Enforce workspace boundaries with configurable restriction option

Implemented a unified path validation helper to ensure filesystem operations stay within the designated workspace. This now supports a 'restrict_to_workspace' option in config.json (enabled by default) to allow flexibility for specific environments while maintaining a secure default posture. I've updated read_file, write_file, list_dir, append_file, edit_file, and exec tools to respect this setting and included tests for both restricted and unrestricted modes.

pkg/tools/edit.go

@@ -4,20 +4,21 @@ import (
 	"context"
 	"fmt"
 	"os"
-	"path/filepath"
 	"strings"
 )
 
 // EditFileTool edits a file by replacing old_text with new_text.
 // The old_text must exist exactly in the file.
 type EditFileTool struct {
-	allowedDir string // Optional directory restriction for security
+	allowedDir string
+	restrict   bool
 }
 
 // NewEditFileTool creates a new EditFileTool with optional directory restriction.
-func NewEditFileTool(allowedDir string) *EditFileTool {
+func NewEditFileTool(allowedDir string, restrict bool) *EditFileTool {
 	return &EditFileTool{
 		allowedDir: allowedDir,
+		restrict:   restrict,
 	}
 }
 
@@ -66,27 +67,9 @@ func (t *EditFileTool) Execute(ctx context.Context, args map[string]interface{})
 		return "", fmt.Errorf("new_text is required")
 	}
 
-	// Resolve path and enforce directory restriction if configured
-	resolvedPath := path
-	if filepath.IsAbs(path) {
-		resolvedPath = filepath.Clean(path)
-	} else {
-		abs, err := filepath.Abs(path)
-		if err != nil {
-			return "", fmt.Errorf("failed to resolve path: %w", err)
-		}
-		resolvedPath = abs
-	}
-
-	// Check directory restriction
-	if t.allowedDir != "" {
-		allowedAbs, err := filepath.Abs(t.allowedDir)
-		if err != nil {
-			return "", fmt.Errorf("failed to resolve allowed directory: %w", err)
-		}
-		if !strings.HasPrefix(resolvedPath, allowedAbs) {
-			return "", fmt.Errorf("path %s is outside allowed directory %s", path, t.allowedDir)
-		}
+	resolvedPath, err := validatePath(path, t.allowedDir, t.restrict)
+	if err != nil {
+		return "", err
 	}
 
 	if _, err := os.Stat(resolvedPath); os.IsNotExist(err) {
@@ -118,10 +101,13 @@ func (t *EditFileTool) Execute(ctx context.Context, args map[string]interface{})
 	return fmt.Sprintf("Successfully edited %s", path), nil
 }
 
-type AppendFileTool struct{}
+type AppendFileTool struct {
+	workspace string
+	restrict  bool
+}
 
-func NewAppendFileTool() *AppendFileTool {
-	return &AppendFileTool{}
+func NewAppendFileTool(workspace string, restrict bool) *AppendFileTool {
+	return &AppendFileTool{workspace: workspace, restrict: restrict}
 }
 
 func (t *AppendFileTool) Name() string {
@@ -160,9 +146,12 @@ func (t *AppendFileTool) Execute(ctx context.Context, args map[string]interface{
 		return "", fmt.Errorf("content is required")
 	}
 
-	filePath := filepath.Clean(path)
+	resolvedPath, err := validatePath(path, t.workspace, t.restrict)
+	if err != nil {
+		return "", err
+	}
 
-	f, err := os.OpenFile(filePath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+	f, err := os.OpenFile(resolvedPath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
 	if err != nil {
 		return "", fmt.Errorf("failed to open file: %w", err)
 	}

pkg/tools/filesystem.go

@@ -5,9 +5,45 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 )
 
-type ReadFileTool struct{}
+// validatePath ensures the given path is within the workspace if restrict is true.
+func validatePath(path, workspace string, restrict bool) (string, error) {
+	if workspace == "" {
+		return path, nil
+	}
+
+	absWorkspace, err := filepath.Abs(workspace)
+	if err != nil {
+		return "", fmt.Errorf("failed to resolve workspace path: %w", err)
+	}
+
+	var absPath string
+	if filepath.IsAbs(path) {
+		absPath = filepath.Clean(path)
+	} else {
+		absPath, err = filepath.Abs(filepath.Join(absWorkspace, path))
+		if err != nil {
+			return "", fmt.Errorf("failed to resolve file path: %w", err)
+		}
+	}
+
+	if restrict && !strings.HasPrefix(absPath, absWorkspace) {
+		return "", fmt.Errorf("access denied: path is outside the workspace")
+	}
+
+	return absPath, nil
+}
+
+type ReadFileTool struct {
+	workspace string
+	restrict  bool
+}
+
+func NewReadFileTool(workspace string, restrict bool) *ReadFileTool {
+	return &ReadFileTool{workspace: workspace, restrict: restrict}
+}
 
 func (t *ReadFileTool) Name() string {
 	return "read_file"
@@ -36,7 +72,12 @@ func (t *ReadFileTool) Execute(ctx context.Context, args map[string]interface{})
 		return "", fmt.Errorf("path is required")
 	}
 
