tp_input.c

早期freebsd实现

			break;

		case DR_TPDU_type: 
			IFTRACE(D_TPINPUT)
				tptrace(TPPTmisc, "DR recvd", hdr->tpdu_DRreason, 0, 0, 0);
			ENDTRACE
			if (sref != tpcb->tp_fref) {
				printf("INPUT: inv sufx DRsref 0x%x tp_fref 0x%x\n",
					sref, tpcb->tp_fref);
			}
					
			CHECK( (sref != 0 && sref != tpcb->tp_fref &&
					tpcb->tp_state != TP_CRSENT), 
				(TP_ERROR_SNDC | E_TP_MISM_REFS),ts_inv_sufx, respond,
				(1 + (caddr_t)&hdr->tpdu_DRsref - (caddr_t)hdr))

			e.ATTR(DR_TPDU).e_reason = hdr->tpdu_DRreason;
			e.ATTR(DR_TPDU).e_sref =  (u_short)sref;
			takes_data = TRUE;
			e.ev_number = DR_TPDU;
			IncStat(ts_DR_rcvd);
			break;

		case ER_TPDU_type:
			IFTRACE(D_TPINPUT)
				tptrace(TPPTmisc, "ER recvd", hdr->tpdu_ERreason,0,0,0);
			ENDTRACE
			e.ev_number = ER_TPDU;
			e.ATTR(ER_TPDU).e_reason = hdr->tpdu_ERreason;
			IncStat(ts_ER_rcvd);
			break;

		case AK_TPDU_type: 

			e.ATTR(AK_TPDU).e_subseq = subseq;
			e.ATTR(AK_TPDU).e_fcc_present = fcc_present;

			if (tpcb->tp_xtd_format) {
#ifdef BYTE_ORDER
				union seq_type seqeotX;

				seqeotX.s_seqeot = ntohl(hdr->tpdu_seqeotX);
				e.ATTR(AK_TPDU).e_seq = seqeotX.s_seq;
				e.ATTR(AK_TPDU).e_cdt = ntohs(hdr->tpdu_AKcdtX);
#else
				e.ATTR(AK_TPDU).e_cdt = hdr->tpdu_AKcdtX;
				e.ATTR(AK_TPDU).e_seq = hdr->tpdu_AKseqX;
#endif /* BYTE_ORDER */
			} else {
				e.ATTR(AK_TPDU).e_cdt = hdr->tpdu_AKcdt;
				e.ATTR(AK_TPDU).e_seq = hdr->tpdu_AKseq;
			}
			IFTRACE(D_TPINPUT)
				tptrace(TPPTmisc, "AK recvd seq cdt subseq fcc_pres", 
					e.ATTR(AK_TPDU).e_seq, e.ATTR(AK_TPDU).e_cdt,
					subseq, fcc_present);
			ENDTRACE

			e.ev_number = AK_TPDU;
			IncStat(ts_AK_rcvd);
			IncPStat(tpcb, tps_AK_rcvd);
			break;

		case XAK_TPDU_type: 
			if (tpcb->tp_xtd_format) {
#ifdef BYTE_ORDER
				union seq_type seqeotX;

				seqeotX.s_seqeot = ntohl(hdr->tpdu_seqeotX);
				e.ATTR(XAK_TPDU).e_seq = seqeotX.s_seq;
#else
				e.ATTR(XAK_TPDU).e_seq = hdr->tpdu_XAKseqX;
#endif /* BYTE_ORDER */
			} else {
				e.ATTR(XAK_TPDU).e_seq = hdr->tpdu_XAKseq;
			}
			e.ev_number = XAK_TPDU;
			IncStat(ts_XAK_rcvd);
			IncPStat(tpcb, tps_XAK_rcvd);
			break;

		case XPD_TPDU_type: 
			if (tpcb->tp_xtd_format) {
#ifdef BYTE_ORDER
				union seq_type seqeotX;

				seqeotX.s_seqeot = ntohl(hdr->tpdu_seqeotX);
				e.ATTR(XPD_TPDU).e_seq = seqeotX.s_seq;
#else
				e.ATTR(XPD_TPDU).e_seq = hdr->tpdu_XPDseqX;
#endif /* BYTE_ORDER */
			} else {
				e.ATTR(XPD_TPDU).e_seq = hdr->tpdu_XPDseq;
			}
			takes_data = TRUE;
			e.ev_number = XPD_TPDU;
			IncStat(ts_XPD_rcvd);
			IncPStat(tpcb, tps_XPD_rcvd);
			break;

		case DT_TPDU_type:
			{ /* the y option will cause occasional packets to be dropped.
			   * A little crude but it works.
			   */

