PR#3
PREFIX /DATA/A2OSX
NEW
INC 1
AUTO 6
				.LIST OFF	
				.OP	65C02
*--------------------------------------
* ARP.CLEAR
*--------------------------------------
ARP.CLEAR		ldx #K.ARPCACHE.SIZE*S.ARPCACHE
.1				stz ARP.CACHE-1,x
				dex
				bne .1
				clc
				rts
*--------------------------------------
* ARP.QUERY
*  In:
*   PULLW PTR to IP
*   PULLW PTR to MAC (to fill)
*  Out:
*   CC: hit: MAC filled
*   CS: missed 
*--------------------------------------
ARP.QUERY		>PULLW ZPARPIP			IP
				>PULLW ZPARPMAC			MAC
				jmp ARP.QUERY.I
*--------------------------------------
* ARP.ADD
*  In:
*   PULLW PTR to IP
*   PULLW PTR to MAC
*--------------------------------------
ARP.ADD			>PULLW ZPARPIP			IP
				>PULLW ZPARPMAC			MAC
				lda #S.ARPCACHE.STATUS.RESOLVED
				jmp ARP.ADD.I
*--------------------------------------
* ARP.GETCACHE
*  Out:
*   Y,A = PTR to ARP.CACHE
*--------------------------------------
ARP.GETCACHE	>LDYA L.ARP.CACHE
				clc
				rts
*--------------------------------------
*				PRIVATE
*--------------------------------------
ARP.RESOLVE		ldy #S.IP.DST
				lda (ZPFrameBase1),y
				iny
.1				and (ZPFrameBase1),y
				iny
				cpy #S.IP.DST+4
				bne .1
				cmp #$FF
				bne .3					not a broadcast....
				
				ldy #S.ETH.DSTMAC
.2				sta (ZPFrameBase1),y
				iny
				cpy #S.ETH.DSTMAC+6
				bne .2
				clc
				rts
				
.3				ldy #S.IP.DST+3
				ldx #3
.4				lda (ZPFrameBase1),y
				eor IPCFG+S.IPCFG.IP,x
				and	IPCFG+S.IPCFG.MASK,x
				bne .5
				dey
				dex
				bpl .4

				lda ZPFrameBase1		Same network, query ARP for dest IP
				clc
				adc #S.IP.DST
				sta ZPARPIP
				lda ZPFrameBase1+1
				adc /S.IP.DST
				sta ZPARPIP+1
				bra .6
				
.5				lda	L.IPCFG				Not Same network, query ARP for GW
				clc
				adc #S.IPCFG.GW
				sta ZPARPIP
				lda	L.IPCFG+1
				adc /S.IPCFG.GW
				sta ZPARPIP+1
				
.6				lda ZPFrameBase1
				clc
				adc #S.ETH.DSTMAC
				sta ZPARPMAC
				lda ZPFrameBase1+1
				adc /S.ETH.DSTMAC
				sta ZPARPMAC+1
*--------------------------------------
ARP.QUERY.I		ldx #0
				
.1				phx
				lda ARP.CACHE,x
				beq .5					empty ARP Cache entry, try next...
				
				ldy #0
.2				lda ARP.CACHE+S.ARPCACHE.IP,x
				cmp (ZPARPIP),y
				bne .5					wrong IP, try next...
				inx
				iny
				cpy #4
				bne .2
			
				plx
				lda ARP.CACHE,x			get back status
				bpl .4					Pending...
			
				ldy #0					already resolved, get MAC
.3				lda ARP.CACHE+S.ARPCACHE.MAC,x
				sta (ZPARPMAC),y
				inx
				iny
				cpy #6
				bne .3
				clc
				rts
				
.4				inc ARP.CACHE+S.ARPCACHE.RETRYCNT,x		Pending, increase Retry Count
				bne .41
				stz ARP.CACHE,x							reached max retry,mark as free
.41				sec
				rts
				
.5				pla
				clc
				adc #S.ARPCACHE
				tax
				cmp #K.ARPCACHE.SIZE*S.ARPCACHE
				bne .1

				jsr NEW.ARP.FRAME		nothing in ARP cache, send ARP request				
				bcs .9
				phx
				ldy #S.ARP.OPERATION+1
				lda #S.ARP.OPERATION.REQ
				sta (ZPFrameBase1),y
				
				ldx #5
				ldy #S.ARP.SHA+5
.71				lda IPCFG+S.IPCFG.MAC,x
				sta (ZPFrameBase1),y
				dey
				dex
				bpl .71
				
				ldx #3
				ldy #S.ARP.SPA+3
.72				lda IPCFG+S.IPCFG.IP,x
				sta (ZPFrameBase1),y
				dey
				dex
				bpl .72
				
				ldy #3
.73				lda (ZPARPIP),y
				pha
				dey
				bpl .73
				
				ldy #S.ARP.TPA
.74				pla
				sta (ZPFrameBase1),y
				iny
				cpy #S.ARP.TPA+4
				bne .74
				
				lda #255
				ldy #S.ETH.DSTMAC
.75				sta (ZPFrameBase1),y
				iny 
				cpy #S.ETH.DSTMAC+6
				bne .75
				
				jsr SEND.ARP.FRAME.I
				bcs .76
				
				jsr ARP.ADD.PENDING		ZPARPIP still pointing IP
				
.76				pla
				>SYSCALL SYS.FreeMemA

				sec		
.9				rts		
*--------------------------------------
ARP.ADD.PENDING	lda #S.ARPCACHE.STATUS.PENDING

ARP.ADD.I		sta Status
				
				ldx #0
.1				lda ARP.CACHE,x			get	status
				beq .7					empty ARP cache entry

				phx
				
				ldy #0
.2				lda (ZPARPIP),y
				cmp ARP.CACHE+S.ARPCACHE.IP,x
				bne .4
				inx
				iny
				cpy #4
				bne .2
				plx
				bra .7					same IP,update MAC
				
.4				pla						get back index in ARP.CACHE
				clc
				adc #S.ARPCACHE
				cmp #K.ARPCACHE.SIZE*S.ARPCACHE
				beq .5					Cache is full ?
				tax
				bra .1
				
.5				ldx #K.ARPCACHE.SIZE*S.ARPCACHE-S.ARPCACHE

.6				lda ARP.CACHE+S.ARPCACHE-1,x
				sta ARP.CACHE-1,x
				dex
				bne .6
				
				ldx #K.ARPCACHE.SIZE*S.ARPCACHE-S.ARPCACHE
				
.7				lda Status
				sta ARP.CACHE,x			mark ARP entry Status
				inx
				stz ARP.CACHE,x			Init retry count
				inx
				ldy #0
.8				lda (ZPARPIP),y			store IP in cache
				sta ARP.CACHE,x
				inx
				iny
				cpy #4
				bne .8
				
				lda Status
				bpl .82					no MAC if "pending"
								
				ldy #0
.81				lda (ZPARPMAC),y		store MAC in cache
				sta ARP.CACHE,x
				inx
				iny
				cpy #6
				bne .81
.82				clc
				rts
*--------------------------------------
MAN
SAVE LIB/LIBTCPIP.S.ARP
LOAD LIB/LIBTCPIP.S
ASM