/* LUFA Library Copyright (C) Dean Camera, 2009. dean [at] fourwalledcubicle [dot] com www.fourwalledcubicle.com */ /* Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com) Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that the copyright notice and this permission notice and warranty disclaimer appear in supporting documentation, and that the name of the author not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. The author disclaim all warranties with regard to this software, including all implied warranties of merchantability and fitness. In no event shall the author be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of this software. */ /** \file * * Internet Control Message Protocol (ICMP) packet handling routines. This protocol handles * Echo requests from the host, to indicate a successful network connection between the host * and the virtual server. */ #include "ICMP.h" /** Processes an ICMP packet inside an Ethernet frame, and writes the appropriate response * to the output Ethernet frame if the host is issuing a ICMP ECHO request. * * \param InDataStart Pointer to the start of the incomming packet's ICMP header * \param OutDataStart Pointer to the start of the outgoing packet's ICMP header * * \return The number of bytes written to the out Ethernet frame if any, NO_RESPONSE otherwise */ int16_t ICMP_ProcessICMPPacket(void* InDataStart, void* OutDataStart) { ICMP_Header_t* ICMPHeaderIN = (ICMP_Header_t*)InDataStart; ICMP_Header_t* ICMPHeaderOUT = (ICMP_Header_t*)OutDataStart; DecodeICMPHeader(InDataStart); /* Determine if the ICMP packet is an echo request (ping) */ if (ICMPHeaderIN->Type == ICMP_TYPE_ECHOREQUEST) { /* Fill out the ICMP response packet */ ICMPHeaderOUT->Type = ICMP_TYPE_ECHOREPLY; ICMPHeaderOUT->Code = 0; ICMPHeaderOUT->Checksum = 0; ICMPHeaderOUT->Id = ICMPHeaderIN->Id; ICMPHeaderOUT->Sequence = ICMPHeaderIN->Sequence; uint16_t DataSize = FrameIN.FrameLength - ((((uint16_t)InDataStart + sizeof(ICMP_Header_t)) - (uint16_t)FrameIN.FrameData)); /* Copy the remaining payload to the response - echo requests should echo back any sent data */ memcpy(&((uint8_t*)OutDataStart)[sizeof(ICMP_Header_t)], &((uint8_t*)InDataStart)[sizeof(ICMP_Header_t)], DataSize); ICMPHeaderOUT->Checksum = Ethernet_Checksum16(ICMPHeaderOUT, (DataSize + sizeof(ICMP_Header_t))); /* Return the size of the response so far */ return (DataSize + sizeof(ICMP_Header_t)); } return NO_RESPONSE; }