下面给出一个通过自定义源IP地址和源端口演示如何发送UDP数据包的例子，或许对你了解有所帮助.你也可以设计自己的协议，如发送SY N 数据浪涌，或其它类型的自定义协议。
{
Raw 数据包 Sender
使用：Delphi + Winsock 2

描述：
通过使用Raw sockets我们可以在internet上发送含有任意格式的数据包。它可以让你可能设计自己的协议。尽管可能接收有点困难，但黑客们可能用它来制造S YN数据浪涌。IP欺骗因此变得十分容易。

注意：
1。下面的源程序可能只在Win2000下可靠。
2。你只能发送Raw数据包。但不能接收。
3。运行此程序时你必须是管理员身份。
4。此源程序需要一个含有一个按钮和一个Memo元件的Form.

---------------------------------------------------------------------
在运行此程序前，你必须改变 SrcIP+SrcPort+DestIP+DestPort为合适的值。
---------------------------------------------------------------------
未弄明白此源程序之前请不要运行它。
---------------------------------------------------------------------
}

unit main;
interface

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

Const
SrcIP = '123.123.123.1';
SrcPort = 1234;
DestIP = '123.123.123.2';
DestPort = 4321;

Max_Message = 4068;
Max_Packet = 4096;

type

TPacketBuffer = Array[0..Max_Packet-1] of byte;

TForm1 = class(TForm)
Button1: TButton;
Memo1: TMemo;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
procedure SendIt;
end;

// IP Header
type
T_IP_Header = record
ip_verlen : Byte;
ip_tos : Byte;
ip_totallength : Word;
ip_id : Word;
ip_offset : Word;
ip_ttl : Byte;
ip_protocol : Byte;
ip_checksum : Word;
ip_srcaddr : LongWord;
ip_destaddr : LongWord;
end;

// UDP Header
Type
T_UDP_Header = record
src_portno : Word;
dst_portno : Word;
udp_length : Word;
udp_checksum : Word;
end;

// Some Winsock 2 type declarations
u_char = Char;
u_short = Word;
u_int = Integer;
u_long = Longint;

SunB = packed record
s_b1, s_b2, s_b3, s_b4: u_char;
end;
SunW = packed record
s_w1, s_w2: u_short;
end;
in_addr = record
case integer of
0: (S_un_b: SunB);
1: (S_un_w: SunW);
2: (S_addr: u_long);
end;
TInAddr = in_addr;
Sockaddr_in = record
case Integer of
0: (sin_family: u_short;
sin_port: u_short;
sin_addr: TInAddr;
sin_zero: array[0..7] of Char);
1: (sa_family: u_short;
sa_data: array[0..13] of Char)
end;
TSockAddr = Sockaddr_in;
TSocket = u_int;

const
WSADESCRIPTION_LEN = 256;
WSASYS_STATUS_LEN = 128;

type
PWSAData = ^TWSAData;
WSAData = record // !!! also WSDATA
wVersion: Word;
wHighVersion: Word;
szDescription: array[0..WSADESCRIPTION_LEN] of Char;
szSystemStatus: array[0..WSASYS_STATUS_LEN] of Char;
iMaxSockets: Word;
iMaxUdpDg: Word;
lpVendorInfo: PChar;
end;
TWSAData = WSAData;

// Define some winsock 2 functions
function closesocket(s: TSocket): Integer; stdcall;
function socket(af, Struct, protocol: Integer): TSocket; stdcall;
function sendto(s: TSocket; var Buf; len, flags: Integer; var addrto: TSockAddr;
tolen: Integer): Integer; stdcall;{}
function setsockopt(s: TSocket; level, optname: Integer; optval: PChar;
optlen: Integer): Integer; stdcall;
function inet_addr(cp: PChar): u_long; stdcall; {PInAddr;} { TInAddr }
function htons(hostshort: u_short): u_short; stdcall;
function WSAGetLastError: Integer; stdcall;
function WSAStartup(wVersionRequired: word; var WSData: TWSAData): Integer; stdcall;
function WSACleanup: Integer; stdcall;

const
AF_INET = 2; // internetwork: UDP, TCP, etc.

