Function DeviceIoControl [src]

A Zig wrapper around NtDeviceIoControlFile and NtFsControlFile syscalls. It implements similar behavior to DeviceIoControl and is meant to serve as a direct substitute for that call. TODO work out if we need to expose other arguments to the underlying syscalls.

Prototype

pub fn DeviceIoControl( h: HANDLE, ioControlCode: ULONG, in: ?[]const u8, out: ?[]u8, ) DeviceIoControlError!void

Parameters

h: HANDLEioControlCode: ULONGin: ?[]const u8out: ?[]u8

Possible Errors

AccessDenied

Unexpected

UnrecognizedVolume

The volume does not contain a recognized file system. File system drivers might not be loaded, or the volume may be corrupt.

Source

  pub fn DeviceIoControl(
    h: HANDLE,
    ioControlCode: ULONG,
    in: ?[]const u8,
    out: ?[]u8,
) DeviceIoControlError!void {
    // Logic from: https://doxygen.reactos.org/d3/d74/deviceio_8c.html
    const is_fsctl = (ioControlCode >> 16) == FILE_DEVICE_FILE_SYSTEM;

    var io: IO_STATUS_BLOCK = undefined;
    const in_ptr = if (in) |i| i.ptr else null;
    const in_len = if (in) |i| @as(ULONG, @intCast(i.len)) else 0;
    const out_ptr = if (out) |o| o.ptr else null;
    const out_len = if (out) |o| @as(ULONG, @intCast(o.len)) else 0;

    const rc = blk: {
        if (is_fsctl) {
            break :blk ntdll.NtFsControlFile(
                h,
                null,
                null,
                null,
                &io,
                ioControlCode,
                in_ptr,
                in_len,
                out_ptr,
                out_len,
            );
        } else {
            break :blk ntdll.NtDeviceIoControlFile(
                h,
                null,
                null,
                null,
                &io,
                ioControlCode,
                in_ptr,
                in_len,
                out_ptr,
                out_len,
            );
        }
    };
    switch (rc) {
        .SUCCESS => {},
        .PRIVILEGE_NOT_HELD => return error.AccessDenied,
        .ACCESS_DENIED => return error.AccessDenied,
        .INVALID_DEVICE_REQUEST => return error.AccessDenied, // Not supported by the underlying filesystem
        .INVALID_PARAMETER => unreachable,
        .UNRECOGNIZED_VOLUME => return error.UnrecognizedVolume,
        else => return unexpectedStatus(rc),
    }
}  