lock, flags);
 	}
 
+	synchronize_srcu(&netpoll_srcu);
+
 	if (atomic_dec_and_test(&npinfo->refcnt)) {
 		const struct net_device_ops *ops;
 
@@ -940,25 +1265,27 @@ void __netpoll_cleanup(struct netpoll *np)
 		if (ops->ndo_netpoll_cleanup)
 			ops->ndo_netpoll_cleanup(np->dev);
 
-		RCU_INIT_POINTER(np->dev->npinfo, NULL);
+		rcu_assign_pointer(np->dev->npinfo, NULL);
 		call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
 	}
 }
 EXPORT_SYMBOL_GPL(__netpoll_cleanup);
 
-static void rcu_cleanup_netpoll(struct rcu_head *rcu_head)
+static void netpoll_async_cleanup(struct work_struct *work)
 {
-	struct netpoll *np = container_of(rcu_head, struct netpoll, rcu);
+	struct netpoll *np = container_of(work, struct netpoll, cleanup_work);
 
+	rtnl_lock();
 	__netpoll_cleanup(np);
+	rtnl_unlock();
 	kfree(np);
 }
 
-void __netpoll_free_rcu(struct netpoll *np)
+void __netpoll_free_async(struct netpoll *np)
 {
-	call_rcu_bh(&np->rcu, rcu_cleanup_netpoll);
+	schedule_work(&np->cleanup_work);
 }
-EXPORT_SYMBOL_GPL(__netpoll_free_rcu);
+EXPORT_SYMBOL_GPL(__netpoll_free_async);
 
 void netpoll_cleanup(struct netpoll *np)
 {