				IFDEBUG(D_DROP)
					if(time.tv_usec & 0x4 && hdr->tpdu_DTseq & 0x1) {
						IncStat(ts_ydebug);
						goto discard;
					}
				ENDDEBUG
			}
			if (tpcb->tp_class == TP_CLASS_0) {
			tp0_data:
				e.ATTR(DT_TPDU).e_seq = 0; /* actually don't care */
				e.ATTR(DT_TPDU).e_eot = (((struct tp0du *)hdr)->tp0du_eot);
			} else if (tpcb->tp_xtd_format) {
#ifdef BYTE_ORDER
				union seq_type seqeotX;

				seqeotX.s_seqeot = ntohl(hdr->tpdu_seqeotX);
				e.ATTR(DT_TPDU).e_seq = seqeotX.s_seq;
				e.ATTR(DT_TPDU).e_eot = seqeotX.s_eot;
#else
				e.ATTR(DT_TPDU).e_seq = hdr->tpdu_DTseqX;
				e.ATTR(DT_TPDU).e_eot = hdr->tpdu_DTeotX;
#endif /* BYTE_ORDER */
			} else {
				e.ATTR(DT_TPDU).e_seq = hdr->tpdu_DTseq;
				e.ATTR(DT_TPDU).e_eot = hdr->tpdu_DTeot;
			}
			if(e.ATTR(DT_TPDU).e_eot)
				IncStat(ts_eot_input);
			takes_data = TRUE;
			e.ev_number = DT_TPDU;
			IncStat(ts_DT_rcvd);
			IncPStat(tpcb, tps_DT_rcvd);
			break;

		case GR_TPDU_type: 
			tp_indicate(T_DISCONNECT, tpcb, ECONNABORTED);
			/* drop through */
		default:
			/* this should NEVER happen because there is a
			 * check for dutype well above here
			 */
			error = E_TP_INV_TPDU; /* causes an ER  */
			IFDEBUG(D_TPINPUT)
				printf("INVALID dutype 0x%x\n", hdr->tpdu_type);
			ENDDEBUG
			IncStat(ts_inv_dutype);
			goto respond;
		}
	}
	/* peel off the tp header; 
	 * remember that the du_li doesn't count itself.
	 * This may leave us w/ an empty mbuf at the front of a chain.
	 * We can't just throw away the empty mbuf because hdr still points
	 * into the mbuf's data area and we're still using hdr (the tpdu header)
	 */
	m->m_len -= ((int)hdr->tpdu_li + 1);
	m->m_data += ((int)hdr->tpdu_li + 1);

	if (takes_data) {
		int max = tpdu_info[ hdr->tpdu_type ] [TP_MAX_DATA_INDEX];
		int datalen = tpdu_len - hdr->tpdu_li - 1, mbtype = MT_DATA;
		struct {
			struct tp_disc_reason dr;
			struct cmsghdr x_hdr;
		} x;
#define c_hdr x.x_hdr
		register struct mbuf *n;

