public static void Close(PipeHandle handle)
{
handle.State = InterProcessConnectionState.Closing;
NamedPipeNative.CloseHandle(handle.Handle);
handle.Handle = IntPtr.Zero;
handle.State = InterProcessConnectionState.Closed;
}
public static void Connect(PipeHandle handle)
{
handle.State = InterProcessConnectionState.WaitingForClient;
bool connected = NamedPipeNative.ConnectNamedPipe(handle.Handle, null);
handle.State = InterProcessConnectionState.ConnectedToClient;
if (!connected && NamedPipeNative.GetLastError() != NamedPipeNative.ERROR_PIPE_CONNECTED)
{
handle.State = InterProcessConnectionState.Error;
throw new NamedPipeIOException("Error connecting pipe. Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
}
}
public static PipeHandle ConnectToPipe(string pipeName, string serverName)
{
PipeHandle handle = new PipeHandle();
// Build the name of the pipe.
string name = @"\\" + serverName + @"\pipe\" + pipeName;
for (int i = 1; i <= ATTEMPTS; i++)
{
handle.State = InterProcessConnectionState.ConnectingToServer;
// Try to connect to the server
handle.Handle = NamedPipeNative.CreateFile(name, NamedPipeNative.GENERIC_READ | NamedPipeNative.GENERIC_WRITE, 0, null, NamedPipeNative.OPEN_EXISTING, 0, 0);
if (handle.Handle.ToInt32() != NamedPipeNative.INVALID_HANDLE_VALUE)
{
// The client managed to connect to the server pipe
handle.State = InterProcessConnectionState.ConnectedToServer;
// Set the read mode of the pipe channel
uint mode = NamedPipeNative.PIPE_READMODE_MESSAGE;
if (NamedPipeNative.SetNamedPipeHandleState(handle.Handle, ref mode, IntPtr.Zero, IntPtr.Zero))
{
break;
}
if (i >= ATTEMPTS)
{
handle.State = InterProcessConnectionState.Error;
throw new NamedPipeIOException("Error setting read mode on pipe " + name + " . Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
}
}
if (i >= ATTEMPTS)
{
if (NamedPipeNative.GetLastError() != NamedPipeNative.ERROR_PIPE_BUSY)
{
handle.State = InterProcessConnectionState.Error;
// After a certain number of unsuccessful attempt raise an exception
throw new NamedPipeIOException("Error connecting to pipe " + name + " . Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
}
else
{
handle.State = InterProcessConnectionState.Error;
throw new NamedPipeIOException("Pipe " + name + " is too busy. Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
}
}
else
{
// The pipe is busy so lets wait for some time and try again
if (NamedPipeNative.GetLastError() == NamedPipeNative.ERROR_PIPE_BUSY)
NamedPipeNative.WaitNamedPipe(name, WAIT_TIME);
}
}
return handle;
}
public static void WriteBytes(PipeHandle handle, byte[] bytes)
{
byte[] numReadWritten = new byte[4];
uint len;
if (bytes == null)
{
bytes = new byte[0];
}
if (bytes.Length == 0)
{
bytes = new byte[1];
bytes = System.Text.Encoding.UTF8.GetBytes(" ");
}
// Get the message length
len = (uint)bytes.Length;
handle.State = InterProcessConnectionState.Writing;
// Write four bytes that define the message length
if (NamedPipeNative.WriteFile(handle.Handle, BitConverter.GetBytes(len), 4, numReadWritten, 0))
{
// Write the whole message
if (!NamedPipeNative.WriteFile(handle.Handle, bytes, len, numReadWritten, 0))
{
handle.State = InterProcessConnectionState.Error;
throw new NamedPipeIOException("Error writing to pipe. Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
}
}
else
{
handle.State = InterProcessConnectionState.Error;
throw new NamedPipeIOException("Error writing to pipe. Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
}
handle.State = InterProcessConnectionState.Flushing;
Flush(handle);
handle.State = InterProcessConnectionState.FlushedData;
}
public static void Write(PipeHandle handle, string text)
{
WriteBytes(handle, System.Text.Encoding.UTF8.GetBytes(text));
}
public static bool TryConnectToPipe(string pipeName, string serverName, out PipeHandle handle)
{
handle = new PipeHandle();
// Build the pipe name string
string name = @"\\" + serverName + @"\pipe\" + pipeName;
handle.State = InterProcessConnectionState.ConnectingToServer;
// Try to connect to a server pipe
