;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ;; ;; Copyright (C) KolibriOS team 2004-2012. All rights reserved. ;; ;; Distributed under terms of the GNU General Public License ;; ;; ;; ;; IPv4.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 ;; ;; ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; $Revision$ MAX_FRAGMENTS = 64 struct IPv4_header VersionAndIHL db ? ; Version[0-3 bits] and IHL(header length)[4-7 bits] TypeOfService db ? ; precedence [7-5] minimize delay [4], maximize throughput [3], maximize riliability [2] minimize momentary cost [1] and zero [0] TotalLength dw ? Identification dw ? FlagsAndFragmentOffset dw ? ; Flags[0-2] and FragmentOffset[3-15] TimeToLive db ? ; Protocol db ? HeaderChecksum dw ? SourceAddress dd ? DestinationAddress dd ? ends struct FRAGMENT_slot ttl dw ? ; Time to live for this entry, 0 for empty slot's id dw ? ; Identification field from IP header SrcIP dd ? ; .. from IP header DstIP dd ? ; .. from IP header ptr dd ? ; Pointer to first packet ends struct FRAGMENT_entry ; This structure will replace the ethernet header in fragmented ip packets PrevPtr dd ? ; Pointer to previous fragment entry (-1 for first packet) NextPtr dd ? ; Pointer to next fragment entry (-1 for last packet) Owner dd ? ; Pointer to structure of driver rb 2 ; to match ethernet header size ;;; FIXME ; Ip header begins here (we will need the IP header to re-construct the complete packet) ends align 4 uglobal IP_LIST rd MAX_NET_DEVICES SUBNET_LIST rd MAX_NET_DEVICES DNS_LIST rd MAX_NET_DEVICES GATEWAY_LIST rd MAX_NET_DEVICES BROADCAST_LIST rd MAX_NET_DEVICES IP_PACKETS_TX rd MAX_NET_DEVICES IP_PACKETS_RX rd MAX_NET_DEVICES FRAGMENT_LIST rb MAX_FRAGMENTS * sizeof.FRAGMENT_slot endg ;----------------------------------------------------------------- ; ; IPv4_init ; ; This function resets all IP variables ; ;----------------------------------------------------------------- macro IPv4_init { xor eax, eax mov edi, IP_LIST mov ecx, 7*MAX_NET_DEVICES + (sizeof.FRAGMENT_slot*MAX_FRAGMENTS)/4 rep stosd } ;----------------------------------------------------------------- ; ; Decrease TimeToLive of all fragment slots ; ;----------------------------------------------------------------- macro IPv4_decrease_fragment_ttls { local .loop, .next mov esi, FRAGMENT_LIST mov ecx, MAX_FRAGMENTS .loop: cmp [esi + FRAGMENT_slot.ttl], 0 je .next dec [esi + FRAGMENT_slot.ttl] jz .died .next: add esi, sizeof.FRAGMENT_slot dec ecx jnz .loop jmp .done .died: DEBUGF 1,"Fragment slot timed-out!\n" ;;; TODO: clear all entry's of timed-out slot jmp .next .done: } macro IPv4_checksum ptr { ; This is the fast procedure to create or check an IP header without options ; 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 push ebx xor ebx, ebx add bl, [ptr+1] adc bh, [ptr+0] adc bl, [ptr+3] adc bh, [ptr+2] adc bl, [ptr+5] adc bh, [ptr+4] adc bl, [ptr+7] adc bh, [ptr+6] adc bl, [ptr+9] adc bh, [ptr+8] ; we skip 11th and 12th byte, they are the checksum bytes and should be 0 for re-calculation adc bl, [ptr+13] adc bh, [ptr+12] adc bl, [ptr+15] adc bh, [ptr+14] adc bl, [ptr+17] adc