Mir2源码详解之服务端-登录网关(LoginGate）

传奇这款游戏，一直对我的影响很大。当年为了玩传奇，逃课，被老师叫过N次家长。言归正传，网上有很多源码，当然了，都是delphi的。并且很多源码还不全，

由于一直学习的c、c++。delphi还真不懂。无奈硬着头皮上。好了。废话不多说。开始。

登录网关，负责游戏最开始的登录处理（与账户服务器LoginSvr通讯）。验证登录器输入的账户密码是否正确。

界面上的控件很多。其实干活的就 就 三个：“TServerSocket”、“TClientSocket”、“DecodeTimer”这三个控件。

ServerSocket：负责与登录器进行通讯，它做的操作：

1、接收连接，代码如下：

{
函数功能：接受客户端连接，发送消息到 登录服务器
}
procedure TFrmMain.ServerSocketClientConnect(Sender: TObject;
  Socket: TCustomWinSocket);
var
  UserSession:pTUserSession;
  sRemoteIPaddr,sLocalIPaddr:String;
  nSockIndex:Integer;
  IPaddr  :pTSockaddr;
begin
  Socket.nIndex:=-1;
  // 客户端IP地址
  sRemoteIPaddr:=Socket.RemoteAddress;

  if g_boDynamicIPDisMode then  begin
    sLocalIPaddr:=ClientSocket.Socket.RemoteAddress;
  end else begin
    sLocalIPaddr:=Socket.LocalAddress;
  end;

  // 过滤ip
  if IsBlockIP(sRemoteIPaddr) then begin
    MainOutMessage('过滤连接: ' + sRemoteIPaddr,1);
    Socket.Close;
    exit;
  end;
  // 当前IP是否可以连接
  if IsConnLimited(sRemoteIPaddr) then begin
    case BlockMethod of
    // 断开
      mDisconnect: begin
        Socket.Close;
      end;
    // 动态过滤
      mBlock: begin
        New(IPaddr);
        IPaddr.nIPaddr:=inet_addr(PChar(sRemoteIPaddr));
        TempBlockIPList.Add(IPaddr);
        CloseConnect(sRemoteIPaddr);
      end;
    // 永久过滤
      mBlockList: begin
        New(IPaddr);
        IPaddr.nIPaddr:=inet_addr(PChar(sRemoteIPaddr));
        BlockIPList.Add(IPaddr);
        CloseConnect(sRemoteIPaddr);
      end;
    end;
    MainOutMessage('端口攻击: ' + sRemoteIPaddr,1);
    exit;
  end;

  // 如果网关准备好了
  if boGateReady then begin
    for nSockIndex:= 0 to GATEMAXSESSION - 1 do begin
      UserSession:=@g_SessionArray[nSockIndex];
      if UserSession.Socket = nil then begin
        UserSession.Socket:=Socket;
        UserSession.sRemoteIPaddr:=sRemoteIPaddr;
        UserSession.nSendMsgLen:=0;
        UserSession.bo0C:=False;
        UserSession.dw10Tick:=GetTickCount();
        UserSession.dwConnctCheckTick:=GetTickCount();

        UserSession.boSendAvailable:=True;
        UserSession.boSendCheck:=False;
        UserSession.nCheckSendLength:=0;
        UserSession.n20:=0;
        UserSession.dwUserTimeOutTick:=GetTickCount();
        UserSession.SocketHandle:=Socket.SocketHandle;
        UserSession.sIP:=sRemoteIPaddr;
        UserSession.MsgList.Clear;
        Socket.nIndex:=nSockIndex;
        Inc(nSessionCount);
        break;
      end;
    end;
    // 和本地登录服务器进行通讯
    if Socket.nIndex >= 0 then begin
      ClientSocket.Socket.SendText('%O' +
                                   IntToStr(Socket.SocketHandle) +
                                   '/' +
                                   sRemoteIPaddr +
                                   '/' +
                                   sLocalIPaddr +
                                   '$');
      MainOutMessage('Connect: ' + sRemoteIPaddr,5);
    end else begin
      Socket.Close;
      MainOutMessage('Kick Off: ' + sRemoteIPaddr,1);
    end;
  end else begin //0x004529EF
    Socket.Close;
    MainOutMessage('Kick Off: ' + sRemoteIPaddr,1);
  end;
end;

