windows: add support for NTSTATUS values

The native NT API returns error values from a different namespace as the
usual Win32 one. This means it needs to be typed differently. This
commit adds broad support for using NTSTATUS values in a new type called
NTStatus.

First we add the type as a basic uint32. Then we add all of the
predefined constants from ntstatus.h, by augmenting mkerrors.bash to do
automatic extraction. There's a convenece way to convert an NT error to
a Win32 error, so we add the NTStatus.Errno() function. Since NTStatus
is an error type, we define an Error() function that returns a string by
asking ntdll.dll for its contents, in the exact same way that
syscall.Errno.Error() does, by calling FormatMessage. Since functions
need to actually use this, we add the rule that if a `//sys` declaration
returns an error value called "ntstatus", then the type underlying the
error interface is an NTStatus instead of an Errno. Finally we fix one
function that was returning an error interface of an Errno rather than
an NTStatus.

Change-Id: I06296b9563bbec526759d12a19f13ac6ad46dcc3
Reviewed-on: https://go-review.googlesource.com/c/sys/+/297330
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Trust: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

windows/mkerrors.bash

@@ -9,6 +9,8 @@ shopt -s nullglob
 
 winerror="$(printf '%s\n' "/mnt/c/Program Files (x86)/Windows Kits/"/*/Include/*/shared/winerror.h | sort -Vr | head -n 1)"
 [[ -n $winerror ]] || { echo "Unable to find winerror.h" >&2; exit 1; }
+ntstatus="$(printf '%s\n' "/mnt/c/Program Files (x86)/Windows Kits/"/*/Include/*/shared/ntstatus.h | sort -Vr | head -n 1)"
+[[ -n $ntstatus ]] || { echo "Unable to find ntstatus.h" >&2; exit 1; }
 
 declare -A errors
 
@@ -59,5 +61,10 @@ declare -A errors
 		echo "$key $vtype = $value"
 	done < "$winerror"
 
+	while read -r line; do
+		[[ $line =~ ^#define\ (STATUS_[^\s]+)\ +\(\(NTSTATUS\)((0x)?[0-9a-fA-F]+)L?\) ]] || continue
+		echo "${BASH_REMATCH[1]} NTStatus = ${BASH_REMATCH[2]}"
+	done < "$ntstatus"
+
 	echo ")"
 } | gofmt > "zerrors_windows.go"

windows/mkwinsyscall/mkwinsyscall.go

@@ -318,12 +318,18 @@ func (r *Rets) SetErrorCode() string {
 	const code = `if r0 != 0 {
 		%s = %sErrno(r0)
 	}`
+	const ntstatus = `if r0 != 0 {
+		ntstatus = NTStatus(r0)
+	}`
 	if r.Name == "" && !r.ReturnsError {
 		return ""
 	}
 	if r.Name == "" {
 		return r.useLongHandleErrorCode("r1")
 	}
+	if r.Type == "error" && r.Name == "ntstatus" {
+		return ntstatus
+	}
 	if r.Type == "error" {
 		return fmt.Sprintf(code, r.Name, syscalldot())
 	}

windows/syscall_windows.go

@@ -8,6 +8,7 @@ package windows
 
 import (
 	errorspkg "errors"
+	"fmt"
 	"sync"
 	"syscall"
 	"time"
@@ -65,9 +66,8 @@ const (
 	LOCKFILE_FAIL_IMMEDIATELY = 0x00000001
 	LOCKFILE_EXCLUSIVE_LOCK   = 0x00000002
 
-	// Return values of SleepEx and other APC functions
-	STATUS_USER_APC    = 0x000000C0
-	WAIT_IO_COMPLETION = STATUS_USER_APC
+	// Return value of SleepEx and other APC functions
+	WAIT_IO_COMPLETION = 0x000000C0
 )
 
