Get information about the installed network adapters

Question

I am using Delphi XE2 Update 4 on Windows XP sp3

I am looking to get max possible information from installed network adapters, specially the broadcast ip.

Fo

Answer 1

Jan Schulz's code works fine when properly converted to unicode-friendly Delphi.

I've done some corrections:

• As TOndrej has pointed, char must be converted to AnsiChar when needed. In this case, this only occurs in the Padding field of the SockAddr_Gen record, which was not only screwing the record, but also causing SizeOf(Interface_Info), and subsequently NoOfInterfaces, to return a wrong result. Since it's not really a character, it is better to define it as a byte.

• Dropped PChars used to hold results of inet_ntoa calls, and assigning TNetworkInterface string fields directly.

• Strings in TNetworkInterface are fine, because they are not passed to any api calls. Also, ComputerName is passed to GetComputerName api, which expects a PWideChar/PChar.

---

Unit USock;

Interface

Uses Windows, Winsock;


{ Unit to identify the network interfaces
  This code requires at least Win98/ME/2K, 95 OSR 2 or NT service pack #3
  as WinSock 2 is used (WS2_32.DLL) }


// Constants found in manual on non-officially documented M$ Winsock functions
Const SIO_GET_INTERFACE_LIST = $4004747F;
      IFF_UP                 = $00000001;
      IFF_BROADCAST          = $00000002;
      IFF_LOOPBACK           = $00000004;
      IFF_POINTTOPOINT       = $00000008;
      IFF_MULTICAST          = $00000010;


Type SockAddr_Gen          = Packed Record
                               AddressIn             : SockAddr_In;
                               Padding               : Packed Array [0..7] of Byte;
                             end;

     Interface_Info        = Record
                               iiFlags               : u_Long;
                               iiAddress             : SockAddr_Gen;
                               iiBroadcastAddress    : SockAddr_Gen;
                               iiNetmask             : SockAddr_Gen;
                             end;

     tNetworkInterface     = Record
                               ComputerName          : String;
                               AddrIP                : String;
                               SubnetMask            : String;
                               AddrNet               : String;
                               AddrLimitedBroadcast  : String;
                               AddrDirectedBroadcast : String;
                               IsInterfaceUp         : Boolean;
                               BroadcastSupport      : Boolean;
                               IsLoopback            : Boolean;
                             end;

     tNetworkInterfaceList = Array of tNetworkInterface;


Function WSAIoctl (aSocket              : TSocket;
                   aCommand             : DWord;
                   lpInBuffer           : Pointer;
                   dwInBufferLen        : DWord;
                   lpOutBuffer          : Pointer;
                   dwOutBufferLen       : DWord;
                   lpdwOutBytesReturned : LPDWord;
                   lpOverLapped         : Pointer;
                   lpOverLappedRoutine  : Pointer) : Integer; stdcall; external 'WS2_32.DLL';

Function GetNetworkInterfaces (Var aNetworkInterfaceList : tNetworkInterfaceList): Boolean;


implementation


Function GetNetworkInterfaces (Var aNetworkInterfaceList : tNetworkInterfaceList): Boolean;
// Returns a complete list the of available network interfaces on a system (IPv4)
// Copyright by Dr. Jan Schulz, 23-26th March 2007
// This version can be used for free and non-profit projects. In any other case get in contact
// Written with information retrieved from MSDN
// www.code10.net
Var aSocket             : TSocket;
    aWSADataRecord      : WSAData;
    NoOfInterfaces      : Integer;
    NoOfBytesReturned   : u_Long;
    InterfaceFlags      : u_Long;
    NameLength          : DWord;
    pAddrIP             : SockAddr_In;
    pAddrSubnetMask     : SockAddr_In;
    pAddrBroadcast      : Sockaddr_In;
    DirBroadcastDummy   : In_Addr;
    NetAddrDummy        : In_Addr;
    Buffer              : Array [0..30] of Interface_Info;
    i                   : Integer;
Begin
  Result := False;
  SetLength (aNetworkInterfaceList, 0);

  // Startup of old the WinSock
  // WSAStartup ($0101, aWSADataRecord);

  // Startup of WinSock2
  WSAStartup(MAKEWORD(2, 0), aWSADataRecord);

  // Open a socket
  aSocket := Socket (AF_INET, SOCK_STREAM, 0);

  // If impossible to open a socket, not worthy to go any further
  If (aSocket = INVALID_SOCKET) THen Exit;

  Try
    If WSAIoCtl (aSocket, SIO_GET_INTERFACE_LIST, NIL, 0,
                 @Buffer, 1024, @NoOfBytesReturned, NIL, NIL) <> SOCKET_ERROR THen
    Begin
      NoOfInterfaces := NoOfBytesReturned  Div SizeOf (Interface_Info);
      SetLength (aNetworkInterfaceList, NoOfInterfaces);

      // For each of the identified interfaces get:
      For i := 0 to NoOfInterfaces - 1 do
      Begin

