WebSVN – Kolibri OS – Diff – /kernel/branches/net/network/IPv4.inc

 ;;          GNU GENERAL PUBLIC LICENSE                             ;;
 ;;             Version 2, June 1991                                ;;
 ;;                                                                 ;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-$Revision: 1257 $
+$Revision: 1473 $
 ;       pointer to IP Packet data in edx
 ;  OUT: /
+;
 ;-----------------------------------------------------------------
 align 4
-IPv4_handler:	 ; TODO: clean up this mess
+IPv4_handler:	 ; TODO: implement handler for IP options
-		 ; for instance, there should be only one piece of code wich make the jump to an underlying protocol, and not two..
 		 ; TODO2: add code for IPv4 sockets (raw sockets)
-	DEBUGF	1,"IP_Handler - start\n"
+	DEBUGF	1,"IP_Handler - start\n"
-	push	edx ebx
+;-------------------------------------------
+; 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
 	; save checksum, and clear it in original packet
-	mov	di , [edx + IPv4_Packet.HeaderChecksum]
-	mov	word [edx + IPv4_Packet.HeaderChecksum], 0
+;-------------------------------
-	; Re-calculate checksum
+; Now, re-calcualte the checksum
-	movzx	ecx, byte [edx + IPv4_Packet.VersionAndIHL]	; Calculate Header length by using IHL field
-	and	ecx, 0x0000000F  ;
-	shl	cx , 2		 ;
-	mov	esi, edx
-	xor	edx, edx
-	call	checksum_1
-	call	checksum_2
+	; Re-calculate checksum
+	push	edx ebx
+	mov	esi, edx
+	call	checksum_ip_header
 	pop	ebx edx
-	; now compare the two..
+	; now see if it was correct
+	cmp	[edx + IPv4_Packet.HeaderChecksum], 0
+	jne	.dump						; if checksum isn't valid then dump packet
+	DEBUGF	1,"IPv4 Checksum is correct\n"
 	cmp	dx, di
-	pop	ebx edx
+;-------------------------------------------------------
-	jne	.dump						; if checksum isn't valid then dump packet
+; Time to find out what interface this packet belongs to
+; Therefore we will scan the current list of IP's
-	DEBUGF	1,"IPv4 Checksum is correct\n",di
+	mov	eax, [edx + IPv4_Packet.DestinationAddress]
+	mov	edi, BROADCAST
+	mov	ecx, MAX_IP+1
+  .find_ip_loop:
 	cmp	eax, dword [edi]
-	mov	eax, [edx + IPv4_Packet.DestinationAddress]
+	jz	.ip_ok
-	mov	edi, BROADCAST
+	add	edi, 4
-	mov	ecx, MAX_IP+1
+	dec	ecx
+	jnz	.find_ip_loop
-	repnz	scasd
+	; it was not on the list, perhaps it's a loopback ?
+	not	eax
+	test	eax, 127 shl 24 ; 127.x.x.x
+	jz	.ip_ok
-	jz	.ip_ok
+	;  TODO: we need to check for broadcasts (other then 255.255.255.255)
-	not	eax
+	DEBUGF	2,"Destination address does not match!\n"
-	test	eax, 127 shl 24 ; 127.x.x.x
-	jz	.ip_ok
+	jmp	.dump
-;  TODO: we need to check for broadcasts (other then 255.255.255.255)
-	jmp	.dump
-  .ip_ok:
-	call	ETH_struc2dev					; TODO: make this work on other protocols too!
-	inc	[IP_PACKETS_RX+4*edi]
+;---------------------------------------------------
-	DEBUGF	1,"packet comes from %u.%u.%u.%u\n",\
+; Now we can update stats and find the device number
-	[edx + IPv4_Packet.SourceAddress]:1,[edx + IPv4_Packet.SourceAddress + 1]:1,[edx + IPv4_Packet.SourceAddress + 2]:1,[edx + IPv4_Packet.SourceAddress + 3]:1
+  .ip_ok:
+	call	ETH_struc2dev					; TODO: make this work on other protocols too!
+	inc	[IP_PACKETS_RX+4*edi]
+	DEBUGF	1,"Packet comes from %u.%u.%u.%u\n",\
+	[edx + IPv4_Packet.SourceAddress]:1,[edx + IPv4_Packet.SourceAddress + 1]:1,[edx + IPv4_Packet.SourceAddress + 2]:1,[edx + IPv4_Packet.SourceAddress + 3]:1
-	mov	al , [edx + IPv4_Packet.VersionAndIHL]
 	and	al , 0x0f					; get IHL(header length)
 	cmp	al , 0x05					; IHL!= 5*4(20 bytes)
-	jnz	.dump						; TODO: dont dump packets wich have optional fiels !!!                   /!\
+;----------------------------------
 ; Check if the packet is fragmented
-	cmp	byte [edx + IPv4_Packet.TimeToLive], 0
 	je	.dump
 	test	[edx + IPv4_Packet.FlagsAndFragmentOffset], 1 shl 5	; Is 'more fragments' flag set ?
