tp_input.c

早期freebsd实现

				tp_newsocket(so, faddr, cons_channel, 
					class_to_use, 
					((tpcb->tp_netservice == IN_CLNS) ? IN_CLNS :
					(dgout_routine == tpcons_output)?ISO_CONS:ISO_CLNS))
					) == (struct socket *)0 ) {
				/* note - even if netservice is IN_CLNS, as far as
				 * the tp entity is concerned, the only differences
				 * are CO vs CL
				 */
				IFDEBUG(D_CONN)
					printf("tp_newsocket returns 0\n");
				ENDDEBUG
				goto discard;
			clear_parent_tcb:
				tpcb = 0;
				goto respond;
			}
			tpcb = sototpcb(so);
			insque(tpcb, parent_tpcb);

			/*
			 * Stash the addresses in the net level pcb 
			 * kind of like a pcbconnect() but don't need
			 * or want all those checks.
			 */
			(tpcb->tp_nlproto->nlp_putnetaddr)(tpcb->tp_npcb, faddr, TP_FOREIGN);
			(tpcb->tp_nlproto->nlp_putnetaddr)(tpcb->tp_npcb, laddr, TP_LOCAL);

			/* stash the f suffix in the new tpcb */
			if (tpcb->tp_fsuffixlen = fsufxlen) {
				bcopy(fsufxloc, tpcb->tp_fsuffix, fsufxlen);
				(tpcb->tp_nlproto->nlp_putsufx)
						(tpcb->tp_npcb, fsufxloc, fsufxlen, TP_FOREIGN);
			}
			/* stash the l suffix in the new tpcb */
			tpcb->tp_lsuffixlen = lsufxlen;
			bcopy(lsufxloc, tpcb->tp_lsuffix, lsufxlen);
			(tpcb->tp_nlproto->nlp_putsufx)
					(tpcb->tp_npcb, lsufxloc, lsufxlen, TP_LOCAL);
#ifdef TP_PERF_MEAS
			if( tpcb->tp_perf_on = perf_meas ) { /* assignment */
				/* ok, let's create an mbuf for stashing the
				 * statistics if one doesn't already exist 
				 */
				(void) tp_setup_perf(tpcb);
			}
#endif /* TP_PERF_MEAS */
			tpcb->tp_fref = sref;

			/* We've already checked for consistency with the options 
			 * set in tpp,  but we couldn't set them earlier because 
			 * we didn't want to change options in the LISTENING tpcb.
			 * Now we set the options in the new socket's tpcb.
			 */
			(void) tp_consistency( tpcb, TP_FORCE, &tpp);

			if(!tpcb->tp_use_checksum)
				IncStat(ts_csum_off);
			if(tpcb->tp_xpd_service)
				IncStat(ts_use_txpd);
			if(tpcb->tp_xtd_format)
				IncStat(ts_xtd_fmt);

			tpcb->tp_peer_acktime = acktime;

			/* 
			 * The following kludge is used to test retransmissions and 
			 * timeout during connection establishment.
			 */
			IFDEBUG(D_ZDREF)
				IncStat(ts_zdebug);
				/*tpcb->tp_fref = 0;*/
			ENDDEBUG
		}
		LOCAL_CREDIT(tpcb);
		IncStat(ts_CR_rcvd);
		if (!tpcb->tp_cebit_off) {
			tpcb->tp_win_recv = tp_start_win << 8;
			tpcb->tp_cong_sample.cs_size = 0;
			CONG_INIT_SAMPLE(tpcb);
			CONG_UPDATE_SAMPLE(tpcb, ce_bit);
		}
	} else if ( dutype == ER_TPDU_type ) {
		/* 
		 * ER TPDUs have to be recognized separately
		 * because they don't necessarily have a tpcb
		 * with them and we don't want err out looking for such
		 * a beast.
		 * We could put a bunch of little kludges in the 
		 * next section of code so it would avoid references to tpcb
		 * if dutype == ER_TPDU_type but we don't want code for ERs to
		 * mess up code for data transfer.
		 */
		IncStat(ts_ER_rcvd);
		e.ev_number = ER_TPDU;
		e.ATTR(ER_TPDU).e_reason =  (u_char)hdr->tpdu_ERreason;
		CHECK (((int)dref <= 0 || dref >= tp_refinfo.tpr_size || 
			(tpcb = tp_ref[dref].tpr_pcb ) == (struct tp_pcb *) 0 ||
			tpcb->tp_refstate == REF_FREE ||
			tpcb->tp_refstate == REF_FROZEN),
		       E_TP_MISM_REFS, ts_inv_dref, discard, 0)

