commit 5e161c102d4a99be4903d0074ea2513ebcdb985b (tree)
parent 1e087d3a64e6b504524c32f72b22faffef78b41e
Author: Veikka Tuominen <git@vexu.eu>
Date: Tue, 21 Mar 2023 15:03:33 +0200
Merge pull request #14841 from squeek502/is-cygwin-pty-stuff
`os.isCygwinPty`: Fix a bug, replace kernel32 call, and optimize
Diffstat:
4 files changed, 75 insertions(+), 11 deletions(-)
diff --git a/lib/std/fs/file.zig b/lib/std/fs/file.zig
@@ -379,6 +379,9 @@ pub const File = struct {
const rc = windows.ntdll.NtQueryInformationFile(self.handle, &io_status_block, &info, @sizeOf(windows.FILE_ALL_INFORMATION), .FileAllInformation);
switch (rc) {
.SUCCESS => {},
+ // Buffer overflow here indicates that there is more information available than was able to be stored in the buffer
+ // size provided. This is treated as success because the type of variable-length information that this would be relevant for
+ // (name, volume name, etc) we don't care about.
.BUFFER_OVERFLOW => {},
.INVALID_PARAMETER => unreachable,
.ACCESS_DENIED => return error.AccessDenied,
@@ -830,6 +833,9 @@ pub const File = struct {
const rc = windows.ntdll.NtQueryInformationFile(self.handle, &io_status_block, &info, @sizeOf(windows.FILE_ALL_INFORMATION), .FileAllInformation);
switch (rc) {
.SUCCESS => {},
+ // Buffer overflow here indicates that there is more information available than was able to be stored in the buffer
+ // size provided. This is treated as success because the type of variable-length information that this would be relevant for
+ // (name, volume name, etc) we don't care about.
.BUFFER_OVERFLOW => {},
.INVALID_PARAMETER => unreachable,
.ACCESS_DENIED => return error.AccessDenied,
diff --git a/lib/std/os.zig b/lib/std/os.zig
@@ -3239,22 +3239,48 @@ pub fn isatty(handle: fd_t) bool {
pub fn isCygwinPty(handle: fd_t) bool {
if (builtin.os.tag != .windows) return false;
- const size = @sizeOf(windows.FILE_NAME_INFO);
- var name_info_bytes align(@alignOf(windows.FILE_NAME_INFO)) = [_]u8{0} ** (size + windows.MAX_PATH);
+ // If this is a MSYS2/cygwin pty, then it will be a named pipe with a name in one of these formats:
+ // msys-[...]-ptyN-[...]
+ // cygwin-[...]-ptyN-[...]
+ //
+ // Example: msys-1888ae32e00d56aa-pty0-to-master
+
+ // First, just check that the handle is a named pipe.
+ // This allows us to avoid the more costly NtQueryInformationFile call
+ // for handles that aren't named pipes.
+ {
+ var io_status: windows.IO_STATUS_BLOCK = undefined;
+ var device_info: windows.FILE_FS_DEVICE_INFORMATION = undefined;
+ const rc = windows.ntdll.NtQueryVolumeInformationFile(handle, &io_status, &device_info, @sizeOf(windows.FILE_FS_DEVICE_INFORMATION), .FileFsDeviceInformation);
+ switch (rc) {
+ .SUCCESS => {},
+ else => return false,
+ }
+ if (device_info.DeviceType != windows.FILE_DEVICE_NAMED_PIPE) return false;
+ }
- if (windows.kernel32.GetFileInformationByHandleEx(
- handle,
- windows.FileNameInfo,
- @ptrCast(*anyopaque, &name_info_bytes),
- name_info_bytes.len,
- ) == 0) {
- return false;
+ const name_bytes_offset = @offsetOf(windows.FILE_NAME_INFO, "FileName");
+ // `NAME_MAX` UTF-16 code units (2 bytes each)
+ // Note: This buffer may not be long enough to handle *all* possible paths (PATH_MAX_WIDE would be necessary for that),
+ // but because we only care about certain paths and we know they must be within a reasonable length,
+ // we can use this smaller buffer and just return false on any error from NtQueryInformationFile.