 // StringToUTF16 is deprecated. Use UTF16FromString instead.
@@ -375,7 +375,8 @@ func NewCallbackCDecl(fn interface{}) uintptr {
 //sys	stringFromGUID2(rguid *GUID, lpsz *uint16, cchMax int32) (chars int32) = ole32.StringFromGUID2
 //sys	coCreateGuid(pguid *GUID) (ret error) = ole32.CoCreateGuid
 //sys	CoTaskMemFree(address unsafe.Pointer) = ole32.CoTaskMemFree
-//sys	rtlGetVersion(info *OsVersionInfoEx) (ret error) = ntdll.RtlGetVersion
+//sys	rtlNtStatusToDosError(ntstatus NTStatus) (ret syscall.Errno) = ntdll.RtlNtStatusToDosError
+//sys	rtlGetVersion(info *OsVersionInfoEx) (ntstatus error) = ntdll.RtlGetVersion
 //sys	rtlGetNtVersionNumbers(majorVersion *uint32, minorVersion *uint32, buildNumber *uint32) = ntdll.RtlGetNtVersionNumbers
 //sys	getProcessPreferredUILanguages(flags uint32, numLanguages *uint32, buf *uint16, bufSize *uint32) (err error) = kernel32.GetProcessPreferredUILanguages
 //sys	getThreadPreferredUILanguages(flags uint32, numLanguages *uint32, buf *uint16, bufSize *uint32) (err error) = kernel32.GetThreadPreferredUILanguages
@@ -1514,3 +1515,21 @@ func getUILanguages(flags uint32, f func(flags uint32, numLanguages *uint32, buf
 func SetConsoleCursorPosition(console Handle, position Coord) error {
 	return setConsoleCursorPosition(console, *((*uint32)(unsafe.Pointer(&position))))
 }
+
+func (s NTStatus) Errno() syscall.Errno {
+	return rtlNtStatusToDosError(s)
+}
+
+func langID(pri, sub uint16) uint32 { return uint32(sub)<<10 | uint32(pri) }
+
+func (s NTStatus) Error() string {
+	b := make([]uint16, 300)
+	n, err := FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_FROM_HMODULE|FORMAT_MESSAGE_ARGUMENT_ARRAY, modntdll.Handle(), uint32(s), langID(LANG_ENGLISH, SUBLANG_ENGLISH_US), b, nil)
+	if err != nil {
+		return fmt.Sprintf("NTSTATUS 0x%08x", uint32(s))
+	}
+	// trim terminating \r and \n
+	for ; n > 0 && (b[n-1] == '\n' || b[n-1] == '\r'); n-- {
+	}
+	return string(utf16.Decode(b[:n]))
+}

windows/syscall_windows_test.go

@@ -486,3 +486,11 @@ func TestIsWow64Process2(t *testing.T) {
 		t.Errorf("IsWow64Process2 is wrong: want %v have %v", runtime.GOARCH, processMachine)
 	}
 }
+
+func TestNTStatusString(t *testing.T) {
+	want := "The name limit for the local computer network adapter card was exceeded."
+	got := windows.STATUS_TOO_MANY_NAMES.Error()
+	if want != got {
+		t.Errorf("NTStatus.Error did not return an expected error string - want %q; got %q", want, got)
+	}
+}

windows/types_windows.go

@@ -10,6 +10,10 @@ import (
 	"unsafe"
 )
 
+// NTStatus corresponds with NTSTATUS, error values returned by ntdll.dll and
+// other native functions.
+type NTStatus uint32
+
 const (
 	// Invented values to support what package os expects.
 	O_RDONLY   = 0x00000

windows/zsyscall_windows.go

@@ -346,6 +346,7 @@ var (
 	procNetUserGetInfo                                       = modnetapi32.NewProc("NetUserGetInfo")
 	procRtlGetNtVersionNumbers                               = modntdll.NewProc("RtlGetNtVersionNumbers")
 	procRtlGetVersion                                        = modntdll.NewProc("RtlGetVersion")
+	procRtlNtStatusToDosError                                = modntdll.NewProc("RtlNtStatusToDosError")
 	procCLSIDFromString                                      = modole32.NewProc("CLSIDFromString")
 	procCoCreateGuid                                         = modole32.NewProc("CoCreateGuid")
 	procCoTaskMemFree                                        = modole32.NewProc("CoTaskMemFree")
@@ -2951,14 +2952,20 @@ func rtlGetNtVersionNumbers(majorVersion *uint32, minorVersion *uint32, buildNum
 	return
 }
 
-func rtlGetVersion(info *OsVersionInfoEx) (ret error) {
+func rtlGetVersion(info *OsVersionInfoEx) (ntstatus error) {
 	r0, _, _ := syscall.Syscall(procRtlGetVersion.Addr(), 1, uintptr(unsafe.Pointer(info)), 0, 0)
 	if r0 != 0 {
-		ret = syscall.Errno(r0)
+		ntstatus = NTStatus(r0)
 	}
 	return
 }
 
+func rtlNtStatusToDosError(ntstatus NTStatus) (ret syscall.Errno) {
+	r0, _, _ := syscall.Syscall(procRtlNtStatusToDosError.Addr(), 1, uintptr(ntstatus), 0, 0)
+	ret = syscall.Errno(r0)
+	return
+}
+
 func clsidFromString(lpsz *uint16, pclsid *GUID) (ret error) {
 	r0, _, _ := syscall.Syscall(procCLSIDFromString.Addr(), 2, uintptr(unsafe.Pointer(lpsz)), uintptr(unsafe.Pointer(pclsid)), 0)
 	if r0 != 0 {