        With aNetworkInterfaceList[i] do
        Begin

          // Get the name of the machine
          NameLength := MAX_COMPUTERNAME_LENGTH + 1;
          SetLength (ComputerName, NameLength)  ;
          If Not GetComputerName (PChar (Computername), NameLength) THen ComputerName := '';

          // Get the IP address
          pAddrIP                  := Buffer[i].iiAddress.AddressIn;
          AddrIP                   := string(inet_ntoa (pAddrIP.Sin_Addr));

          // Get the subnet mask
          pAddrSubnetMask          := Buffer[i].iiNetMask.AddressIn;
          SubnetMask               := string(inet_ntoa (pAddrSubnetMask.Sin_Addr));

          // Get the limited broadcast address
          pAddrBroadcast           := Buffer[i].iiBroadCastAddress.AddressIn;
          AddrLimitedBroadcast     := string(inet_ntoa (pAddrBroadcast.Sin_Addr));

          // Calculate the net and the directed broadcast address
          NetAddrDummy.S_addr      := Buffer[i].iiAddress.AddressIn.Sin_Addr.S_Addr;
          NetAddrDummy.S_addr      := NetAddrDummy.S_addr And Buffer[i].iiNetMask.AddressIn.Sin_Addr.S_Addr;
          DirBroadcastDummy.S_addr := NetAddrDummy.S_addr Or Not Buffer[i].iiNetMask.AddressIn.Sin_Addr.S_Addr;

          AddrNet                  := string(inet_ntoa ((NetAddrDummy)));
          AddrDirectedBroadcast    := string(inet_ntoa ((DirBroadcastDummy)));

          // From the evaluation of the Flags we receive more information
          InterfaceFlags           := Buffer[i].iiFlags;

          // Is the network interface up or down ?
          If (InterfaceFlags And IFF_UP) = IFF_UP THen IsInterfaceUp := True
                                                  Else IsInterfaceUp := False;

          // Does the network interface support limited broadcasts ?
          If (InterfaceFlags And IFF_BROADCAST) = IFF_BROADCAST THen BroadcastSupport := True
                                                                Else BroadcastSupport := False;

          // Is the network interface a loopback interface ?
          If (InterfaceFlags And IFF_LOOPBACK) = IFF_LOOPBACK THen IsLoopback := True
                                                              Else IsLoopback := False;
        end;
      end;
    end;
  Except
    //Result := False;
  end;

  // Cleanup the mess
  CloseSocket (aSocket);
  WSACleanUp;
  Result := True;
end;

end.

Answer 2

For what its worth, if you need the broadcast IP for a specific adapter, you can use SIO_GET_BROADCAST_ADDRESS instead.

With that said, a non-Winsock solution would be to use GetAdaptersInfo() or GetAdaptersAddresses() instead. This way, you don't have to create a SOCKET to get the info, you can enumerate both IPv4 and IPv6 adapters at the same time, as well as other adapters that Winsock does not recognize.

For GetAdaptersInfo(), the IP_ADAPTER_INFO.IpAddressList list contains IPv4 IPs and Subnet masks (on XP+, uni-directional adapters are included in the output, but you can use GetUniDirectionalAdapterInfo() to filter them out).

For GetAdaptersAddresses(), the IP_ADAPTER_ADDRESSES.FirstUnicastAddress list contains both IPv4 and IPv6 IPs, and IPv4 Subnet masks on Vista+. For XP and earlier, you can use GetIpAddrTable() to retrieve IPv4 Subnet masks and match them to the IPv4 IPs from GetAdaptersAddresses().

Once you have an IPv4 IP and Subnet mask, calculating its Broadcast IP is very simple:

BroadcastIP := (IP and SubnetMask) or (not SubnetMask);

Answer 3

As you have changed String declarations to AnsiString, also change Char declarations to AnsiChar.

Answer 4

Following Remy Lebeau sugestion and help documenting this thread I found this source code in delphi, tested with XP and W7, that brings the information using GetAdaptersInfo().

Credits to Brad Prendergast original post updated by Markus Humm final version

I have added the subnet mask reporting to make clear to newbies like me where the information is stored:

uses IpHlpApi, IpTypes;

procedure RetrieveLocalAdapterInformation(strings: TStrings);
var
  pAdapterInfo, pTempAdapterInfo: PIP_ADAPTER_INFO;
  AdapterInfo: IP_ADAPTER_INFO;
  BufLen: DWORD;
  Status: DWORD;
  strMAC: String;
  i: Integer;
begin
  strings.Clear;

  BufLen:= sizeof(AdapterInfo);
  pAdapterInfo:= @AdapterInfo;

