fix: use route -n to avoid reverse lookup timeout (#323)

This caused the update page to render blank

Bug: https://pms.uniontech.com/bug-view-351859.html

Author: zhaohuiw42

src/internal/updateplatform/systeminfo_utils.go

@@ -554,28 +554,34 @@ func UpdateTokenConfigFile(includeDiskInfo bool, getHardwareIdByHelper bool) str
 }
 
 func getDefaultMac() (string, error) {
-	res, err := exec.Command("route").Output()
+	res, err := exec.Command("route", "-n").Output()
 	if err != nil {
 		return "", err
 	}
-	lines := strings.Split(string(res), "\n")
-	var dev string
-	for _, line := range lines {
-		if strings.Contains(line, "default") {
-			devs := strings.Split(line, " ")
-			dev = devs[len(devs)-1]
-			break
-		}
-	}
+	dev := getDefaultRouteIface(string(res))
 	if len(dev) == 0 {
 		return "", nil
 	}
 
-	mac, err := os.ReadFile("/sys/class/net/" + dev + "/address")
+	mac, err := os.ReadFile(filepath.Join("/sys/class/net", dev, "address"))
 	if err != nil {
 		return "", err
 	}
-	return string(mac), nil
+	return strings.TrimSpace(string(mac)), nil
+}
+
+func getDefaultRouteIface(routeOutput string) string {
+	lines := strings.Split(routeOutput, "\n")
+	for _, line := range lines {
+		fields := strings.Fields(line)
+		if len(fields) < 8 {
+			continue
+		}
+		if fields[0] == "0.0.0.0" {
+			return fields[len(fields)-1]
+		}
+	}
+	return ""
 }
 
 func getClientPackageInfo(client string) string {

src/internal/updateplatform/systeminfo_utils_test.go

@@ -14,3 +14,35 @@ func TestSystemInfoUtil(t *testing.T) {
 	sys := getSystemInfo(true, true)
 	assert.NotEmpty(t, sys)
 }
+
+func TestGetDefaultRouteIface(t *testing.T) {
+	tests := []struct {
+		name   string
+		output string
+		want   string
+	}{
+		{
+			name: "default route found",
+			output: `Kernel IP routing table
+Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
+0.0.0.0         10.20.33.1      0.0.0.0         UG    100    0        0 eno1
+10.20.33.0      0.0.0.0         255.255.255.0   U     100    0        0 eno1
+`,
+			want: "eno1",
+		},
+		{
+			name: "no default route",
+			output: `Kernel IP routing table
+Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
+10.20.33.0      0.0.0.0         255.255.255.0   U     100    0        0 eno1
+`,
+			want: "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.want, getDefaultRouteIface(tt.output))
+		})
+	}
+}