A2osX/LIB/LIBTCPIP.S.ICMP.txt

PR#3
PREFIX /A2OSX.BUILD
LOMEM $A00
INC 1
AUTO 6
				.LIST OFF	
*--------------------------------------
ICMP.IN			ldy #S.ICMP.TYPE
				lda (ZPFrameInPtr),y
				cmp #S.ICMP.TYPE.ECHOREP
				beq ICMP.IN.ECHOREP
				
				cmp #S.ICMP.TYPE.ECHOREQ
				bne ICMP.IN.EXIT
*--------------------------------------
ICMP.IN.ECHOREQ	ldy #S.IP.DST+3
				ldx #3
				
.1				lda (ZPFrameInPtr),y
				cmp IPCFG+S.IPCFG.IP,x
				bne ICMP.IN.EXIT
				dey
				dex
				bne .1
				
				ldy #S.ICMP.TYPE
				lda #S.ICMP.TYPE.ECHOREP
				sta (ZPFrameInPtr),y

				ldy #S.IP.SRC+3
				ldx #3 
				
.2				lda (ZPFrameInPtr),y			
				sta ARP.TmpCache+S.ARPCACHE.IP,x
				dey
				dex
				bpl .2
				
				ldy #S.IP.DST+3
				ldx #3 
				
.3				lda ARP.TmpCache+S.ARPCACHE.IP,x
				sta (ZPFrameInPtr),y			
				dey
				dex
				bpl .3
				
				ldy #S.ETH.SRCMAC+5
				ldx #5
				
.4				lda (ZPFrameInPtr),y			
				sta ARP.TmpCache+S.ARPCACHE.MAC,x
				dey
				dex
				bpl .4
				
				lda #K.ARP.TTL
				sta ARP.TmpCache+S.ARPCACHE.TTL
				lda /K.ARP.TTL
				sta ARP.TmpCache+S.ARPCACHE.TTL+1
				
				lda #S.ARPCACHE.STATUS.RESOLVED
				jsr ARP.ADD.I
				
				lda hFrameIn
				sta	hFrameOut				DO NOT DISCARD this frame,it is SOURCE frame!!!
				>LDYA ZPFrameInPtr
				>STYA ZPFrameOutPtr
				jmp FRM.SendIP
				
ICMP.IN.EXIT	lda hFrameIn
				>SYSCALL FreeMem.A
				rts
*--------------------------------------
ICMP.IN.ECHOREP	jsr IP.FillSKT.TemplateSrcDst
				
				lda #S.IP.PROTOCOL.ICMP
				sta SKT.Template+S.SOCKET.RAW.PROTO
				
				ldy #S.ICMP.IDENTIFIER
				lda (ZPFrameInPtr),y
				sta SKT.Template+S.SOCKET.DST.PORT+1
				iny
				lda (ZPFrameInPtr),y
				sta SKT.Template+S.SOCKET.DST.PORT

				lda hSocketTable
				>SYSCALL GetMemPtr.A
				>STYA ZPPtrSKT
				
				ldx #0
				
.3				lda (ZPPtrSKT)
				beq .7
				cmp #S.SOCKET.SOCK.RAW
				bne .7
				
				ldy #S.SOCKET.SRC.ADDR
				
.4				lda (ZPPtrSKT),y
				cmp SKT.Template,y
				bne .7
				iny
				cpy #S.SOCKET.SRC.PORT
				bne .5
				
				iny
				iny
				
.5				cpy #S.SOCKET.DST.PORT	Compare SRC.ADDR,DST.ADDR,DST.PORT
				bne .4
				
				lda hFrameIn
				jsr SKT.AddToQueueA
				bcs .9					Q full, discard...
				
				rts						DO NOT Discard this queued frame
				
.7				lda ZPPtrSKT
				clc
				adc #S.SOCKET
				sta ZPPtrSKT
				bcc .8
				inc ZPPtrSKT+1
				
.8				inx
				cpx #K.SKTTABLE.SIZE
				bne .3
				
.9				lda hFrameIn
				>SYSCALL FreeMem.A
				rts			
*--------------------------------------
ICMP.ComputeChecksum
				>PUSHW ZPFrameOutLen
				>PUSHWI S.ICMP.TYPE-2

				ldy #S.ICMP.CHECKSUM
				lda #0
				sta (ZPFrameOutPtr),y
				iny
				sta (ZPFrameOutPtr),y

				jsr IP.ComputeChecksum

				phy
				ldy #S.ICMP.CHECKSUM
				sta (ZPFrameOutPtr),y
				iny
				pla
				sta (ZPFrameOutPtr),y
				rts
*--------------------------------------
MAN
SAVE /A2OSX.SRC/LIB/LIBTCPIP.S.ICMP
LOAD /A2OSX.SRC/LIB/LIBTCPIP.S
ASM