protected virtual Chunk[] iackDeal(InitAckChunk iack) { iack.getAdRecWinCredit(); iack.getInitialTSN(); iack.getNumInStreams(); iack.getNumOutStreams(); /* * NOTE: TO DO - this is a protocol violation - this should be done with * multiple TCBS and set in cookie echo * NOT HERE */ _peerVerTag = iack.getInitiateTag(); _winCredit = iack.getAdRecWinCredit(); _farTSN = iack.getInitialTSN() - 1; _maxOutStreams = Math.Min(iack.getNumInStreams(), MAXSTREAMS); _maxInStreams = Math.Min(iack.getNumOutStreams(), MAXSTREAMS); iack.getSupportedExtensions(_supportedExtensions); byte[] data = iack.getCookie(); CookieEchoChunk ce = new CookieEchoChunk(); ce.setCookieData(data); Chunk[] reply = new Chunk[1] { ce }; this._state = State.COOKIEECHOED; return(reply); }
/** * <code> * 2) Authenticate the State Cookie as one that it previously generated * by comparing the computed MAC against the one carried in the * State Cookie. If this comparison fails, the SCTP packet, * including the COOKIE ECHO and any DATA chunks, should be silently * discarded, * * 3) Compare the port numbers and the Verification Tag contained * within the COOKIE ECHO chunk to the actual port numbers and the * Verification Tag within the SCTP common header of the received * packet. If these values do not match, the packet MUST be * silently discarded. * * 4) Compare the creation timestamp in the State Cookie to the current * local time. If the elapsed time is longer than the lifespan * carried in the State Cookie, then the packet, including the * COOKIE ECHO and any attached DATA chunks, SHOULD be discarded, * and the endpoint MUST transmit an ERROR chunk with a "Stale * Cookie" error cause to the peer endpoint. * * 5) If the State Cookie is valid, create an association to the sender * of the COOKIE ECHO chunk with the information in the TCB data * carried in the COOKIE ECHO and enter the ESTABLISHED state. * * 6) Send a COOKIE ACK chunk to the peer acknowledging receipt of the * COOKIE ECHO. The COOKIE ACK MAY be bundled with an outbound DATA * chunk or SACK chunk; however, the COOKIE ACK MUST be the first * chunk in the SCTP packet. * * 7) Immediately acknowledge any DATA chunk bundled with the COOKIE * ECHO with a SACK (subsequent DATA chunk acknowledgement should * follow the rules defined in Section 6.2). As mentioned in step * 6, if the SACK is bundled with the COOKIE ACK, the COOKIE ACK * MUST appear first in the SCTP packet. * </code> */ private Chunk[] cookieEchoDeal(CookieEchoChunk echo) { Chunk[] reply = new Chunk[0]; if (_state == State.CLOSED || _state == State.COOKIEWAIT || _state == State.COOKIEECHOED) { // Authenticate the State Cookie CookieHolder cookie; if (null != (cookie = checkCookieEcho(echo.getCookieData()))) { // Compare the creation timestamp in the State Cookie to the current local time. uint howStale = howStaleIsMyCookie(cookie); if (howStale == 0) { //enter the ESTABLISHED state _state = State.ESTABLISHED; /* * Send a COOKIE ACK chunk to the peer acknowledging receipt of the * COOKIE ECHO. The COOKIE ACK MAY be bundled with an outbound DATA * chunk or SACK chunk; however, the COOKIE ACK MUST be the first * chunk in the SCTP packet. */ reply = new Chunk[1]; reply[0] = new CookieAckChunk(); } else { reply = new Chunk[1]; /* If the elapsed time is longer than the lifespan * carried in the State Cookie, then the packet, including the * COOKIE ECHO and any attached DATA chunks, SHOULD be discarded, * and the endpoint MUST transmit an ERROR chunk with a "Stale * Cookie" error cause to the peer endpoint.*/ StaleCookieError sce = new StaleCookieError(); sce.setMeasure(howStale * 1000); ErrorChunk ec = new ErrorChunk(sce); reply[0] = ec; } } else { Logger.Error("Got a COOKIE_ECHO that doesn't match any we sent. ?!?"); } } else { Logger.Debug("Got an COOKIE_ECHO when not closed - ignoring it"); } return(reply); }