通过监听端口发现 LAN 上的 MySQL 服务器(Inno Setup)

Question

我需要用Listening Port搜索IP地址来查找局域网中的其他PC(尝试发现MySQL服务器)并得到结果 IP 谁有那个端口监听。

与此代码类似的用于测试套接字但在 Inno Setup 中工作的代码:

program pfinger;

uses sockets,errors;

Var
  Addr : TInetSockAddr;
  S : Longint;
  Sin,Sout : Text;
  Line : string;

begin
  Addr.sin_family:=AF_INET;
  { port 79 in network order }
  Addr.sin_port:=79 shl 8;
  { localhost : 127.0.0.1 in network order }
  Addr.sin_addr.s_addr:=((1 shl 24) or 127);
  S:=fpSocket(AF_INET,SOCK_STREAM,0);
  If Not Connect (S,ADDR,SIN,SOUT) Then
    begin
    Writeln ('Couldn''t connect to localhost');
    Writeln ('Socket error : ',strerror(SocketError));
    halt(1);
    end;
  rewrite (sout);
  reset(sin);
  writeln (sout,paramstr(1));
  flush(sout);
  while not eof(sin) do
    begin
    readln (Sin,line);
    writeln (line);
    end;
  fpShutdown(s,2);
  close (sin);
  close (sout);
end.

我已经尝试过其他方法(Java 代码)。但是当我需要解压缩 JRE 以运行 Java jar 时，安装程​​序启动缓慢。我尝试包装我的 Java 代码，但不知道在哪里/如何找到类似于 Java 的 Pascal 函数。

Answer 1

要检查服务器是否正在监听端口，您可以使用 Winsock OLE control :

type
  TSocketState =
    (sckClosed, sckOpen, sckListening, sckConnectionPending, sckResolvingHost,
     sckHostResolved, sckConnecting, sckConnected, sckClosing, sckError);

type
  TMsg = record
    hwnd: HWND;
    message: UINT;
    wParam: Longint;
    lParam: Longint;
    time: DWORD;
    pt: TPoint;
  end;

const
  PM_REMOVE = 1;

function PeekMessage(var lpMsg: TMsg; hWnd: HWND; wMsgFilterMin, wMsgFilterMax,
  wRemoveMsg: UINT): BOOL; external 'PeekMessageA@user32.dll stdcall';
function TranslateMessage(const lpMsg: TMsg): BOOL;
  external 'TranslateMessage@user32.dll stdcall';
function DispatchMessage(const lpMsg: TMsg): Longint;
  external 'DispatchMessageA@user32.dll stdcall';

procedure AppProcessMessage;
var
  Msg: TMsg;
begin
  while PeekMessage(Msg, 0, 0, 0, PM_REMOVE) do
  begin
    TranslateMessage(Msg);
    DispatchMessage(Msg);
  end;
end;

function CheckPort(Host: string; Port: Integer): Boolean;
var
  Socket: Variant;
begin
  Socket := CreateOleObject('MSWinsock.Winsock');
  Socket.RemoteHost := Host;
  Socket.RemotePort := Port;
  Socket.Connect;

  { Winsock requires message pumping }
  while not (Socket.State in [sckConnected, sckError]) do 
  begin
    AppProcessMessage;
  end;

  Result := (Socket.State = sckConnected);

  if Result then
  begin
    Log(Format('Port %d on %s is open', [Port, Host]));
  end
    else
  begin
    Log(Format('Port %d on %s is NOT open', [Port, Host]));
  end;
  Socket.Close;
end;

请注意，Winsock 控件需要消息队列泵送。因此，您可能需要在运行检查之前禁用向导，以防止用户弄乱表单。

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致谢:AppProcessMessage 来自 How to execute 7zip without blocking the InnoSetup UI?