vxlan: do not receive IPv4 packets on IPv6 socket (a43a9ef6) · Commits · 戴 / test

By default (subject to the sysctl settings), IPv6 sockets listen also for IPv4 traffic. Vxlan is not prepared for that and expects IPv6 header in packets received through an IPv6 socket. In addition, it's currently not possible to have both IPv4 and IPv6 vxlan tunnel on the same port (unless bindv6only sysctl is enabled), as it's not possible to create and bind both IPv4 and IPv6 vxlan interfaces and there's no way to specify both IPv4 and IPv6 remote/group IP addresses. Set IPV6_V6ONLY on vxlan sockets to fix both of these issues. This is not done globally in udp_tunnel, as l2tp and tipc seems to work okay when receiving IPv4 packets on IPv6 socket and people may rely on this behavior. The other tunnels (geneve and fou) do not support IPv6. Signed-off-by:

Jiri Benc <jbenc@redhat.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/net/vxlan.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -2530,6 +2530,7 @@ static struct socket vxlan_create_sock(struct net net, bool ipv6,
		udp_conf.family = AF_INET6;
		udp_conf.use_udp6_rx_checksums =
		!(flags & VXLAN_F_UDP_ZERO_CSUM6_RX);
		udp_conf.ipv6_v6only = 1;
		} else {
		udp_conf.family = AF_INET;
		}

include/net/udp_tunnel.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -31,7 +31,8 @@ struct udp_port_cfg {
		__be16 peer_udp_port;
		unsigned int use_udp_checksums:1,
		use_udp6_tx_checksums:1,
		use_udp6_rx_checksums:1;
		use_udp6_rx_checksums:1,
		ipv6_v6only:1;
		};

		int udp_sock_create4(struct net net, struct udp_port_cfg cfg,

net/ipv6/ip6_udp_tunnel.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -23,6 +23,15 @@ int udp_sock_create6(struct net net, struct udp_port_cfg cfg,
		if (err < 0)
		goto error;

		if (cfg->ipv6_v6only) {
		int val = 1;

		err = kernel_setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
		(char *) &val, sizeof(val));
		if (err < 0)
		goto error;
		}

		udp6_addr.sin6_family = AF_INET6;
		memcpy(&udp6_addr.sin6_addr, &cfg->local_ip6,
		sizeof(udp6_addr.sin6_addr));

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