;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; Copyright (C) KolibriOS team 2004-2010. 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: 1519 $
MAX_FRAGMENTS equ 64
MAX_IP equ MAX_NET_DEVICES
IP_MAX_INTERFACES equ MAX_IP
struct IPv4_Packet
.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 ?
.DataOrOptional:
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
.size:
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 ; TODO: fix this hack
.Data: ; Ip header begins here (we will need the IP header to re-construct the complete packet)
ends
align 4
uglobal
IP_LIST rd MAX_IP
SUBNET_LIST rd MAX_IP
DNS_LIST rd MAX_IP
GATEWAY_LIST rd MAX_IP
IP_PACKETS_TX rd MAX_IP
IP_PACKETS_RX rd MAX_IP
FRAGMENT_LIST rb MAX_FRAGMENTS*FRAGMENT_slot.size
endg
;-----------------------------------------------------------------
;
; IPv4_init
;
; This function resets all IP variables
;
; IN: /
; OUT: /
;
;-----------------------------------------------------------------
align 4
IPv4_init:
or eax, -1
mov edi, IP_LIST
mov ecx, 4*MAX_IP
rep stosd
inc eax
mov edi, FRAGMENT_LIST
mov ecx, FRAGMENT_slot.size*MAX_FRAGMENTS/4 + 2*MAX_IP
rep stosd
ret
;-----------------------------------------------------------------
;
; IPv4_Handler:
;
; Will check if IP 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 IP Packet data in edx
; OUT: /
;
;-----------------------------------------------------------------
align 4
IPv4_handler: ; TODO: implement handler for IP options
; TODO2: add code for raw sockets
DEBUGF 1,"IPv4_Handler, packet from: %u.%u.%u.%u ",\
[edx + IPv4_Packet.SourceAddress]:1,[edx + IPv4_Packet.SourceAddress + 1]:1,[edx + IPv4_Packet.SourceAddress + 2]:1,[edx + IPv4_Packet.SourceAddress + 3]:1
DEBUGF 1,"to: %u.%u.%u.%u\n",\
[edx + IPv4_Packet.DestinationAddress]:1,[edx + IPv4_Packet.DestinationAddress + 1]:1,[edx + IPv4_Packet.DestinationAddress + 2]:1,[edx + IPv4_Packet.DestinationAddress + 3]:1
;-------------------------------------------
; Check if the packet still has time to live
cmp byte [edx + IPv4_Packet.TimeToLive], 0
je .dump
;--------------------------------------
; First, check if IP packet has options
movzx eax, [edx + IPv4_Packet.VersionAndIHL]
and al , 0x0f ; get IHL(header length)
cmp al , 0x05 ; IHL!= 5*4(20 bytes)
jnz .has_options
;-------------------------------
; Now, re-calculate the checksum
push edx ebx
mov esi, edx
call IPv4_checksum
pop ebx edx
cmp [edx + IPv4_Packet.HeaderChecksum], 0
jne .dump ; if checksum isn't valid then dump packet
DEBUGF 1,"IPv4 Checksum is correct\n"
;-----------------------------------
; Check if destination IP is correct
call NET_ptr_to_num
shl edi, 2
; check if it matches local ip
mov eax, dword[IP_LIST+edi]
cmp [edx + IPv4_Packet.DestinationAddress], eax
je .ip_ok
; check for broadcast
mov eax, dword[SUBNET_LIST+edi]
not eax
or eax, dword[IP_LIST+edi]
cmp [edx + IPv4_Packet.DestinationAddress], eax
je .ip_ok
; or a special broadcast
cmp [edx + IPv4_Packet.DestinationAddress], -1
je .ip_ok
; maybe it's a multicast then
mov eax, [edx + IPv4_Packet.DestinationAddress]
and eax, 0xff000000
; cmp eax, 224 shl 24
; je .ip_ok
; or a loopback address
cmp eax, 127 shl 24
je .ip_ok
; or it's not meant for us..
