Golang UDP to UDP relay

golang_udp_relay.go

package udp_relay

import (
	"net"

	log "github.com/sirupsen/logrus"
)

var (
	// Max buffer size for the socket io
	Buffer = 10240
)

// UDPRelay is a function that relays data from a UDP socket to another UDP socket
// TODO: Add timeouts on connections
func UDPRelay(source string, target string) {
	sourceAddr, err := net.ResolveUDPAddr("udp", source)
	if err != nil {
		log.WithError(err).Fatal("Could not resolve source address:", source)
		return
	}

	targetAddr, err := net.ResolveUDPAddr("udp", target)
	if err != nil {
		log.WithError(err).Fatal("Could not resolve target address:", target)
		return
	}

	sourceConn, err := net.ListenUDP("udp", sourceAddr)
	if err != nil {
		log.WithError(err).Fatal("Could not listen on address:", source)
		return
	}

	defer sourceConn.Close()

	conn, err := net.DialUDP("udp", nil, targetAddr)
	if err != nil {
		log.WithError(err).Fatal("Could not connect to target address:", target)
		return
	}

	defer conn.Close()

	log.Printf("Starting... Source at %v, Target at %v...", source, target)

	for {
		b := make([]byte, Buffer)
		n, addr, err := sourceConn.ReadFromUDP(b)

		if err != nil {
			log.WithError(err).Error("Could not receive a packet")
			continue
		}

		log.Debugf("Packet received: addr=%s bytes=%v", addr.String(), n)

		if _, err := conn.Write(b[0:n]); err != nil {
			log.WithError(err).Warn("Could not forward packet.")
		}
	}
}