tp.trans

早期freebsd实现

		if ($P.tp_state == TP_OPEN)
			tp_indicate(T_DISCONNECT, $P, 0);
		else {
			int so_error = ECONNREFUSED;
			if ($$.e_reason != (E_TP_NO_SESSION ^ TP_ERROR_MASK) &&
			    $$.e_reason != (E_TP_NO_CR_ON_NC ^ TP_ERROR_MASK) &&
			    $$.e_reason != (E_TP_REF_OVERFLOW ^ TP_ERROR_MASK))
				so_error = ECONNABORTED;
			tp_indicate(T_DISCONNECT, $P, so_error);
		}
		tp_soisdisconnected($P);
		if ($P.tp_class != TP_CLASS_0) {
			if ($P.tp_state == TP_OPEN ) {
				tp_euntimeout($P, TM_data_retrans); /* all */
				tp_cuntimeout($P, TM_retrans);
				tp_cuntimeout($P, TM_inact);
				tp_cuntimeout($P, TM_sendack);
				$P.tp_flags &= ~TPF_DELACK;
			}
			tp_cuntimeout($P, TM_retrans);
			if( $$.e_sref !=  0 ) 
				(void) tp_emit(DC_TPDU_type, $P, 0, 0, MNULL);
		}
	}
;

SAME 			<==		TP_CLOSED 									DR_TPDU 
	DEFAULT
	{
		if( $$.e_sref != 0 )
			(void) tp_emit(DC_TPDU_type, $P, 0, 0, MNULL); 
		/* reference timer already set - reset it to be safe (???) */
		tp_euntimeout($P, TM_reference); /* all */
		tp_etimeout($P, TM_reference, (int)$P.tp_refer_ticks);
	}
;

/* NBS(34) */
TP_REFWAIT 		<==  	TP_CRSENT  									ER_TPDU
	DEFAULT
	{	
		tp_cuntimeout($P, TM_retrans);
		tp_indicate(ER_TPDU, $P, $$.e_reason);
		tp_soisdisconnected($P);
	}
;

/* NBS(27) */
TP_REFWAIT		<==		TP_CLOSING									DR_TPDU
	DEFAULT
	{	 
		tp_cuntimeout($P, TM_retrans);
		tp_soisdisconnected($P);
	}
;
/* these two transitions are the same but can't be combined because xebec
 * can't handle the use of $$.e_reason if they're combined
 */
/* NBS(27) */
TP_REFWAIT		<==		TP_CLOSING									ER_TPDU
	DEFAULT
	{	 
		tp_indicate(ER_TPDU, $P, $$.e_reason);
		tp_cuntimeout($P, TM_retrans);
		tp_soisdisconnected($P);
	}
;
/* NBS(27) */
TP_REFWAIT		<==		TP_CLOSING									DC_TPDU 
	DEFAULT
	{	 
		tp_cuntimeout($P, TM_retrans);
		tp_soisdisconnected($P);
	}
;

/* NBS(21) */
SAME 			<== 	TP_CLOSED 						[ CC_TPDU, CR_TPDU ]
	DEFAULT
	{	/* don't ask me why we have to do this - spec says so */
		(void) tp_emit(DR_TPDU_type, $P, 0, E_TP_NO_SESSION, MNULL);
		/* don't bother with retransmissions of the DR */
	}
;

/* NBS(34) */
TP_REFWAIT 		<== 	TP_OPEN  				 					ER_TPDU
	($P.tp_class == TP_CLASS_0)
	{
		tp_soisdisconnecting($P.tp_sock);
		tp_indicate(ER_TPDU, $P, $$.e_reason);
		tp_soisdisconnected($P);
		tp_netcmd( $P, CONN_CLOSE );
	}
;

TP_CLOSING 		<== 	[ TP_AKWAIT, TP_OPEN ]  					ER_TPDU
	DEFAULT
	{
		if ($P.tp_state == TP_OPEN) {
			tp_euntimeout($P, TM_data_retrans); /* all */
			tp_cuntimeout($P, TM_inact);
			tp_cuntimeout($P, TM_sendack);
		}
		tp_soisdisconnecting($P.tp_sock);
		tp_indicate(ER_TPDU, $P, $$.e_reason);
		$P.tp_retrans = $P.tp_Nretrans;
		tp_ctimeout($P, TM_retrans, (int)$P.tp_dr_ticks);
		(void) tp_emit(DR_TPDU_type, $P, 0, E_TP_PROTO_ERR, MNULL);
	}
;
/* NBS(6) */
TP_OPEN			<==		TP_CRSENT									CC_TPDU 
	($P.tp_class == TP_CLASS_0) 
	{	
		tp_cuntimeout($P, TM_retrans);
		IncStat(ts_tp0_conn);
		$P.tp_fcredit = 1;
		soisconnected($P.tp_sock);
	}
;