DEBUGF 2,"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_Packet.FlagsAndFragmentOffset], 1 shl 5 ; Is 'more fragments' flag set ?
jnz .has_fragments ; If so, we definately have a fragmented packet
test [edx + IPv4_Packet.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 eax, byte [edx + IPv4_Packet.VersionAndIHL] ; Calculate Header length by using IHL field
and eax, 0x0000000f ;
shl eax, 2 ;
movzx ecx, word [edx + IPv4_Packet.TotalLength] ; Calculate length of encapsulated Packet
xchg cl , ch ;
sub ecx, eax ;
add eax, edx
push eax
mov esi, [edx + IPv4_Packet.SourceAddress] ; These values might be of interest to the higher protocols
mov edi, [edx + IPv4_Packet.DestinationAddress] ;
mov al , [edx + IPv4_Packet.Protocol]
pop edx ; Offset to data (tcp/udp/icmp/.. Packet)
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,"unknown Internet protocol: %u\n", al
.dump:
DEBUGF 2,"IP_Handler - dumping\n"
; inc [dumped_rx_count]
call kernel_free
add esp, 4 ; pop (balance stack)
ret
;---------------------------
; Fragmented packet handler
.has_fragments:
movzx eax, [edx + IPv4_Packet.FlagsAndFragmentOffset]
xchg al , ah
shl ax , 3
DEBUGF 1,"Fragmented packet, offset:%u, id:%x\n", ax, [edx + IPv4_Packet.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,"Middle fragmented packet received!\n"
call IPv4_find_fragment_slot
cmp esi, -1
je .dump
mov word [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,"First fragmented 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, FRAGMENT_slot.size
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 word [esi + FRAGMENT_slot.ttl], 15 ; RFC recommends 15 secs as ttl
mov ax , word [edx + IPv4_Packet.Identification]
mov word [esi + FRAGMENT_slot.id], ax
mov eax, dword [edx + IPv4_Packet.SourceAddress]
mov dword [esi + FRAGMENT_slot.SrcIP], eax
mov eax, dword [edx + IPv4_Packet.DestinationAddress]
mov dword [esi + FRAGMENT_slot.DstIP], eax
pop eax
mov dword [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,"Last fragmented 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, word [esi + FRAGMENT_entry.Data + IPv4_Packet.TotalLength] ; Add total length
xchg cl, ch
DEBUGF 1,"Packet size: %u\n", cx
add ax, cx
movzx cx, byte [esi + FRAGMENT_entry.Data + IPv4_Packet.VersionAndIHL] ; Sub Header length
and cx, 0x000F
shl cx, 2
DEBUGF 1,"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_Packet.TotalLength] ; Note: This time we dont substract Header length
xchg cl , ch
DEBUGF 1,"Packet size: %u\n", cx
add ax , cx
DEBUGF 1,"Total Received data size: %u\n", eax
push eax
mov ax , [edx + IPv4_Packet.FlagsAndFragmentOffset]
xchg al , ah
shl ax , 3
add cx , ax
pop eax
DEBUGF 1,"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, word [edx + FRAGMENT_entry.Data + IPv4_Packet.FlagsAndFragmentOffset] ; Calculate the fragment offset
xchg cl , ch ; intel byte order
shl cx , 3 ; multiply by 8 and clear first 3 bits
DEBUGF 1,"Fragment offset: %u\n", cx
lea edi, [eax + ecx] ; Notice that edi will be equal to eax for first fragment
movzx ebx, byte [edx + FRAGMENT_entry.Data + IPv4_Packet.VersionAndIHL] ; Find header size (in ebx) of fragment
and bx , 0x000F ;
shl bx , 2 ;
lea esi, [edx + FRAGMENT_entry.Data] ; Set esi to the correct begin of fragment
movzx ecx, word [edx + FRAGMENT_entry.Data + IPv4_Packet.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 word [edx + IPv4_Packet.TotalLength], cx
add esp, 8
xchg cl, ch ;
push ecx ;;;;
push eax ;;;;
; mov esi, edx ; This prints the IP packet to the debug board (usefull when using serial output debug..)
