PR#3
PREFIX /A2OSX.SRC
LOMEM $900
INC 1
AUTO 6
				.LIST OFF	
*--------------------------------------
TCP.IN			jsr IP.FillSKT.TemplateSrcDst
				
				ldy #S.TCP.SRCPORT
				lda (ZPFrameInPtr),y
				sta SKT.Template+S.SOCKET.DST.PORT+1
				iny
				lda (ZPFrameInPtr),y
				sta SKT.Template+S.SOCKET.DST.PORT
				
				ldy #S.TCP.DSTPORT
				lda (ZPFrameInPtr),y
				sta SKT.Template+S.SOCKET.SRC.PORT+1
				iny
				lda (ZPFrameInPtr),y
				sta SKT.Template+S.SOCKET.SRC.PORT
				
				lda hSocketTable
				>SYSCALL GetMemPtrA
				>STYA ZPPtrSKT
				
				ldx #0
				
.3				lda (ZPPtrSKT)
				beq .7
				cmp #S.SOCKET.SOCK.STREAM
				bne .7
				
				ldy #S.SOCKET.SRC.ADDR
				
.4				lda SKT.Template,y
				cmp (ZPPtrSKT),y
				bne .7						Not for this socket...
				
				iny
				cpy #S.SOCKET.SRC.PORT+2
				bne .4
				
				ldy #S.SOCKET.SO
				lda (ZPPtrSKT),y
				and #S.SOCKET.SO.ACCEPTCONN		Listening socket?
				beq .5					no, go check if Dst Match
	
				ldy #S.TCP.OPTIONS		yes, only accept SYN packet
				lda (ZPFrameInPtr),y

				and #S.TCP.OPTIONS.SYN
				beq .7					maybe a regular frame for a regular socket
				
				jmp TCP.IN.JMP.LISTEN
			
.5				ldy #S.SOCKET.DST.ADDR

.6				lda SKT.Template,y			regular socket, check remote ADDR/PORT
				cmp (ZPPtrSKT),y
				bne .7
				iny
				cpy #S.SOCKET.DST.PORT+2
				bne .6
				
				stx hSocket
				ldy #S.SOCKET.TCP.STATUS
				lda (ZPPtrSKT),y
				asl
				tax
				jmp (L.TCP.IN.JMP,x)
				
.7				lda ZPPtrSKT
				clc
				adc #S.SOCKET
				sta ZPPtrSKT
				bcc .8
				inc ZPPtrSKT+1
				
.8				inx
				cpx #K.SKTTABLE.SIZE
				bne .3
				
.9				clc						Discard frame
				rts
*--------------------------------------
TCP.IN.JMP.CLOSED
				clc
				rts
*--------------------------------------
TCP.IN.JMP.LISTEN
				lda #S.SOCKET.SOCK.STREAM
				sta SKT.Template+S.SOCKET.SOCK

				stz SKT.Template+S.SOCKET.SO

				>PUSHW L.SKT.Template

				jsr SKT.New
				bcs .9
				
				phy
				pha
				txa
				
				jsr SKT.AddToQueueA
				
				pla
				sta ZPPtrSKT+1
				pla
				sta ZPPtrSKT
				
				bcc .3					Queued successfully ?

				lda #0					error
				sta (ZPPtrSKT)			clear this socket
				lda #ERR.SKT.OOS
.9				rts
				
.3				jsr ARP.AddFromFrameInPtr

				ldy #S.TCP.SEQ.NUMBER+3
				ldx #3
				
				sec
				
.1				lda (ZPFrameInPtr),y	Set ACK=SEQ+1 for new socket...
				adc #0
				sta TmpDWord,x
				dey
				dex
				bpl .1
				
				ldx #3
				ldy #S.SOCKET.SQ.ACKNUM+3
				
.4				lda TmpDWord,x			Update new socket with ACK number
				sta (ZPPtrSKT),y
				dey
				dex
				bpl .4
				
				ldy #S.SOCKET.TCP.STATUS
				lda #S.SOCKET.TCP.STATUS.SYNRCVD
				sta (ZPPtrSKT),y
				
