diff options
Diffstat (limited to 'lib/lufa/Demos/Device/LowLevel/RNDISEthernet/Lib/ARP.c')
| -rw-r--r-- | lib/lufa/Demos/Device/LowLevel/RNDISEthernet/Lib/ARP.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/lib/lufa/Demos/Device/LowLevel/RNDISEthernet/Lib/ARP.c b/lib/lufa/Demos/Device/LowLevel/RNDISEthernet/Lib/ARP.c new file mode 100644 index 000000000..24008705c --- /dev/null +++ b/lib/lufa/Demos/Device/LowLevel/RNDISEthernet/Lib/ARP.c @@ -0,0 +1,87 @@ +/* + LUFA Library + Copyright (C) Dean Camera, 2017. + + dean [at] fourwalledcubicle [dot] com + www.lufa-lib.org +*/ + +/* + Copyright 2017 Dean Camera (dean [at] fourwalledcubicle [dot] com) + + Permission to use, copy, modify, distribute, and sell this + software and its documentation for any purpose is hereby granted + without fee, 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 disclaims 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 + * + * Address Resolution Protocol (ARP) packet handling routines. This protocol handles the + * conversion of physical MAC addresses to protocol IP addresses between the host and the + * device. + */ + +#include "ARP.h" + +/** Processes an ARP packet inside an Ethernet frame, and writes the appropriate response + * to the output Ethernet frame if the host is requesting the IP or MAC address of the + * virtual server device on the network. + * + * \param[in] InDataStart Pointer to the start of the incoming packet's ARP header + * \param[out] OutDataStart Pointer to the start of the outgoing packet's ARP header + * + * \return The number of bytes written to the out Ethernet frame if any, NO_RESPONSE otherwise + */ +int16_t ARP_ProcessARPPacket(void* InDataStart, + void* OutDataStart) +{ + DecodeARPHeader(InDataStart); + + ARP_Header_t* ARPHeaderIN = (ARP_Header_t*)InDataStart; + ARP_Header_t* ARPHeaderOUT = (ARP_Header_t*)OutDataStart; + + /* Ensure that the ARP request is a IPv4 request packet */ + if ((SwapEndian_16(ARPHeaderIN->ProtocolType) == ETHERTYPE_IPV4) && + (SwapEndian_16(ARPHeaderIN->Operation) == ARP_OPERATION_REQUEST)) + { + /* If the ARP packet is requesting the MAC or IP of the virtual webserver, return the response */ + if (IP_COMPARE(&ARPHeaderIN->TPA, &ServerIPAddress) || + MAC_COMPARE(&ARPHeaderIN->THA, &ServerMACAddress)) + { + /* Fill out the ARP response header */ + ARPHeaderOUT->HardwareType = ARPHeaderIN->HardwareType; + ARPHeaderOUT->ProtocolType = ARPHeaderIN->ProtocolType; + ARPHeaderOUT->HLEN = ARPHeaderIN->HLEN; + ARPHeaderOUT->PLEN = ARPHeaderIN->PLEN; + ARPHeaderOUT->Operation = SwapEndian_16(ARP_OPERATION_REPLY); + + /* Copy over the sender MAC/IP to the target fields for the response */ + ARPHeaderOUT->THA = ARPHeaderIN->SHA; + ARPHeaderOUT->TPA = ARPHeaderIN->SPA; + + /* Copy over the new sender MAC/IP - MAC and IP addresses of the virtual webserver */ + ARPHeaderOUT->SHA = ServerMACAddress; + ARPHeaderOUT->SPA = ServerIPAddress; + + /* Return the size of the response so far */ + return sizeof(ARP_Header_t); + } + } + + return NO_RESPONSE; +} + |