WebSVN – Kolibri OS – Diff – /kernel/branches/net/network/udp.inc

 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;                                                                 ;;
 ;; Copyright (C) KolibriOS team 2004-2010. All rights reserved.    ;;
 ;; Distributed under terms of the GNU General Public License       ;;
 ;;                                                                 ;;
 ;;  UDP.INC                                                        ;;
 ;;                                                                 ;;
 ;;  Part of the tcp/ip network stack for KolibriOS                 ;;
 ;;                                                                 ;;
 ;;    Written by hidnplayr@kolibrios.org                           ;;
 ;;                                                                 ;;
 ;;          GNU GENERAL PUBLIC LICENSE                             ;;
 ;;             Version 2, June 1991                                ;;
 ;;                                                                 ;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-$Revision: 1519 $
+$Revision: 1529 $
 struct	UDP_Packet
 	.SourcePort		dw  ?
 	.DestinationPort	dw  ?
 	.Length 		dw  ?  ; Length of (UDP Header + Data)
 	.Checksum		dw  ?
 	.Data:
 ends
 align 4
 uglobal
 	UDP_PACKETS_TX		rd  MAX_IP
 	UDP_PACKETS_RX		rd  MAX_IP
 endg
 ;-----------------------------------------------------------------
+;
 ; UDP_init
+;
 ;  This function resets all UDP variables
+;
-;  IN:  /
-;  OUT: /
-;
 ;-----------------------------------------------------------------
-align 4
-UDP_init:
+macro	UDP_init {
 	xor	eax, eax
 	mov	edi, UDP_PACKETS_TX
 	mov	ecx, 2*MAX_IP
 	rep	stosd
+}
+macro	UDP_checksum	IP1, IP2  { ; esi = ptr to udp packet, ecx = packet size, destroys: ecx, edx
+; Pseudoheader
+	mov	edx, IP_PROTO_UDP
+	add	dl, [IP1+1+4]
+	adc	dh, [IP1+0+4]
+	adc	dl, [IP1+3+4]
+	adc	dh, [IP1+2+4]
+	adc	dl, [IP2+1+8]
+	adc	dh, [IP2+0+8]
+	adc	dl, [IP2+3+8]
+	adc	dh, [IP2+2+8]
+	adc	dl, cl ; byte[esi+UDP_Packet.Length+1]
+	adc	dh, ch ; byte[esi+UDP_Packet.Length+0]
+; Done with pseudoheader, now do real header
+	adc	dl, byte[esi+UDP_Packet.SourcePort+1]
+	adc	dh, byte[esi+UDP_Packet.SourcePort+0]
+	adc	dl, byte[esi+UDP_Packet.DestinationPort+1]
+	adc	dh, byte[esi+UDP_Packet.DestinationPort+0]
+	adc	dl, byte[esi+UDP_Packet.Length+1]
+	adc	dh, byte[esi+UDP_Packet.Length+0]
+	adc	edx, 0
+; Done with header, now do data
+	push	esi
+	movzx	ecx, [esi+UDP_Packet.Length]
+	rol	cx , 8
+	sub	cx , UDP_Packet.Data
+	add	esi, UDP_Packet.Data
+	call	checksum_1
+	call	checksum_2
+	pop	esi
+	add	[esi+UDP_Packet.Checksum], dx	; this final instruction will set or clear ZF :)
 	ret
 ;-----------------------------------------------------------------
+;
 ; UDP_input:
+;
 ;  Called by IPv4_input,
 ;  this procedure will inject the udp data diagrams in the application sockets.
+;
-;  IN:  Pointer to buffer in [esp]
+;  IN:   [esp]  = Pointer to buffer
-;       size of buffer in [esp+4]
+;       [esp+4] = size of buffer
-;       pointer to device struct in ebx
+;       ebx = ptr to device struct
-;       UDP Packet size in ecx
+;       ecx = UDP Packet size
-;       pointer to UDP Packet in edx
+;       edx = ptr to UDP header
+;
 ;       esi = ipv4 source address
 ;       edi = ipv4 dest   address
+;
 ;  OUT: /
+;
 ;-----------------------------------------------------------------
 align 4
 UDP_input:
 	DEBUGF	1,"UDP_input, size:%u\n", ecx
 ; First validate, checksum:
-	cmp	[edx + UDP_Packet.Checksum], 0
+	neg	[esi+UDP_Packet.Checksum]	; substract chechksum from 0
-	jz	.no_checksum
+	jz	.no_checksum			; if checksum is zero, it is considered valid and we continue processing
-	xchg	edi, esi	; save ipv4 source address to edi so we can use it later
+						; otherwise, we will re-calculate the checksum and add it to this value, thus creating 0 when it is correct
+	push	edx
-	push	edx
+	push	edi
-	push	esi edi
+	push	esi
+	mov	esi, edx
+	UDP_checksum (esp), (esp+4)
-	mov	esi, edx
+	pop	edi
-	call	UDP_checksum	; this destroys edx, ecx and esi (but not edi...)
