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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;                                                                 ;;

;; Copyright (C) KolibriOS team 2004-2009. All rights reserved.    ;;

;; Distributed under terms of the GNU General Public License       ;;

;;                                                                 ;;

;;  ARP.INC                                                        ;;

;;                                                                 ;;

;;  Part of the tcp/ip network stack for KolibriOS                 ;;

;;                                                                 ;;

;;  Based on the work of [Johnny_B] and [smb]                      ;;

;;                                                                 ;;

;;    Written by hidnplayr@kolibrios.org                           ;;

;;                                                                 ;;

;;          GNU GENERAL PUBLIC LICENSE                             ;;

;;             Version 2, June 1991                                ;;

;;                                                                 ;;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

$Revision: 1206 $

ARP_NO_ENTRY		equ  0

ARP_VALID_MAPPING	equ  1

ARP_AWAITING_RESPONSE	equ  2

ARP_RESPONSE_TIMEOUT	equ  3

ARP_REQUEST_TTL 	= 20 ; in seconds

ARP_ENTRY_TTL		= 600 ; in seconds

ETHER_ARP		equ  0x0608

ARP_REQ_OPCODE		equ  0x0100  ; request

ARP_REP_OPCODE		equ  0x0200  ; reply

ARP_TABLE_SIZE		equ  20      ; Size of table

struct ARP_ENTRY

       .IP		dd  ?

       .MAC		dp  ?

       .Status		dw  ?

       .TTL		dw  ?  ; in seconds

       .size:

ends

struct ARP_Packet

       .HardwareType	dw  ?

       .ProtocolType	dw  ?

       .HardwareSize	db  ?

       .ProtocolSize	db  ?

       .Opcode		dw  ?

       .SenderMAC	dp  ?

       .SenderIP	dd  ?

       .TargetMAC	dp  ?

       .TargetIP	dd  ?

ends

; The TTL field is decremented every second, and is deleted when it

; reaches 0. It is refreshed every time a packet is received

; If the TTL field is 0xFFFF it is a static entry and is never deleted

; The status field can be the following values:

; 0x0000  entry not used

; 0x0001  entry holds a valid mapping

; 0x0002  entry contains an IP address, awaiting ARP response

; 0x0003  No response received to ARP request.

; The last status value is provided to allow the network layer to delete

; a packet that is queued awaiting an ARP response

align 4

uglobal

	NumARP		dd ?

	ARPTable	rb ARP_ENTRY.size * ARP_TABLE_SIZE

	ARP_PACKETS_TX	rd  MAX_NET_DEVICES

	ARP_PACKETS_RX	rd  MAX_NET_DEVICES

endg

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

;

; ARP_init

;

;  This function resets all ARP variables

;

;  IN:  /

;  OUT: /

;

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

align 4

ARP_init:

	xor	eax, eax

	mov	[NumARP], eax

	mov	edi, ARP_PACKETS_TX

	mov	ecx, 2*MAX_NET_DEVICES

	rep	stosd

	ret

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

;

; ARP_IP_to_MAC

;

;  This function resets all ARP variables

;

;  IN: eax = IPv4 address

;  OUT: eax = -1 on error, else eax = first two bytes of mac

;                   ( high 16 bits are zero)

;       ebx = last four bytes of mac                                  ; TODO: special eax value for 'request send'

;

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

align 4

ARP_IP_to_MAC:

	DEBUGF 1,"ARP_IP_to_MAC\n"

    ; first, check destination IP to see if it is on 'this' network.

    ; The test is:

    ; if ( destIP & subnet_mask == stack_ip & subnet_mask )

    ;   destination is local

    ; else

    ;  destination is remote, so pass to gateway

	xor	edx, edx ; TODO: find device num in edx

	mov	ebx, [IP_LIST+edx]

	and	ebx, [SUBNET_LIST+edx]

	mov	ecx, eax

	and	ecx, [SUBNET_LIST+edx]

	cmp	ecx, ebx

	je	.local

	mov	eax, [GATEWAY_LIST+edx]

	DEBUGF 1,"requested IP is not on subnet, using gateway\n"

  .local:

   ; try to find it on the list

	mov	ecx, [NumARP]

	test	ecx, ecx

	jz	.not_in_list

	mov	esi, ARPTable + ARP_ENTRY.IP

  .scan_loop:

	cmp	[esi], eax

	je	.found_it

	add	esi, ARP_ENTRY.size

	loop	.scan_loop

  .not_in_list:

	DEBUGF 1,"IP not found on list, preparing for ARP request\n"

   ; if not, reserve an entry in list and send an ARP request packet

	push	eax

	push	word ARP_REQUEST_TTL

	push	word ARP_AWAITING_RESPONSE

	push	dword 0

	push	word 0

	push	eax

	call	ARP_add_entry

	cmp	eax, -1

	je	.full

	pop	eax

	call	ARP_create_request

	ret

  .found_it:

	add    esi, ARP_ENTRY.MAC

	DEBUGF 1,"Found MAC! (%x-%x-%x-%x-%x-%x)\n",[esi+0]:2,[esi+1]:2,[esi+2]:2,[esi+3]:2,[esi+4]:2,[esi+5]:2

	movzx  eax, word [esi]

	mov    ebx, [esi+2]

	ret

  .full:

	add	esp, 4

	mov	eax, -1

	ret

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

;

; ARP_create_packet

;

; IN:  ip in eax

;

; OUT: /

;

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

align 4

ARP_create_request:

	DEBUGF 1,"Create ARP Packet\n"

	call	IPv4_dest_to_dev

	push	eax						; DestIP

	mov	eax, [IP_LIST+4*edi]				; senderIP

	push	eax

	mov	edi, [ETH_DRV_LIST + 4*edi]

	lea	eax, [edi + ETH_DEVICE.mac]

	mov	ebx, ETH_BROADCAST

	mov	ecx, 60 ; minimum packet size

	mov	edx, edi ;;;

	mov	di , ETHER_ARP

	call	ETH_create_Packet

	cmp	edi, -1

	je	.exit

	mov	ecx, eax

	mov	[edi + ARP_Packet.HardwareType], 0x0100 ;Ethernet

	mov	[edi + ARP_Packet.ProtocolType], 0x0008 ;IP

	mov	[edi + ARP_Packet.HardwareSize], 6   ;MAC-addr length

	mov	[edi + ARP_Packet.ProtocolSize], 4   ;IP-addr length

	mov	[edi + ARP_Packet.Opcode], ARP_REQ_OPCODE      ;Request

	add	edi, ARP_Packet.SenderMAC			; sendermac

	lea	esi, [ebx + ETH_DEVICE.mac]			;

	movsw							;

	movsd							;

	pop	eax						;

	stosd							;

	mov	eax, -1 					; destmac

	stosd							;

	stosw							;

	pop	eax

	stosd							;

	DEBUGF 1,"ARP Packet for device %x created successfully\n", ebx

	push	edx ecx

	jmp	ETH_Sender

  .exit:

	add	esp, 8

	DEBUGF 1,"Create ARP Packet - failed\n"

	mov	eax, -1

	ret

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

;

; ARP_decrease_entry_ttls

;

; IN: /

; OUT: /

;

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

align 4

ARP_decrease_entry_ttls:

	mov	ecx, [NumARP]

	test	ecx, ecx

	jz	.exit

	mov	ebx, ARPTable

.timer_loop:

	cmp	[ebx + ARP_ENTRY.TTL], 0xFFFF

	je	.timer_loop_end  ;if TTL==0xFFFF then it's static entry

	cmp	[ebx + ARP_ENTRY.TTL], 0

	jnz	.timer_loop_end_with_dec  ;if TTL!=0

	; Ok, TTL is 0

	;if Status==AWAITING_RESPONSE and TTL==0

	;then we have to change it to ARP_RESPONSE_TIMEOUT

	cmp	[ebx + ARP_ENTRY.Status], ARP_AWAITING_RESPONSE

	jne	@f

	mov	[ebx + ARP_ENTRY.Status], ARP_RESPONSE_TIMEOUT

	mov	[ebx + ARP_ENTRY.TTL], word 0x000A   ;10 sec

	jmp	.timer_loop_end

  @@:

	;if TTL==0 and Status==VALID_MAPPING, we have to delete it

	;if TTL==0 and Status==RESPONSE_TIMEOUT, delete too

	mov	esi, [NumARP]

	sub	esi, ecx	  ;esi=index of entry, will be deleted

	push	ebx ecx

	call	ARP_del_entry

	pop	ecx ebx

	jmp	.timer_loop_end

.timer_loop_end_with_dec:

	dec	[ebx + ARP_ENTRY.TTL]  ;decrease TTL

.timer_loop_end:

	add	ebx, ARP_ENTRY.size

	loop	.timer_loop

.exit:

	ret

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

;

; ARP_add_entry (or update)

;

; IN: arp entry in stack: esp     .IP

;                         esp+4   .MAC

;                         esp+10  .Status

;                         esp+12  .TTL

;                         esp+14

;

; OUT: eax = entry #, -1 on error

;

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

; TODO: use a mutex

align 4

ARP_add_entry:

	DEBUGF 1,"ARP add entry: "

	mov	ecx, [NumARP]

	test	ecx, ecx

	jz	.add

	mov	eax, dword[esp + ARP_ENTRY.MAC]

	mov	bx , word[esp + ARP_ENTRY.MAC + 4]

	mov	esi, ARPTable

.loop:

	cmp	dword [esi + ARP_ENTRY.MAC], eax

	jne	.maybe_next

	cmp	word [esi + ARP_ENTRY.MAC + 4], bx

	jne	.maybe_next

	cmp	dword[esi + ARP_ENTRY.TTL], 0xFFFF ; static entry

	jne	.notstatic

	cmp	dword[esp + ARP_ENTRY.TTL], 0xFFFF

	jne	.error

.notstatic:

	mov	ebx, [NumARP]

	xchg	ebx, ecx

	sub	ecx, ebx

	jmp	.add

.maybe_next:

	add	esi, ARP_ENTRY.size

	loop	.loop

	mov	ecx, [NumARP]

	cmp	ecx, ARP_TABLE_SIZE

	jge	.error

.add:

	push	ecx

	imul	ecx, ARP_ENTRY.size

	lea	edi, [ecx + ARPTable]

	lea	esi, [esp + 8]

	mov	ecx, ARP_ENTRY.size/2

	repz	movsw

	inc	[NumARP]

	pop	eax

.exit:

	pop	ebx    ; return addr

	add	esp, ARP_ENTRY.size

	DEBUGF 1,"Exiting\n"

	jmp	ebx

.error:

	DEBUGF 1,"error! \n"

	mov	eax, -1

	jmp	.exit

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

;

; ARP_del_entry

;

; IN: entry # in esi

; OUT: /

;

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

align 4

ARP_del_entry:

	DEBUGF 1,"ARP del entry %u, total entrys: %u\n", esi, [NumARP]

	cmp	esi, [NumARP]

	jge	.error

	DEBUGF 1,"deleting the entry..\n"

	imul	esi, ARP_ENTRY.size

	mov	ecx, (ARP_TABLE_SIZE - 1) * ARP_ENTRY.size

	sub	ecx, esi

	lea	edi, [ebx + esi]	    ;edi=ptr to entry that should be deleted

	lea	esi, [edi + ARP_ENTRY.size] ;esi=ptr to next entry

	shr	ecx,1	   ;ecx/2 => ARP_ENTRY_SIZE MUST BE EVEN NUMBER!

	rep	movsw

	dec	[NumARP] ;decrease arp-entries counter

.error:

	ret

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

;

; ARP_Handler:

;

;  This function handles ARP protocol over ethernet

;  (other protocols may follow in the future)

;

;  IN:  Pointer to buffer in [esp]

;       size of buffer in [esp+4]

;       packet size (without ethernet header) in ecx

;  OUT: /

;

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

align 4

ARP_handler:

	DEBUGF	1,"ARP_Handler - start\n"

	cmp	ecx, 28

	jl	.exit

	cmp	word [edx + ARP_Packet.Opcode], ARP_REP_OPCODE	; Is this a reply packet?

	jne	.maybe_request

	DEBUGF	1,"ARP_Handler - it's a reply packet from %u.%u.%u.%u\n",\

	[edx + ARP_Packet.SenderIP]:1,[edx + ARP_Packet.SenderIP+1]:1,[edx + ARP_Packet.SenderIP+2]:1,[edx + ARP_Packet.SenderIP+3]:1,

	mov	ecx, [NumARP]

	test	ecx, ecx

	jz	.exit

	mov	eax, [edx + ARP_Packet.SenderIP]

	mov	esi, ARPTable+ARP_ENTRY.IP

  .loop:

	cmp	[esi], eax

	je	.gotit

	add	esi, ARP_ENTRY.size

	loop	.loop

	jmp	.exit

  .gotit:

	DEBUGF	1,"ARP_Handler - found matching entry\n"

	cmp	[esi+ARP_ENTRY.Status], 0x0300	 ;if it is a static entry, dont touch it

	je	.exit

	DEBUGF	1,"ARP_Handler - updating entry\n"

	mov	[esi+ARP_ENTRY.Status], ARP_VALID_MAPPING

	mov	[esi+ARP_ENTRY.TTL], ARP_ENTRY_TTL

	mov	eax, dword [edx + ARP_Packet.SenderMAC]

	mov	dword [esi+ARP_ENTRY.MAC], eax

	mov	ax , word [edx + ARP_Packet.SenderMAC + 4]

	mov	word [esi+ARP_ENTRY.MAC+4], ax

	jmp	.exit

;------

  .maybe_request:

	cmp	word [edx + ARP_Packet.Opcode], ARP_REQ_OPCODE	; Is this a request packet?

	jne	.exit

	call	ETH_struc2dev

	DEBUGF	1,"ARP Request packet through device: %u\n", edi

	inc	[ARP_PACKETS_RX+4*edi]

	cmp	edi, -1

	jz	.exit

	mov	eax, edi

	shl	eax, 2

	add	eax, IP_LIST

	mov	eax, [eax]

	cmp	eax, [edx + ARP_Packet.TargetIP]		; Is it looking for my IP address?

	jnz	.exit

	push	eax

	push	edi

; OK, it is a request for one of our MAC addresses. Build the frame and send it

; We can reuse the buffer.  (faster then using ARP_create_packet)

	cld

	lea	esi, [edx + ARP_Packet.SenderMAC]

	lea	edi, [edx + ARP_Packet.TargetMAC]

	movsd							; Move Sender Mac to Dest MAC

	movsw							;

	movsd							; Move sender IP to Dest IP

	pop	esi

	mov	esi, [ETH_DRV_LIST + 4*esi]

	lea	esi, [esi + ETH_DEVICE.mac]

	lea	edi, [edx + ARP_Packet.SenderMAC]

	movsd							; Copy MAC address from in MAC_LIST

	movsw							;

	pop	eax

	stosd							; Write our IP

	mov	word [edx + ARP_Packet.Opcode], ARP_REP_OPCODE

; Now, Fill in ETHERNET header

	mov	edi, [esp]

	lea	esi, [edx + ARP_Packet.TargetMAC]

	movsd

	movsw

	lea	esi, [edx + ARP_Packet.SenderMAC]

	movsd

	movsw

;        mov     ax , ETHER_ARP

;        stosw

	DEBUGF	1,"ARP_Handler - Sending reply \n"

	jmp	ETH_Sender					; And send it!

     .exit:

	call	kernel_free

	add	esp, 4						; pop (balance stack)

	DEBUGF 1,"ARP_Handler - exiting\n"

	ret

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

;

; ARP_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

ARP_API:

	movzx	eax, bh

	shl	eax, 2

	test	bl, bl

	jz	.packets_tx	; 0

	dec	bl

	jz	.packets_rx	; 1

	dec	bl

	jz	.entries	; 2

	dec	bl

	jz	.read		; 3

	dec	bl

	jz	.write		; 4

	dec	bl

	jz	.remove 	; 5

	dec	bl

.error:

	mov	eax, -1

	ret

.packets_tx:

	add	eax, ARP_PACKETS_TX

	mov	eax, [eax]

	ret

.packets_rx:

	add	eax, ARP_PACKETS_RX

	mov	eax, [eax]

	ret

.entries:

	mov	eax, [NumARP]

	ret

.read:

	cmp	ecx, [NumARP]

	jge	.error

	; edi = pointer to buffer

	; ecx = # entry

	imul	ecx, ARP_ENTRY.size

	add	ecx, ARPTable

	mov	esi, ecx

	mov	ecx, ARP_ENTRY.size/2

	rep	movsw

	xor	eax, eax

	ret

.write:

	; esi = pointer to buffer

	sub	esp, ARP_ENTRY.size

	mov	edi, esp

	mov	ecx, ARP_ENTRY.size/2

	rep	movsw

	jmp	ARP_add_entry	     ;out: eax = entry number, -1 on error

.remove:

	; ecx = # entry

	mov	esi, ecx

	call	ARP_del_entry

	ret