				ldy #S.SOCKET.TCP.OPTIONS
				lda #S.TCP.OPTIONS.SYN+S.TCP.OPTIONS.ACK
				sta (ZPPtrSKT),y
				
				jsr TCP.Out
				bcs .9
				
				ldy #S.SOCKET.TCP.STATUS
				lda #S.SOCKET.TCP.STATUS.SYNSENT
				sta (ZPPtrSKT),y
				
				
				clc
				rts
*--------------------------------------
TCP.IN.JMP.SYNSENT
				clc
				rts
*--------------------------------------
TCP.IN.JMP.SYNRCVD
				ldy #S.TCP.OPTIONS				only accept ACK packet
				lda (ZPFrameInPtr),y
				cmp #S.TCP.OPTIONS.ACK
				bne .8
				
				ldx #3
				ldy #S.SOCKET.SQ.SEQNUM+3
				
				sec
				
.10				lda (ZPPtrSKT),y
				adc #0
				sta TmpDWord,x
				dey
				dex
				bpl .10
				
				ldx #3
				ldy #S.TCP.ACK.NUMBER+3
.11				lda (ZPFrameInPtr),y
				cmp TmpDWord,x
				bne .8
				dey
				dex
				bpl .11
				
				ldx #3
				ldy #S.SOCKET.SQ.SEQNUM+3
.12				lda TmpDWord,x
				sta (ZPPtrSKT),y
				dey
				dex
				bpl .12
				
				ldy #S.SOCKET.TCP.STATUS
				lda #S.SOCKET.TCP.STATUS.ESTBLSH
				sta (ZPPtrSKT),y
				
								
.8				clc
				rts
*--------------------------------------
TCP.IN.JMP.ESTBLSH
				ldy #S.TCP.OPTIONS
				lda (ZPFrameInPtr),y
				bit #S.TCP.OPTIONS.ACK
				beq .2
				
				ldy #S.TCP.ACK.NUMBER+3	Get new ACK number from FrameIn...
				ldx #3
				
.1				lda (ZPFrameInPtr),y
				sta TmpDWord,x
				dey
				dex
				bpl .1
				
				ldy #S.SOCKET.SQ.ACKNUM Substract old Ack from socket
				sec
				lda (ZPPtrSKT),y
				sbc TmpDWord
				pha						save result LO for FreeData

				lda TmpDWord
				sta (ZPPtrSKT),y		and store new ACK in skt
				
				iny
				lda (ZPPtrSKT),y
				sbc TmpDWord+1
				
				tax						save result HI for FreeData
				
				lda TmpDWord+1			we stop here, will never be more than K.TCP.WSIZE
				sta (ZPPtrSKT),y
			
				iny
				lda TmpDWord+2
				sta (ZPPtrSKT),y

				iny
				lda TmpDWord+3
				sta (ZPPtrSKT),y
				
				pla
				jsr SKT.FreeDataFromSktOutAX
*----------
.2				lda ZPDataInLen
				ora ZPDataInLen+1
				beq .8					No data in this incoming frame...
				
				ldy #S.TCP.SEQ.NUMBER+3
				ldx #3

.3				lda (ZPFrameInPtr),y
				sta TmpDWord,x
				dey
				dex
				bpl .3
				
				
				
				jsr TCP.SetDataInPtrAndLen
				jsr SKT.AddDataToSktIn
				
				
.8				clc
				rts
*--------------------------------------
TCP.IN.JMP.CLWAIT
TCP.IN.JMP.LASTACK
TCP.IN.JMP.FINWT1
TCP.IN.JMP.FINWT2
TCP.IN.JMP.CLOSING
TCP.IN.JMP.TIMEWT
				clc
				rts
*--------------------------------------
TCP.OUT			ldy #S.SOCKET.TCP.OPTIONS
				lda (ZPPtrSKT),y
				bit #S.TCP.OPTIONS.SYN
				beq TCP.OUT.ESTBLSH
				
				>LDYAI 0
				jsr TCP.NewFrame
				bcs .9				
				
				ldy #S.TCP.OPTIONS
				lda #S.TCP.OPTIONS.SYN+S.TCP.OPTIONS.ACK
				sta (ZPFrameOutPtr),y	

				jsr TCP.SendFrame
				bcs .9
				
				ldy #S.TCP.OPTIONS
				lda #0
				sta (ZPFrameOutPtr),y	

				ldy #S.SOCKET.TCP.STATUS
				lda #S.SOCKET.TCP.STATUS.SYNSENT
				sta (ZPFrameOutPtr),y	
				
				clc
.9				rts
*--------------------------------------
TCP.OUT.ESTBLSH	ldy #S.SOCKET.SQ.OUTUSED
				lda (ZPPtrSKT),y
				
				pha
				
				iny
				lda (ZPPtrSKT),y
				ply
				bne .1
				
				tax
				beq .2					Y,A=0 : nothing to send....
				