+	pop	esi	; we dont need it, but it is smaller then add esp, 4
-	pop	edx
-	cmp	[edx + UDP_Packet.Checksum], 0
+	pop	edx
 	jnz	.checksum_mismatch
   .no_checksum:
 	DEBUGF	1,"UDP Checksum is correct\n"
 	; Look for a socket where
 	; IP Packet UDP Destination Port = local Port
 	; IP Packet SA = Remote IP
 	mov	eax, net_sockets
   .try_more:
 	mov	si , [edx + UDP_Packet.DestinationPort]   ; get the local port from the IP Packet's UDP header
 	rol	si , 8
   .next_socket:
 	mov	eax, [eax + SOCKET.NextPtr]
 	or	eax, eax
 	jz	.dump
 	cmp	[eax + SOCKET.Domain], AF_INET4
 	jne	.next_socket
 	cmp	[eax + SOCKET.Type], IP_PROTO_UDP
 	jne	.next_socket
 	cmp	[eax + UDP_SOCKET.LocalPort], si
 	jne	.next_socket
 	DEBUGF	1,"using socket: %x\n", eax
 	;;; TODO: when packet is processed, check more sockets!
 	cmp	[eax + IP_SOCKET.RemoteIP], 0xffffffff
 	je	@f
 	cmp	[eax + IP_SOCKET.RemoteIP], edi 	; edi is the packets source address
 	jne	.try_more
        @@:
 	cmp	[eax + UDP_SOCKET.firstpacket], 0
 	jz	.updateport
 	mov	si, [edx + UDP_Packet.SourcePort]
 	rol	si, 8
 	cmp	[eax + UDP_SOCKET.RemotePort], si
 	jne	.dump
 	push	ebx
 	lea	ebx, [eax + SOCKET.lock]
 	call	wait_mutex
 	pop	ebx
   .updatesock:
 	inc	[UDP_PACKETS_RX]
 	DEBUGF	1,"Found valid UDP packet for socket %x\n", eax
 	lea	esi, [edx + UDP_Packet.Data]
 	movzx	ecx, [edx + UDP_Packet.Length]
 	rol	cx , 8
 	sub	cx , UDP_Packet.Data
 	jmp	SOCKET_input
   .updateport:
 	push	ebx
 	lea	ebx, [eax + SOCKET.lock]
 	call	wait_mutex
 	pop	ebx
 	mov	si, [edx + UDP_Packet.SourcePort]
 	rol	si, 8
 	DEBUGF	1,"Changing remote port to: %u\n", si
 	mov	[eax + UDP_SOCKET.RemotePort], si
 	inc	[eax + UDP_SOCKET.firstpacket]
 	jmp	.updatesock
   .checksum_mismatch:
 	DEBUGF	2,"UDP_Handler - checksum mismatch\n"
-;        mov     esi, edx
-;       @@:                         ;
-;        lodsb                      ;
-;        DEBUGF  2,"%x ", eax:2     ;
-;        loop    @r                 ;
   .dump:
 	call	kernel_free
 	add	esp, 4 ; pop (balance stack)
 	DEBUGF	2,"UDP_Handler - dumping\n"
 	ret
 ;-----------------------------------------------------------------
+;
 ; UDP_output
+;
 ; IN: eax = socket pointer
 ;     ecx = number of bytes to send
 ;     esi = pointer to data
+;
 ;-----------------------------------------------------------------
 align 4
 UDP_output:
 	DEBUGF	1,"UDP_output: socket:%x, bytes: %u, data ptr: %x\n", eax, ecx, esi
 	mov	dx, [eax + UDP_SOCKET.RemotePort]
 	DEBUGF	1,"remote port: %u\n", dx
 	rol	dx, 8
 	rol	edx, 16
 	mov	dx, [eax + UDP_SOCKET.LocalPort]
 	DEBUGF	1,"local port: %u\n", dx
 	rol	dx, 8
 	mov	ebx, [eax + IP_SOCKET.LocalIP]
 	mov	eax, [eax + IP_SOCKET.RemoteIP]
-	mov	di , IP_PROTO_UDP
+	mov	di, IP_PROTO_UDP shl 8 + 128
 	sub	esp, 8						; Data ptr and data size will be placed here
 	add	ecx, UDP_Packet.Data
 ;;; TODO: fragment id
 	push	edx esi
-	call	IPv4_create_packet
+	call	IPv4_output
 	jz	.fail
 	mov	[esp + 8], eax					; pointer to buffer start
 	mov	[esp + 8 + 4], edx				; buffer size
 	rol	cx, 8
 	mov	[edi + UDP_Packet.Length], cx
-	ror	cx, 8
+	rol	[edi + UDP_Packet.Length], 8
 	pop	esi
 	push	edi ecx
 	sub	ecx, UDP_Packet.Data
 	add	edi, UDP_Packet.Data
 	shr	ecx, 2
 	rep	movsd
 	mov	ecx, [esp]
 	and	ecx, 3
 	rep	movsb
 	pop	ecx edi
 	pop	dword [edi + UDP_Packet.SourcePort]
-	mov	[edi + UDP_Packet.Checksum], 0			; set it to zero, to calculate checksum
 ; Checksum
 	mov	esi, edi
+	mov	[edi + UDP_Packet.Checksum], 0
-	pushd	[edi-4] ; destination address                   ; TODO: fix this, IPv4 packet could have options..