+ const num_name_bytes = windows.MAX_PATH * 2;
+ var name_info_bytes align(@alignOf(windows.FILE_NAME_INFO)) = [_]u8{0} ** (name_bytes_offset + num_name_bytes);
+
+ var io_status_block: windows.IO_STATUS_BLOCK = undefined;
+ const rc = windows.ntdll.NtQueryInformationFile(handle, &io_status_block, &name_info_bytes, @intCast(u32, name_info_bytes.len), .FileNameInformation);
+ switch (rc) {
+ .SUCCESS => {},
+ .INVALID_PARAMETER => unreachable,
+ else => return false,
}
const name_info = @ptrCast(*const windows.FILE_NAME_INFO, &name_info_bytes[0]);
- const name_bytes = name_info_bytes[size .. size + @as(usize, name_info.FileNameLength)];
+ const name_bytes = name_info_bytes[name_bytes_offset .. name_bytes_offset + @as(usize, name_info.FileNameLength)];
const name_wide = mem.bytesAsSlice(u16, name_bytes);
- return mem.indexOf(u16, name_wide, &[_]u16{ 'm', 's', 'y', 's', '-' }) != null or
+ // Note: The name we get from NtQueryInformationFile will be prefixed with a '\', e.g. \msys-1888ae32e00d56aa-pty0-to-master
+ return (mem.startsWith(u16, name_wide, &[_]u16{ '\\', 'm', 's', 'y', 's', '-' }) or
+ mem.startsWith(u16, name_wide, &[_]u16{ '\\', 'c', 'y', 'g', 'w', 'i', 'n', '-' })) and
mem.indexOf(u16, name_wide, &[_]u16{ '-', 'p', 't', 'y' }) != null;
}
diff --git a/lib/std/os/windows.zig b/lib/std/os/windows.zig
@@ -2452,6 +2452,29 @@ pub const FILE_INFORMATION_CLASS = enum(c_int) {
FileMaximumInformation,
};
+pub const FILE_FS_DEVICE_INFORMATION = extern struct {
+ DeviceType: DEVICE_TYPE,
+ Characteristics: ULONG,
+};
+
+pub const FS_INFORMATION_CLASS = enum(c_int) {
+ FileFsVolumeInformation = 1,
+ FileFsLabelInformation,
+ FileFsSizeInformation,
+ FileFsDeviceInformation,
+ FileFsAttributeInformation,
+ FileFsControlInformation,
+ FileFsFullSizeInformation,
+ FileFsObjectIdInformation,
+ FileFsDriverPathInformation,
+ FileFsVolumeFlagsInformation,
+ FileFsSectorSizeInformation,
+ FileFsDataCopyInformation,
+ FileFsMetadataSizeInformation,
+ FileFsFullSizeInformationEx,
+ FileFsMaximumInformation,
+};
+
pub const OVERLAPPED = extern struct {
Internal: ULONG_PTR,
InternalHigh: ULONG_PTR,
diff --git a/lib/std/os/windows/ntdll.zig b/lib/std/os/windows/ntdll.zig
@@ -18,6 +18,7 @@ const IO_STATUS_BLOCK = windows.IO_STATUS_BLOCK;
const LARGE_INTEGER = windows.LARGE_INTEGER;
const OBJECT_INFORMATION_CLASS = windows.OBJECT_INFORMATION_CLASS;
const FILE_INFORMATION_CLASS = windows.FILE_INFORMATION_CLASS;
+const FS_INFORMATION_CLASS = windows.FS_INFORMATION_CLASS;
const UNICODE_STRING = windows.UNICODE_STRING;
const RTL_OSVERSIONINFOW = windows.RTL_OSVERSIONINFOW;
const FILE_BASIC_INFORMATION = windows.FILE_BASIC_INFORMATION;
@@ -232,6 +233,14 @@ pub extern "ntdll" fn NtQueryObject(
ReturnLength: ?*ULONG,
) callconv(WINAPI) NTSTATUS;
+pub extern "ntdll" fn NtQueryVolumeInformationFile(
+ FileHandle: HANDLE,
+ IoStatusBlock: *IO_STATUS_BLOCK,
+ FsInformation: *anyopaque,
+ Length: ULONG,
+ FsInformationClass: FS_INFORMATION_CLASS,
+) callconv(WINAPI) NTSTATUS;
+
pub extern "ntdll" fn RtlWakeAddressAll(
Address: ?*const anyopaque,
) callconv(WINAPI) void;
