Fix hostname listen.

.github/workflows/test-startup.yml

@@ -29,7 +29,18 @@ jobs:
           sudo systemctl daemon-reload
 
       - name: Start go-mmproxy
-        run: sudo systemctl start go-mmproxy || sudo systemctl status go-mmproxy.service
+        run: sudo systemctl start go-mmproxy || sudo journalctl -xeu go-mmproxy.service
+
+      - name: Check go-mmproxy status
+        run: systemctl is-active go-mmproxy
+
+      - name: Replace listen address of go-mmproxy with a hostname
+        run: |
+          sudo sed -i 's/-l 0.0.0.0:1234/-l %H:1234/' /etc/systemd/system/go-mmproxy.service
+          sudo systemctl daemon-reload
+
+      - name: Restart go-mmproxy
+        run: sudo systemctl restart go-mmproxy || sudo journalctl -xeu go-mmproxy.service
 
       - name: Check go-mmproxy status
         run: systemctl is-active go-mmproxy

main.go

@@ -130,7 +130,7 @@ func main() {
 	}
 
 	var err error
-	if Opts.ListenAddr, err = netip.ParseAddrPort(Opts.ListenAddrStr); err != nil {
+	if Opts.ListenAddr, err = ParseHostPort(Opts.ListenAddrStr); err != nil {
 		Opts.Logger.Error("listen address is malformed", "error", err)
 		os.Exit(1)
 	}

utils.go

@@ -7,6 +7,8 @@ package main
 import (
 	"fmt"
 	"net"
+	"net/netip"
+	"strconv"
 	"syscall"
 )
 
@@ -30,6 +32,29 @@ func CheckOriginAllowed(remoteIP net.IP) bool {
 	return false
 }
 
+func ParseHostPort(hostport string) (netip.AddrPort, error) {
+	host, portStr, err := net.SplitHostPort(hostport)
+	if err != nil {
+		return netip.AddrPort{}, fmt.Errorf("failed to parse host and port: %w", err)
+	}
+
+	ips, err := net.LookupIP(host)
+	if err != nil {
+		return netip.AddrPort{}, fmt.Errorf("failed to lookup IP addresses: %w", err)
+	}
+	if len(ips) == 0 {
+		return netip.AddrPort{}, fmt.Errorf("no IP addresses found")
+	}
+
+	port, err := strconv.ParseUint(portStr, 10, 16)
+	if err != nil {
+		return netip.AddrPort{}, fmt.Errorf("failed to parse port: %w", err)
+	}
+
+	ip, _ := netip.AddrFromSlice(ips[0])
+	return netip.AddrPortFrom(ip, uint16(port)), nil
+}
+
 func DialUpstreamControl(sport int) func(string, string, syscall.RawConn) error {
 	return func(network, address string, c syscall.RawConn) error {
 		var syscallErr error