Create CNAME

internal/daemon/hosts.go

@@ -292,6 +292,23 @@ type BackupInfo struct {
 	Size      int64
 }
 
+// GetBackupContent returns the content of a backup file.
+func (m *HostsManager) GetBackupContent(name string) (string, error) {
+	backupPath := filepath.Join(m.backupDir, name)
+
+	// Validate backup name to prevent path traversal
+	if filepath.Base(name) != name || !strings.HasPrefix(name, "hosts.") || !strings.HasSuffix(name, ".bak") {
+		return "", fmt.Errorf("invalid backup name")
+	}
+
+	content, err := os.ReadFile(backupPath)
+	if err != nil {
+		return "", fmt.Errorf("failed to read backup: %w", err)
+	}
+
+	return string(content), nil
+}
+
 // RestoreBackup restores a backup by name.
 func (m *HostsManager) RestoreBackup(name string) error {
 	backupPath := filepath.Join(m.backupDir, name)

internal/daemon/server.go

@@ -258,6 +258,9 @@ func (s *Server) handleRequest(req *protocol.Request, creds *PeerCredentials) *p
 	case protocol.RequestBackups:
 		return s.handleBackups()
 
+	case protocol.RequestBackupContent:
+		return s.handleBackupContent(req)
+
 	case protocol.RequestAdd:
 		resp := s.handleAdd(req)
 		if s.auditLogger != nil {
@@ -514,6 +517,25 @@ func (s *Server) handleBackups() *protocol.Response {
 	return resp
 }
 
+func (s *Server) handleBackupContent(req *protocol.Request) *protocol.Response {
+	var payload protocol.BackupContentPayload
+	if err := req.ParsePayload(&payload); err != nil {
+		return protocol.NewErrorResponse(protocol.ErrCodeInvalidRequest, "invalid payload")
+	}
+
+	if payload.BackupName == "" {
+		return protocol.NewErrorResponse(protocol.ErrCodeInvalidRequest, "backup name is required")
+	}
+
+	content, err := s.hosts.GetBackupContent(payload.BackupName)
+	if err != nil {
+		return protocol.NewErrorResponse(protocol.ErrCodeNotFound, fmt.Sprintf("failed to get backup content: %v", err))
+	}
+
+	resp, _ := protocol.NewOKResponse(protocol.BackupContentData{Content: content})
+	return resp
+}
+
 func (s *Server) handleAdd(req *protocol.Request) *protocol.Response {
 	var payload protocol.AddPayload
 	if err := req.ParsePayload(&payload); err != nil {