// Copyright (c) Microsoft Corporation.
// Licensed under the MIT license.

#include "precomp.h"
#include "DeviceHandle.h"

#include "WinNTControl.h"

#define FILE_SYNCHRONOUS_IO_NONALERT 0x00000020

/*++
Routine Description:
- This routine creates a handle to an input or output client of the given
 server. No control io is sent to the server as this request must be coming
 from the server itself.

Arguments:
- Handle - Receives a handle to the new client.
- ServerHandle - Supplies a handle to the server to which to attach the
 newly created client.
- Name - Supplies the name of the client object.
- Inheritable - Supplies a flag indicating if the handle must be inheritable.

Return Value:
- NTSTATUS indicating if the client was successfully created.
--*/
[[nodiscard]]
NTSTATUS
DeviceHandle::CreateClientHandle(
 _Out_ PHANDLE Handle,
 _In_ HANDLE ServerHandle,
 _In_ PCWSTR Name,
 _In_ BOOLEAN Inheritable)
{
 return _CreateHandle(Handle,
 Name,
 GENERIC_WRITE | GENERIC_READ | SYNCHRONIZE,
 ServerHandle,
 Inheritable,
 FILE_SYNCHRONOUS_IO_NONALERT);
}

/*++
Routine Description:
- This routine creates a new server on the driver and returns a handle to it.

Arguments:
- Handle - Receives a handle to the new server.
- Inheritable - Supplies a flag indicating if the handle must be inheritable.

Return Value:
- NTSTATUS indicating if the console was successfully created.
--*/
[[nodiscard]]
NTSTATUS
DeviceHandle::CreateServerHandle(
 _Out_ PHANDLE Handle,
 _In_ BOOLEAN Inheritable)
{
 return _CreateHandle(Handle,
 L"\\Device\\ConDrv\\Server",
 GENERIC_ALL,
 NULL,
 Inheritable,
 0);
}

/*++
Routine Description:
- This routine opens a handle to the console driver.

Arguments:
- Handle - Receives the handle.
- DeviceName - Supplies the name to be used to open the console driver.
- DesiredAccess - Supplies the desired access mask.
- Parent - Optionally supplies the parent object.
- Inheritable - Supplies a boolean indicating if the new handle is to be made inheritable.
- OpenOptions - Supplies the open options to be passed to NtOpenFile. A common
 option for clients is FILE_SYNCHRONOUS_IO_NONALERT, to make the handle
 synchronous.

Return Value:
- NTSTATUS indicating if the handle was successfully created.
--*/
[[nodiscard]]
NTSTATUS
DeviceHandle::_CreateHandle(
 _Out_ PHANDLE Handle,
 _In_ PCWSTR DeviceName,
 _In_ ACCESS_MASK DesiredAccess,
 _In_opt_ HANDLE Parent,
 _In_ BOOLEAN Inheritable,
 _In_ ULONG OpenOptions)

{
 ULONG Flags = OBJ_CASE_INSENSITIVE;

 if (Inheritable)
 {
 WI_SetFlag(Flags, OBJ_INHERIT);
 }

 UNICODE_STRING Name;
 Name.Buffer = (wchar_t*)DeviceName;
 Name.Length = (USHORT)(wcslen(DeviceName) * sizeof(wchar_t));
 Name.MaximumLength = Name.Length + sizeof(wchar_t);

 OBJECT_ATTRIBUTES ObjectAttributes;
 InitializeObjectAttributes(&ObjectAttributes,
 &Name,
 Flags,
 Parent,
 NULL);

 IO_STATUS_BLOCK IoStatus;
 return WinNTControl::NtOpenFile(Handle,
 DesiredAccess,
 &ObjectAttributes,
 &IoStatus,
 FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
 OpenOptions);
}