$Revision$ ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ;; ;; Copyright (C) KolibriOS team 2004-2007. All rights reserved. ;; ;; Distributed under terms of the GNU General Public License ;; ;; ;; ;; ARP.INC ;; ;; ;; ;; Address Resolution Protocol ;; ;; ;; ;; Last revision: 10.11.2006 ;; ;; ;; ;; This file contains the following: ;; ;; arp_table_manager - Manages an ARPTable ;; ;; arp_request - Sends an ARP request on the ethernet ;; ;; arp_handler - Called when an ARP packet is received ;; ;; ;; ;; Changes history: ;; ;; 22.09.2003 - [Mike Hibbett] : mikeh@oceanfree.net ;; ;; 11.11.2006 - [Johnny_B] and [smb] ;; ;; ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ARP_NO_ENTRY equ 0 ARP_VALID_MAPPING equ 1 ARP_AWAITING_RESPONSE equ 2 ARP_RESPONSE_TIMEOUT equ 3 struc ARP_ENTRY ;=14 bytes { .IP dd ? ;+00 .MAC dp ? ;+04 .Status dw ? ;+10 .TTL dw ? ;+12 : ( in seconds ) } virtual at 0 ARP_ENTRY ARP_ENTRY end virtual ; 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 ; The follow is the ARP Table. ; This table must be manually updated and the kernel recompilied if ; changes are made to it. ; Empty entries are filled with zeros ARP_ENTRY_SIZE equ 14 ; Number of bytes per entry ARP_TABLE_SIZE equ 20 ; Size of table ARP_TABLE_ENTRIES equ 0 ; Number of static entries in the table ;TO ADD A STATIC ENTRY, DONT FORGET, PUT "ARPTable" from "uglobal" to "iglobal"!!! ;AND ALSO - IP and MAC have net byte-order, BUT STATUS AND TTL HAVE A MIRROR BYTE-ORDER!!! uglobal ARPTable: ;example, static entry -> db 11,22,33,44, 0x11,0x22,0x33,0x44,0x55,0x66, 0x01,0x00, 0xFF,0xFF times ( ARP_TABLE_SIZE - ARP_TABLE_ENTRIES ) * ARP_ENTRY_SIZE db 0 endg iglobal NumARP: dd ARP_TABLE_ENTRIES ARPTable_ptr dd ARPTable ;pointer to ARPTable endg ARP_REQ_OPCODE equ 0x0100 ;request ARP_REP_OPCODE equ 0x0200 ;reply struc ARP_PACKET { .HardwareType dw ? ;+00 .ProtocolType dw ? ;+02 .HardwareSize db ? ;+04 .ProtocolSize db ? ;+05 .Opcode dw ? ;+06 .SenderMAC dp ? ;+08 .SenderIP dd ? ;+14 .TargetMAC dp ? ;+18 .TargetIP dd ? ;+24 } virtual at 0 ARP_PACKET ARP_PACKET end virtual ;*************************************************************************** ; Function ; arp_table_manager [by Johnny_B] ; ; Description ; Does a most required operations with ARP-table ; IN: ; Operation: see Opcode's constants below ; Index: Index of entry in the ARP-table ; Extra: Extra parameter for some Opcodes ; OUT: ; EAX = Returned value depends on opcodes, more detailed see below ; ;*************************************************************************** ;Opcode's constants ARP_TABLE_ADD equ 1 ARP_TABLE_DEL equ 2 ARP_TABLE_GET equ 3 ARP_TABLE_GET_ENTRIES_NUMBER equ 4 ARP_TABLE_IP_TO_MAC equ 5 ARP_TABLE_TIMER equ 6 ;Index's constants EXTRA_IS_ARP_PACKET_PTR equ 0 ;if Extra contain pointer to ARP_PACKET EXTRA_IS_ARP_ENTRY_PTR equ -1 ;if Extra contain pointer to ARP_ENTRY align 4 proc arp_table_manager stdcall uses ebx esi edi ecx edx,\ Opcode:DWORD,Index:DWORD,Extra:DWORD mov ebx, dword[ARPTable_ptr] ;ARPTable base mov ecx, dword[NumARP] ;ARP-entries counter mov eax, dword[Opcode] cmp eax, ARP_TABLE_TIMER je .timer cmp eax, ARP_TABLE_ADD je .add cmp eax, ARP_TABLE_DEL je .del cmp eax, ARP_TABLE_GET je .get cmp eax, ARP_TABLE_IP_TO_MAC je .ip_to_mac cmp eax, ARP_TABLE_GET_ENTRIES_NUMBER je .get_entries_number jmp .exit ;if unknown opcode ;;BEGIN TIMER ;;Description: it must be callback every second. It is responsible for removing expired routes. ;;IN: Operation: ARP_TABLE_TIMER ;; Index: must be zero ;; Extra: must be zero ;;OUT: ;; EAX=not defined ;; .timer: test ecx, ecx jz .exit ;if NumARP=0 nothing to do sub ecx, ARP_TABLE_ENTRIES ;ecx=dynamic entries number jz .exit ;if NumARP=number of static entries then exit add ebx, ARP_TABLE_ENTRIES*ARP_ENTRY_SIZE ;ebx=dynamic entries base .timer_loop: movsx esi, word [ebx + ARP_ENTRY.TTL] cmp esi, 0xFFFFFFFF je .timer_loop_end ;if TTL==0xFFFF then it's static entry test esi, esi 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 word [ebx + ARP_ENTRY.Status], ARP_AWAITING_RESPONSE jne @f mov word [ebx + ARP_ENTRY.Status], ARP_RESPONSE_TIMEOUT mov word [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, dword[NumARP] sub esi, ecx ;esi=index of entry, will be deleted stdcall arp_table_manager,ARP_TABLE_DEL,esi,0 ;opcode,index,extra jmp .timer_loop_end .timer_loop_end_with_dec: dec word [ebx + ARP_ENTRY.TTL] ;decrease TTL .timer_loop_end: add ebx, ARP_ENTRY_SIZE loop .timer_loop jmp .exit ;;END TIMER ;;BEGIN ADD ;;Description: it adds an entry in the table. If ARP-table already ;; contains same IP, it will be updated. ;;IN: Operation: ARP_TABLE_ADD ;; Index: specifies what contains Extra-parameter ;; Extra: if Index==EXTRA_IS_ARP_PACKET_PTR, ;; then Extra contains pointer to ARP_PACKET, ;; otherwise Extra contains pointer to ARP_ENTRY ;;OUT: ;; EAX=index of entry, that has been added ;; .add: sub esp, ARP_ENTRY_SIZE ;Allocate ARP_ENTRY_SIZE byte in stack mov esi, [Extra] ;pointer mov edi, [Index] ;opcode cmp edi, EXTRA_IS_ARP_PACKET_PTR je .arp_packet_to_entry ;if Extra contain ptr to ARP_PACKET and we have to form arp-entry ;else it contain ptr to arp-entry cld ; esi already has been loaded mov edi, esp ;ebx + eax=ARPTable_base + ARP-entry_base(where we will add) mov ecx,ARP_ENTRY_SIZE/2 ;ARP_ENTRY_SIZE must be even number!!! rep movsw ;copy jmp .search .arp_packet_to_entry: mov edx, dword[esi + ARP_PACKET.SenderIP] ;esi=base of ARP_PACKET mov [esp + ARP_ENTRY.IP], edx cld lea esi, [esi + ARP_PACKET.SenderMAC] lea edi, [esp + ARP_ENTRY.MAC] movsd movsw mov word[esp + ARP_ENTRY.Status], ARP_VALID_MAPPING ; specify the type - a valid entry mov word[esp + ARP_ENTRY.TTL], 0x0E10 ; = 1 hour .search: mov edx, dword[esp + ARP_ENTRY.IP] ;edx=IP-address, which we'll search mov ecx, dword[NumARP] ;ecx=ARP-entries counter jecxz .add_to_end ;if ARP-entries number == 0 imul eax, ecx, ARP_ENTRY_SIZE ;eax=current table size(in bytes) @@: sub eax, ARP_ENTRY_SIZE cmp dword[ebx + eax + ARP_ENTRY.IP], edx loopnz @b jz .replace ; found, replace existing entry, ptr to it is in eax .add_to_end: ;else add to end or eax,-1 ;set eax=0xFFFFFFFF if adding is impossible mov ecx, dword[NumARP] cmp ecx, ARP_TABLE_SIZE je .add_exit ;if arp-entries number is equal to arp-table maxsize imul eax, dword[NumARP], ARP_ENTRY_SIZE ;eax=ptr to end of ARPTable inc dword [NumARP] ;increase ARP-entries counter .replace: cld mov esi, esp ;esp=base of ARP-entry, that will be added lea edi, [ebx + eax] ;ebx + eax=ARPTable_base + ARP-entry_base(where we will add) mov ecx,ARP_ENTRY_SIZE/2 ;ARP_ENTRY_SIZE must be even number!!! rep movsw mov ecx, ARP_ENTRY_SIZE xor edx, edx ;"div" takes operand from EDX:EAX div ecx ;eax=index of entry, which has been added .add_exit: add esp, ARP_ENTRY_SIZE ;free stack jmp .exit ;;END ADD ;;BEGIN DEL ;;Description: it deletes an entry in the table. ;;IN: Operation: ARP_TABLE_DEL ;; Index: index of entry, that should be deleted ;; Extra: must be zero ;;OUT: ;; EAX=not defined ;; .del: mov esi, [Index] 