说白了，别看 那些IP过滤规则和连接限制什么的。就是 来了一用户，直接保存到一个 UserSession中。然后通知LoginSvr，有人连接了。。现在市面上的什么：GOM引擎、Hero、HGE（原3K、IGE）、Legend、GEEM2、77M2都是换汤不换药。变的就是 加密方式。这里不得不说，JsocketJ就是TServerSocket、TClientSocket的控件，懒得看源码，看了下其属性，大致就可以了解到。

是采用的线程池的select模型。早期的游戏，都采用这种方式，不过，对于私*服，连接量不大，完全足够应付。其实有更好的解决办法，那就是IOCP来管理。效率更高。windows下最适合的模型了。

2、断开连接，代码如下：

procedure TFrmMain.ServerSocketClientDisconnect(Sender: TObject;
  Socket: TCustomWinSocket);
var
  I:Integer;
  UserSession:pTUserSession;
  nSockIndex:Integer;
  sRemoteIPaddr:String;
  IPaddr  :pTSockaddr;
  nIPaddr :Integer;
begin
  sRemoteIPaddr:=Socket.RemoteAddress;
  nIPaddr:=inet_addr(PChar(sRemoteIPaddr));
  nSockIndex:=Socket.nIndex;
  for I := 0 to CurrIPaddrList.Count - 1 do begin
    IPaddr:=CurrIPaddrList.Items[I];
    if IPaddr.nIPaddr = nIPaddr then begin
      Dec(IPaddr.nCount);
      if IPaddr.nCount <= 0 then begin
        Dispose(IPaddr);
        CurrIPaddrList.Delete(I);
      end;
      Break;
    end;

  end;
  if (nSockIndex >= 0) and (nSockIndex < GATEMAXSESSION) then begin
    UserSession:=@g_SessionArray[nSockIndex];
    UserSession.Socket:=nil;
    UserSession.sRemoteIPaddr:='';
    UserSession.SocketHandle:=-1;
    UserSession.MsgList.Clear;
    Dec(nSessionCount);
    if boGateReady then begin
      ClientSocket.Socket.SendText('%X' +
                                   IntToStr(Socket.SocketHandle) +
                                   '$');
      MainOutMessage('DisConnect: ' + sRemoteIPaddr,5);
    end;
  end;
end;

删除，释放，并通知 LoginSvr，有人断开连接了。。。

3、接收数据，代码如下：

procedure TFrmMain.ServerSocketClientRead(Sender: TObject;
  Socket: TCustomWinSocket);
var
  UserSession:pTUserSession;
  nSockIndex:Integer;
  sReviceMsg,s10,s1C:String;
  nPos:Integer;
  nMsgLen:Integer;
begin
  nSockIndex:=Socket.nIndex;
  if (nSockIndex >= 0) and (nSockIndex < GATEMAXSESSION) then begin
    UserSession:=@g_SessionArray[nSockIndex];
    sReviceMsg:=Socket.ReceiveText;
    if (sReviceMsg <> '') and (boServerReady) then begin
      nPos:=Pos('*',sReviceMsg);
      if nPos > 0 then begin
        UserSession.boSendAvailable:=True;
        UserSession.boSendCheck:=False;
        UserSession.nCheckSendLength:=0;
        s10:=Copy(sReviceMsg,1,nPos -1);
        s1C:=Copy(sReviceMsg,nPos + 1,Length(sReviceMsg) - nPos);
        sReviceMsg:=s10 + s1C;
      end;
      nMsgLen:=length(sReviceMsg);
      if (sReviceMsg <> '') and (boGateReady) and (not boKeepAliveTimcOut)then begin
        UserSession.dwConnctCheckTick:=GetTickCount();
        if (GetTickCount - UserSession.dwUserTimeOutTick) < 1000 then begin
          Inc(UserSession.n20,nMsgLen);
        end else UserSession.n20:= nMsgLen;
        ClientSocket.Socket.SendText('%A' +
                                     IntToStr(Socket.SocketHandle) +
                                     '/' +
                                     sReviceMsg +
                                     '$');
      end;
    end;
  end;
end;