TP_OPEN			<==		TP_CRSENT									CC_TPDU 
	DEFAULT
	{	
		IFDEBUG(D_CONN)
			printf("trans: CC_TPDU in CRSENT state flags 0x%x\n", 
				(int)$P.tp_flags);
		ENDDEBUG
		IncStat(ts_tp4_conn);
		$P.tp_fref = $$.e_sref;
		$P.tp_fcredit = $$.e_cdt;
		if (($P.tp_rx_strat & TPRX_FASTSTART) && ($$.e_cdt > 0))
			$P.tp_cong_win = $$.e_cdt * $P.tp_l_tpdusize;
		tp_getoptions($P);
		tp_cuntimeout($P, TM_retrans);
		if ($P.tp_ucddata) {
			IFDEBUG(D_CONN)
				printf("dropping user connect data cc 0x%x\n",
					$P.tp_ucddata->m_len);
			ENDDEBUG
			m_freem($P.tp_ucddata);
			$P.tp_ucddata = 0;
		}
		soisconnected($P.tp_sock);
		if ($$.e_datalen > 0) {
			ASSERT($P.tp_Xrcv.sb_cc == 0); /* should be empty */
			sbappendrecord(&$P.tp_Xrcv, $$.e_data);
			$$.e_data = MNULL;
		}

		(void) tp_emit(AK_TPDU_type, $P, $P.tp_rcvnxt, 0, MNULL);
		tp_ctimeout($P, TM_inact, (int)$P.tp_inact_ticks);
	}
;

/* TP4 only */
SAME			<==		TP_CRSENT									TM_retrans 
	(	$P.tp_retrans > 0 )
	{
		struct mbuf *data = MNULL;
		int error;

		IncStat(ts_retrans_cr);
		$P.tp_cong_win = 1 * $P.tp_l_tpdusize;
		data = MCPY($P.tp_ucddata, M_NOWAIT);
		if($P.tp_ucddata) {
			IFDEBUG(D_CONN)
				printf("TM_retrans.trans m_copy cc 0x%x\n", data);
				dump_mbuf($P.tp_ucddata, "sosnd @ TM_retrans");
			ENDDEBUG
			if( data == MNULL )
				return ENOBUFS;
		}

		$P.tp_retrans --;
		if( error = tp_emit(CR_TPDU_type, $P, 0, 0, data) ) {
			$P.tp_sock->so_error = error;
		}
		tp_ctimeout($P, TM_retrans, (int)$P.tp_cr_ticks);
	}
;

/* TP4 only  */
TP_REFWAIT		<==		TP_CRSENT									TM_retrans 
	DEFAULT /* no more CR retransmissions */
	{ 	
		IncStat(ts_conn_gaveup);
		$P.tp_sock->so_error = ETIMEDOUT;
		tp_indicate(T_DISCONNECT, $P, ETIMEDOUT);
		tp_soisdisconnected($P);
	}
;

/* TP4 only */
SAME 			<==	 TP_AKWAIT											CR_TPDU 
	DEFAULT
	/* duplicate CR (which doesn't really exist in the context of
	 * a connectionless network layer) 
	 * Doesn't occur in class 0.
	 */
	{	
		int error;
		struct mbuf *data = MCPY($P.tp_ucddata, M_WAIT);

		if( error = tp_emit(CC_TPDU_type, $P, 0, 0, data) ) {
			$P.tp_sock->so_error = error;
		}
		$P.tp_retrans = $P.tp_Nretrans;
		tp_ctimeout($P, TM_retrans, (int)$P.tp_cc_ticks);
	}
;

/* TP4 only */
TP_OPEN			<==		TP_AKWAIT 										DT_TPDU 
	( IN_RWINDOW( $P, $$.e_seq,
					$P.tp_rcvnxt, SEQ($P, $P.tp_rcvnxt + $P.tp_lcredit)) )
	{
		int doack;

		/*
		 * Get rid of any confirm or connect data, so that if we
		 * crash or close, it isn't thought of as disconnect data.
		 */
		if ($P.tp_ucddata) {
			m_freem($P.tp_ucddata);
			$P.tp_ucddata = 0;
		}
		tp_ctimeout($P, TM_inact, (int)$P.tp_inact_ticks);
		tp_cuntimeout($P, TM_retrans);
		soisconnected($P.tp_sock);
		tp_ctimeout($P, TM_inact, (int)$P.tp_inact_ticks);