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! cld rep movsw dec dword[NumARP] ;decrease arp-entries counter jmp .exit ;;END DEL ;;BEGIN GET ;;Description: it reads an entry of table into buffer. ;;IN: Operation: ARP_TABLE_GET ;; Index: index of entry, that should be read ;; Extra: pointer to buffer for reading(size must be equal to ARP_ENTRY_SIZE) ;;OUT: ;; EAX=not defined ;; .get: mov esi, [Index] imul esi, ARP_ENTRY_SIZE ;esi=ptr to required ARP_ENTRY mov edi, [Extra] ;edi=buffer for reading mov ecx, ARP_ENTRY_SIZE/2 ; must be even number!!! cld rep movsw jmp .exit ;;END GET ;;BEGIN IP_TO_MAC ;;Description: it gets an IP from Index, scans each entry in the table and writes ;; MAC, that relates to specified IP, into buffer specified in Extra. ;; And if it cannot find an IP-address in the table, it does an ARP-request of that. ;;IN: Operation: ARP_TABLE_IP_TO_MAC ;; Index: IP that should be transformed into MAC ;; Extra: pointer to buffer where will be written the MAC-address. ;;OUT: ;; EAX=ARP table entry status code. ;; If EAX==ARP_NO_ENTRY, IP isn't found in the table and we have sent the request. ;; If EAX==ARP_AWAITING_RESPONSE, we wait the response from remote system. ;; If EAX==ARP_RESPONSE_TIMEOUT, remote system not responds too long. ;; If EAX==ARP_VALID_MAPPING, all is ok, we've got a true MAC. ;; ;; If MAC will equal to a zero, in the buffer. It means, that IP-address was not yet ;; resolved, or that doesn't exist. I recommend you, to do at most 3-5 calls of this ;; function with 1sec delay. sure, only if it not return a valid MAC after a first call. ;; .ip_to_mac: xor eax, eax mov edi, dword[Extra] cld stosd stosw cmp dword[NumARP], 0 je .ip_to_mac_send_request ;if ARP-table not contain an entries, we have to request IP. ;EAX will be containing a zero, it's equal to ARP_NO_ENTRY ; 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 mov eax, [Index] ;eax=required IP mov esi, eax and esi, [subnet_mask] mov ecx, [stack_ip] and ecx, [subnet_mask] cmp esi, ecx je @f ;if we and target IP are located in the same network mov eax, [gateway_ip] @@: mov ecx, dword[NumARP] imul esi, ecx, ARP_ENTRY_SIZE ;esi=current ARP-table size @@: sub esi, ARP_ENTRY_SIZE cmp [ebx + esi], eax ; ebx=ARPTable base loopnz @b ; Return back if non match jnz .ip_to_mac_send_request ; and request IP->MAC if none found in the table ; Return the entry status in eax movzx eax, word[ebx + esi + ARP_ENTRY.Status] ; esi holds index cld lea esi, [ebx + esi + ARP_ENTRY.MAC] mov edi, [Extra] ;edi=ptr to buffer for write MAC movsd movsw jmp .exit .ip_to_mac_send_request: stdcall arp_request,[Index],stack_ip,node_addr ;TargetIP,SenderIP_ptr,SenderMAC_ptr mov eax, ARP_NO_ENTRY jmp .exit ;;END IP_TO_MAC ;;BEGIN GET_ENTRIES_NUMBER ;;Description: returns an ARP-entries number in the ARPTable ;;IN: Operation: ARP_TABLE_GET_ENTRIES_NUMBER ;; Index: must be zero ;; Extra: must be zero ;;OUT: ;; EAX=ARP-entries number in the ARPTable .get_entries_number: mov eax, dword[NumARP] jmp .exit ;;END GET_ENTRIES_NUMBER .exit: ret endp ;*************************************************************************** ; Function ; arp_handler ; ; Description ; Called when an ARP packet is received on the ethernet ; Header + Data is in Ether_buffer[] ; It looks to see if the packet is a request to resolve this Hosts ; IP address. If it is, send the ARP reply packet. ; This Hosts IP address is in dword [stack_ip] ( in network format ) ; This Hosts MAC address is in node_addr[6] ; All registers may be destroyed ; ;*************************************************************************** arp_handler: ; Is this a REQUEST? ; Is this a request for My Host IP ; Yes - So construct a response message. ; Send this message to the ethernet card for transmission stdcall arp_table_manager,ARP_TABLE_ADD,EXTRA_IS_ARP_PACKET_PTR,ETH_FRAME.Data + ARP_PACKET inc dword[arp_rx_count] ;increase ARP-packets counter cmp word[ETH_FRAME.Data + ARP_PACKET.Opcode], ARP_REQ_OPCODE ; Is this a request packet? jne .exit ; No - so exit mov eax, [stack_ip] cmp eax, dword[ETH_FRAME.Data + ARP_PACKET.TargetIP] ; Is it looking for my IP address? jne .exit ; No - so quit now ; OK, it is a request for my MAC address. Build the frame and send it ; We can reuse the packet. mov word[ETH_FRAME.Data + ARP_PACKET.Opcode], ARP_REP_OPCODE cld mov esi, ETH_FRAME.Data + ARP_PACKET.SenderMAC mov edi, ETH_FRAME.Data + ARP_PACKET.TargetMAC movsd movsw mov esi, ETH_FRAME.Data + ARP_PACKET.SenderIP mov edi, ETH_FRAME.Data + ARP_PACKET.TargetIP movsd mov esi, node_addr mov edi, ETH_FRAME.Data + ARP_PACKET.SenderMAC movsd movsw mov esi, stack_ip mov edi, ETH_FRAME.Data + ARP_PACKET.SenderIP movsd ; Now, send it! mov edi, ETH_FRAME.Data + ARP_PACKET.TargetMAC ;ptr to destination MAC address mov bx, ETHER_ARP ;type of protocol mov ecx, 28 ;data size mov esi, ETH_FRAME.Data + ARP_PACKET ;ptr to data call dword [drvr_transmit] ;transmit packet .exit: ret ;*************************************************************************** ; Function ; arp_request [by Johnny_B] ; ; Description ; Sends an ARP request on the ethernet ; IN: ; TargetIP : requested IP address ; SenderIP_ptr : POINTER to sender's IP address(our system's address) ; SenderMAC_ptr : POINTER to sender's MAC address(our system's address) ; OUT: ; EAX=0 (if all is ok), otherwise EAX is not defined ; ; EBX,ESI,EDI will be saved ; ;*************************************************************************** proc arp_request stdcall uses ebx esi edi,\ TargetIP:DWORD, SenderIP_ptr:DWORD, SenderMAC_ptr:DWORD inc dword[arp_tx_count] ; increase counter sub esp, 28 ; allocate memory for ARP_PACKET mov word[esp + ARP_PACKET.HardwareType],0x0100 ;Ethernet mov word[esp + ARP_PACKET.ProtocolType],0x0008 ;IP mov byte[esp + ARP_PACKET.HardwareSize],0x06 ;MAC-addr length mov byte[esp + ARP_PACKET.ProtocolSize],0x04 ;IP-addr length mov word[esp + ARP_PACKET.Opcode],0x0100 ;Request cld mov esi,[SenderMAC_ptr] lea edi,[esp + ARP_PACKET.SenderMAC] ;Our MAC-addr movsd movsw mov esi,[SenderIP_ptr] lea edi,[esp + ARP_PACKET.SenderIP] ;Our IP-addr movsd xor eax, eax lea edi, [esp + ARP_PACKET.TargetMAC] ;Required MAC-addr(zeroed) stosd stosw mov esi, dword[TargetIP] mov dword[esp + ARP_PACKET.TargetIP],esi ;Required IP-addr(we get it as function parameter) ; Now, send it! mov edi, broadcast_add ; Pointer to 48 bit destination address mov bx, ETHER_ARP ; Type of packet mov ecx, 28 ; size of packet lea esi, [esp + ARP_PACKET]; pointer to packet data call dword [drvr_transmit] ; Call the drivers transmit function add esp, 28 ; free memory, allocated before for ARP_PACKET ; Add an entry in the ARP table, awaiting response sub esp, ARP_ENTRY_SIZE ;allocate memory for ARP-entry mov esi, dword[TargetIP] mov dword[esp + ARP_ENTRY.IP],esi lea edi, [esp + ARP_ENTRY.MAC] xor eax, eax stosd stosw mov word[esp + ARP_ENTRY.Status], ARP_AWAITING_RESPONSE mov word[esp + ARP_ENTRY.TTL], 0x000A ; 10 seconds stdcall arp_table_manager,ARP_TABLE_ADD,EXTRA_IS_ARP_ENTRY_PTR,esp add esp, ARP_ENTRY_SIZE ; free memory .exit: ret endp