bh, [ptr+16] adc bl, [ptr+19] adc bh, [ptr+18] adc ebx, 0 push ecx mov ecx, ebx shr ecx, 16 and ebx, 0xffff add ebx, ecx mov ecx, ebx shr ecx, 16 add ebx, ecx not bx jnz .not_zero dec bx .not_zero: xchg bl, bh pop ecx neg word [ptr+10] ; zero will stay zero so we just get the checksum add word [ptr+10], bx ; , else we will get (new checksum - old checksum) in the end, wich should be 0 :) pop ebx } ;----------------------------------------------------------------- ; ; IPv4_input: ; ; Will check if IPv4 Packet isnt damaged ; and call appropriate handler. (TCP/UDP/ICMP/..) ; ; It will also re-construct fragmented packets ; ; IN: Pointer to buffer in [esp] ; size of buffer in [esp+4] ; pointer to device struct in ebx ; pointer to IPv4 header in edx ; size of IPv4 packet in ecx ; OUT: / ; ;----------------------------------------------------------------- align 4 IPv4_input: ; TODO: add IPv4 raw sockets support DEBUGF 1,"IPv4_input, packet from: %u.%u.%u.%u ",\ [edx + IPv4_header.SourceAddress + 0]:1,[edx + IPv4_header.SourceAddress + 1]:1,\ [edx + IPv4_header.SourceAddress + 2]:1,[edx + IPv4_header.SourceAddress + 3]:1 DEBUGF 1,"to: %u.%u.%u.%u\n",\ [edx + IPv4_header.DestinationAddress + 0]:1,[edx + IPv4_header.DestinationAddress + 1]:1,\ [edx + IPv4_header.DestinationAddress + 2]:1,[edx + IPv4_header.DestinationAddress + 3]:1 ;------------------------------- ; re-calculate the checksum IPv4_checksum edx jnz .dump ; if checksum isn't valid then dump packet DEBUGF 1,"IPv4_input: Checksum ok\n" ;----------------------------------- ; Check if destination IP is correct call NET_ptr_to_num shl edi, 2 ; check if it matches local ip mov eax, [edx + IPv4_header.DestinationAddress] cmp eax, [IP_LIST+edi] je .ip_ok ; check for broadcast (IP or (not SUBNET)) cmp eax, [BROADCAST_LIST+edi] je .ip_ok ; or a special broadcast (255.255.255.255) cmp eax, 0xffffffff je .ip_ok ; maybe it's a multicast (224.0.0.0/4) and eax, 0x0fffffff cmp eax, 224 je .ip_ok ; or a loopback address (127.0.0.0/8) and eax, 0x00ffffff cmp eax, 127 je .ip_ok ; or it's just not meant for us.. :( DEBUGF 2,"IPv4_input: Destination address does not match!\n" jmp .dump ;------------------------ ; Now we can update stats .ip_ok: inc [IP_PACKETS_RX+edi] ;---------------------------------- ; Check if the packet is fragmented test [edx + IPv4_header.FlagsAndFragmentOffset], 1 shl 5 ; Is 'more fragments' flag set ? jnz .has_fragments ; If so, we definately have a fragmented packet test [edx + IPv4_header.FlagsAndFragmentOffset], 0xff1f ; If flag is not set, but there is a fragment offset, the packet is last in series of fragmented packets jnz .is_last_fragment ;------------------------------------------------------------------- ; No, it's just a regular IP packet, pass it to the higher protocols .handle_it: ; We reach here if packet hasnt been fragmented, or when it already has been re-constructed movzx esi, [edx + IPv4_header.VersionAndIHL] ; Calculate Header length by using IHL field and esi, 0x0000000f ; shl esi, 2 ; movzx ecx, [edx + IPv4_header.TotalLength] ; Calculate length of encapsulated Packet xchg cl, ch ; sub ecx, esi ; lea edi, [edx + IPv4_header.SourceAddress] ; make edi ptr to source and dest IPv4 address mov al, [edx + IPv4_header.Protocol] add esi, edx ; make esi ptr to data cmp al, IP_PROTO_TCP je TCP_input cmp al, IP_PROTO_UDP je UDP_input cmp al, IP_PROTO_ICMP je ICMP_input DEBUGF 2,"IPv4_input: unknown protocol %u\n", al .dump: DEBUGF 2,"IPv4_input: dumping\n" ; inc [dumped_rx_count] ;;; TODO call kernel_free add esp, 4 ; pop (balance stack) ret ;--------------------------- ; Fragmented packet handler .has_fragments: movzx eax, [edx + IPv4_header.FlagsAndFragmentOffset] xchg al, ah shl ax, 3 DEBUGF 1,"IPv4_input: fragmented packet offset=%u id=%x\n", ax, [edx + IPv4_header.Identification]:4 test ax, ax ; Is this the first packet of the fragment? jz .is_first_fragment ;------------------------------------------------------- ; We have a fragmented IP packet, but it's not the first DEBUGF 1,"IPv4_input: Middle fragment packet received!\n" call IPv4_find_fragment_slot cmp esi, -1 je .dump mov [esi + FRAGMENT_slot.ttl], 15 ; Reset the ttl mov esi, [esi + FRAGMENT_slot.ptr] or edi, -1 .find_last_entry: ; The following routine will try to find the last entry cmp edi, [esi + FRAGMENT_entry.PrevPtr] jne .destroy_slot ; Damn, something screwed up, remove the whole slot (and free buffers too if possible!) mov edi, esi mov esi, [esi + FRAGMENT_entry.NextPtr] cmp esi, -1 jne .find_last_entry ; We found the last entry (pointer is now in edi) ; We are going to overwrite the ethernet header in received packet with a FRAGMENT_entry structure pop eax ; pointer to packet mov [edi + FRAGMENT_entry.NextPtr], eax ; update pointer of previous entry to the new entry mov [eax + FRAGMENT_entry.NextPtr], -1 mov [eax + FRAGMENT_entry.PrevPtr], edi mov [eax + FRAGMENT_entry.Owner], ebx add esp, 4 ret ;------------------------------------ ; We have received the first fragment .is_first_fragment: DEBUGF 1,"IPv4_input: First fragment packet received!\n" ; try to locate a free slot.. mov ecx, MAX_FRAGMENTS mov esi, FRAGMENT_LIST .find_free_slot: cmp word [esi + FRAGMENT_slot.ttl], 0 je .found_free_slot add esi, sizeof.FRAGMENT_slot loop .find_free_slot jmp .dump ; If no free slot was found, dump the packet .found_free_slot: ; We found a free slot, let's fill in the FRAGMENT_slot structure mov [esi + FRAGMENT_slot.ttl], 15 ; RFC recommends 15 secs as ttl mov ax, [edx + IPv4_header.Identification] mov [esi + FRAGMENT_slot.id], ax mov eax,[edx + IPv4_header.SourceAddress] mov [esi + FRAGMENT_slot.SrcIP], eax mov eax, [edx + IPv4_header.DestinationAddress] mov [esi + FRAGMENT_slot.DstIP], eax pop eax mov [esi + FRAGMENT_slot.ptr], eax ; Now, replace ethernet header in original buffer with a FRAGMENT_entry structure mov [eax + FRAGMENT_entry.NextPtr], -1 mov [eax + FRAGMENT_entry.PrevPtr], -1 mov [eax + FRAGMENT_entry.Owner], ebx add esp, 4 ; balance stack and exit ret ;----------------------------------- ; We have received the last fragment .is_last_fragment: DEBUGF 1,"IPv4_input: Last fragment packet received!