Subversion Repositories Kolibri OS

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;;                                                                 ;;

;; 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: 1542 $

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

;

;-----------------------------------------------------------------

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]

	adc	dh, [IP1+0]

	adc	dl, [IP1+3]

	adc	dh, [IP1+2]

	adc	dl, [IP2+1]

	adc	dh, [IP2+0]

	adc	dl, [IP2+3]

	adc	dh, [IP2+2]

	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 :)

}

;-----------------------------------------------------------------

;

; UDP_input:

;

;  Called by IPv4_input,

;  this procedure will inject the udp data diagrams in the application sockets.

;

;  IN:   [esp]  = Pointer to buffer

;       [esp+4] = size of buffer

;       ebx = ptr to device struct

;       ecx = UDP Packet size

;       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:

	neg	[edx+UDP_Packet.Checksum]	; substract chechksum from 0

	jz	.no_checksum			; if checksum is zero, it is considered valid and we continue processing

						; otherwise, we will re-calculate the checksum and add it to this value, thus creating 0 when it is correct

	push	edx

	push	edi

	push	esi

	mov	esi, edx

	UDP_checksum (esp), (esp+4)

	pop	edi

	pop	esi	; we dont need it, but it is smaller then add esp, 4

	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.Protocol], 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"

  .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 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_output

	jz	.fail

	mov	[esp + 8], eax					; pointer to buffer start

	mov	[esp + 8 + 4], edx				; buffer size

	mov	[edi + UDP_Packet.Length], cx

	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]

; Checksum

	mov	esi, edi

	mov	[edi + UDP_Packet.Checksum], 0

	UDP_checksum (edi-4), (edi-8)				; TODO: fix this, IPv4 packet could have options..

	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, 4+4+8

	xor	eax, eax

	ret

;---------------------------------------------------------------------------

;

; 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