Subversion Repositories Kolibri OS

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;;                                                                 ;;

;; Copyright (C) KolibriOS team 2004-2019. 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: 7679 $

ARP_NO_ENTRY            = 0

ARP_VALID_MAPPING       = 1

ARP_AWAITING_RESPONSE   = 2

ARP_RESPONSE_TIMEOUT    = 3

ARP_REQUEST_TTL         = 31          ; 20 s

ARP_ENTRY_TTL           = 937         ; 600 s

ARP_STATIC_ENTRY        = -1

ARP_REQ_OPCODE          = 0x0100      ; request

ARP_REP_OPCODE          = 0x0200      ; reply

ARP_TABLE_SIZE          = 20          ; Size of table

struct  ARP_entry

        IP              dd ?

        MAC             dp ?

        Status          dw ?

        TTL             dw ?

ends

struct  ARP_header

        HardwareType    dw ?

        ProtocolType    dw ?

        HardwareSize    db ?

        ProtocolSize    db ?

        Opcode          dw ?

        SenderMAC       dp ?

        SenderIP        dd ?

        TargetMAC       dp ?

        TargetIP        dd ?

ends

uglobal

align 4

        ARP_table       rb NET_DEVICES_MAX*(ARP_TABLE_SIZE * sizeof.ARP_entry)

        ARP_entries     rd NET_DEVICES_MAX

        ARP_packets_tx  rd NET_DEVICES_MAX

        ARP_packets_rx  rd NET_DEVICES_MAX

        ARP_conflicts   rd NET_DEVICES_MAX

endg

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

;                                                                 ;

; arp_init: Resets all ARP variables.                             ;

;                                                                 ;

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

macro arp_init {

        xor     eax, eax

        mov     edi, ARP_entries

        mov     ecx, 4*NET_DEVICES_MAX

        rep stosd

}

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

;                                                                 ;

; arp_decrease_entry_ttls                                         ;

;                                                                 ;

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

macro arp_decrease_entry_ttls {

local   .loop

local   .exit

; 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

        xor     edi, edi

  .loop_outer:

        mov     ecx, [ARP_entries + 4*edi]

        test    ecx, ecx

        jz      .exit

        mov     esi, (ARP_TABLE_SIZE * sizeof.ARP_entry)

        imul    esi, edi

        add     esi, ARP_table

  .loop:

        cmp     [esi + ARP_entry.TTL], ARP_STATIC_ENTRY

        je      .next

        dec     [esi + ARP_entry.TTL]

        jz      .time_out

  .next:

        add     esi, sizeof.ARP_entry

        dec     ecx

        jnz     .loop

        jmp     .exit

  .time_out:

        cmp     [esi + ARP_entry.Status], ARP_AWAITING_RESPONSE

        je      .response_timeout

        push    esi edi ecx

        call    arp_del_entry

        pop     ecx edi esi

        jmp     .next

  .response_timeout:

        mov     [esi + ARP_entry.Status], ARP_RESPONSE_TIMEOUT

        mov     [esi + ARP_entry.TTL], 10

        jmp     .next

  .exit:

        inc     edi

        cmp     edi, NET_DEVICES_MAX

        jb      .loop_outer

}

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

;                                                                 ;

; arp_input                                                       ;

;                                                                 ;

;  IN:  [esp] = Pointer to buffer                                 ;

;       [esp+4] = size of buffer                                  ;

;       ecx = packet size (without ethernet header)               ;

;       edx = packet ptr                                          ;

;       ebx = device ptr                                          ;

;                                                                 ;

;  OUT: /                                                         ;

;                                                                 ;

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

align 4

arp_input:

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

; Check validity and print some debug info

        cmp     ecx, sizeof.ARP_header

        jb      .exit

        call    net_ptr_to_num4

        cmp     edi, -1

        jz      .exit

        inc     [ARP_packets_rx + edi]          ; update stats

        DEBUGF  DEBUG_NETWORK_VERBOSE, "ARP_input: got packet from %u.%u.%u.%u (device*4=%u)\n",\

        [edx + ARP_header.SenderIP]:1, [edx + ARP_header.SenderIP + 1]:1,\

        [edx + ARP_header.SenderIP + 2]:1, [edx + ARP_header.SenderIP + 3]:1, edi

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

; First, check for IP collision

        mov     eax, [edx + ARP_header.SenderIP]

        cmp     eax, [IPv4_address + edi]

        je      .collision

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

; Handle reply packets

        cmp     [edx + ARP_header.Opcode], ARP_REP_OPCODE

        jne     .maybe_request

        DEBUGF  DEBUG_NETWORK_VERBOSE, "ARP_input: It's a reply\n"

        mov     ecx, [ARP_entries + edi]

        test    ecx, ecx

        jz      .exit

        mov     esi, edi

        imul    esi, (ARP_TABLE_SIZE * sizeof.ARP_entry)/4

        add     esi, ARP_table

  .loop:

        cmp     [esi + ARP_entry.IP], eax

        je      .gotit

        add     esi, sizeof.ARP_entry

        dec     ecx

        jnz     .loop

        DEBUGF  DEBUG_NETWORK_VERBOSE, "ARP_input: no matching entry found\n"

        jmp     .exit

  .gotit: