void __fastcall TConnectionTh::setIPHeader(TIPHdr* ipHeader){
  memset(ipHeader, 0x00, sizeof(TIPHdr));
  ipHeader->ip_hl = 5;
	ipHeader->ip_v = 4;
	ipHeader->ip_tos = 16;
	ipHeader->ip_len = htons(40);
	ipHeader->ip_id = htons(20372);
	ipHeader->ip_off = htons(0x4000);
	ipHeader->ip_ttl = 64;
	ipHeader->ip_p = IPPROTO_TCP;
	ipHeader->ip_src.s_addr = inet_addr("192.168.1.11");
	ipHeader->ip_dst = FHost;
  ipHeader->ip_sum = htons(in_cksum( (char *)ipHeader, sizeof(struct TIPHdr)));
}

void __fastcall TConnectionTh::setTcpHeader(TTcpHdr* tcpHeader, int iTyp, TTCPPseudoHdr* pseudoHdr){
  tcpHeader->th_sport = htons(SRC_PORT);
  tcpHeader->th_dport = htons(FPort);
  tcpHeader->th_seq = htonl(1000000000);
  tcpHeader->th_ack = htonl(1000000000); ;
  tcpHeader->th_x2 = 0;
  tcpHeader->th_off = 0;            //first and only tcp segment
  tcpHeader->th_flags = iTyp;       //initial connection request
  tcpHeader->th_win = htons(1024);
  tcpHeader->th_urp = 0;
  tcpHeader->th_sum = htons(in_cksum( (char *)pseudoHdr, sizeof(struct TTCPPseudoHdr)
                          + sizeof(struct TTcpHdr) ) + 0); //0 => Keine Daten
}

void __fastcall TConnectionTh::setTcpPseudoHeader(TTCPPseudoHdr* pseudohdr){

  pseudohdr->s_addy.s_addr = inet_addr("192.168.1.11");
  pseudohdr->d_addy = FHost;
  pseudohdr->zero = 0x00;
  pseudohdr->protocol = IPPROTO_TCP;
  pseudohdr->length = htons(sizeof(struct TTcpHdr) + 0);  //0 => Keine Daten
}

int __fastcall TConnectionTh::in_cksum(char *data, int count){
		/* Compute Internet Checksum for "count" bytes
		*         beginning at location "addr".
		*/
	register long sum = 0;

	while( count > 1 )  {
		/*  This is the inner loop */
		sum += * (unsigned short *) data++ ;
		count -= 2;
	}

		/*  Add left-over byte, if any */
	if( count > 0 )
		sum += * (unsigned char *) data;

		/*  Fold 32-bit sum to 16 bits */
	while (sum>>16)
	sum = (sum & 0xffff) + (sum >> 16);

	return ~sum;
}

bool __fastcall TConnectionTh::sethdrinclude(int sd) {
  int one = 1;
  return(setsockopt(sd, IPPROTO_IP, IP_HDRINCL, (const char *) &one, sizeof(one)) == 0);
}

unsigned char ucPayload[PACKET_SIZE];
  memset(ucPayload, 0x00, PACKET_SIZE);

  TIPHdr* ipbuffer = (struct TIPHdr*)ucPayload;

  //Der Pseudoheader liegt im gleichen Speicher wie der IP-Header, um die
  //Berechnung der TCP-Checksumme zu erleichtern
  TTCPPseudoHdr* pseudoHdr = (struct TTCPPseudoHdr*)(ucPayload + sizeof(struct TIPHdr) -
                              sizeof(struct TTCPPseudoHdr));

  TTcpHdr* tcpbuffer = (struct TTcpHdr*)(ucPayload + sizeof(struct TIPHdr));

  if(!sethdrinclude(FSock))return;   //Ich will die IP-Header selbst handeln

  while(FState != STATE_FINISH){
    switch(WaitForMultipleObjects(EVENT_COUNT, EventList, false, INFINITE)){
      case(WAIT_TIMEOUT	):    FState=STATE_FINISH;break;
      case(WAIT_OBJECT_0):    ResetEvent(ExitEvent);FState=STATE_FINISH;break;   //Exit
      case(WAIT_OBJECT_0+1):  ResetEvent(SleepEvent);FState=STATE_SLEEPING;break;//Sleep
      case(WAIT_OBJECT_0+2):  {
        ResetEvent(ResumeEvent);
        FState=STATE_RUNNING;
        FOpen = false;
        memset(ucPayload, 0x00, PACKET_SIZE);

        //use same buffer for pseudohdr (used for crc)
        setTcpPseudoHeader(pseudoHdr);
        setTcpHeader(tcpbuffer, TH_SYN, pseudoHdr);
        setIPHeader(ipbuffer);

        FAddr.sin_family = AF_INET;
        FAddr.sin_port = htons(FPort);
        FAddr.sin_addr = ipbuffer->ip_dst;

        if(sendto(
          FSock,
          ucPayload,
          PACKET_SIZE,
          0,
          (struct sockaddr*)&FAddr,
          sizeof(struct sockaddr))!=-1){

          FD_ZERO(&fds);
          FD_SET(FSock, &fds);
          result=select(0, &fds, NULL, NULL, &timeout);
          if((result > 0)&&(result <10000)){     //valid socket
            if(FD_ISSET(FSock, &fds)){
              memset(ucPayload, 0x00, PACKET_SIZE);
              if(recvfrom(FSock, ucPayload, PACKET_SIZE, 0,
                  (struct sockaddr*)&FAddr, &size) != -1)FOpen=true;
            }
          }else FOpen = false;
        }else FOpen = false;
        int i=WSAGetLastError();
        FState=STATE_SLEEPING;
        break;
      }
    }
  }

Liefert bei mir den Fehler 10049(Die angeforderte Adresse ist in diesem Kontext ungültig.)
Kann mir jemand sagen woran das liegt? Bin mit meiner Weisheit wirklich am Ende.

BS: Winxp
Compiler: BCB6

Gruss
Michael

Return(Michael);

What new functionality is added to this feature in Windows XP Service Pack 2?
Restricted traffic over raw sockets

Detailed description

A very small number of Windows applications make use of raw IP sockets, which provide an industry-standard way for applications to create TCP/IP packets with fewer integrity and security checks by the TCP/IP stack. The Windows implementation of TCP/IP still supports receiving traffic on raw IP sockets. However, the ability to send traffic over raw sockets has been restricted in two ways:
•

TCP data cannot be sent over raw sockets.
•

UDP datagrams with invalid source addresses cannot be sent over raw sockets. The IP source address for any outgoing UDP datagram must exist on a network interface or the datagram is dropped.

http://www.microsoft.com/technet/prodtechnol/winxppro/maintain/sp2netwk.mspx