handle.Handle = NamedPipeNative.CreateFile(name, NamedPipeNative.GENERIC_READ | NamedPipeNative.GENERIC_WRITE, 0, null, NamedPipeNative.OPEN_EXISTING, 0, 0);
if (handle.Handle.ToInt32() != NamedPipeNative.INVALID_HANDLE_VALUE)
{
handle.State = InterProcessConnectionState.ConnectedToServer;
return true;
}
else
{
handle.State = InterProcessConnectionState.Error;
return false;
}
}
public static bool TryConnectToPipe(string pipeName, out PipeHandle handle)
{
return TryConnectToPipe(pipeName, ".", out handle);
}
public static byte[] ReadBytes(PipeHandle handle, int maxBytes)
{
byte[] numReadWritten = new byte[4];
byte[] intBytes = new byte[4];
byte[] msgBytes = null;
int len;
// Set the Handle state to Reading
handle.State = InterProcessConnectionState.Reading;
// Read the first four bytes and convert them to integer
if (NamedPipeNative.ReadFile(handle.Handle, intBytes, 4, numReadWritten, 0))
{
len = BitConverter.ToInt32(intBytes, 0);
msgBytes = new byte[len];
// Read the rest of the data
if (!NamedPipeNative.ReadFile(handle.Handle, msgBytes, (uint)len, numReadWritten, 0))
{
handle.State = InterProcessConnectionState.Error;
throw new NamedPipeIOException("Error reading from pipe. Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
}
}
else
{
handle.State = InterProcessConnectionState.Error;
throw new NamedPipeIOException("Error reading from pipe. Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
}
handle.State = InterProcessConnectionState.ReadData;
if (len > maxBytes)
{
return null;
}
return msgBytes;
}
public static string Read(PipeHandle handle, int maxBytes)
{
string returnVal = "";
byte[] bytes = ReadBytes(handle, maxBytes);
if (bytes != null)
{
returnVal = System.Text.Encoding.UTF8.GetString(bytes);
}
return returnVal;
}
public static uint NumberPipeInstances(PipeHandle handle)
{
uint curInstances = 0;
if (NamedPipeNative.GetNamedPipeHandleState(handle.Handle, IntPtr.Zero, ref curInstances, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero))
{
return curInstances;
}
else
{
throw new NamedPipeIOException("Error getting the pipe state. Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
}
}
public static void Flush(PipeHandle handle)
{
handle.State = InterProcessConnectionState.Flushing;
NamedPipeNative.FlushFileBuffers(handle.Handle);
handle.State = InterProcessConnectionState.FlushedData;
}
public static void Disconnect(PipeHandle handle)
{
handle.State = InterProcessConnectionState.Disconnecting;
NamedPipeNative.DisconnectNamedPipe(handle.Handle);
handle.State = InterProcessConnectionState.Disconnected;
}
public static PipeHandle Create(string name, uint outBuffer, uint inBuffer, bool secure)
{
name = @"\\.\pipe\" + name;
PipeHandle handle = new PipeHandle();
IntPtr secAttr = IntPtr.Zero;
SECURITY_ATTRIBUTES sa = new SECURITY_ATTRIBUTES();
if (!secure)
{
SECURITY_DESCRIPTOR sd;
GetNullDaclSecurityDescriptor(out sd);
sa.lpSecurityDescriptor = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(SECURITY_DESCRIPTOR)));
Marshal.StructureToPtr(sd, sa.lpSecurityDescriptor, false);
sa.bInheritHandle = false;
sa.nLength = Marshal.SizeOf(typeof(SECURITY_ATTRIBUTES));
secAttr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(SECURITY_ATTRIBUTES)));
Marshal.StructureToPtr(sa, secAttr, false);
}
try
{
for (int i = 1; i <= ATTEMPTS; i++)
{
handle.State = InterProcessConnectionState.Creating;
handle.Handle = NamedPipeNative.CreateNamedPipe(
name,
NamedPipeNative.PIPE_ACCESS_DUPLEX,
NamedPipeNative.PIPE_TYPE_MESSAGE | NamedPipeNative.PIPE_READMODE_MESSAGE | NamedPipeNative.PIPE_WAIT,
NamedPipeNative.PIPE_UNLIMITED_INSTANCES,
outBuffer,
inBuffer,
NamedPipeNative.NMPWAIT_WAIT_FOREVER,
secAttr);
if (handle.Handle.ToInt32() != NamedPipeNative.INVALID_HANDLE_VALUE)
{
handle.State = InterProcessConnectionState.Created;
break;
}
if (i >= ATTEMPTS)
{
handle.State = InterProcessConnectionState.Error;
throw new NamedPipeIOException("Error creating named pipe " + name + " . Internal error: " + NamedPipeNative.GetLastError().ToString(), NamedPipeNative.GetLastError());
}
}
}
finally
{
if (!secure)
{
Marshal.FreeHGlobal(sa.lpSecurityDescriptor);
Marshal.FreeHGlobal(secAttr);
}
}
return handle;
}