	} else {
		/* tpdu type is CC, XPD, XAK, GR, AK, DR, DC, or DT */

		/* In the next 4 checks,
		 * _tpduf is the fixed part; add 2 to get the dref bits of 
		 * the fixed part (can't take the address of a bit field) 
		 */
#ifdef TPCONS
		if (cons_channel && dutype == DT_TPDU_type) {
			struct isopcb *isop = ((struct isopcb *)
				((struct pklcd *)cons_channel)->lcd_upnext);
			if (isop && isop->isop_refcnt == 1 && isop->isop_socket &&
				(tpcb = sototpcb(isop->isop_socket)) &&
				 (tpcb->tp_class == TP_CLASS_0/* || == CLASS_1 */)) {
				IFDEBUG(D_TPINPUT)
					printf("tpinput_dt: class 0 short circuit\n");
				ENDDEBUG
				dref = tpcb->tp_lref;
				sref = tpcb->tp_fref;
				CHECK( (tpcb->tp_refstate == REF_FREE), 
					E_TP_MISM_REFS,ts_inv_dref, nonx_dref,
					(1 + 2 + (caddr_t)&hdr->_tpduf - (caddr_t)hdr))
				goto tp0_data;
			}

		}
#endif
		{

			CHECK( ((int)dref <= 0 || dref >= tp_refinfo.tpr_size) ,
				E_TP_MISM_REFS,ts_inv_dref, nonx_dref,
				(1 + 2 + (caddr_t)&hdr->_tpduf - (caddr_t)hdr))
			CHECK( ((tpcb = tp_ref[dref].tpr_pcb ) == (struct tp_pcb *) 0 ), 
				E_TP_MISM_REFS,ts_inv_dref, nonx_dref,
				(1 + 2 + (caddr_t)&hdr->_tpduf - (caddr_t)hdr))
			CHECK( (tpcb->tp_refstate == REF_FREE), 
				E_TP_MISM_REFS,ts_inv_dref, nonx_dref,
				(1 + 2 + (caddr_t)&hdr->_tpduf - (caddr_t)hdr))
		}

		IFDEBUG(D_TPINPUT)
			printf("HAVE A TPCB 2: 0x%x\n", tpcb);
		ENDDEBUG

		/* causes a DR to be sent for CC; ER for all else */
		CHECK( (tpcb->tp_refstate == REF_FROZEN),
			(dutype == CC_TPDU_type?E_TP_NO_SESSION:E_TP_MISM_REFS),
			ts_inv_dref, respond,
			(1 + 2 + (caddr_t)&hdr->_tpduf - (caddr_t)hdr))

		IFDEBUG(D_TPINPUT)
			printf("state of dref %d ok, tpcb 0x%x\n", dref,tpcb);
		ENDDEBUG
		/* 
		 * At this point the state of the dref could be
		 * FROZEN: tpr_pcb == NULL,  has ( reference only) timers
		 *		   for example, DC may arrive after the close() has detached
		 *         the tpcb (e.g., if user turned off SO_LISTEN option)
		 * OPENING : a tpcb exists but no timers yet
		 * OPEN  : tpcb exists & timers are outstanding
		 */

        if (!tpcb->tp_cebit_off)
            CONG_UPDATE_SAMPLE(tpcb, ce_bit);

		dusize = tpcb->tp_tpdusize;
		pdusize = tpcb->tp_ptpdusize;

		dutype = hdr->tpdu_type << 8; /* for the switch below */ 

		WHILE_OPTIONS(P, hdr, tpcb->tp_xtd_format) /* { */

#define caseof(x,y) case (((x)<<8)+(y))
		switch( dutype | vbptr(P)->tpv_code ) {