拿到数据，转发到 登录账户服务器。。。。。它主要干的事完了。。

ClientSocket：负责与LoginSvr进行通讯，它做的主要工作就是，

procedure TFrmMain.ClientSocketRead(Sender: TObject;
  Socket: TCustomWinSocket);
var
  sRecvMsg:String;
begin
  sRecvMsg:=Socket.ReceiveText;
  ClientSockeMsgList.Add(sRecvMsg);
end;

你没有看错，就是接收到数据。然后保存到链表，然后等待定时器来解析操作。。

DecodeTimer 定时器的工作。源码中设置的 时间精度是 1毫秒：

procedure TFrmMain.DecodeTimerTimer(Sender : TObject);
var
  sProcessMsg   :String;
  sSocketMsg    :String;
  sSocketHandle :String;
  nSocketIndex  :Integer;
  nMsgCount     :Integer;
  nSendRetCode  :Integer;
  nSocketHandle :Integer;
  dwDecodeTick  :LongWord;
  dwDecodeTime  :LongWord;
  sRemoteIPaddr :String;
  UserSession   :pTUserSession;
  IPaddr  :pTSockaddr;
begin
  ShowMainLogMsg();
  if boDecodeLock or (not boGateReady)then exit;

  try
    dwDecodeTick:=GetTickCount();
    boDecodeLock:=True;
    sProcessMsg:='';
    while (True) do begin
      if ClientSockeMsgList.Count <= 0 then break;
       sProcessMsg:=sProcMsg + ClientSockeMsgList.Strings[0];
       sProcMsg:='';
       ClientSockeMsgList.Delete(0);
       while (True) do begin
         if TagCount(sProcessMsg,'$') < 1 then break;
         sProcessMsg:=ArrestStringEx(sProcessMsg,'%','$',sSocketMsg);
         if sSocketMsg = ''then break;
         if sSocketMsg[1] = '+' then begin
           if sSocketMsg[2] = '-' then begin
             CloseSocket(Str_ToInt(Copy(sSocketMsg,3,Length(sSocketMsg) - 2),0));
             Continue;
           end else begin //0x004521B7
             dwKeepAliveTick:=GetTickCount();
             boKeepAliveTimcOut:=False;
             Continue;
           end;
         end; //0x004521CD
         sSocketMsg:=GetValidStr3(sSocketMsg,sSocketHandle,['/']);
         nSocketHandle:=Str_ToInt(sSocketHandle,-1);
         if nSocketHandle < 0 then
            Continue;
         for nSocketIndex:= 0 to GATEMAXSESSION - 1 do begin
           if g_SessionArray[nSocketIndex].SocketHandle = nSocketHandle then begin
             g_SessionArray[nSocketIndex].MsgList.Add(sSocketMsg);
             break;
           end;
         end;
       end; //0x00452246
     end; //0x452252
     //if sProcessMsg <> '' then ClientSockeMsgList.Add(sProcessMsg);
     if sProcessMsg <> '' then sProcMsg:=sProcessMsg;

     nSendMsgCount:=0;
     n456A2C:=0;
     StringList318.Clear;
     for nSocketIndex:= 0 to GATEMAXSESSION - 1 do begin
       if g_SessionArray[nSocketIndex].SocketHandle <= -1 then Continue;

       //踢除超时无数据传输连接
       if (GetTickCount - g_SessionArray[nSocketIndex].dwConnctCheckTick) > dwKeepConnectTimeOut then begin
         sRemoteIPaddr:=g_SessionArray[nSocketIndex].sRemoteIPaddr;
         case BlockMethod of    //
           mDisconnect: begin
             g_SessionArray[nSocketIndex].Socket.Close;
           end;
           mBlock: begin
             New(IPaddr);
             IPaddr.nIPaddr:=inet_addr(PChar(sRemoteIPaddr));
             TempBlockIPList.Add(IPaddr);
             CloseConnect(sRemoteIPaddr);
           end;
           mBlockList: begin
             New(IPaddr);
             IPaddr.nIPaddr:=inet_addr(PChar(sRemoteIPaddr));
             BlockIPList.Add(IPaddr);
             CloseConnect(sRemoteIPaddr);
           end;
         end;
         MainOutMessage('端口空连接攻击: ' + sRemoteIPaddr,1);
         Continue;
       end;