IP_HDRINCL = 2; // IP Header Include

SOCK_RAW = 3; // raw-protocol interface

IPPROTO_IP = 0; // dummy for IP
IPPROTO_TCP = 6; // tcp
IPPROTO_UDP = 17; // user datagram protocol
IPPROTO_RAW = 255; // raw IP packet

INVALID_SOCKET = TSocket(NOT(0));
SOCKET_ERROR = -1;

var
Form1: TForm1;

implementation

// Import Winsock 2 functions
const WinSocket = 'WS2_32.DLL';

function closesocket; external winsocket name 'closesocket';
function socket; external winsocket name 'socket';
function sendto; external winsocket name 'sendto';
function setsockopt; external winsocket name 'setsockopt';
function inet_addr; external winsocket name 'inet_addr';
function htons; external winsocket name 'htons';
function WSAGetLastError; external winsocket name 'WSAGetLastError';
function WSAStartup; external winsocket name 'WSAStartup';
function WSACleanup; external winsocket name 'WSACleanup';

{$R *.DFM}

//
// Function: checksum
//
// Description:
// This function calculates the 16-bit one's complement sum
// for the supplied buffer
//
function CheckSum(Var Buffer; Size : integer) : Word;
type
TWordArray = Array[0..1] of Word;
var
ChkSum : LongWord;
i : Integer;
begin
ChkSum := 0;
i := 0;
While Size > 1 do begin
ChkSum := ChkSum + TWordArray(Buffer)[i];
inc(i);
Size := Size - SizeOf(Word);
end;

if Size=1 then ChkSum := ChkSum + Byte(TWordArray(Buffer)[i]);

ChkSum := (ChkSum shr 16) + (ChkSum and $FFFF);
ChkSum := ChkSum + (Chksum shr 16);

Result := Word(ChkSum);
end;

procedure BuildHeaders(
FromIP : String;
iFromPort : Word;
ToIP : String;
iToPort : Word;
StrMessage : String;
Var Buf : TPacketBuffer;
Var remote : TSockAddr;
Var iTotalSize : Word
);
Var
dwFromIP : LongWord;
dwToIP : LongWord;
iIPVersion : Word;
iIPSize : Word;
ipHdr : T_IP_Header;
udpHdr : T_UDP_Header;

iUdpSize : Word;
iUdpChecksumSize : Word;
cksum : Word;

Ptr : ^Byte;

procedure IncPtr(Value : Integer);
begin
ptr := pointer(integer(ptr) + Value);
end;

begin
// Convert ip address'ss

dwFromIP := inet_Addr(PChar(FromIP));
dwToIP := inet_Addr(PChar(ToIP));

// Initalize the IP header
//
iTotalSize := sizeof(ipHdr) + sizeof(udpHdr) + length(strMessage);

iIPVersion := 4;
iIPSize := sizeof(ipHdr) div sizeof(LongWord);
//
// IP version goes in the high order 4 bits of ip_verlen. The
// IP header length (in 32-bit words) goes in the lower 4 bits.
//
ipHdr.ip_verlen := (iIPVersion shl 4) or iIPSize;
ipHdr.ip_tos := 0; // IP type of service
ipHdr.ip_totallength := htons(iTotalSize); // Total packet len
ipHdr.ip_id := 0; // Unique identifier: set to 0
ipHdr.ip_offset := 0; // Fragment offset field
ipHdr.ip_ttl := 128; // Time to live
ipHdr.ip_protocol := $11; // Protocol(UDP)
ipHdr.ip_checksum := 0 ; // IP checksum
ipHdr.ip_srcaddr := dwFromIP; // Source address
ipHdr.ip_destaddr := dwToIP; // Destination address
//
// Initalize the UDP header
//
iUdpSize := sizeof(udpHdr) + length(strMessage);

udpHdr.src_portno := htons(iFromPort) ;
udpHdr.dst_portno := htons(iToPort) ;
udpHdr.udp_length := htons(iUdpSize) ;
udpHdr.udp_checksum := 0 ;
//
// Build the UDP pseudo-header for calculating the UDP checksum.
// The pseudo-header consists of the 32-bit source IP address,
// the 32-bit destination IP address, a zero byte, the 8-bit
// IP protocol field, the 16-bit UDP length, and the UDP
// header itself along with its data (padded with a 0 if
// the data is odd length).
//
iUdpChecksumSize := 0;

ptr := @buf[0];
FillChar(Buf, SizeOf(Buf), 0);

