You don't need to send your reply from the event, just make Src a public variable associated with this specific socket, and use SendTo later. I think your issue is trying to set a property, rather than actually sending a packet.
Angus -------- Original Message -------- *Subject:* Re: [twsocket] Force UDP source port when sending *From:* Dod <[EMAIL PROTECTED]> *To:* ICS support mailing <twsocket@elists.org> *Date:* Sat, 28 Jun 2008 18:06:32 +0200 Hello Angus, Thank you, so I cannot force the port to same as listening but if I do it within the OnDataAvailable then the .SendTo will automatically re-use the same socket to send data back using same src port whenever this port is actually used for listening by the server ? So this also mean that the OnDataAvailable procedure may take a while to get outside if I need to do lenghtly operation. Is there a way to "keep" this socket to re-use later ? regards. >> So question is : how to force UDP port source when sending it whenever >> this port is used by a listener socket as the other application do ? >> May be thru sockaddr_in structure ? ARMSL> Yes, this is the (simplified) code from the ICS SNTP Time Server that ARMSL> responds to a UDP request with the time to the same IP and port. ARMSL> http://www.magsys.co.uk/download/software/sntp.zip ARMSL> Angus ARMSL> procedure TTimeServ.WUDPSocketDataAvailable(Sender: TObject; Error: ARMSL> Word); ARMSL> var ARMSL> Buffer : array [0..1023] of char; ARMSL> Src : TSockAddrIn; ARMSL> SrcLen : Integer; ARMSL> NewTime : LongWord; ARMSL> DataPtr : TWSocketData ; ARMSL> begin ARMSL> SrcLen := SizeOf(Src); ARMSL> FWUDPSocket.ReceiveFrom(@Buffer, SizeOf(Buffer), Src, SrcLen); ARMSL> SrcIPAddr := Src ; ARMSL> NewTime := Trunc ((GetUTCTime - 2) * 24 * 60 * 60) ; ARMSL> ByteSwaps (@NewTime, SizeOf(NewTime)) ; ARMSL> DataPtr := @NewTime ; ARMSL> if FWUDPSocket.Sendto (Src, SrcLen, DataPtr, SizeOf(NewTime)) = ARMSL> SOCKET_ERROR then TriggerQueryDone(FWUDPSocket.LastError); ARMSL> end; -- To unsubscribe or change your settings for TWSocket mailing list please goto http://lists.elists.org/cgi-bin/mailman/listinfo/twsocket Visit our website at http://www.overbyte.be -- To unsubscribe or change your settings for TWSocket mailing list please goto http://lists.elists.org/cgi-bin/mailman/listinfo/twsocket Visit our website at http://www.overbyte.be