; ;
; @@: ;
; lodsb ;
; DEBUGF 1,"%x ", eax:2 ;
; loop @r ;
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,"Destroy fragment slot!\n"
; TODO!
jmp .dump
;-----------------------------------
; The IP packet has some options
.has_options:
jmp .dump
;-----------------------------------------------------------------
;
; find fragment slot
;
; IN: pointer to fragmented packet in edx
; OUT: pointer to slot in edi, -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 , word [edx + IPv4_Packet.Identification]
mov ecx, MAX_FRAGMENTS
mov esi, FRAGMENT_LIST
mov ebx, dword [edx + IPv4_Packet.SourceAddress]
mov edx, dword [edx + IPv4_Packet.DestinationAddress]
.find_slot:
cmp word [esi + FRAGMENT_slot.id], ax
jne .try_next
cmp dword [esi + FRAGMENT_slot.SrcIP], ebx
jne .try_next
cmp dword [esi + FRAGMENT_slot.DstIP], edx
je .found_slot
.try_next:
add esi, FRAGMENT_slot.size
loop .find_slot
; pop edx ebx
or esi, -1
; ret
.found_slot:
pop edx ecx ebx eax
ret
;-----------------------------------------------------------------
;
; Decrease TimeToLive of all fragment slots
;
; IN: /
; OUT: /
;
;-----------------------------------------------------------------
align 4
IPv4_decrease_fragment_ttls:
mov esi, FRAGMENT_LIST
mov ecx, MAX_FRAGMENTS
.loop:
cmp [esi + FRAGMENT_slot.ttl], 0
je .try_next
dec [esi + FRAGMENT_slot.ttl]
jnz .try_next
DEBUGF 1,"Fragment slot timed-out!\n"
;;; TODO: clear all entry's of timed-out slot
.try_next:
add esi, 4
loop .loop
ret
;------------------------------------------------------------------
;
;
; IN: dword [esp] = pointer to packet to be fragmented
; dword [esp+4] = buffer size
; edx = pointer to IPv4 header in that packet
; ecx = data length
; ebx = device structure
;
; OUT: /
;
;------------------------------------------------------------------
align 4
IPv4_fragment:
;;; TODO: write code here
call kernel_free
add esp, 4
ret
;------------------------------------------------------------------
;
; Create_IPv4_Packet
;
; IN: eax = dest ip
; ebx = source ip
; ecx = data length
; dx = fragment id ;;;;
; di = 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_create_packet:
DEBUGF 1,"Create IPv4 Packet (size=%u)\n", ecx
cmp ecx, 65500 ; Max IPv4 packet size
jg .exit_
test ebx, ebx ; if source ip = 0
jnz .ip_ok ; and local ip is valid
; use local ip instead
cmp [IP_LIST],0xffffffff ;
je .ip_ok ; TODO: find solution to send broadcast
; on device other then device 0
mov ebx, [IP_LIST] ;
;
.ip_ok: ;
push ecx eax ebx dx di
cmp eax, -1
je .broadcast ; If it is broadcast, just send
call ARP_IP_to_MAC
cmp eax, -1
je .not_found
push ebx
push ax
jmp .send
.broadcast:
push word -1
push dword -1
.send:
call IPv4_dest_to_dev
inc [IP_PACKETS_TX+4*edi]
mov edx, [NET_DRV_LIST + 4*edi]
lea eax, [edx + ETH_DEVICE.mac]
mov ebx, esp
mov ecx, [esp+18] ;; 18 or 22 ??