		CHECK( (max && datalen > max), E_TP_LENGTH_INVAL,
		        ts_inv_length, respond, (max + hdr->tpdu_li + 1) );
		switch( hdr->tpdu_type ) {

		case CR_TPDU_type:
			c_hdr.cmsg_type = TPOPT_CONN_DATA;
			goto make_control_msg;

		case CC_TPDU_type:
			c_hdr.cmsg_type = TPOPT_CFRM_DATA;
			goto make_control_msg;

		case DR_TPDU_type:
			x.dr.dr_hdr.cmsg_len = sizeof(x) - sizeof(c_hdr);
			x.dr.dr_hdr.cmsg_type = TPOPT_DISC_REASON;
			x.dr.dr_hdr.cmsg_level = SOL_TRANSPORT;
			x.dr.dr_reason = hdr->tpdu_DRreason;
			c_hdr.cmsg_type = TPOPT_DISC_DATA;
		make_control_msg:
			datalen += sizeof(c_hdr);
			c_hdr.cmsg_len = datalen;
			c_hdr.cmsg_level = SOL_TRANSPORT;
			mbtype = MT_CONTROL;
			MGET(n, M_DONTWAIT, MT_DATA);
			if (n == 0)
				{m_freem(m); m = 0; datalen = 0; goto invoke; }
			if (hdr->tpdu_type == DR_TPDU_type) {
				datalen += sizeof(x) - sizeof(c_hdr);
				bcopy((caddr_t)&x, mtod(n, caddr_t), n->m_len = sizeof(x));
			} else
				bcopy((caddr_t)&c_hdr, mtod(n, caddr_t),
					  n->m_len = sizeof(c_hdr));
			n->m_next = m;
			m = n;
			/* FALLTHROUGH */

		case XPD_TPDU_type:
			if (mbtype != MT_CONTROL)
				mbtype = MT_OOBDATA;
			m->m_flags |= M_EOR;
			/* FALLTHROUGH */

		case DT_TPDU_type:
			for (n = m; n; n = n->m_next) { 
				MCHTYPE(n, mbtype);
			}
		invoke:
			e.ATTR(DT_TPDU).e_datalen = datalen;
			e.ATTR(DT_TPDU).e_data =  m;
			break;

		default:
			printf(
				"ERROR in tp_input! hdr->tpdu_type 0x%x takes_data 0x%x m 0x%x\n",
				hdr->tpdu_type, takes_data, m);
			break;
		}
		/* prevent m_freem() after tp_driver() from throwing it all away */
		m = MNULL;
	}

	IncStat(ts_tpdu_rcvd);

	IFDEBUG(D_TPINPUT)
		printf( "tp_input: before driver, state 0x%x event 0x%x m 0x%x",
			tpcb->tp_state, e.ev_number, m );
		printf(" e.e_data 0x%x\n", e.ATTR(DT_TPDU).e_data);
		printf("takes_data 0x%x m_len 0x%x, tpdu_len 0x%x\n",
			takes_data, (m==MNULL)?0:m->m_len,  tpdu_len);
	ENDDEBUG

	error = tp_driver(tpcb, &e);

	ASSERT(tpcb != (struct tp_pcb *)0);
	ASSERT(tpcb->tp_sock != (struct socket *)0);
	if( tpcb->tp_sock->so_error == 0 )
		tpcb->tp_sock->so_error = error;

	/* Kludge to keep the state tables under control (adding
	 * data on connect & disconnect & freeing the mbuf containing
	 * the data would have exploded the tables and made a big mess ).
	 */
	switch(e.ev_number) {
		case CC_TPDU:
		case DR_TPDU:
		case CR_TPDU:
			m = e.ATTR(CC_TPDU).e_data; /* same field for all three dutypes */
			IFDEBUG(D_TPINPUT)
				printf("after driver, restoring m to 0x%x, takes_data 0x%x\n", 
				m, takes_data);
			ENDDEBUG
			break;
		default:
			break;
	}
	/* Concatenated sequences are terminated by any tpdu that 
	 * carries data: CR, CC, DT, XPD, DR.
	 * All other tpdu types may be concatenated: AK, XAK, DC, ER.
	 */

separate:
	if ( takes_data == 0 )  {
		ASSERT( m != MNULL );
		/* 
		 * we already peeled off the prev. tp header so 
		 * we can just pull up some more and repeat
		 */

		if( m = tp_inputprep(m) ) {
		IFDEBUG(D_TPINPUT)
			hdr = mtod(m, struct tpdu *);
			printf("tp_input @ separate: hdr 0x%x size %d m 0x%x\n", 
			hdr, (int) hdr->tpdu_li + 1, m);
			dump_mbuf(m, "tp_input after driver, at separate");
		ENDDEBUG

