[root@localhost modules]# firewall-cmd --list-all-zones
block
  target: %%REJECT%%
  icmp-block-inversion: no
  interfaces:
  sources:
  services:
  ports:
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:


dmz
  target: default
  icmp-block-inversion: no
  interfaces:
  sources:
  services: ssh
  ports: 500/udp 4500/udp
  protocols:
  masquerade: yes
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:
    rule protocol value="esp" accept
    rule protocol value="ah" accept

drop
  target: DROP
  icmp-block-inversion: no
  interfaces:
  sources:
  services:
  ports:
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:


external
  target: default
  icmp-block-inversion: no
  interfaces:
  sources:
  services: ssh
  ports:
  protocols:
  masquerade: yes
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:


home
  target: default
  icmp-block-inversion: no
  interfaces:
  sources:
  services: ssh mdns samba-client dhcpv6-client
  ports:
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:


internal
  target: default
  icmp-block-inversion: no
  interfaces:
  sources:
  services: ssh mdns samba-client dhcpv6-client
  ports:
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:


public (active)
  target: default
  icmp-block-inversion: no
  interfaces: enp0s31f6
  sources:
  services: ssh dhcpv6-client http ipsec
  ports: 8069/tcp 3050/tcp 8080/tcp 443/tcp 5904-5905/tcp 64212/tcp 64211/tcp 19735/tcp
  protocols:
  masquerade: yes
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:


trusted
  target: ACCEPT
  icmp-block-inversion: no
  interfaces:
  sources:
  services:
  ports:
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:


work
  target: default
  icmp-block-inversion: no
  interfaces:
  sources:
  services: ssh dhcpv6-client
  ports:
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:

unit myclassImpl;

interface

uses Soap.InvokeRegistry, System.Types, Soap.XSBuiltIns, myclassIntf;

type

 { TMyClass }
  TMyClass = class(TInvokableClass, IMyClass)
  public
    function myFunction(out aMessage: string): Integer; stdcall;
  end;

implementation

uses
  FireDAC.Comp.Client, FireDAC.Stan.Param, FireDAC.Stan.Def, FireDAC.DApt,
  FireDAC.Phys.FBDef, FireDAC.Stan.Intf, FireDAC.Phys,
  FireDAC.Phys.IBBase, FireDAC.Phys.FB, FireDAC.Stan.Option, FireDAC.Stan.Error,
  FireDAC.UI.Intf, FireDAC.Phys.Intf, FireDAC.Stan.Pool,
  FireDAC.Stan.Async, Data.DB, SysUtils, IniFiles;

function TMyClass.myFunction(out aMessage: string): Integer; stdcall;
var
  aDatabase: TFDConnection;
begin
  try
    Result:= 0;
    try
      aDatabase:= TFDConnection.Create(nil);
      aTransaction:= TFDTransaction.Create(nil);
      aQuery:= TFDQuery.Create(nil);
      aDatabase.Params.Text:=
        'Database=my_server:/opt/firebird/my_db.fb' + #13#10 +
        'User_Name=sysdba' + #13#10 +
        'Password=masterkey' + #13#10 +
        'Protocol=TCPIP' + #13#10 +
        'Server=my_server' + #13#10 +
        'CharacterSet=UTF8' + #13#10 +
        'DriverID=FB';
      aDatabase.LoginPrompt:= False;
      aDatabase.Connected:= True;

    finally
      aDatabase.Free;
    end;
  except
    on E: Exception do
    begin
     aMessage:= e.Message;
     Result:= 10;
    end;
  end;
end;

initialization
{ Invokable classes must be registered }
   InvRegistry.RegisterInvokableClass(Tmyclass);
end.