udp.pas

NBTSTAT 获取 MAC GROUP

//CopyRight(c)2001 zw84611
//[e-mail]  
unit udp;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, winsock,
  StdCtrls;

const
  WM_SOCK = WM_USER + 1;     //自定义windows消息
  UDPPORT = 6767;            //设定UDP端口号
  NBTPORT = 137;

type
  Tfrmmain = class(TForm)
    Button1: TButton;
    ListBox1: TListBox;
    Edit1: TEdit;
    procedure FormCreate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
    s: TSocket;
    addr: TSockAddr;
    FSockAddrIn : TSockAddrIn; //利用消息实时获知UDP消息
    procedure ReadData(var Message: TMessage); message WM_SOCK;
  public
    { Public declarations }
    procedure SendData(b:array of byte);

    procedure GetInfo(buffer: Array of byte;len:integer);
  end;

var
  frmmain: Tfrmmain;

implementation

{$R *.DFM}

procedure Tfrmmain.FormCreate(Sender: TObject);
var
   TempWSAData: TWSAData;
   //optval: integer;
begin
     // 初始化SOCKET
     if WSAStartup($101, TempWSAData)=1 then
        showmessage('StartUp Error!');

     s := Socket(AF_INET, SOCK_DGRAM, 0);
     if (s = INVALID_SOCKET) then   //Socket创建失败
     begin
          showmessage(inttostr(WSAGetLastError())+'  Socket创建失败');
          CloseSocket(s);
     end;
     //本机SockAddr绑定
     addr.sin_family := AF_INET;
     addr.sin_addr.S_addr := INADDR_ANY;
     addr.sin_port := htons(UDPPORT);
     if Bind(s, addr, sizeof(addr)) <> 0  then
       begin
         showmessage('bind fail');
       end;
     WSAAsyncSelect(s, frmmain.Handle , WM_SOCK, FD_READ);
     //对方SockAddrIn设定
     FSockAddrIn.SIn_Family := AF_INET;
     FSockAddrIn.SIn_Port := htons(NBTPORT);
end;

procedure Tfrmmain.FormClose(Sender: TObject; var Action: TCloseAction);
begin
    CloseSocket(s);
end;

procedure Tfrmmain.GetInfo(buffer: Array of byte;len:integer);
var
    str:string;
    i,j,pos,name_num: integer;
begin

  name_num:=0;
  for i:=1 to len do
  begin
    if((buffer[i]=$21)and(buffer[i+1]=$00)and(buffer[i+2]=$01))
    then
    begin
      name_num:=buffer[i+9];
      break;
    end;
  end;
  if name_num=0 then exit;
  pos:=i+10;

  str:='';
  for i:=pos to (pos+18*name_num-1) do
  begin
    if (((i-pos)mod 18) =0) then
    begin
      for j:=0 to 14 do
      begin
        if trim(char(buffer[i+j]))='' then buffer[i+j]:=ord(' ');
        str:=str+char(buffer[i+j]);
      end;
    if (buffer[i+16] and $80)=$80 then
    begin
      str:=str+format('<%x>',[buffer[i+15]]);
      str:=str+'<GROUP>';
      ListBox1.Items.Add(str);
    end
    else
    begin
      str:=str+format('<%x>',[buffer[i+15]]);
      str:=str+'<UNIQUE>';
      ListBox1.Items.Add(str);
    end;
    str:='';
    end;
  end;

  for i:=0 to 5 do
  begin
    str:=str+format('%.2x.',[buffer[i+pos+18*name_num]]);
  end;
  delete(str,length(str),1);
  str:='MAC:'+str;
  ListBox1.Items.Add(str);
  ListBox1.Items.Add('------------------------------------------------------');
  ListBox1.TopIndex :=ListBox1.Items.count-1;

end;

procedure Tfrmmain.ReadData(var Message: TMessage);
var
   buffer: Array [1..500] of byte;
   len{,i}: integer;
   flen: integer;
   Event: word;
   value: string;

begin
     value:='';
     flen:=sizeof(FSockAddrIn);
     FSockAddrIn.SIn_Port := htons(NBTPORT);
     Event := WSAGetSelectEvent(Message.LParam);
     if Event = FD_READ then
     begin
          len := recvfrom(s, buffer, sizeof(buffer), 0, FSockAddrIn, flen);
          {for i:=1 to len do value:=value+format('%x',[buffer[i]]);
          ListBox1.items.add(value);
          value:='';
          for i:=1 to len do if char(buffer[i])<>#0 then value:=value+char(buffer[i]);
          ListBox1.items.add(value);}
          if len<> 0 then GetInfo(buffer,len);
     end;
end;

procedure Tfrmmain.SendData(b:array of byte);
var
   len: integer;
begin

     FSockAddrIn.SIn_Addr.S_addr := inet_addr(pchar(edit1.text));
     len := sendto(s, b[0],50, 0, FSockAddrIn, sizeof(FSockAddrIn));
     //if (WSAGetLastError() <> WSAEWOULDBLOCK) and (WSAGetLastError() <> 0) then showmessage(inttostr(WSAGetLastError()));
     if len = SOCKET_ERROR then
        showmessage('send fail');
     if len <> 50 then
        showmessage('Not Send all');
end;

procedure Tfrmmain.Button1Click(Sender: TObject);
const NbtstatPacket:array[0..49]of byte
      =($0,$0,$0,$10,$0,$1,
      $0,$0,$0,$0,$0,$0,$20,$43,$4b,
      $41,$41,$41,$41,$41,$41,$41,$41,
      $41,$41,$41,$41,$41,$41,$41,$41,
      $41,$41,$41,$41,$41,$41,$41,$41,
      $41,$41,$41,$41,$41,$41,$0,$0,$21,$0,$1);
begin

  senddata(NbtstatPacket);
  
end;

end.