\n" call IPv4_find_fragment_slot cmp esi, -1 je .dump mov esi, [esi + FRAGMENT_slot.ptr] ; We found the first entry, let's calculate total size of the packet in eax, so we can allocate a buffer push esi xor eax, eax or edi, -1 .count_bytes: cmp [esi + FRAGMENT_entry.PrevPtr], edi jne .destroy_slot_pop ; Damn, something screwed up, remove the whole slot (and free buffers too if possible!) mov cx, [esi + sizeof.FRAGMENT_entry + IPv4_header.TotalLength] ; Add total length xchg cl, ch DEBUGF 1,"IPv4_input: Packet size=%u\n", cx add ax, cx movzx cx, [esi + sizeof.FRAGMENT_entry + IPv4_header.VersionAndIHL] ; Sub Header length and cx, 0x000F shl cx, 2 DEBUGF 1,"IPv4_input: Header size=%u\n", cx sub ax, cx mov edi, esi mov esi, [esi + FRAGMENT_entry.NextPtr] cmp esi, -1 jne .count_bytes mov esi, [esp+4] mov [edi + FRAGMENT_entry.NextPtr], esi ; Add this packet to the chain, this simplifies the following code mov [esi + FRAGMENT_entry.NextPtr], -1 mov [esi + FRAGMENT_entry.PrevPtr], edi mov [esi + FRAGMENT_entry.Owner], ebx mov cx, [edx + IPv4_header.TotalLength] ; Note: This time we dont substract Header length xchg cl, ch DEBUGF 1,"IPv4_input: Packet size=%u\n", cx add ax, cx DEBUGF 1,"IPv4_input: Total Received data size=%u\n", eax push eax mov ax, [edx + IPv4_header.FlagsAndFragmentOffset] xchg al, ah shl ax, 3 add cx, ax pop eax DEBUGF 1,"IPv4_input: Total Fragment size=%u\n", ecx cmp ax, cx jne .destroy_slot_pop push eax push eax call kernel_alloc test eax, eax je .destroy_slot_pop ; If we dont have enough space to allocate the buffer, discard all packets in slot mov edx, [esp+4] ; Get pointer to first fragment entry back in edx .rebuild_packet_loop: movzx ecx, [edx + sizeof.FRAGMENT_entry + IPv4_header.FlagsAndFragmentOffset] ; Calculate the fragment offset xchg cl, ch ; intel byte order shl cx, 3 ; multiply by 8 and clear first 3 bits DEBUGF 1,"IPv4_input: Fragment offset=%u\n", cx lea edi, [eax + ecx] ; Notice that edi will be equal to eax for first fragment movzx ebx, [edx + sizeof.FRAGMENT_entry + IPv4_header.VersionAndIHL] ; Find header size (in ebx) of fragment and bx, 0x000F ; shl bx, 2 ; lea esi, [edx + sizeof.FRAGMENT_entry] ; Set esi to the correct begin of fragment movzx ecx, [edx + sizeof.FRAGMENT_entry + IPv4_header.TotalLength] ; Calculate total length of fragment xchg cl, ch ; intel byte order cmp edi, eax ; Is this packet the first fragment ? je .first_fragment sub cx, bx ; If not, dont copy the header add esi, ebx ; .first_fragment: push cx ; First copy dword-wise, then byte-wise shr cx, 2 ; rep movsd ; pop cx ; and cx, 3 ; rep movsb ; push eax push edx ; Push pointer to fragment onto stack mov ebx, [edx + FRAGMENT_entry.Owner] ; we need to remeber the owner, in case this is the last packet mov edx, [edx + FRAGMENT_entry.NextPtr] ; Set edx to the next pointer call kernel_free ; free the previous fragment buffer (this uses the value from stack) pop eax cmp edx, -1 ; Check if it is last fragment in chain jne .rebuild_packet_loop pop ecx xchg cl, ch mov edx, eax mov [edx + IPv4_header.TotalLength], cx add esp, 8 xchg cl, ch push ecx push eax jmp .handle_it ; edx = buf ptr, ecx = size, [esp] buf ptr, [esp+4], total size, ebx=device ptr .destroy_slot_pop: add esp, 4 .destroy_slot: DEBUGF 1,"IPv4_input: Destroy fragment slot!