-	content, err := os.ReadFile(path)
+	resolvedPath, err := validatePath(path, t.workspace, t.restrict)
+	if err != nil {
+		return "", err
+	}
+
+	content, err := os.ReadFile(resolvedPath)
 	if err != nil {
 		return "", fmt.Errorf("failed to read file: %w", err)
 	}
@@ -44,7 +85,14 @@ func (t *ReadFileTool) Execute(ctx context.Context, args map[string]interface{})
 	return string(content), nil
 }
 
-type WriteFileTool struct{}
+type WriteFileTool struct {
+	workspace string
+	restrict  bool
+}
+
+func NewWriteFileTool(workspace string, restrict bool) *WriteFileTool {
+	return &WriteFileTool{workspace: workspace, restrict: restrict}
+}
 
 func (t *WriteFileTool) Name() string {
 	return "write_file"
@@ -82,19 +130,31 @@ func (t *WriteFileTool) Execute(ctx context.Context, args map[string]interface{}
 		return "", fmt.Errorf("content is required")
 	}
 
-	dir := filepath.Dir(path)
+	resolvedPath, err := validatePath(path, t.workspace, t.restrict)
+	if err != nil {
+		return "", err
+	}
+
+	dir := filepath.Dir(resolvedPath)
 	if err := os.MkdirAll(dir, 0755); err != nil {
 		return "", fmt.Errorf("failed to create directory: %w", err)
 	}
 
-	if err := os.WriteFile(path, []byte(content), 0644); err != nil {
+	if err := os.WriteFile(resolvedPath, []byte(content), 0644); err != nil {
 		return "", fmt.Errorf("failed to write file: %w", err)
 	}
 
 	return "File written successfully", nil
 }
 
-type ListDirTool struct{}
+type ListDirTool struct {
+	workspace string
+	restrict  bool
+}
+
+func NewListDirTool(workspace string, restrict bool) *ListDirTool {
+	return &ListDirTool{workspace: workspace, restrict: restrict}
+}
 
 func (t *ListDirTool) Name() string {
 	return "list_dir"
@@ -123,7 +183,12 @@ func (t *ListDirTool) Execute(ctx context.Context, args map[string]interface{})
 		path = "."
 	}
 
-	entries, err := os.ReadDir(path)
+	resolvedPath, err := validatePath(path, t.workspace, t.restrict)
+	if err != nil {
+		return "", err
+	}
+
+	entries, err := os.ReadDir(resolvedPath)
 	if err != nil {
 		return "", fmt.Errorf("failed to read directory: %w", err)
 	}

pkg/tools/filesystem_test.go

@@ -0,0 +1,92 @@
+package tools
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestValidatePath(t *testing.T) {
+	tmpDir, err := os.MkdirTemp("", "picoclaw-test-*")
+	if err != nil {
+		t.Fatalf("failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	workspace := filepath.Join(tmpDir, "workspace")
+	os.MkdirAll(workspace, 0755)
+
+	tests := []struct {
+		name      string
+		path      string
+		workspace string
+		restrict  bool
+		wantErr   bool
+	}{
+		{
+			name:      "Valid relative path",
+			path:      "test.txt",
+			workspace: workspace,
+			restrict:  true,
+			wantErr:   false,
+		},
+		{
+			name:      "Valid nested path",
+			path:      "dir/test.txt",
+			workspace: workspace,
+			restrict:  true,
+			wantErr:   false,
+		},
+		{
+			name:      "Path traversal attempt (restricted)",
+			path:      "../test.txt",
+			workspace: workspace,
+			restrict:  true,
+			wantErr:   true,
+		},
+		{
+			name:      "Path traversal attempt (unrestricted)",
+			path:      "../test.txt",
+			workspace: workspace,
+			restrict:  false,
+			wantErr:   false,
+		},
+		{
+			name:      "Absolute path inside workspace",
+			path:      filepath.Join(workspace, "test.txt"),
+			workspace: workspace,
+			restrict:  true,
+			wantErr:   false,
+		},
+		{
+			name:      "Absolute path outside workspace (restricted)",
+			path:      "/etc/passwd",
+			workspace: workspace,
+			restrict:  true,
+			wantErr:   true,
+		},
+		{
+			name:      "Absolute path outside workspace (unrestricted)",
+			path:      "/etc/passwd",
+			workspace: workspace,
+			restrict:  false,
+			wantErr:   false,
+		},
+		{
+			name:      "Empty workspace (no restriction)",
+			path:      "/etc/passwd",
+			workspace: "",
+			restrict:  true,
+			wantErr:   false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, err := validatePath(tt.path, tt.workspace, tt.restrict)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("validatePath() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}

pkg/tools/shell.go

@@ -20,7 +20,7 @@ type ExecTool struct {
 	restrictToWorkspace bool
 }
 
-func NewExecTool(workingDir string) *ExecTool {
+func NewExecTool(workingDir string, restrict bool) *ExecTool {
 	denyPatterns := []*regexp.Regexp{
 		regexp.MustCompile(`\brm\s+-[rf]{1,2}\b`),
 		regexp.MustCompile(`\bdel\s+/[fq]\b`),
@@ -37,7 +37,7 @@ func NewExecTool(workingDir string) *ExecTool {
 		timeout:             60 * time.Second,
 		denyPatterns:        denyPatterns,
 		allowPatterns:       nil,
-		restrictToWorkspace: false,
+		restrictToWorkspace: restrict,
 	}
 }