.1				cpy #K.TCP.MSS
				pha
				sbc /K.TCP.MSS			OUTDATA > MSS ?
				pla
				bcs .2					no....get data len

				>LDYAI K.TCP.MSS		yes get only MSS
				
.2				>STYA TmpOffset

				jsr TCP.NewFrame
				bcs .9

				jsr SKT.GetDataFromSktOut
				
				ldy #S.SOCKET.SQ.SEQNUM	compute new SEQ.NUM
				lda (ZPPtrSKT),y
				clc
				adc TmpOffset
				sta TmpDWord
				
				iny
				lda (ZPPtrSKT),y
				adc TmpOffset+1
				sta TmpDWord+1
				
				iny
				lda (ZPPtrSKT),y
				adc #0
				sta TmpDWord+2
				
				iny
				lda (ZPPtrSKT),y
				adc #0
				sta TmpDWord+3
				
				ldy #S.TCP.SEQ.NUMBER+3
				ldx #3
				
.3				lda TmpDWord,x
				sta (ZPFrameOutPtr),y
				dey
				dex
				bpl .3
				
				ldy #S.SOCKET.TCP.OPTIONS
				lda (ZPPtrSKT),y
				bit #S.TCP.OPTIONS.ACK
				beq .7
				
				ldy #S.TCP.OPTIONS
				lda (ZPFrameOutPtr),y
				ora #S.TCP.OPTIONS.ACK
				sta (ZPFrameOutPtr),y
				
.7				jsr TCP.SendFrame
				bcs .9
				
				ldy #S.SOCKET.TCP.OPTIONS
				lda (ZPPtrSKT),y
				and #$ff^S.TCP.OPTIONS.ACK
				sta (ZPPtrSKT),y
				
				ldx #3
				ldy #S.SOCKET.SQ.SEQNUM+3
				
.71				lda TmpDWord,x
				sta (ZPPtrSKT),y
				dey
				dex
				bpl .71
				
.8				clc
.9				rts
*--------------------------------------
TCP.GetSktAckNum
				ldy #S.TCP.ACK.NUMBER
				ldx #4
				
.1				lda (ZPFrameInPtr),y
				pha
				iny
				dex
				bne .1
				
				ldy #S.SOCKET.SQ.ACKNUM+3
				ldx #4
				
.2				pla
				sta (ZPPtrSKT),y
				dey
				dex
				bne .2
				rts
*--------------------------------------
TCP.UpdateSktAckNum
				ldy #S.SOCKET.SQ.ACKNUM+3
				lda (ZPPtrSKT),y
				clc
				adc ZPDataInLen
				sta (ZPPtrSKT),y
				dey
				lda (ZPPtrSKT),y
				adc ZPDataInLen+1
				sta (ZPPtrSKT),y
				dey
				lda (ZPPtrSKT),y
				adc #0
				sta (ZPPtrSKT),y
				dey
				lda (ZPPtrSKT),y
				adc #0
				sta (ZPPtrSKT),y
				rts
*--------------------------------------
TCP.SetDataInPtrAndLen
				ldy #S.TCP.DATAOFFSET
				lda (ZPFrameInPtr),y
				and #$F0
				lsr
				lsr		
				adc #S.TCP
				sta TmpOffset
				
				lda #0
*				clc				
				adc /S.TCP
				sta TmpOffset+1			TmpOffset=Data Offset in Frame

				lda ZPFrameInPtr
*				clc				
				adc TmpOffset
				sta ZPDataInPtr
				
				lda ZPFrameInPtr+1
				adc #0
				sta ZPDataInPtr+1
				
				lda ZPFrameInLen
				sec
				sbc TmpOffset
				sta ZPDataInLen
				
				lda ZPFrameInLen+1
				sbc TmpOffset+1
				sta ZPDataInLen+1
				rts
*--------------------------------------
TCP.NewFrame	ldx #S.IP.PROTOCOL.TCP
				jsr FRM.NewIP
				bcs .9
				
