Regression - NET5.0 RC1 returns empty MAC address for network interface on Linux #42870
Description
I've noticed that my app is returning empty Mac adress info when running on Linux. So I made a small snippet to test the code, Network interfaces are returned just fine, but MAC address from Network interface is empty. On net5.0 rc.1 & win-x64 it works normally as well as with Net Core 3.1.8 on Linux ARM32 machine.
using System;
using System.Linq;
using System.Net.NetworkInformation;
using System.Net.Sockets;
namespace GetMyIP
{
class Program
{
static void Main(string[] args)
{
var macAddress = GetMacAddress();
Console.WriteLine("MAC:" + macAddress);
Console.WriteLine("Is null: " + macAddress == null);
Console.WriteLine("Bytes:" + macAddress.GetAddressBytes().Length);
Console.WriteLine("Hash code:" + macAddress.GetHashCode());
}
/// <summary>
/// Gets the MAC address of the current PC.
/// </summary>
/// <returns></returns>
public static PhysicalAddress GetMacAddress()
{
var nic = GetNetworkInterface();
if (nic != null)
{
Console.WriteLine($"Selected interface:{nic.Name}");
return nic.GetPhysicalAddress();
}
return new PhysicalAddress(new byte[] { 1, 2, 3, 4, 5, 6 });
}
public static string GetMyIp()
{
var firstUpInterface = GetNetworkInterface();
if (firstUpInterface != null)
{
var props = firstUpInterface.GetIPProperties();
// get first IPV4 address assigned to this interface
var firstIpV4Address = props.UnicastAddresses
.Where(c => c.Address.AddressFamily == AddressFamily.InterNetwork)
.Select(c => c.Address)
.FirstOrDefault();
return firstIpV4Address.ToString();
}
return null;
}
private static NetworkInterface GetNetworkInterface()
{
// order interfaces by speed and filter out down and loopback
// take first of the remaining
var interfaces = NetworkInterface.GetAllNetworkInterfaces().ToList();
foreach(var i in interfaces)
{
Console.WriteLine($"I name:{i.Name}, desc: {i.Description}, op stats: {i.OperationalStatus}, i net intrface type: {i.NetworkInterfaceType}");
}
if (interfaces == null || interfaces.Count == 0)
return null;
//.OrderByDescending(c => c.Speed)
var firstUpInterface = interfaces.
FirstOrDefault(c => c.NetworkInterfaceType != NetworkInterfaceType.Loopback
&& c.OperationalStatus == OperationalStatus.Up
&& c.Name.ToLower().Contains("eth")
&& (!c.Description.ToLower().Contains("virtu"))
&& (!c.Description.Contains("Pseudo")));
return firstUpInterface;
}
}
}Output on netcoreapp3.1:
xxx:/tmp/GetMyIp# dotnet ./GetMyIP.dll
I name:lo, desc: lo, op stats: Unknown, i net intrface type: Loopback
I name:eth0, desc: eth0, op stats: Up, i net intrface type: Ethernet
I name:sit0, desc: sit0, op stats: Down, i net intrface type: Unknown
Selected interface:eth0
MAC:70xxxxxxxx3E
False
Bytes:6
Hash code:634752358
Output on net5.0 rc.1:
xxx:/tmp/GetMyIp# dotnet GetMyIP.dll
I name:lo, desc: lo, op stats: Up, i net intrface type: Loopback
I name:eth0, desc: eth0, op stats: Up, i net intrface type: Ethernet
I name:sit0, desc: sit0, op stats: Down, i net intrface type: Unknown
Selected interface:eth0
MAC:
False
Bytes:0
Hash code:1
GetAddressBytes() returns empty array and hash code is "1"
Update: tested also on My PC under WSL with NET5 rc.1 and the result is empty:
I name:eth0, desc: eth0, op stats: Up, i net intrface type: Ethernet
I name:eth1, desc: eth1, op stats: Up, i net intrface type: Ethernet
I name:eth2, desc: eth2, op stats: Up, i net intrface type: Ethernet
I name:eth3, desc: eth3, op stats: Down, i net intrface type: Ethernet
I name:lo, desc: lo, op stats: Up, i net intrface type: Loopback
I name:eth4, desc: eth4, op stats: Down, i net intrface type: Ethernet
Selected interface:eth0
MAC:
False
Bytes:0
Hash code:1
Hello World!