add ecx, IPv4_Packet.DataOrOptional
mov di , ETHER_IPv4
;;; TODO: detect if packet is too large for ethernet, if so, call IPv4_fragment
call ETH_create_packet ;;; TODO: figure out a way to make this work with other protocols too
add esp, 6
test edi, edi
jz .exit
mov [edi + IPv4_Packet.VersionAndIHL], 0x45 ; IPv4, normal length (no Optional header)
mov [edi + IPv4_Packet.TypeOfService], 0
xchg ch, cl
mov [edi + IPv4_Packet.TotalLength], cx
mov [edi + IPv4_Packet.FlagsAndFragmentOffset], 0x0000
mov [edi + IPv4_Packet.TimeToLive], 128
mov [edi + IPv4_Packet.HeaderChecksum], 0
pop cx
mov [edi + IPv4_Packet.Protocol], cl
pop cx
mov [edi + IPv4_Packet.Identification], cx
pop ecx
mov [edi + IPv4_Packet.SourceAddress], ecx
pop ecx
mov [edi + IPv4_Packet.DestinationAddress], ecx
push eax edx esi
mov esi, edi
call IPv4_checksum
pop esi edx eax ecx
add edi, IPv4_Packet.DataOrOptional
DEBUGF 1,"IPv4 Packet for device %x created successfully\n", ebx
ret
.not_found:
DEBUGF 1,"Create IPv4 Packet - ARP entry not found!\n"
;;;;;;
.exit:
add esp, 16
.exit_:
DEBUGF 1,"Create IPv4 Packet - failed\n"
and edi, 0
ret
align 4
IPv4_checksum:
; This is the fast procedure to create or check a 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
xor edx, edx
add dl, [esi+1]
adc dh, [esi+0]
adc dl, [esi+3]
adc dh, [esi+2]
adc dl, [esi+5]
adc dh, [esi+4]
adc dl, [esi+7]
adc dh, [esi+6]
adc dl, [esi+9]
adc dh, [esi+8]
; we skip 11th and 12th byte, they are the checksum bytes and should be 0 for re-calculation
adc dl, [esi+13]
adc dh, [esi+12]
adc dl, [esi+15]
adc dh, [esi+14]
adc dl, [esi+17]
adc dh, [esi+16]
adc dl, [esi+19]
adc dh, [esi+18]
adc edx, 0
call checksum_2
neg word [esi+10] ; zero will stay zero so we just get the checksum
add word [esi+10], dx ; , else we will get (new checksum - old checksum) in the end, wich should be 0 :)
ret
;---------------------------------------------------------------------------
;
; IPv4_dest_to_dev
;
; IN: Destination IP in eax
; OUT: device id in edi
;
;---------------------------------------------------------------------------
align 4
IPv4_dest_to_dev:
DEBUGF 1,"IPv4 destination to device: "
xor edi, edi
mov ecx, MAX_IP
.loop:
mov ebx, [IP_LIST+edi] ; we dont need to worry about non exisiting ip interfaces
and ebx, [SUBNET_LIST+edi] ; they have IP and SUBNET set to all one's, so they will have no match except 255.255.255.255
; (only a moron would insert that ip into this function..)
mov edx, eax
and edx, [SUBNET_LIST+edi]
cmp ebx, edx
je .found_it
add edi, 4
loop .loop
xor edi, edi ; if none found, use device 0 as default device
.found_it:
shr edi, 2
DEBUGF 1,"%u\n",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
test bl, bl
jz .packets_tx ; 0
dec bl
jz .packets_rx ; 1
dec bl
jz .read_ip ; 2
dec bl
jz .write_ip ; 3
dec bl
jz .read_dns ; 4
dec bl
jz .write_dns ; 5
dec bl
jz .read_subnet ; 6
dec bl
jz .write_subnet ; 7
dec bl
jz .read_gateway ; 8
dec bl
jz .write_gateway ; 9
.error:
mov eax, -1
ret
.packets_tx:
add eax, IP_PACKETS_TX
mov eax, [eax]
ret
.packets_rx:
add eax, IP_PACKETS_RX
mov eax, [eax]
ret
.read_ip:
add eax, IP_LIST
mov eax, [eax]
ret
.write_ip:
add eax, IP_LIST
mov [eax], ecx
xor eax, eax
ret
.read_dns:
add eax, DNS_LIST
mov eax, [eax]
ret
.write_dns:
add eax, DNS_LIST
mov [eax], ecx
xor eax, eax
ret
.read_subnet:
add eax, SUBNET_LIST
mov eax, [eax]
ret
.write_subnet:
add eax, SUBNET_LIST
mov [eax], ecx
xor eax, eax
ret
.read_gateway:
add eax, GATEWAY_LIST
mov eax, [eax]
ret
.write_gateway:
add eax, GATEWAY_LIST
mov [eax], ecx
xor eax, eax
ret