;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; ICMP.INC
;;
;; Internet Control Message Protocol ( RFC 792 )
;;
;; Last revision: 11.11.2006
;;
;; This file contains the following:
;; icmp_rx - processes ICMP-packets received by the IP layer
;;
;; Changes history:
;; 22.09.2003 - [Mike Hibbett] : mikeh@oceanfree.net
;; 11.11.2006 - [Johnny_B] and [smb]
;;
;; Current status:
;; This implemetation of ICMP proto supports message of ECHO type.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
struc ICMP_PACKET
{ .Type db ? ;+00
.Code db ? ;+01
.Checksum dw ? ;+02
.Identifier dw ? ;+04
.SequenceNumber dw ? ;+06
.Data db ? ;+08
}
virtual at 0
ICMP_PACKET ICMP_PACKET
end virtual
; Example:
; ECHO message format
;
;
; 0 1 2 3
; 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
; +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
; | Type | Code | Checksum |
; +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
; | Identifier | Sequence Number |
; +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
; | Data ...
; +-+-+-+-+-
;
;
; ICMP types & codes, RFC 792 and FreeBSD's ICMP sources
;
ICMP_ECHOREPLY equ 0 ; echo reply message
ICMP_UNREACH equ 3
ICMP_UNREACH_NET equ 0 ; bad net
ICMP_UNREACH_HOST equ 1 ; bad host
ICMP_UNREACH_PROTOCOL equ 2 ; bad protocol
ICMP_UNREACH_PORT equ 3 ; bad port
ICMP_UNREACH_NEEDFRAG equ 4 ; IP_DF caused drop
ICMP_UNREACH_SRCFAIL equ 5 ; src route failed
ICMP_UNREACH_NET_UNKNOWN equ 6 ; unknown net
ICMP_UNREACH_HOST_UNKNOWN equ 7 ; unknown host
ICMP_UNREACH_ISOLATED equ 8 ; src host isolated
ICMP_UNREACH_NET_PROHIB equ 9 ; prohibited access
ICMP_UNREACH_HOST_PROHIB equ 10 ; ditto
ICMP_UNREACH_TOSNET equ 11 ; bad tos for net
ICMP_UNREACH_TOSHOST equ 12 ; bad tos for host
ICMP_UNREACH_FILTER_PROHIB equ 13 ; admin prohib
ICMP_UNREACH_HOST_PRECEDENCE equ 14 ; host prec vio.
ICMP_UNREACH_PRECEDENCE_CUTOFF equ 15 ; prec cutoff
ICMP_SOURCEQUENCH equ 4 ; packet lost, slow down
ICMP_REDIRECT equ 5 ; shorter route, codes:
ICMP_REDIRECT_NET equ 0 ; for network
ICMP_REDIRECT_HOST equ 1 ; for host
ICMP_REDIRECT_TOSNET equ 2 ; for tos and net
ICMP_REDIRECT_TOSHOST equ 3 ; for tos and host
ICMP_ALTHOSTADDR equ 6 ; alternate host address
ICMP_ECHO equ 8 ; echo service
ICMP_ROUTERADVERT equ 9 ; router advertisement
ICMP_ROUTERADVERT_NORMAL equ 0 ; normal advertisement
ICMP_ROUTERADVERT_NOROUTE_COMMON equ 16 ; selective routing
ICMP_ROUTERSOLICIT equ 10 ; router solicitation
ICMP_TIMXCEED equ 11 ; time exceeded, code:
ICMP_TIMXCEED_INTRANS equ 0 ; ttl==0 in transit
ICMP_TIMXCEED_REASS equ 1 ; ttl==0 in reass
ICMP_PARAMPROB equ 12 ; ip header bad
ICMP_PARAMPROB_ERRATPTR equ 0 ; error at param ptr
ICMP_PARAMPROB_OPTABSENT equ 1 ; req. opt. absent
ICMP_PARAMPROB_LENGTH equ 2 ; bad length