       while (True) do begin;
         if g_SessionArray[nSocketIndex].MsgList.Count <= 0 then break;
         UserSession:=@g_SessionArray[nSocketIndex];
         nSendRetCode:=SendUserMsg(UserSession,UserSession.MsgList.Strings[0]);
         if (nSendRetCode >= 0) then
         begin
           if nSendRetCode = 1 then begin
             UserSession.dwConnctCheckTick:=GetTickCount();
             UserSession.MsgList.Delete(0);
             Continue;
           end;
           if UserSession.MsgList.Count > 100 then begin
             nMsgCount:=0;
             while nMsgCount <> 51 do begin
               UserSession.MsgList.Delete(0);
               Inc(nMsgCount);
             end;
           end;
           Inc(n456A2C,UserSession.MsgList.Count);
           MainOutMessage(UserSession.sIP +
                      ' : ' +
                      IntToStr(UserSession.MsgList.Count),5);
           Inc(nSendMsgCount);
         end else begin //0x004523A4
           UserSession.SocketHandle:= -1;
           UserSession.Socket:= nil;
           UserSession.MsgList.Clear;
         end;
       end;
     end;
     if (GetTickCount - dwSendKeepAliveTick) > 2 * 1000 then begin
       dwSendKeepAliveTick:=GetTickCount();
       if boGateReady then
         ClientSocket.Socket.SendText('%--$');
     end;
     if (GetTickCount - dwKeepAliveTick) > 10 * 1000 then begin
       boKeepAliveTimcOut:=True;
       ClientSocket.Close;
     end;
  finally
    boDecodeLock:=False;
  end;
  dwDecodeTime:=GetTickCount - dwDecodeTick;
  if dwDecodeMsgTime < dwDecodeTime then dwDecodeMsgTime:=dwDecodeTime;
  if dwDecodeMsgTime > 50 then Dec(dwDecodeMsgTime,50);
end;

又是一坨代码，简而言之，就是把刚才保存接收到的数据。分发到 每个用户的自己的消息链表中，然后遍历，发送出去，
代码如下：

// 发送用户消息
function TFrmMain.SendUserMsg(UserSession:pTUserSession;sSendMsg:String):Integer;
begin
  Result:= -1;
  // 如果
  if UserSession.Socket <> nil then begin
    // 取反
    if not UserSession.bo0C then begin
      // 如果不能发送,则置可用
      if not UserSession.boSendAvailable and (GetTickCount > UserSession.dwSendLockTimeOut) then begin
          UserSession.boSendAvailable  := True;
          UserSession.nCheckSendLength := 0;
          boSendHoldTimeOut            := True;
          dwSendHoldTick               := GetTickCount();
      end; //004525DD
      if UserSession.boSendAvailable then begin
        if UserSession.nCheckSendLength >= 250 then begin
          if not UserSession.boSendCheck then begin
            UserSession.boSendCheck:=True;
            sSendMsg:='*' + sSendMsg;
          end;
          if UserSession.nCheckSendLength >= 512 then begin
            UserSession.boSendAvailable:=False;
            UserSession.dwSendLockTimeOut:=GetTickCount + 3 * 1000;
          end;
        end; //00452620
        UserSession.Socket.SendText(sSendMsg);
        Inc(UserSession.nSendMsgLen,length(sSendMsg));
        Inc(UserSession.nCheckSendLength,length(sSendMsg));
        Result:= 1;
      end else begin //0x0045264A
        Result:= 0;
      end;
    end else begin //0x00452651
      Result:= 0;
    end;
  end;
end;

登录网关，是不是很简单，这不是 重点，重点是市面上的很多引擎的登录网关都基于这套机制，只需要逆向分析下其加密算法，一个自定义网关则出来了。至于过滤规则，什么IP通道，都是浮云。。。。