  Status:= GetAdaptersInfo(nil, BufLen);
  pAdapterInfo:= AllocMem(BufLen);
  try
    Status:= GetAdaptersInfo(pAdapterInfo, BufLen);

    if (Status <> ERROR_SUCCESS) then
      begin
        case Status of
          ERROR_NOT_SUPPORTED:
            strings.Add('GetAdaptersInfo is not supported by the operating ' +
                        'system running on the local computer.');
          ERROR_NO_DATA:
            strings.Add('No network adapter on the local computer.');
        else
            strings.Add('GetAdaptersInfo failed with error #' + IntToStr(Status));
        end;
        Dispose(pAdapterInfo);
        Exit;
      end;

    while (pAdapterInfo <> nil) do
      begin
        strings.Add('Description: ' + pAdapterInfo^.Description);
        strings.Add('Name: ' + pAdapterInfo^.AdapterName);

        strMAC := '';
        for I := 0 to pAdapterInfo^.AddressLength - 1 do
            strMAC := strMAC + '-' + IntToHex(pAdapterInfo^.Address[I], 2);

        Delete(strMAC, 1, 1);
        strings.Add('MAC address: ' + strMAC);
        strings.Add('IP address: ' + pAdapterInfo^.IpAddressList.IpAddress.S);
        strings.Add('IP subnet mask: ' + pAdapterInfo^.IpAddressList.IpMask.S);
        strings.Add('Gateway: ' + pAdapterInfo^.GatewayList.IpAddress.S);
        strings.Add('DHCP enabled: ' + IntTOStr(pAdapterInfo^.DhcpEnabled));
        strings.Add('DHCP: ' + pAdapterInfo^.DhcpServer.IpAddress.S);
        strings.Add('Have WINS: ' + BoolToStr(pAdapterInfo^.HaveWins,True));
        strings.Add('Primary WINS: ' + pAdapterInfo^.PrimaryWinsServer.IpAddress.S);
        strings.Add('Secondary WINS: ' + pAdapterInfo^.SecondaryWinsServer.IpAddress.S);

        pTempAdapterInfo := pAdapterInfo;
        pAdapterInfo:= pAdapterInfo^.Next;
      if assigned(pAdapterInfo) then Dispose(pTempAdapterInfo);
    end;
  finally
    Dispose(pAdapterInfo);
  end;
end;

Answer 5

Update for Delphi 10.2 Tokyo supported.

procedure TForm4.RetrieveLocalAdapterInformation;
var
  pAdapterInfo: PIP_ADAPTER_INFO;
  AdapterInfo: IP_ADAPTER_INFO;
  BufLen: DWORD;
  Status: DWORD;
  strMAC: String;
  i: Integer;

  strings: TStrings;
begin
  strings:= Tstringlist.create;
  strings.Clear;

  BufLen:= sizeof(AdapterInfo);
  pAdapterInfo:= @AdapterInfo;

  Status:= GetAdaptersInfo(nil, BufLen);
  pAdapterInfo:= AllocMem(BufLen);
  try
    Status:= GetAdaptersInfo(pAdapterInfo, BufLen);

    if (Status <> ERROR_SUCCESS) then
      begin
        case Status of
          ERROR_NOT_SUPPORTED:
            strings.Add('GetAdaptersInfo is not supported by the operating ' +
                        'system running on the local computer.');
          ERROR_NO_DATA:
            strings.Add('No network adapter on the local computer.');
        else
            strings.Add('GetAdaptersInfo failed with error #' + IntToStr(Status));
        end;
        Dispose(pAdapterInfo);
        Exit;
      end;

    while (pAdapterInfo <> nil) do
      begin
      memo1.Lines.Add('');
         memo1.Lines.Add('Description: ------------------------' + pAdapterInfo^.Description);
         memo1.Lines.Add('Name: ' + pAdapterInfo^.AdapterName);

        strMAC := '';
        for I := 0 to pAdapterInfo^.AddressLength - 1 do
            strMAC := strMAC + '-' + IntToHex(pAdapterInfo^.Address[I], 2);

        Delete(strMAC, 1, 1);
         memo1.Lines.Add('MAC address: ' + strMAC);
         memo1.Lines.Add('IP address: ' + pAdapterInfo^.IpAddressList.IpAddress.S);
         memo1.Lines.Add('IP subnet mask: ' + pAdapterInfo^.IpAddressList.IpMask.S);
         memo1.Lines.Add('Gateway: ' + pAdapterInfo^.GatewayList.IpAddress.S);
         memo1.Lines.Add('DHCP enabled: ' + IntTOStr(pAdapterInfo^.DhcpEnabled));
         memo1.Lines.Add('DHCP: ' + pAdapterInfo^.DhcpServer.IpAddress.S);
         memo1.Lines.Add('Have WINS: ' + BoolToStr(pAdapterInfo^.HaveWins,True));
         memo1.Lines.Add('Primary WINS: ' + pAdapterInfo^.PrimaryWinsServer.IpAddress.S);
         memo1.Lines.Add('Secondary WINS: ' + pAdapterInfo^.SecondaryWinsServer.IpAddress.S);

        pAdapterInfo:= pAdapterInfo^.Next;
    end;
  finally
    Dispose(pAdapterInfo);
    strings.free;
  end;
end;

procedure TForm4.Button1Click(Sender: TObject);
begin
   RetrieveLocalAdapterInformation//
end;