udp_decode.rs

// So this code looks wrong to me.  What the correct way to "switch" on ethertype to get the next layer?

let packet = // some bytes from a PCAP file
let ether = EthernetPacket::new(&packet).expect("could not parse Ethernet frame");
// I don't know if the next line is valid; what if there's no Vlan layer and it doesn't parse ether.payload()?
let vlan = VlanPacket::new(ether.payload()).expect("could not parse Vlan frame");
let payload = if ether.get_ethertype() == ethernet::EtherTypes::Vlan {
    vlan.payload()
} else {
    ether.payload()
};
let ip = Ipv4Packet::new(payload).expect("could not parse Ipv4 frame");
let udp = UdpPacket::new(ip.payload()).expect("could not parse Udp frame");
let data = udp.payload();
// process `data`