				jsr SKT.SetFrameOutDstIP

				ldy #S.SOCKET.SRC.PORT
				lda (ZPPtrSKT),y
				tax
				iny
				lda (ZPPtrSKT),y
 				ldy #S.TCP.SRCPORT
				sta (ZPFrameOutPtr),y
				iny
				txa
				sta (ZPFrameOutPtr),y
				
				ldy #S.SOCKET.DST.PORT
				lda (ZPPtrSKT),y
				tax
				iny
				lda (ZPPtrSKT),y
 				ldy #S.TCP.DSTPORT
				sta (ZPFrameOutPtr),y
				iny
				txa
				sta (ZPFrameOutPtr),y
				
				ldy #S.TCP.DATAOFFSET
				lda #$50				Header size = 5 DWORDS
				sta (ZPFrameOutPtr),y
				
				ldy #S.SOCKET.SQ.INFREE
				lda (ZPPtrSKT),y
				pha
				iny
				lda (ZPPtrSKT),y
				
				ldy #S.TCP.WINDOW
				sta (ZPFrameOutPtr),y
				iny
				pla
				sta (ZPFrameOutPtr),y
				
				
				clc
.9				rts
*--------------------------------------
TCP.SendFrame	ldy #S.SOCKET.SQ.SEQNUM+7
				ldx #7
				
.1				lda (ZPPtrSKT),y
				pha
				dey
				dex
				bpl .1
				
				ldy #S.TCP.SEQ.NUMBER
				
.2				pla
				sta (ZPFrameOutPtr),y
				iny
				cpy #S.TCP.SEQ.NUMBER+8
				bne .2
				
				jmp FRM.SendIP
*--------------------------------------
TCP.ComputeChecksum
				lda #0					RESET.TCP.CHECKSUM
				ldy #S.TCP.CHECKSUM
				sta (ZPFrameOutPtr),y
				iny
				sta (ZPFrameOutPtr),y
				
				>LDYA ZPFrameOutPtr
				>STYA ZPTmpPtr1
				
				lda ZPFrameOutLen
				sec
				sbc #S.IP-2
				sta ZPDataInLen
				
				lda ZPFrameOutLen+1
				sbc /S.IP-2
				sta ZPDataInLen+1
				
				clc
				
*				lda ZPDataInLen+1
*				adc #0					RESERVED (all zero)
				sta IP.CHECKSUM

				lda ZPDataInLen
				adc #S.IP.PROTOCOL.TCP
				sta IP.CHECKSUM+1
				
				ldy #S.IP.SRC
				
				ldx #4					4 words for SRC & DST IP
				
.10				lda (ZPFrameOutPtr),y
				adc IP.CHECKSUM
				sta IP.CHECKSUM
				iny
				lda (ZPFrameOutPtr),y
				adc IP.CHECKSUM+1
				sta IP.CHECKSUM+1
				iny
				dex
				bne .10
				
				ldy #S.IP
				
.1				jsr DecDataInLen
				beq .8
				
				lda (ZPTmpPtr1),y
				adc IP.CHECKSUM
				sta IP.CHECKSUM

				iny
				bne .20
				inc ZPTmpPtr1+1
				
.20				jsr DecDataInLen
				bne .2
				lda #0
				bra .21

.2				lda (ZPTmpPtr1),y

.21				adc IP.CHECKSUM+1
				sta IP.CHECKSUM+1
				
				iny
				bne .1
				inc ZPTmpPtr1+1
				bra .1
				
.8				ldy #S.TCP.CHECKSUM
				lda IP.CHECKSUM
				adc #0					Don't forget to add last carry!!!
				eor #$FF
				sta (ZPFrameOutPtr),y
				iny
				lda IP.CHECKSUM+1
				adc #0					Don't forget to add last carry!!!
				eor #$FF
				sta (ZPFrameOutPtr),y
				rts
*--------------------------------------
MAN
SAVE LIB/LIBTCPIP.S.TCP
LOAD LIB/LIBTCPIP.S
ASM