		/* see also next 2 transitions, if you make any changes */

		doack = tp_stash($P, $E);
		IFDEBUG(D_DATA)
			printf("tp_stash returns %d\n",doack);
		ENDDEBUG

		if (doack) {
			(void) tp_emit(AK_TPDU_type, $P, $P.tp_rcvnxt, 0, MNULL ); 
			tp_ctimeout($P, TM_sendack, (int)$P.tp_keepalive_ticks);
		} else
			tp_ctimeout( $P, TM_sendack, (int)$P.tp_sendack_ticks);
		
		IFDEBUG(D_DATA)
			printf("after stash calling sbwakeup\n");
		ENDDEBUG
	}
;

SAME			<==		TP_OPEN 									DT_TPDU 
	( $P.tp_class == TP_CLASS_0 )
	{
		tp0_stash($P, $E);
		sbwakeup( &$P.tp_sock->so_rcv );

		IFDEBUG(D_DATA)
			printf("after stash calling sbwakeup\n");
		ENDDEBUG
	}
;

/* TP4 only */
SAME			<==		TP_OPEN 									DT_TPDU 
	( IN_RWINDOW( $P, $$.e_seq,
					$P.tp_rcvnxt, SEQ($P, $P.tp_rcvnxt + $P.tp_lcredit)) )
	{
		int doack; /* tells if we must ack immediately */

		tp_ctimeout($P, TM_inact, (int)$P.tp_inact_ticks);
		sbwakeup( &$P.tp_sock->so_rcv );

		doack = tp_stash($P, $E);
		IFDEBUG(D_DATA)
			printf("tp_stash returns %d\n",doack);
		ENDDEBUG

		if(doack)
			(void) tp_emit(AK_TPDU_type, $P, $P.tp_rcvnxt, 0, MNULL ); 
		else
			tp_ctimeout_MIN( $P, TM_sendack, (int)$P.tp_sendack_ticks);
		
		IFDEBUG(D_DATA)
			printf("after stash calling sbwakeup\n");
		ENDDEBUG
	}
;

/* Not in window  - we must ack under certain circumstances, namely
 * a) if the seq number is below lwe but > lwe - (max credit ever given)
 * (to handle lost acks) Can use max-possible-credit for this ^^^.
 * and 
 * b) seq number is > uwe but < uwe + previously sent & withdrawn credit
 *
 * (see 12.2.3.8.1 of ISO spec, p. 73)
 * We just always ack.
 */
/* TP4 only */
SAME 			<== 	[ TP_OPEN, TP_AKWAIT ]							DT_TPDU
	DEFAULT /* Not in window */
	{ 	
		IFTRACE(D_DATA)
			tptrace(TPPTmisc, "NIW seq rcvnxt lcredit ",
				$$.e_seq, $P.tp_rcvnxt, $P.tp_lcredit, 0);
		ENDTRACE
		IncStat(ts_dt_niw);
		m_freem($$.e_data);
		tp_ctimeout($P, TM_inact, (int)$P.tp_inact_ticks);
		(void) tp_emit(AK_TPDU_type, $P, $P.tp_rcvnxt, 0, MNULL ); 
	}
;

/* TP4 only */
TP_OPEN			<==		TP_AKWAIT										AK_TPDU
	DEFAULT
	{
		if ($P.tp_ucddata) {
			m_freem($P.tp_ucddata);
			$P.tp_ucddata = 0;
		}
		(void) tp_goodack($P, $$.e_cdt, $$.e_seq, $$.e_subseq);
		tp_cuntimeout($P, TM_retrans);

		soisconnected($P.tp_sock);
		IFTRACE(D_CONN)
			struct socket *so = $P.tp_sock;
			tptrace(TPPTmisc, 
			"called sosiconn: so so_state rcv.sb_sel rcv.sb_flags",
				so, so->so_state, so->so_rcv.sb_sel, so->so_rcv.sb_flags);
			tptrace(TPPTmisc, 
			"called sosiconn 2: so_qlen so_error so_rcv.sb_cc so_head",
				so->so_qlen, so->so_error, so->so_rcv.sb_cc, so->so_head);
		ENDTRACE

		tp_ctimeout($P, TM_sendack, (int)$P.tp_keepalive_ticks);
		tp_ctimeout($P, TM_inact, (int)$P.tp_inact_ticks);
	}
;

