/// <summary>
/// Marshales native pointer to <see cref="ProtoEnt"/> instance.
/// </summary>
/// <param name="ptr">Pointer returned by <see cref="getprotobyname"/> or <see cref="getprotobynumber"/>.</param>
/// <remarks>The wrapper avoids freeing of pointer returned from winsoc native library. The returned pointer is managed by winsoc library and must not be freed by CLI.</remarks>
internal static ProtoEnt FromIntPtr(IntPtr ptr)
{
if (ptr == IntPtr.Zero)
return null;
// marshall returned object to ProtoEnt class:
ProtoEnt result = new ProtoEnt();
Marshal.PtrToStructure(ptr, result);
return result;
}
/// <summary>
/// Gets protocol number by name (tcp/udp/icmp etc')
/// </summary>
/// <param name="name">protocol name</param>
/// <returns>protocol number</returns>
public static int GetProtoByName(string name)
{
// Vorbedingung
if (string.IsNullOrEmpty(name))
{
throw new ArgumentNullException("name");
}
//check first in protocols file
if (File.Exists(etcFileHelper.GetFullFilename(etcFileHelper.ProtocolFilename)))
{
var protocols = etcFileHelper.ReadProtocols(etcFileHelper.GetFullFilename(etcFileHelper.ProtocolFilename));
var protocol = protocols.FirstOrDefault(i => i.Name.ToLower() == name.ToLower());
if (protocol != null)
{
return(protocol.ProtocolNumber);
}
}
//failed, use API.
int result = 0;
int intResult = -1;
if (int.TryParse(name, out intResult))
{
result = System.Convert.ToInt32(name, CultureInfo.InvariantCulture);
}
else
{
WSAData dummy = new WSAData();
int sccuessful = NativeMethods.WSAStartup(0x0202, ref dummy);
if (sccuessful != 0)
{
throw CreateWSAException();
}
IntPtr intPtr = NativeMethods.GetProtocolByName(name);
try
{
if (intPtr != IntPtr.Zero)
{
ProtoEnt protoent = (ProtoEnt)Marshal.PtrToStructure(intPtr, typeof(ProtoEnt));
result = System.Convert.ToInt32(protoent.p_proto);
}
else
{
throw CreateWSAException();
}
}
finally
{
sccuessful = NativeMethods.WSACleanup();
if (sccuessful != 0)
{
throw CreateWSAException();
}
}
}
return(result);
}