\n" ; TODO! jmp .dump ;----------------------------------------------------------------- ; ; find fragment slot ; ; IN: pointer to fragmented packet in edx ; OUT: pointer to slot in esi, -1 on error ; ;----------------------------------------------------------------- align 4 IPv4_find_fragment_slot: ;;; TODO: the RFC says we should check protocol number too push eax ebx ecx edx mov ax, [edx + IPv4_header.Identification] mov ecx, MAX_FRAGMENTS mov esi, FRAGMENT_LIST mov ebx, [edx + IPv4_header.SourceAddress] mov edx, [edx + IPv4_header.DestinationAddress] .find_slot: cmp [esi + FRAGMENT_slot.id], ax jne .try_next cmp [esi + FRAGMENT_slot.SrcIP], ebx jne .try_next cmp [esi + FRAGMENT_slot.DstIP], edx je .found_slot .try_next: add esi, sizeof.FRAGMENT_slot loop .find_slot or esi, -1 .found_slot: pop edx ecx ebx eax ret ;------------------------------------------------------------------ ; ; IPv4_output ; ; IN: eax = dest ip ; ebx = output device ptr/0 for automatic choice ; ecx = data length ; edx = source ip ; di = TTL shl 8 + protocol ; ; OUT: eax = pointer to buffer start ; ebx = pointer to device struct (needed for sending procedure) ; ecx = unchanged (packet size of embedded data) ; edx = size of complete buffer ; edi = pointer to start of data (0 on error) ; ;------------------------------------------------------------------ align 4 IPv4_output: DEBUGF 1,"IPv4_output: size=%u\n", ecx cmp ecx, 65500 ; Max IPv4 packet size ja .too_large push ecx eax edx di cmp eax, 1 shl 24 + 127 je .loopback call IPv4_dest_to_dev ; outputs device number in edi, dest ip in eax call ARP_IP_to_MAC test eax, 0xffff0000 ; error bits jnz .arp_error push ebx ; push the mac onto the stack push ax inc [IP_PACKETS_TX + edi] ; update stats mov ebx, [NET_DRV_LIST + edi] lea eax, [ebx + ETH_DEVICE.mac] mov edx, esp mov ecx, [esp + 10 + 6] add ecx, sizeof.IPv4_header mov di, ETHER_IPv4 call ETH_output jz .eth_error add esp, 6 ; pop the mac out of the stack .continue: xchg cl, ch ; internet byte order mov [edi + IPv4_header.VersionAndIHL], 0x45 ; IPv4, normal length (no Optional header) mov [edi + IPv4_header.TypeOfService], 0 ; nothing special, just plain ip packet mov [edi + IPv4_header.TotalLength], cx mov [edi + IPv4_header.Identification], 0 ; fragment id: FIXME mov [edi + IPv4_header.FlagsAndFragmentOffset], 0 pop word [edi + IPv4_header.TimeToLive] ; ttl shl 8 + protocol ; [edi + IPv4_header.Protocol] mov [edi + IPv4_header.HeaderChecksum], 0 popd [edi + IPv4_header.SourceAddress] popd [edi + IPv4_header.DestinationAddress] pop ecx IPv4_checksum edi add edi, sizeof.IPv4_header DEBUGF 1,"IPv4_output: success!\n" ret .eth_error: DEBUGF 1,"IPv4_output: ethernet error\n" add esp, 3*4+2+6 xor edi, edi ret .arp_error: DEBUGF 1,"IPv4_output: ARP error=%x\n", eax add esp, 3*4+2 xor edi, edi ret .too_large: DEBUGF 1,"IPv4_output: Packet too large!