Move(ipHdr.ip_srcaddr, ptr^, SizeOf(ipHdr.ip_srcaddr));
IncPtr(SizeOf(ipHdr.ip_srcaddr));

iUdpChecksumSize := iUdpChecksumSize + sizeof(ipHdr.ip_srcaddr);

Move(ipHdr.ip_destaddr, ptr^, SizeOf(ipHdr.ip_destaddr));
IncPtr(SizeOf(ipHdr.ip_destaddr));

iUdpChecksumSize := iUdpChecksumSize + sizeof(ipHdr.ip_destaddr);

IncPtr(1);

Inc(iUdpChecksumSize);

Move(ipHdr.ip_protocol, ptr^, sizeof(ipHdr.ip_protocol));
IncPtr(sizeof(ipHdr.ip_protocol));
iUdpChecksumSize := iUdpChecksumSize + sizeof(ipHdr.ip_protocol);

Move(udpHdr.udp_length, ptr^, sizeof(udpHdr.udp_length));
IncPtr(sizeof(udpHdr.udp_length));
iUdpChecksumSize := iUdpChecksumSize + sizeof(udpHdr.udp_length);

move(udpHdr, ptr^, sizeof(udpHdr));
IncPtr(sizeof(udpHdr));
iUdpChecksumSize := iUdpCheckSumSize + sizeof(udpHdr);

Move(StrMessage[1], ptr^, Length(strMessage));
IncPtr(Length(StrMessage));

iUdpChecksumSize := iUdpChecksumSize + length(strMessage);

cksum := checksum(buf, iUdpChecksumSize);
udpHdr.udp_checksum := cksum;

//
// Now assemble the IP and UDP headers along with the data
// so we can send it
//
FillChar(Buf, SizeOf(Buf), 0);
Ptr := @Buf[0];

Move(ipHdr, ptr^, SizeOf(ipHdr)); IncPtr(SizeOf(ipHdr));
Move(udpHdr, ptr^, SizeOf(udpHdr)); IncPtr(SizeOf(udpHdr));
Move(StrMessage[1], ptr^, length(StrMessage));

// Apparently, this SOCKADDR_IN structure makes no difference.
// Whatever we put as the destination IP addr in the IP header
// is what goes. Specifying a different destination in remote
// will be ignored.
//
remote.sin_family := AF_INET;
remote.sin_port := htons(iToPort);
remote.sin_addr.s_addr := dwToIP;
end;

procedure TForm1.SendIt;
Var
sh : TSocket;
bOpt : Integer;
ret : Integer;
Buf : TPacketBuffer;
Remote : TSockAddr;
Local : TSockAddr;
iTotalSize : Word;
wsdata : TWSAdata;

begin
// Startup Winsock 2
ret := WSAStartup($0002, wsdata);
if ret<>0 then begin
memo1.lines.add('WSA Startup failed.');
exit;
end;
with memo1.lines do begin
add('WSA Startup:');
add('Desc.: '+wsData.szDescription);
add('Status: '+wsData.szSystemStatus);
end;

try
// Create socket
sh := Socket(AF_INET, SOCK_RAW, IPPROTO_UDP);
if (sh = INVALID_SOCKET) then begin
memo1.lines.add('Socket() failed: '+IntToStr(WSAGetLastError));
exit;
end;
Memo1.lines.add('Socket Handle = '+IntToStr(sh));

// Option: Header Include
bOpt := 1;
ret := SetSockOpt(sh, IPPROTO_IP, IP_HDRINCL, @bOpt, SizeOf(bOpt));
if ret = SOCKET_ERROR then begin
Memo1.lines.add('setsockopt(IP_HDRINCL) failed: '+IntToStr(WSAGetLastError));
exit;
end;

// Build the packet
BuildHeaders( SrcIP, SrcPort,
DestIP, DestPort,
'THIS IS A TEST PACKET',
Buf, Remote, iTotalSize );

// Send the packet
ret := SendTo(sh, buf, iTotalSize, 0, Remote, SizeOf(Remote));
if ret = SOCKET_ERROR then
Memo1.Lines.Add('sendto() failed: '+IntToStr(WSAGetLastError))
else
Memo1.Lines.Add('send '+IntToStr(ret)+' bytes.');

// Close socket
CloseSocket(sh);
finally
// Close Winsock 2
WSACleanup;
end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
SendIt;
end;

end.