-	movzx	eax, word [edx + IPv4_Packet.FlagsAndFragmentOffset]
+	jnz	.has_fragments						; If so, we definately have a fragmented packet
 	xchg	al , ah
 	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
 	test	ax , 1 shl 13					; Is 'more fragments' flag set ?
-	jnz	.yes_fragments					; If so, we definately have a fragmented packet
-	test	ax , 0x1fff					; If flag is not set, but there is a fragment offset, the packet is last in series of fragmented packets
+;-------------------------------------------------------------------
-	jnz	.last_fragment
+; No, it's just a regular IP packet, pass it to the higher protocols
 	je	UDP_handler
 	cmp	al , IP_PROTO_ICMP
 	je	ICMP_handler
-	DEBUGF	1,"unknown protocol: %u\n",al
+	DEBUGF	2,"unknown Internet protocol: %u\n", al
   .dump:
-	DEBUGF	1,"IP_Handler - done\n"
+	DEBUGF	2,"IP_Handler - dumping\n"
 ;        inc     [dumped_rx_count]
+	call	kernel_free
+	add	esp, 4						; pop (balance stack)
+	ret
-	call	kernel_free
+;---------------------------
+; Fragmented packet handler
 	add	esp, 4						; pop (balance stack)
-	ret
+  .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
-  .yes_fragments:
+	ret
 	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?
+; We have received the first fragment
 	add	esp, 4						; balance stack and exit
+	ret
-	ret
-  .not_first_fragment:
-	DEBUGF	1,"Middle fragmented packet received!\n"
-	call	.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 noww 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 last fragment
   .is_last_fragment:
-  .last_fragment:
+	DEBUGF	1,"Last fragmented packet received!\n"
 	DEBUGF	1,"Last fragmented packet received!\n"
-	call	.find_fragment_slot
+	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
-	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
-	push	esi
+	xor	eax, eax
-	xor	eax, eax					;
+	or	edi, -1
 	or	edi, -1
 	and	cx, 3										;
 	rep	movsb										;
 	push	eax
+	push	edx										; Push pointer to fragment onto stack
-	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
 	xchg	cl, ch
 	mov	edx, eax
 	mov	word [edx + IPv4_Packet.TotalLength], cx
 	add	esp, 8
+	xchg	cl, ch		    ;
 	xchg	cl, ch		   ;  This prints the IP packet to the debug board (usefull when using serial output debug..)
-	push	ecx  ;;;;
+	push	ecx		   ;;;;
+	push	eax		   ;;;;
-	push	eax	;;;;
-;        mov     esi, edx           ;
+;        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                 ;
-	movzx	eax, byte [edx + IPv4_Packet.VersionAndIHL]	; Calculate Header length by using IHL field
-	and	ax, 0x000F					;
-	shl	ax, 2						;
-	sub	ecx, eax
+	jmp	.handle_it	    ; edx = buf ptr, ecx = size, [esp] buf ptr, [esp+4], total size, ebx=device ptr
+  .destroy_slot_pop:
-	add	eax, edx
+	add	esp, 4
-	push	eax
-	mov	al , [edx + IPv4_Packet.Protocol]
+  .destroy_slot:
-	mov	esi, [edx + IPv4_Packet.SourceAddress]
-	mov	edi, [edx + IPv4_Packet.DestinationAddress]
-	pop	edx						; Offset to data (tcp/udp/icmp/.. Packet)
-	cmp	al , IP_PROTO_TCP
-	je	TCP_handler
+	DEBUGF	1,"Destroy fragment slot!\n"
+	; TODO!
-	cmp	al , IP_PROTO_UDP
+	jmp	.dump
-	je	UDP_handler
-	cmp	al , IP_PROTO_ICMP
-	je	ICMP_handler_fragments
-	DEBUGF	1,"IP_Handler - unknown protocol:%u\n",al
-	call	kernel_free
 	add	esp, 8						; pop (balance stack)
+;
 ; IN: pointer to fragmented packet in edx         ; TODO: the RFC says we should check protocol too
 ; OUT: pointer to slot in edi, -1 on error
+;
 ;-----------------------------------------------------------------
+align 4
-  .find_fragment_slot:
+IPv4_find_fragment_slot:
 	push	eax ebx ecx edx
 	mov	ax , word [edx + IPv4_Packet.Identification]
 	mov	ecx, MAX_FRAGMENTS
 	pop	ecx
 	mov	[edi + IPv4_Packet.SourceAddress], ecx
 	pop	ecx
 	mov	[edi + IPv4_Packet.DestinationAddress], ecx
-	push	eax ebx edx
-	; calculate checksum
-	xor	edx, edx
+	push	eax edx esi
-	mov	esi, edi
-	mov	ecx, IPv4_Packet.DataOrOptional
-	call	checksum_1
+	mov	esi, edi
-	call	checksum_2
-	mov	[edi + IPv4_Packet.HeaderChecksum], dx
+	call	checksum_ip_header
-	pop	edx ebx eax ecx
+	pop	esi edx eax ecx
 	add	edi, IPv4_Packet.DataOrOptional

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(root)/kernel/branches/net/network/IPv4.inc @ 1774 – Rev 1257 → 1473