			caseof( CC_TPDU_type, TPP_addl_opt ): 
					/* not in class 0; 1 octet */
					vb_getval(P, u_char, addlopt);
					break;
			caseof( CC_TPDU_type, TPP_tpdu_size ): 
				{
					u_char odusize = dusize;
					vb_getval(P, u_char, dusize);
					CHECK( (dusize < TP_MIN_TPDUSIZE ||
							dusize > TP_MAX_TPDUSIZE || dusize > odusize),
						E_TP_INV_PVAL, ts_inv_pval, respond,
						(1 + (caddr_t)&vbptr(P)->tpv_val - (caddr_t)hdr) )
					IFDEBUG(D_TPINPUT)
						printf("CC dusize 0x%x\n", dusize);
					ENDDEBUG
				}
					break;
			caseof( CC_TPDU_type, TPP_ptpdu_size ): 
				{
					u_short opdusize = pdusize;
					switch (vbptr(P)->tpv_len) {
					case 1: pdusize = vbval(P, u_char); break;
					case 2: pdusize = ntohs(vbval(P, u_short)); break;
					default: ;
					IFDEBUG(D_TPINPUT)
						printf("malformed prefered TPDU option\n");
					ENDDEBUG
					}
					CHECK( (pdusize == 0 ||
							(opdusize && (pdusize > opdusize))),
						E_TP_INV_PVAL, ts_inv_pval, respond,
						(1 + (caddr_t)&vbptr(P)->tpv_val - (caddr_t)hdr) )
				}
					break;
			caseof( CC_TPDU_type, TPP_calling_sufx):
					IFDEBUG(D_TPINPUT)
						printf("CC calling (local) sufxlen 0x%x\n", lsufxlen);
					ENDDEBUG
					lsufxloc = (caddr_t) &vbptr(P)->tpv_val;
					lsufxlen = vbptr(P)->tpv_len;
					break;
			caseof(	CC_TPDU_type, TPP_acktime ):
					/* class 4 only, 2 octets */
					vb_getval(P, u_short, acktime);
					acktime = ntohs(acktime);
					acktime = acktime/500; /* convert to slowtimo ticks */
					if( (short)acktime <=0 )
						acktime = 2;
					break;
			caseof(	CC_TPDU_type, TPP_called_sufx):
					fsufxloc = (caddr_t) &vbptr(P)->tpv_val;
					fsufxlen = vbptr(P)->tpv_len;
					IFDEBUG(D_TPINPUT)
						printf("CC called (foreign) sufx len %d\n", fsufxlen);
					ENDDEBUG
					break;

			caseof( CC_TPDU_type,	TPP_checksum):		
			caseof( DR_TPDU_type,	TPP_checksum):		
			caseof( DT_TPDU_type,	TPP_checksum):		
			caseof( XPD_TPDU_type,	TPP_checksum):		
					if( tpcb->tp_use_checksum )  {
						CHECK( iso_check_csum(m, tpdu_len), 
							E_TP_INV_PVAL, ts_bad_csum, discard, 0)
					}
					break;

			/*  this is different from the above because in the context
			 *  of concat/ sep tpdu_len might not be the same as hdr len 
			 */
			caseof( AK_TPDU_type,	TPP_checksum):		
			caseof( XAK_TPDU_type,	TPP_checksum):		
			caseof( DC_TPDU_type,	TPP_checksum):		
					if( tpcb->tp_use_checksum )  {
						CHECK( iso_check_csum(m, (int)hdr->tpdu_li + 1), 
							E_TP_INV_PVAL, ts_bad_csum, discard, 0)
					}
					break;
#ifdef notdef
			caseof( DR_TPDU_type, TPP_addl_info ):
				/* ignore - its length and meaning are
				 * user defined and there's no way
				 * to pass this info to the user anyway
				 */
				break;
#endif /* notdef */

			caseof( AK_TPDU_type, TPP_subseq ):
				/* used after reduction of window */
				vb_getval(P, u_short, subseq);
				subseq = ntohs(subseq);
				IFDEBUG(D_ACKRECV)
					printf("AK dref 0x%x Subseq 0x%x\n", dref, subseq);
				ENDDEBUG
				break;

			caseof( AK_TPDU_type, TPP_flow_cntl_conf ):
				{
					u_int 	ylwe;
					u_short ysubseq, ycredit;

					fcc_present = TRUE;
					vb_getval(P, u_int,	 	ylwe);
					vb_getval(P, u_short, 	ysubseq);
					vb_getval(P, u_short, 	ycredit);
					ylwe = ntohl(ylwe);
					ysubseq = ntohs(ysubseq);
					ycredit = ntohs(ycredit);
					IFDEBUG(D_ACKRECV)
						printf("%s%x, subseq 0x%x, cdt 0x%x dref 0x%x\n", 
							"AK FCC lwe 0x", ylwe, ysubseq, ycredit, dref);
					ENDDEBUG
				}
				break;

			default: 
				IFDEBUG(D_TPINPUT)
					printf("param ignored dutype 0x%x, code  0x%x\n",
						dutype, vbptr(P)->tpv_code);
				ENDDEBUG
				IFTRACE(D_TPINPUT)
					tptrace(TPPTmisc, "param ignored dutype code ",
						dutype, vbptr(P)->tpv_code ,0,0);
				ENDTRACE
				IncStat(ts_param_ignored);
				break;
#undef caseof
		}
		/* } */ END_WHILE_OPTIONS(P)

