From: Stefano Brivio
Date: Tue, 6 Nov 2018 22:38:57 +0100
> + /* Network header needs to point to the outer IPv4 header inside ICMP */
> + skb_reset_network_header(skb);
> + iph = ip_hdr(skb);
> + /* Transport header needs to point to the UDP header */
> +
For both IPv4 and IPv6, if we can't match errors to a socket, try
tunnels before ignoring them. Look up a socket with the original source
and destination ports as found in the UDP packet inside the ICMP payload,
this will work for tunnels that force the same destination port for both
endpoints,
