version: dynamically get file version

6 files changed, 136 insertions, 26 deletions

diff --git a/version/os_linux.go b/version/debugging_linux.go
index 7e5c4f1c..df5dbd2f 100644
--- a/version/os_linux.go
+++ b/version/debugging_linux.go
@@ -5,13 +5,11 @@
 
 package version
 
-import (
-	"bytes"
-	"fmt"
-	"golang.org/x/sys/unix"
-)
+// For testing the updater package from linux. Debug stuff only.
 
-// This isn't a Linux program, yes, but having the updater package work across platforms is quite helpful for testing.
+func IsOfficialPath(path string) bool {
+	return true
+}
 
 func utsToStr(u [65]byte) string {
 	i := bytes.IndexByte(u[:], 0)
@@ -28,3 +26,7 @@ func OsName() string {
 	}
 	return fmt.Sprintf("%s %s %s", utsToStr(utsname.Sysname), utsToStr(utsname.Release), utsToStr(utsname.Version))
 }
+
+func RunningVersion() string {
+	return "0.0.0.0"
+}
diff --git a/version/mksyscall.go b/version/mksyscall.go
index abd538e5..3c993928 100644
--- a/version/mksyscall.go
+++ b/version/mksyscall.go
@@ -5,4 +5,4 @@
 
 package version
 
-//go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -output zsyscall_windows.go os_windows.go
+//go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -output zsyscall_windows.go os_windows.go version_windows.go
diff --git a/version/official_linux.go b/version/official_linux.go
deleted file mode 100644
index d3ca3349..00000000
--- a/version/official_linux.go
+++ /dev/null
@@ -1,12 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
- */
-
-package version
-
-// For testing the updater package from linux. Debug stuff only.
-
-func IsOfficialPath(path string) bool {
-	return true
-}
diff --git a/version/version.go b/version/useragent.go
index 951d2731..321bc0a6 100644
--- a/version/version.go
+++ b/version/useragent.go
@@ -5,16 +5,12 @@
 
 package version
 
-// #include "../version.h"
-import "C"
 import (
 	"fmt"
 	"golang.zx2c4.com/wireguard/device"
 	"runtime"
 )
 