		/* NOTE: the variable dutype has been shifted left! */

		switch( hdr->tpdu_type ) {
		case CC_TPDU_type: 
			/* If CC comes back with an unacceptable class
			 * respond with a DR or ER
			 */

			opt = hdr->tpdu_CCoptions; /* 1 byte */

			{
				tpp = tpcb->_tp_param;
				tpp.p_class = (1<<hdr->tpdu_CCclass);
				tpp.p_tpdusize = dusize;
				tpp.p_ptpdusize = pdusize;
				tpp.p_dont_change_params = 0;
				tpp.p_xtd_format = (opt & TPO_XTD_FMT) == TPO_XTD_FMT;
				tpp.p_xpd_service = (addlopt & TPAO_USE_TXPD) == TPAO_USE_TXPD;
				tpp.p_use_checksum = (addlopt & TPAO_NO_CSUM) == 0;
#ifdef notdef
				tpp.p_use_efc = (opt & TPO_USE_EFC) == TPO_USE_EFC;
				tpp.p_use_nxpd = (addlopt & TPAO_USE_NXPD) == TPAO_USE_NXPD;
				tpp.p_use_rcc = (addlopt & TPAO_USE_RCC) == TPAO_USE_RCC;
#endif /* notdef */

			CHECK(
				tp_consistency(tpcb, TP_FORCE, &tpp) != 0, 
				E_TP_NEGOT_FAILED, ts_negotfailed, respond,
				(1 + 2 + (caddr_t)&hdr->_tpdufr.CRCC - (caddr_t)hdr) 
					/* ^ more or less the location of class */
				)
			IFTRACE(D_CONN)
				tptrace(TPPTmisc, 
					"after 1 consist class, out, tpconsout",
					tpcb->tp_class, dgout_routine, tpcons_output, 0
					);
			ENDTRACE
			CHECK(
				((class_to_use == TP_CLASS_0)&&
					(dgout_routine != tpcons_output)),
				E_TP_NEGOT_FAILED, ts_negotfailed, respond,
				(1 + 2 + (caddr_t)&hdr->_tpdufr.CRCC - (caddr_t)hdr) 
					/* ^ more or less the location of class */
				)
#ifdef TPCONS
				if (tpcb->tp_netservice == ISO_CONS &&
					class_to_use == TP_CLASS_0) {
					struct isopcb *isop = (struct isopcb *)tpcb->tp_npcb;
					struct pklcd *lcp = (struct pklcd *)isop->isop_chan;
					lcp->lcd_flags &= ~X25_DG_CIRCUIT;
				}
#endif
			}
			if( ! tpcb->tp_use_checksum)
				IncStat(ts_csum_off);
			if(tpcb->tp_xpd_service)
				IncStat(ts_use_txpd);
			if(tpcb->tp_xtd_format)
				IncStat(ts_xtd_fmt);

			IFTRACE(D_CONN)
				tptrace(TPPTmisc, "after CC class flags dusize CCclass",
					tpcb->tp_class, tpcb->tp_flags, tpcb->tp_tpdusize, 
					hdr->tpdu_CCclass);
			ENDTRACE

			/* if called or calling suffices appeared on the CC, 
			 * they'd better jive with what's in the pcb
			 */
			if( fsufxlen ) {
				CHECK( ((tpcb->tp_fsuffixlen != fsufxlen) ||
					bcmp(fsufxloc, tpcb->tp_fsuffix, fsufxlen)),
					E_TP_INV_PVAL,ts_inv_sufx, respond, 
					(1+fsufxloc - (caddr_t)hdr))
			}
			if( lsufxlen ) {
				CHECK( ((tpcb->tp_lsuffixlen != lsufxlen) ||
					bcmp(lsufxloc, tpcb->tp_lsuffix, lsufxlen)),
					E_TP_INV_PVAL,ts_inv_sufx, respond, 
					(1+lsufxloc - (caddr_t)hdr))
			}

			e.ATTR(CC_TPDU).e_sref =  sref;
			e.ATTR(CC_TPDU).e_cdt  =  hdr->tpdu_CCcdt;
			takes_data = TRUE;
			e.ev_number = CC_TPDU;
			IncStat(ts_CC_rcvd);
			break;

		case DC_TPDU_type:
			if (sref != tpcb->tp_fref)
				printf("INPUT: inv sufx DCsref 0x%x, tp_fref 0x%x\n",
					sref, tpcb->tp_fref);
					
			CHECK( (sref != tpcb->tp_fref), 
				E_TP_MISM_REFS, ts_inv_sufx, discard,
				(1 + (caddr_t)&hdr->tpdu_DCsref - (caddr_t)hdr))
		
			e.ev_number = DC_TPDU;
			IncStat(ts_DC_rcvd);