ICMP_TSTAMP equ 13 ; timestamp request
ICMP_TSTAMPREPLY equ 14 ; timestamp reply
ICMP_IREQ equ 15 ; information request
ICMP_IREQREPLY equ 16 ; information reply
ICMP_MASKREQ equ 17 ; address mask request
ICMP_MASKREPLY equ 18 ; address mask reply
ICMP_TRACEROUTE equ 30 ; traceroute
ICMP_DATACONVERR equ 31 ; data conversion error
ICMP_MOBILE_REDIRECT equ 32 ; mobile host redirect
ICMP_IPV6_WHEREAREYOU equ 33 ; IPv6 where-are-you
ICMP_IPV6_IAMHERE equ 34 ; IPv6 i-am-here
ICMP_MOBILE_REGREQUEST equ 35 ; mobile registration req
ICMP_MOBILE_REGREPLY equ 36 ; mobile registreation reply
ICMP_SKIP equ 39 ; SKIP
ICMP_PHOTURIS equ 40 ; Photuris
ICMP_PHOTURIS_UNKNOWN_INDEX equ 1 ; unknown sec index
ICMP_PHOTURIS_AUTH_FAILED equ 2 ; auth failed
ICMP_PHOTURIS_DECRYPT_FAILED equ 3 ; decrypt failed
;***************************************************************************
; Function
; icmp_rx [by Johnny_B]
;
; Description
; ICMP protocol handler
; This is a kernel function, called by ip_rx
;
; IN:
; buffer_number - # of IP-buffer. This buffer must be reused or marked as empty afterwards
; IPPacketBase - IP_PACKET base address
; IPHeaderLength - Header length of IP_PACKET
;
; OUT:
; EAX=not defined
;
; All used registers will be saved
;
;***************************************************************************
proc icmp_rx stdcall uses ebx esi edi,\
buffer_number:DWORD,IPPacketBase:DWORD,IPHeaderLength:DWORD
mov esi,[IPPacketBase] ;esi=IP_PACKET base address
mov edi, esi
add edi,[IPHeaderLength] ;edi=ICMP_PACKET base address
cmp byte[edi + ICMP_PACKET.Type], ICMP_ECHO ; Is this an echo request? discard if not
jz .icmp_echo
mov eax, [buffer_number]
call freeBuff
jmp .exit
.icmp_echo:
; swap the source and destination addresses
mov ecx, [esi + IP_PACKET.DestinationAddress]
mov ebx, [esi + IP_PACKET.SourceAddress]
mov [esi + IP_PACKET.DestinationAddress], ebx
mov [esi + IP_PACKET.SourceAddress], ecx
; recalculate the IP header checksum
mov eax,[IPHeaderLength]
stdcall checksum_jb,esi,eax ;buf_ptr,buf_size
mov byte[esi + IP_PACKET.HeaderChecksum], ah
mov byte[esi + IP_PACKET.HeaderChecksum + 1], al ; ?? correct byte order?
mov byte[edi + ICMP_PACKET.Type], ICMP_ECHOREPLY ; change the request to a response
mov word[edi + ICMP_PACKET.Checksum], 0 ; clear ICMP checksum prior to re-calc
; Calculate the length of the ICMP data ( IP payload)
xor eax, eax
mov ah, byte[esi + IP_PACKET.TotalLength]
mov al, byte[esi + IP_PACKET.TotalLength + 1]
sub ax, word[IPHeaderLength] ;ax=ICMP-packet length
stdcall checksum_jb,edi,eax ;buf_ptr,buf_size
mov byte[edi + ICMP_PACKET.Checksum], ah
mov byte[edi + ICMP_PACKET.Checksum + 1], al
; Queue packet for transmission
mov ebx, [buffer_number]
mov eax, NET1OUT_QUEUE
call queue
.exit:
ret
endp