Establishing a Connection with a Destination

After a Winsock Kernel (WSK) application has bound a connection-oriented socket to a local transport address, it can connect the socket to a remote transport address in order to establish a connection with the remote system. A WSK application must connect a connection-oriented socket to a remote transport address before it can send or receive data over the socket.

A WSK application connects a socket to a remote transport address by calling the WskConnect function. The WskConnect function is pointed to by the WskConnect member of the socket's provider dispatch structure. A socket's provider dispatch structure is pointed to by the Dispatch member of the socket object structure ( WSK_SOCKET) that was returned by the WSK subsystem during the creation of the socket.

The following code example shows how a WSK application can connect a connection-oriented socket to a remote transport address.


// Prototype for the connect IoCompletion routine
NTSTATUS
  ConnectComplete(
    PDEVICE_OBJECT DeviceObject,
    PIRP Irp,
    PVOID Context
    );

// Function to connect a socket to a remote transport address
NTSTATUS
  ConnectSocket(
    PWSK_SOCKET Socket,
    PSOCKADDR RemoteAddress
    )
{
  PWSK_PROVIDER_CONNECTION_DISPATCH Dispatch;
  PIRP Irp;
  NTSTATUS Status;

  // Get pointer to the socket's provider dispatch structure
  Dispatch =
    (PWSK_PROVIDER_CONNECTION_DISPATCH)(Socket->Dispatch);

  // Allocate an IRP
  Irp =
    IoAllocateIrp(
      1,
      FALSE
      );

  // Check result
  if (!Irp)
  {
    // Return error
    return STATUS_INSUFFICIENT_RESOURCES;
  }

  // Set the completion routine for the IRP
  IoSetCompletionRoutine(
    Irp,
    ConnectComplete,
    Socket,  // Use the socket object for the context
    TRUE,
    TRUE,
    TRUE
    );

  // Initiate the connect operation on the socket
  Status =
    Dispatch->WskConnect(
      Socket,
      RemoteAddress,
      0,  // No flags
      Irp
      );

  // Return the status of the call to WskConnect()
  return Status;
}

// Connect IoCompletion routine
NTSTATUS
  ConnectComplete(
    PDEVICE_OBJECT DeviceObject,
    PIRP Irp,
    PVOID Context
    )
{
  UNREFERENCED_PARAMETER(DeviceObject);

  PWSK_SOCKET Socket;

  // Check the result of the connect operation
  if (Irp->IoStatus.Status == STATUS_SUCCESS)
  {
    // Get the socket object from the context
    Socket = (PWSK_SOCKET)Context;

    // Perform the next operation on the socket
    ...
  }

  // Error status
  else
  {
    // Handle error
    ...
  }

  // Free the IRP
  IoFreeIrp(Irp);

  // Always return STATUS_MORE_PROCESSING_REQUIRED to
  // terminate the completion processing of the IRP.
  return STATUS_MORE_PROCESSING_REQUIRED;
}

A WSK application can call the WskSocketConnect function to create, bind, and connect a connection-oriented socket in a single function call.

 

 

Send comments about this topic to Microsoft

Show:
© 2015 Microsoft