+	UDP_checksum (edi-4), (edi-8)				; TODO: fix this, IPv4 packet could have options..
-	pushd	[edi-8] ; source address
-	call	UDP_checksum
 	inc	[UDP_PACKETS_TX]
 	DEBUGF	1,"Sending UDP Packet to device %x\n", ebx
 	call	[ebx + NET_DEVICE.transmit]
 	ret
   .fail:
+	DEBUGF	1,"UDP_output: failed\n"
-	add	esp, 8+8
+	add	esp, 4+4+8
+	xor	eax, eax
 	ret
-;-----------------------------------------------------------------
-;
-; UDP_checksum
-;
-; This is the fast procedure to create or check a UDP header
-;  - To create a new checksum, the checksum field must be set to 0 before computation
-;  - To check an existing checksum, leave the checksum as is,
-;     and it will be 0 after this procedure, if it was correct
-;
-;  IN:  push source ip
-;       push dest ip
-;       esi = packet ptr
-;
-;  OUT: checksum is filled in in packet! (but also in dx)
-;
-;-----------------------------------------------------------------
-align 4
-UDP_checksum:
-; Pseudoheader
-	mov	edx, IP_PROTO_UDP		; NO shl 8 here ! (it took me ages to figure this one out)
-	add	dl, [esp+1+4]
-	adc	dh, [esp+0+4]
-	adc	dl, [esp+3+4]
-	adc	dh, [esp+2+4]
-	adc	dl, [esp+1+8]
-	adc	dh, [esp+0+8]
-	adc	dl, [esp+3+8]
-	adc	dh, [esp+2+8]
-	adc	dl, cl ; byte[esi+UDP_Packet.Length+1]
-	adc	dh, ch ; byte[esi+UDP_Packet.Length+0]
-; Done with pseudoheader, now do real header
-	adc	dl, byte[esi+UDP_Packet.SourcePort+1]
-	adc	dh, byte[esi+UDP_Packet.SourcePort+0]
-	adc	dl, byte[esi+UDP_Packet.DestinationPort+1]
-	adc	dh, byte[esi+UDP_Packet.DestinationPort+0]
-	adc	dl, byte[esi+UDP_Packet.Length+1]
-	adc	dh, byte[esi+UDP_Packet.Length+0]
-	adc	edx, 0
-; Done with header, now do data
-	push	esi
-	movzx	ecx, [esi+UDP_Packet.Length]
-	rol	cx , 8
-	sub	cx , UDP_Packet.Data
-	add	esi, UDP_Packet.Data
-	call	checksum_1
-	call	checksum_2
-	pop	esi
-	neg	[esi+UDP_Packet.Checksum]	    ; zero will stay zero so we just get the checksum
-	add	[esi+UDP_Packet.Checksum], dx	    ;  , else we will get (new checksum - old checksum) in the end, wich should be 0 :)
-	ret	8
 ;---------------------------------------------------------------------------
+;
 ; UDP_API
+;
 ; This function is called by system function 75
+;
 ; IN:  subfunction number in bl
 ;      device number in bh
 ;      ecx, edx, .. depends on subfunction
+;
 ; OUT:
+;
 ;---------------------------------------------------------------------------
 align 4
 UDP_API:
 	movzx	eax, bh
 	shl	eax, 2
 	test	bl, bl
 	jz	.packets_tx	; 0
 	dec	bl
 	jz	.packets_rx	; 1
 .error:
 	mov	eax, -1
 	ret
 .packets_tx:
 	add	eax, UDP_PACKETS_TX
 	mov	eax, [eax]
 	ret
 .packets_rx:
 	add	eax, UDP_PACKETS_RX
 	mov	eax, [eax]
 	ret

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(root)/kernel/branches/net/network/udp.inc – Rev 1519 → 1529