			IncStat(ts_concat_rcvd);
			goto again;
		}
	}
	if ( m != MNULL ) {
		IFDEBUG(D_TPINPUT)
			printf("tp_input : m_freem(0x%x)\n", m);
		ENDDEBUG
		m_freem(m);
		IFDEBUG(D_TPINPUT)
			printf("tp_input : after m_freem 0x%x\n", m);
		ENDDEBUG
	}
	return (ProtoHook) tpcb;

discard:
	/* class 4: drop the tpdu */
	/* class 2,0: Should drop the net connection, if you can figure out
	 * to which connection it applies
	 */
	IFDEBUG(D_TPINPUT)
		printf("tp_input DISCARD\n");
	ENDDEBUG
	IFTRACE(D_TPINPUT)
		tptrace(TPPTmisc, "tp_input DISCARD m",  m,0,0,0);
	ENDTRACE
	m_freem(m);
	IncStat(ts_recv_drop);
	return (ProtoHook)0;

nonx_dref:
	switch (dutype) {
	default:
		goto discard;
	case CC_TPDU_type:
		/* error = E_TP_MISM_REFS; */
		break;
	case DR_TPDU_type:
		error |= TP_ERROR_SNDC;
	}
respond:
	IFDEBUG(D_TPINPUT)
		printf("RESPOND: error 0x%x, errlen 0x%x\n", error, errlen);
	ENDDEBUG
	IFTRACE(D_TPINPUT)
		tptrace(TPPTmisc, "tp_input RESPOND m error sref", m, error, sref, 0);
	ENDTRACE
	if (sref == 0)
		goto discard;
	(void) tp_error_emit(error, (u_long)sref, (struct sockaddr_iso *)faddr,
				(struct sockaddr_iso *)laddr, m, errlen, tpcb,
				cons_channel, dgout_routine);
	IFDEBUG(D_ERROR_EMIT)
		printf("tp_input after error_emit\n");
	ENDDEBUG

#ifdef lint
	printf("",sref,opt);
#endif /* lint */
	IncStat(ts_recv_drop);
	return (ProtoHook)0;
}


/*
 * NAME: tp_headersize()
 *
 * CALLED FROM:
 *  tp_emit() and tp_sbsend()
 *  TP needs to know the header size so it can figure out how
 *  much data to put in each tpdu.
 *
 * FUNCTION, ARGUMENTS, and RETURN VALUE:
 *  For a given connection, represented by (tpcb), and 
 *  tpdu type (dutype), return the size of a tp header.
 *
 * RETURNS:	  the expected size of the heade in bytesr
 *
 * SIDE EFFECTS:	
 *
 * NOTES:	 It would be nice if it got the network header size as well.
 */
int
tp_headersize(dutype, tpcb) 
	int 			dutype;
	struct tp_pcb 	*tpcb;
{
	register int size = 0;

	IFTRACE(D_CONN)
		tptrace(TPPTmisc, "tp_headersize dutype class xtd_format",
			dutype, tpcb->tp_class, tpcb->tp_xtd_format, 0);
	ENDTRACE
	if( !( (tpcb->tp_class == TP_CLASS_0) || 
			(tpcb->tp_class == TP_CLASS_4) || 
			(dutype == DR_TPDU_type) || 
			(dutype == CR_TPDU_type) )) {
				printf("tp_headersize:dutype 0x%x, class 0x%x", 
			dutype, tpcb->tp_class);
	/* TODO: identify this and GET RID OF IT */
	}
	ASSERT( (tpcb->tp_class == TP_CLASS_0) || 
			(tpcb->tp_class == TP_CLASS_4) || 
			(dutype == DR_TPDU_type) || 
			(dutype == CR_TPDU_type) );

	if( tpcb->tp_class == TP_CLASS_0 ) {
		size =  tpdu_info[ dutype ] [TP_LEN_CLASS_0_INDEX];
	} else  {
		size = tpdu_info[ dutype ] [tpcb->tp_xtd_format];
	} 
	return size;
	/* caller must get network level header size separately */
}