-const WireGuardWindowsVersion = C.WIREGUARD_WINDOWS_VERSION
-
 func UserAgent() string {
-	return fmt.Sprintf("WireGuard/%s (wireguard-go %s; %s; %s; %s)", WireGuardWindowsVersion, device.WireGuardGoVersion, OsName(), runtime.Version(), runtime.GOARCH)
+	return fmt.Sprintf("WireGuard/%s (wireguard-go %s; %s; %s; %s)", RunningVersion(), device.WireGuardGoVersion, OsName(), runtime.Version(), runtime.GOARCH)
 }
diff --git a/version/version_windows.go b/version/version_windows.go
new file mode 100644
index 00000000..e567e7a0
--- /dev/null
+++ b/version/version_windows.go
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package version
+
+import (
+	"errors"
+	"fmt"
+	"golang.org/x/sys/windows"
+	"os"
+	"runtime"
+	"strings"
+	"unsafe"
+)
+
+//sys GetFileVersionInfoSize(filename *uint16, zero *uint32) (size uint32, err error) = version.GetFileVersionInfoSizeW
+//sys GetFileVersionInfo(filename *uint16, zero uint32, size uint32, block *byte) (err error) = version.GetFileVersionInfoW
+//sys VerQueryValue(block *byte, section *uint16, value **byte, size *uint32) (err error) = version.VerQueryValueW
+
+type vsFixedFileInfo struct {
+	Signature        uint32
+	StrucVersion     uint32
+	FileVersionMS    uint32
+	FileVersionLS    uint32
+	ProductVersionMS uint32
+	ProductVersionLS uint32
+	FileFlagsMask    uint32
+	FileFlags        uint32
+	FileOS           uint32
+	FileType         uint32
+	FileSubtype      uint32
+	FileDateMS       uint32
+	FileDateLS       uint32
+}
+
+const vsFixedFileInfoSignature = 0xFEEF04BD
+
+var cachedVersion string
+
+func RunningVersion() string {
+	if len(cachedVersion) != 0 {
+		return cachedVersion
+	}
+	key16 := []uint16{'\\', 0x00}
+	self, err := os.Executable()
+	if err != nil {
+		panic(err)
+	}
+	self16, err := windows.UTF16PtrFromString(self)
+	if err != nil {
+		panic(err)
+	}
+	var zero uint32
+	size, err := GetFileVersionInfoSize(self16, &zero)
+	if err != nil {
+		panic(err)
+	}
+	buffer := make([]byte, size)
+	err = GetFileVersionInfo(self16, zero, size, &buffer[0])
+	if err != nil {
+		panic(err)
+	}
+	var fixedFileInfo *vsFixedFileInfo
+	err = VerQueryValue(&buffer[0], &key16[0], (**byte)(unsafe.Pointer(&fixedFileInfo)), &size)
+	if err != nil {
+		panic(err)
+	}
+	if uintptr(size) < unsafe.Sizeof(vsFixedFileInfo{}) || fixedFileInfo == nil || fixedFileInfo.Signature != vsFixedFileInfoSignature {
+		panic(errors.New("Incorrect return of VS_FIXEDFILEINFO"))
+	}
+	version := fmt.Sprintf("%d.%d.%d.%d", (fixedFileInfo.FileVersionMS>>16)&0xffff, (fixedFileInfo.FileVersionMS>>0)&0xffff, (fixedFileInfo.FileVersionLS>>16)&0xffff, (fixedFileInfo.FileVersionLS>>0)&0xffff)
+	runtime.KeepAlive(buffer) // The win32 API aliases it in fixedFileInfo, but Go doesn't know that.
+	if strings.HasSuffix(version, ".0") {
+		version = version[:len(version)-2]
+	}
+	if strings.HasSuffix(version, ".0") {
+		version = version[:len(version)-2]
+	}
+	cachedVersion = version
+	return version
+}
diff --git a/version/zsyscall_windows.go b/version/zsyscall_windows.go
index 9f11ce70..ef4e11d7 100644
--- a/version/zsyscall_windows.go
+++ b/version/zsyscall_windows.go
@@ -37,9 +37,13 @@ func errnoErr(e syscall.Errno) error {
 }
 
 var (
-	modntdll = windows.NewLazySystemDLL("ntdll.dll")
+	modntdll   = windows.NewLazySystemDLL("ntdll.dll")
+	modversion = windows.NewLazySystemDLL("version.dll")
 
-	procRtlGetVersion = modntdll.NewProc("RtlGetVersion")
+	procRtlGetVersion           = modntdll.NewProc("RtlGetVersion")
+	procGetFileVersionInfoSizeW = modversion.NewProc("GetFileVersionInfoSizeW")
+	procGetFileVersionInfoW     = modversion.NewProc("GetFileVersionInfoW")
+	procVerQueryValueW          = modversion.NewProc("VerQueryValueW")
 )
 
 func rtlGetVersion(versionInfo *osVersionInfo) (nterr uint32) {
@@ -47,3 +51,40 @@ func rtlGetVersion(versionInfo *osVersionInfo) (nterr uint32) {
 	nterr = uint32(r0)
 	return
 }
+
+func GetFileVersionInfoSize(filename *uint16, zero *uint32) (size uint32, err error) {
+	r0, _, e1 := syscall.Syscall(procGetFileVersionInfoSizeW.Addr(), 2, uintptr(unsafe.Pointer(filename)), uintptr(unsafe.Pointer(zero)), 0)
+	size = uint32(r0)
+	if size == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func GetFileVersionInfo(filename *uint16, zero uint32, size uint32, block *byte) (err error) {
+	r1, _, e1 := syscall.Syscall6(procGetFileVersionInfoW.Addr(), 4, uintptr(unsafe.Pointer(filename)), uintptr(zero), uintptr(size), uintptr(unsafe.Pointer(block)), 0, 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func VerQueryValue(block *byte, section *uint16, value **byte, size *uint32) (err error) {
+	r1, _, e1 := syscall.Syscall6(procVerQueryValueW.Addr(), 4, uintptr(unsafe.Pointer(block)), uintptr(unsafe.Pointer(section)), uintptr(unsafe.Pointer(value)), uintptr(unsafe.Pointer(size)), 0, 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}