Fix parsing network service name on darwin

The network service name appears on the previous line, not the same line
with "Device" name.

Updates #57

cmd/ctrld/net_darwin.go

@@ -3,6 +3,7 @@ package main
 import (
 	"bufio"
 	"bytes"
+	"io"
 	"net"
 	"os/exec"
 	"strings"
@@ -14,21 +15,30 @@ func patchNetIfaceName(iface *net.Interface) error {
 		return err
 	}
 
-	scanner := bufio.NewScanner(bytes.NewReader(b))
+	if name := networkServiceName(iface.Name, bytes.NewReader(b)); name != "" {
+		iface.Name = name
+		mainLog.Debug().Str("network_service", name).Msg("found network service name for interface")
+	}
+	return nil
+}
+
+func networkServiceName(ifaceName string, r io.Reader) string {
+	scanner := bufio.NewScanner(r)
+	prevLine := ""
 	for scanner.Scan() {
 		line := scanner.Text()
 		if strings.Contains(line, "*") {
 			// Network services is disabled.
 			continue
 		}
-		if !strings.Contains(line, "Device: "+iface.Name) {
+		if !strings.Contains(line, "Device: "+ifaceName) {
+			prevLine = line
 			continue
 		}
-		parts := strings.Split(line, ",")
-		if _, networkServiceName, ok := strings.Cut(parts[0], "(Hardware Port: "); ok {
-			mainLog.Debug().Str("network_service", networkServiceName).Msg("found network service name for interface")
-			iface.Name = networkServiceName
+		parts := strings.SplitN(prevLine, " ", 2)
+		if len(parts) == 2 {
+			return strings.TrimSpace(parts[1])
 		}
 	}
-	return nil
+	return ""
 }

cmd/ctrld/net_darwin_test.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const listnetworkserviceorderOutput = `
+(1) USB 10/100/1000 LAN 2
+(Hardware Port: USB 10/100/1000 LAN, Device: en7)
+
+(2) Ethernet
+(Hardware Port: Ethernet, Device: en0)
+
+(3) Wi-Fi
+(Hardware Port: Wi-Fi, Device: en1)
+
+(4) Bluetooth PAN
+(Hardware Port: Bluetooth PAN, Device: en4)
+
+(5) Thunderbolt Bridge
+(Hardware Port: Thunderbolt Bridge, Device: bridge0)
+
+(6) kernal
+(Hardware Port: com.wireguard.macos, Device: )
+
+(7) WS BT
+(Hardware Port: com.wireguard.macos, Device: )
+
+(8) ca-001-stg
+(Hardware Port: com.wireguard.macos, Device: )
+
+(9) ca-001-stg-2
+(Hardware Port: com.wireguard.macos, Device: )
+
+`
+
+func Test_networkServiceName(t *testing.T) {
+	tests := []struct {
+		ifaceName          string
+		networkServiceName string
+	}{
+		{"en7", "USB 10/100/1000 LAN 2"},
+		{"en0", "Ethernet"},
+		{"en1", "Wi-Fi"},
+		{"en4", "Bluetooth PAN"},
+		{"bridge0", "Thunderbolt Bridge"},
+	}
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.ifaceName, func(t *testing.T) {
+			t.Parallel()
+			name := networkServiceName(tc.ifaceName, strings.NewReader(listnetworkserviceorderOutput))
+			assert.Equal(t, tc.networkServiceName, name)
+		})
+	}
+}