\n" xor edi, edi ret .loopback: mov dword [esp + 2], eax add ecx, sizeof.IPv4_header mov di, ETHER_IPv4 call LOOP_output jmp .continue ;------------------------------------------------------------------ ; ; IPv4_output_raw ; ; IN: eax = socket ptr ; ecx = data length ; esi = data ptr ; ; OUT: / ; ;------------------------------------------------------------------ align 4 IPv4_output_raw: DEBUGF 1,"IPv4_output_raw: size=%u ptr=%x socket=%x\n", ecx, esi, eax cmp ecx, 1480 ;;;;; FIXME ja .too_large sub esp, 8 push esi eax call IPv4_dest_to_dev call ARP_IP_to_MAC test eax, 0xffff0000 ; error bits jnz .arp_error push ebx ; push the mac push ax inc [IP_PACKETS_TX + edi] mov ebx, [NET_DRV_LIST + edi] lea eax, [ebx + ETH_DEVICE.mac] mov edx, esp mov ecx, [esp + 6 + 4] add ecx, sizeof.IPv4_header mov di, ETHER_IPv4 call ETH_output jz .error add esp, 6 ; pop the mac mov dword[esp+4+4], edx mov dword[esp+4+4+4], eax pop eax esi ;; todo: check socket options if we should add header, or just compute checksum push edi ecx rep movsb pop ecx edi ; [edi + IPv4_header.VersionAndIHL] ; IPv4, normal length (no Optional header) ; [edi + IPv4_header.TypeOfService] ; nothing special, just plain ip packet ; [edi + IPv4_header.TotalLength] ; [edi + IPv4_header.TotalLength] ; internet byte order ; [edi + IPv4_header.FlagsAndFragmentOffset] mov [edi + IPv4_header.HeaderChecksum], 0 ; [edi + IPv4_header.TimeToLive] ; ttl shl 8 + protocol ; [edi + IPv4_header.Protocol] ; [edi + IPv4_header.Identification] ; fragment id ; [edi + IPv4_header.SourceAddress] ; [edi + IPv4_header.DestinationAddress] IPv4_checksum edi ;;;; todo: checksum for IP packet with options! add edi, sizeof.IPv4_header DEBUGF 1,"IPv4_output_raw: device=%x\n", ebx call [ebx + NET_DEVICE.transmit] ret .error: add esp, 6 .arp_error: add esp, 8+4+4 .too_large: DEBUGF 1,"IPv4_output_raw: Failed\n" sub edi, edi ret ;-------------------------------------------------------- ; ; ; IN: dword [esp] = pointer to buffer containing ipv4 packet to be fragmented ; dword [esp+4] = buffer size ; esi = pointer to ip header in that buffer ; ecx = max size of fragments ; ; OUT: / ; ;-------------------------------------------------------- align 4 IPv4_fragment: DEBUGF 1,"IPv4_fragment\n" and ecx, not 111b ; align 4 cmp ecx, sizeof.IPv4_header + 8 ; must be able to put at least 8 bytes jb .err2 push esi ecx mov eax, [esi + IPv4_header.DestinationAddress] call ARP_IP_to_MAC pop ecx esi cmp eax, -1 jz .err2 push ebx push ax mov ebx, [NET_DRV_LIST] lea eax, [ebx + ETH_DEVICE.mac] push eax push esi ; ptr to ip header sub ecx, sizeof.IPv4_header ; substract header size push ecx ; max data size push dword 0 ; offset .new_fragment: DEBUGF 1,"Ipv4_fragment: new fragment" mov eax, [esp + 3*4] lea ebx, [esp + 4*4] mov di , ETHER_IPv4 call ETH_output cmp edi, -1 jz .err ; copy header mov esi, [esp + 2*4] mov ecx, 5 ; 5 dwords: TODO: use IHL field of the header! rep movsd ; copy data mov esi, [esp + 2*4] add esi, sizeof.IPv4_header add esi, [esp] ; offset mov ecx, [esp + 1*4] DEBUGF 1,"IPv4_fragment: copying %u bytes\n", ecx rep movsb ; now, correct header mov ecx, [esp + 1*4] add ecx, sizeof.IPv4_header xchg cl, ch mov [edi + IPv4_header.TotalLength], cx mov ecx, [esp] ; offset xchg cl, ch ; cmp dword[esp + 4*4], 