Using in_addr in C#

Question

I'm trying to interact with a native DLL using P/Invoke, but it requires an in_addr struct parameter. I keep seeing many different kinds of definitions for it, but which is the best to use?

Also, how can I convert a C# IPAddress object to an in_addr struct?

Answer 1

Try the following

[StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
public struct in_addr {

    /// Anonymous1
    public Anonymous1 S_un;
}

[StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Explicit)]
public struct Anonymous1 {

    /// Anonymous2
    [System.Runtime.InteropServices.FieldOffsetAttribute(0)]
    public Anonymous2 S_un_b;

    /// Anonymous3
    [System.Runtime.InteropServices.FieldOffsetAttribute(0)]
    public Anonymous3 S_un_w;

    /// u_long->unsigned int
    [System.Runtime.InteropServices.FieldOffsetAttribute(0)]
    public uint S_addr;
}

[StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
public struct Anonymous2 {

    /// u_char->unsigned char
    public byte s_b1;

    /// u_char->unsigned char
    public byte s_b2;

    /// u_char->unsigned char
    public byte s_b3;

    /// u_char->unsigned char
    public byte s_b4;
}

[StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
public struct Anonymous3 {

    /// u_short->unsigned short
    public ushort s_w1;

    /// u_short->unsigned short
    public ushort s_w2;
}

Generated with PInvoke Interop Assistant

EDIT Cleaned up the anonymous names.