motiejus/zig
1
Fork 0
Code Releases Activity

Add Zig wrapper for kernel32.DeviceIoControl

Browse Source 
This commit adds a Zig wrapper for `kernel32.DeviceIoControl` which
applies ReactOS logic for deciding whether to use
`ntdll.NtDeviceIoControlFile` or `ntdll.NtFsControlFile` based on the
value of passed `IO_CONTROL_CODE`. The decision logic is based on the
logic found in ReactOS found in the following [link].

Thanks to Daurnimator for finding this bit in ReactOS!

[link]: https://doxygen.reactos.org/d3/d74/deviceio_8c.html
This commit is contained in:
Jakub Konka
2020-07-28 14:21:33 +02:00
committed by Andrew Kelley
parent 606b6462ce
commit 4fdfaf69c8
1 changed files with 14 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
lib/std/os/windows.zig
View File

@@ -215,24 +215,28 @@ pub fn CreateEventExW(attributes: ?*SECURITY_ATTRIBUTES, nameW: [*:0]const u16,
}
}
pub const FsControlFileError = error{Unexpected};
pub const DeviceIoControlError = error{Unexpected};
// TODO work out if we need to expose other arguments to the underlying
// NtFsControlFile syscall
pub fn FsControlFile(
/// 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.
pub fn DeviceIoControl(
h: HANDLE,
fsControlCode: ULONG,
ioControlCode: ULONG,
in: ?[]const u8,
out: ?[]u8,
) FsControlFileError!void {
) DeviceIoControlError!void {
// Logic from: https://doxygen.reactos.org/d3/d74/deviceio_8c.html
const syscall = if ((ioControlCode >> 16) == FILE_DEVICE_FILE_SYSTEM) ntdll.NtFsControlFile else ntdll.NtDeviceIoControlFile;
var io: IO_STATUS_BLOCK = undefined;
const rc = ntdll.NtFsControlFile(
const rc = syscall(
h,
null,
null,
null,
&io,
fsControlCode,
ioControlCode,
if (in) |i| i.ptr else null,
if (in) |i| @intCast(ULONG, i.len) else 0,
if (out) |o| o.ptr else null,
@@ -731,7 +735,7 @@ pub fn CreateSymbolicLinkW(
@memcpy(buffer[@sizeOf(SYMLINK_DATA)..], @ptrCast([*]const u8, target_path), target_path.len * 2);
const paths_start = @sizeOf(SYMLINK_DATA) + target_path.len * 2;
@memcpy(buffer[paths_start..].ptr, @ptrCast([*]const u8, target_path), target_path.len * 2);
_ = try FsControlFile(symlink_handle, FSCTL_SET_REPARSE_POINT, buffer[0..buf_len], null);
_ = try DeviceIoControl(symlink_handle, FSCTL_SET_REPARSE_POINT, buffer[0..buf_len], null);
}
pub const ReadLinkError = error{
@@ -809,7 +813,7 @@ pub fn ReadLinkW(dir: ?HANDLE, sub_path_w: [*:0]const u16, out_buffer: []u8) Rea
defer CloseHandle(result_handle);
var reparse_buf: [MAXIMUM_REPARSE_DATA_BUFFER_SIZE]u8 = undefined;
_ = try FsControlFile(result_handle, FSCTL_GET_REPARSE_POINT, null, reparse_buf[0..]);
_ = try DeviceIoControl(result_handle, FSCTL_GET_REPARSE_POINT, null, reparse_buf[0..]);
const reparse_struct = @ptrCast(*const REPARSE_DATA_BUFFER, @alignCast(@alignOf(REPARSE_DATA_BUFFER), &reparse_buf[0]));
switch (reparse_struct.ReparseTag) {