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ICMP checksum validation + cleanup of echo reply code

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git-svn-id: svn://kolibrios.org@1544 a494cfbc-eb01-0410-851d-a64ba20cac60
This commit is contained in:
hidnplayr 2010-08-01 14:47:24 +00:00
parent 5b0ea56111
commit 714722b812
1 changed files with 58 additions and 42 deletions
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100
kernel/branches/net/network/icmp.inc
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@ -119,8 +119,6 @@ macro ICMP_init {
rep stosd rep stosd
} }
;----------------------------------------------------------------- ;-----------------------------------------------------------------
@ -143,17 +141,32 @@ macro ICMP_init {
align 4 align 4
ICMP_input: ICMP_input:
;;; TODO: check checksum!
DEBUGF 1,"ICMP_input - start\n" DEBUGF 1,"ICMP_input - start\n"
; First, check the checksum (altough some implementations ignore it)
push edx esi ecx
push [edx + ICMP_Packet.Checksum]
mov [edx + ICMP_Packet.Checksum], 0
mov esi, edx
xor edx, edx
call checksum_1
call checksum_2
pop si
cmp dx, si
pop ecx esi edx
jne .checksum_mismatch
cmp byte [edx + ICMP_Packet.Type], ICMP_ECHO ; Is this an echo request? cmp byte [edx + ICMP_Packet.Type], ICMP_ECHO ; Is this an echo request?
jne .check_sockets jne .check_sockets
; We well re-use the packet sow e can create the response as fast as possible
; Notice: this only works on pure ethernet (however, IP packet options are not a problem this time :)
DEBUGF 1,"ICMP_input - echo request\n" DEBUGF 1,"ICMP_input - echo request\n"
mov byte [edx + ICMP_Packet.Type], ICMP_ECHOREPLY ; Change Packet type to reply mov byte [edx + ICMP_Packet.Type], ICMP_ECHOREPLY ; Change Packet type to reply
mov word [edx + ICMP_Packet.Checksum], 0 ; Set checksum to 0, needed to calculate new checksum
; Update stats (and validate device ptr)
call NET_ptr_to_num call NET_ptr_to_num
cmp edi,-1 cmp edi,-1
je .dump je .dump
@ -162,48 +175,48 @@ ICMP_input:
; exchange dest and source address in IP header ; exchange dest and source address in IP header
; exchange dest and source MAC in ETH header ; exchange dest and source MAC in ETH header
mov esi, [esp] mov esi, [esp] ; Start of buffer
push dword [esi + ETH_FRAME.DstMAC]
push dword [esi + ETH_FRAME.SrcMAC]
pop dword [esi + ETH_FRAME.DstMAC]
pop dword [esi + ETH_FRAME.SrcMAC]
push word [esi + ETH_FRAME.DstMAC + 4]
push word [esi + ETH_FRAME.SrcMAC + 4]
pop word [esi + ETH_FRAME.DstMAC + 4]
pop word [esi + ETH_FRAME.SrcMAC + 4]
mov eax, dword [esi + ETH_FRAME.DstMAC] add esi, ETH_FRAME.Data
mov ecx, dword [esi + ETH_FRAME.SrcMAC] push [esi + IPv4_Packet.SourceAddress]
mov dword [esi + ETH_FRAME.SrcMAC], eax push [esi + IPv4_Packet.DestinationAddress]
mov dword [esi + ETH_FRAME.DstMAC], ecx pop [esi + IPv4_Packet.SourceAddress]
pop [esi + IPv4_Packet.DestinationAddress]
mov ax, word [esi + ETH_FRAME.DstMAC + 4]
mov cx, word [esi + ETH_FRAME.SrcMAC + 4]
mov word [esi + ETH_FRAME.SrcMAC + 4], ax
mov word [esi + ETH_FRAME.DstMAC + 4], cx
mov eax, dword [esi + ETH_FRAME.Data + IPv4_Packet.SourceAddress]
mov ecx, dword [esi + ETH_FRAME.Data + IPv4_Packet.DestinationAddress]
mov dword [esi + ETH_FRAME.Data + IPv4_Packet.DestinationAddress], eax
mov dword [esi + ETH_FRAME.Data + IPv4_Packet.SourceAddress], ecx
; Recalculate ip header checksum ; Recalculate ip header checksum
add esi, ETH_FRAME.Data ; Point esi to start of IP Packet
movzx ecx, byte [esi + IPv4_Packet.VersionAndIHL] ; Calculate IP Header length by using IHL field movzx ecx, byte [esi + IPv4_Packet.VersionAndIHL] ; Calculate IP Header length by using IHL field
and ecx, 0x0000000F ; and ecx, 0x0f
shl cx , 2 shl cx, 2
push ebx edx ecx esi mov edi, ecx ; IP header length
xor edx, edx mov eax, edx ; ICMP packet start addr
call checksum_1
call checksum_2 push esi ; Calculate the IP checksum
pop esi xor edx, edx ;
mov word [esi + IPv4_Packet.HeaderChecksum], dx ; Store it in the IP Packet header call checksum_1 ;
call checksum_2 ;
pop esi ;
mov word [esi + IPv4_Packet.HeaderChecksum], dx ;
; Recalculate ICMP CheckSum ; Recalculate ICMP CheckSum
movzx eax, word[esi + IPv4_Packet.TotalLength] ; Find length of IP Packet movzx ecx, word[esi + IPv4_Packet.TotalLength] ; Find length of IP Packet
xchg ah , al ; xchg ch, cl ;
sub eax, [esp] ; Now we know the length of ICMP data in eax sub ecx, edi ; IP packet length - IP header length = ICMP packet length
mov ecx, eax
mov esi, [esp + 4]
xor edx, edx
call checksum_1
call checksum_2
mov ax , dx
pop ecx edx ebx
mov word [edx + ICMP_Packet.Checksum], ax
mov esi, eax ; Calculate ICMP checksum
xor edx, edx ;
call checksum_1 ;
call checksum_2 ;
mov word [eax + ICMP_Packet.Checksum], dx ;
; Transmit the packet (notice that packet ptr and packet size have been on stack since start of the procedure!)
call [ebx + NET_DEVICE.transmit] call [ebx + NET_DEVICE.transmit]
ret ret
@ -249,7 +262,10 @@ ICMP_input:
jmp SOCKET_input jmp SOCKET_input
.dump: .checksum_mismatch:
DEBUGF 1,"ICMP_Handler - checksum mismatch\n"
.dump:
DEBUGF 1,"ICMP_Handler - dumping\n" DEBUGF 1,"ICMP_Handler - dumping\n"
call kernel_free call kernel_free