/* TP4 only */
TP_OPEN 		<== 	[ TP_OPEN, TP_AKWAIT ]						XPD_TPDU
	($P.tp_Xrcvnxt == $$.e_seq)
	{
		if( $P.tp_state == TP_AKWAIT ) {
			if ($P.tp_ucddata) {
				m_freem($P.tp_ucddata);
				$P.tp_ucddata = 0;
			}
			tp_cuntimeout($P, TM_retrans);
			soisconnected($P.tp_sock);
			tp_ctimeout($P, TM_sendack, (int)$P.tp_keepalive_ticks);
			tp_ctimeout($P, TM_inact, (int)$P.tp_inact_ticks);
		} 
		IFTRACE(D_XPD)
		tptrace(TPPTmisc, "XPD tpdu accepted Xrcvnxt, e_seq datalen m_len\n",
				$P.tp_Xrcvnxt,$$.e_seq,  $$.e_datalen, $$.e_data->m_len);
		ENDTRACE

		$P.tp_sock->so_state |= SS_RCVATMARK;
		$$.e_data->m_flags |= M_EOR;
		sbinsertoob(&$P.tp_Xrcv, $$.e_data);
		IFDEBUG(D_XPD)
			dump_mbuf($$.e_data, "XPD TPDU: tp_Xrcv");
		ENDDEBUG
		tp_indicate(T_XDATA, $P, 0);
		sbwakeup( &$P.tp_Xrcv );

		(void) tp_emit(XAK_TPDU_type, $P, $P.tp_Xrcvnxt, 0, MNULL);
		SEQ_INC($P, $P.tp_Xrcvnxt);
	}
;

/* TP4 only */
SAME			<==		TP_OPEN 									T_USR_Xrcvd
	DEFAULT
	{
		if( $P.tp_Xrcv.sb_cc == 0 ) {
			/* kludge for select(): */ 
			/* $P.tp_sock->so_state &= ~SS_OOBAVAIL; */
		}
	}
	/* OLD WAY:
	 * Ack only after the user receives the XPD.  This is better for 
	 * users that use one XPD right after another.
	 * Acking right away (the NEW WAY, see the prev. transition) is 
	 * better for occasional * XPD, when the receiving user doesn't 
	 * want to read the XPD immediately (which is session's behavior).
	 *
		int error = tp_emit(XAK_TPDU_type, $P, $P.tp_Xrcvnxt, 0, MNULL);
		SEQ_INC($P, $P.tp_Xrcvnxt);
		return error;
	*/
;

/* NOTE: presently if the user doesn't read the connection data
 * before and expedited data PDU comes in, the connection data will
 * be dropped. This is a bug.  To avoid it, we need somewhere else
 * to put the connection data.
 * On the other hand, we need not to have it sitting around forever.
 * This is a problem with the idea of trying to accommodate
 * data on connect w/ a passive-open user interface. 
 */
/* TP4 only */

SAME	 		<== 	[ TP_AKWAIT, TP_OPEN ] 							XPD_TPDU
	DEFAULT /* not in window or cdt==0 */
	{
		IFTRACE(D_XPD)
			tptrace(TPPTmisc, "XPD tpdu niw (Xrcvnxt, e_seq) or not cdt (cc)\n",
				$P.tp_Xrcvnxt, $$.e_seq,  $P.tp_Xrcv.sb_cc , 0);
		ENDTRACE
		if( $P.tp_Xrcvnxt != $$.e_seq )
			IncStat(ts_xpd_niw);
		if( $P.tp_Xrcv.sb_cc ) {
			/* might as well kick 'em again */
			tp_indicate(T_XDATA, $P, 0);
			IncStat(ts_xpd_dup);
		}
		m_freem($$.e_data);
		tp_ctimeout($P, TM_inact, (int)$P.tp_inact_ticks);
		/* don't send an xack because the xak gives "last one received", not
		 * "next one i expect" (dumb)
		 */
	}
;

/* Occurs (AKWAIT, OPEN) when parent (listening) socket gets aborted, and tries
 * to detach all its "children"
 * Also (CRSENT) when user kills a job that's doing a connect()
 */
TP_REFWAIT		<== 	TP_CRSENT 										T_DETACH
	($P.tp_class == TP_CLASS_0)
	{
		struct socket *so = $P.tp_sock;

		/* detach from parent socket so it can finish closing */
		if (so->so_head) {
			if (!soqremque(so, 0) && !soqremque(so, 1))
				panic("tp: T_DETACH");
			so->so_head = 0;
		}
		tp_soisdisconnecting($P.tp_sock);
		tp_netcmd( $P, CONN_CLOSE);
		tp_soisdisconnected($P);
	}
;