boxdd: Add custom working directory support

experimental/boxdd/cmd_run_windows.go

@@ -2,9 +2,7 @@ package main
 
 import (
 	"os"
-	"path/filepath"
 	"runtime"
-	"strings"
 	"time"
 
 	E "github.com/sagernet/sing/common/exceptions"
@@ -29,10 +27,12 @@ func preparePlatformWorkingDirectory() error {
 	if listenAddress != "" {
 		return os.MkdirAll(workingDirectory, 0o700)
 	}
-	if !strings.EqualFold(filepath.Clean(workingDirectory), filepath.Clean(defaultServiceWorkingDirectory)) {
-		return E.New("the Windows service working directory must be ", defaultServiceWorkingDirectory)
+	serviceWorkingDirectory, err := resolveWindowsServiceWorkingDirectory(workingDirectory)
+	if err != nil {
+		return err
 	}
-	return ensureWindowsWorkingDirectory(workingDirectory)
+	workingDirectory = serviceWorkingDirectory
+	return ensureWindowsWorkingDirectory(serviceWorkingDirectory)
 }
 
 type windowsService struct{}

experimental/boxdd/cmd_service_windows.go

@@ -3,7 +3,6 @@ package main
 import (
 	"errors"
 	"os"
-	"path/filepath"
 	"strings"
 	"time"
 
@@ -65,19 +64,24 @@ func serviceInstall() error {
 	if err != nil {
 		return E.Cause(err, "get executable path")
 	}
-	if !strings.EqualFold(filepath.Clean(commandServiceFlagWorkingDirectory), filepath.Clean(defaultServiceWorkingDirectory)) {
-		return E.New("the Windows service working directory must be ", defaultServiceWorkingDirectory)
+	serviceWorkingDirectory, err := resolveWindowsServiceWorkingDirectory(commandServiceFlagWorkingDirectory)
+	if err != nil {
+		return E.Cause(err, "validate working directory")
 	}
 	executablePath, err = secureWindowsInstallation(executablePath, commandServiceFlagAllowUnsafeInstallation)
 	if err != nil {
 		return E.Cause(err, "secure installation")
 	}
+	err = ensureWindowsWorkingDirectory(serviceWorkingDirectory)
+	if err != nil {
+		return E.Cause(err, "secure working directory")
+	}
 	manager, err := mgr.Connect()
 	if err != nil {
 		return E.Cause(err, "connect to service manager")
 	}
 	defer manager.Disconnect()
-	arguments := []string{"run", "--working-directory", defaultServiceWorkingDirectory}
+	arguments := []string{"run", "--working-directory", serviceWorkingDirectory}
 	config := mgr.Config{
 		DisplayName:  serviceDisplayName,
 		Description:  serviceDescriptionText,
@@ -132,11 +136,6 @@ func serviceInstall() error {
 		rollback()
 		return E.Cause(err, "secure service")
 	}
-	err = ensureWindowsWorkingDirectory(defaultServiceWorkingDirectory)
-	if err != nil {
-		rollback()
-		return E.Cause(err, "secure working directory")
-	}
 	err = eventlog.InstallAsEventCreate(serviceName, eventlog.Error|eventlog.Warning|eventlog.Info)
 	if err != nil && !strings.Contains(err.Error(), "already exists") {
 		rollback()

experimental/boxdd/security_windows.go

@@ -336,6 +336,40 @@ func validateFixedNTFSVolume(path string) (string, error) {
 	return filepath.Clean(volumePath), nil
 }
 
+func resolveWindowsServiceWorkingDirectory(path string) (string, error) {
+	if path == "" {
+		return "", E.New("missing daemon working directory")
+	}
+	absolutePath, err := filepath.Abs(path)
+	if err != nil {
+		return "", E.Cause(err, "resolve daemon working directory")
+	}
+	cleanPath := filepath.Clean(absolutePath)
+	parentPath := filepath.Dir(cleanPath)
+	parentAttributes, err := windowsFileAttributes(parentPath)
+	if err != nil {
+		return "", E.Cause(err, "query daemon working directory parent")
+	}
+	if parentAttributes&windows.FILE_ATTRIBUTE_DIRECTORY == 0 {
+		return "", E.New("daemon working directory parent is not a directory")
+	}
+	if parentAttributes&windows.FILE_ATTRIBUTE_REPARSE_POINT != 0 {
+		return "", E.New("daemon working directory parent is a reparse point")
+	}
+	volumeRoot, err := validateFixedNTFSVolume(parentPath)
+	if err != nil {
+		return "", E.Cause(err, "validate daemon working directory volume")
+	}
+	if strings.EqualFold(cleanPath, filepath.Clean(volumeRoot)) {
+		return "", E.New("daemon working directory must not be a volume root")
+	}
+	err = validateInstallationAncestors(parentPath, volumeRoot, true)
+	if err != nil {
+		return "", E.Cause(err, "validate daemon working directory ancestors")
+	}
+	return cleanPath, nil
+}
+
 func validateInstallationAncestors(path string, volumeRoot string, validatePermissions bool) error {
 	currentPath := filepath.Clean(path)
 	cleanVolumeRoot := filepath.Clean(volumeRoot)