0 ; last fragment?;<<<<<< ; je .last_fragment or cx, 1 shl 2 ; more fragments ; .last_fragment: mov [edi + IPv4_header.FlagsAndFragmentOffset], cx mov [edi + IPv4_header.HeaderChecksum], 0 ;<<<<<<<<<<<<<<<<<<<<<<<<<<<<< send the packet mov ecx, [esp + 1*4] push edx eax IPv4_checksum edi call [ebx + NET_DEVICE.transmit] ;<<<<<<<<<<<<<<<<<<<<<<<<<<<<< mov ecx, [esp+4] add [esp], ecx mov ecx, [esp+3*4+6+4] ; ptr to begin of buff add ecx, [esp+3*4+6+4+4] ; buff size sub ecx, [esp+2*4] ; ptr to ip header add ecx, [esp] ; offset DEBUGF 1,"Ipv4_fragment: %u bytes remaining\n", ecx cmp ecx, [esp+1*4] jae .new_fragment mov [esp+4], ecx ; set fragment size to remaining packet size jmp .new_fragment .err: DEBUGF 1,"Ipv4_fragment: failed\n" .done: add esp, 12 + 4 + 6 .err2: DEBUGF 1,"Ipv4_fragment: dumping\n" call kernel_free add esp, 4 ret ;--------------------------------------------------------------------------- ; ; IPv4_dest_to_dev ; ; IN: eax = Destination IP ; OUT: edi = device id * 4 ; eax = ip of gateway if nescessary, unchanged otherwise ; ;--------------------------------------------------------------------------- align 4 IPv4_dest_to_dev: cmp eax, 0xffffffff je .broadcast xor edi, edi mov ecx, MAX_NET_DEVICES .loop: mov ebx, [IP_LIST+edi] and ebx, [SUBNET_LIST+edi] jz .next mov edx, eax and edx, [SUBNET_LIST+edi] cmp ebx, edx je .found_it .next: add edi, 4 dec ecx jnz .loop .invalid: xor edi, edi ; if none found, use device 0 as default mov eax, [GATEWAY_LIST] .found_it: DEBUGF 1,"IPv4_dest_to_dev: %u\n", edi ret .broadcast: xor edi, edi ret ;--------------------------------------------------------------------------- ; ; IPv4_get_frgmnt_num ; ; IN: / ; OUT: fragment number in ax ; ;--------------------------------------------------------------------------- align 4 IPv4_get_frgmnt_num: xor ax, ax ;;; TODO: replace this with real code ret ;--------------------------------------------------------------------------- ; ; IPv4_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 IPv4_api: movzx eax, bh shl eax, 2 and ebx, 0x000000ff cmp ebx, .number ja .error jmp dword [.table + 4*ebx] .table: dd .packets_tx ; 0 dd .packets_rx ; 1 dd .read_ip ; 2 dd .write_ip ; 3 dd .read_dns ; 4 dd .write_dns ; 5 dd .read_subnet ; 6 dd .write_subnet ; 7 dd .read_gateway ; 8 dd .write_gateway ; 9 .number = ($ - .table) / 4 - 1 .error: mov eax, -1 ret .packets_tx: mov eax, [IP_PACKETS_TX + eax] ret .packets_rx: mov eax, [IP_PACKETS_RX + eax] ret .read_ip: mov eax, [IP_LIST + eax] ret .write_ip: mov [IP_LIST + eax], ecx ; pre-calculate the local broadcast address mov ebx, [SUBNET_LIST + eax] not ebx or ecx, ebx mov [BROADCAST_LIST + eax], ecx xor eax, eax ret .read_dns: mov eax, [DNS_LIST + eax] ret .write_dns: mov [DNS_LIST + eax], ecx xor eax, eax ret .read_subnet: mov eax, [SUBNET_LIST + eax] ret .write_subnet: mov [SUBNET_LIST + eax], ecx ; pre-calculate the local broadcast address mov ebx, [IP_LIST + eax] not ecx or ecx, ebx mov [BROADCAST_LIST + eax], ecx xor eax, eax ret .read_gateway: mov eax, [GATEWAY_LIST + eax] ret .write_gateway: mov [GATEWAY_LIST + eax], ecx xor eax, eax ret