diff options
Diffstat (limited to 'Demos/Device/ClassDriver/RNDISEthernet/Lib/DHCP.c')
| -rw-r--r-- | Demos/Device/ClassDriver/RNDISEthernet/Lib/DHCP.c | 129 | 
1 files changed, 129 insertions, 0 deletions
| diff --git a/Demos/Device/ClassDriver/RNDISEthernet/Lib/DHCP.c b/Demos/Device/ClassDriver/RNDISEthernet/Lib/DHCP.c new file mode 100644 index 0000000000..7adc648360 --- /dev/null +++ b/Demos/Device/ClassDriver/RNDISEthernet/Lib/DHCP.c @@ -0,0 +1,129 @@ +/* +             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 + * + *  Dynamic Host Configuration Protocol (DHCP) packet handling routines. This protocol + *  handles the automatic IP negotiation to the host, so that the host will use the provided + *  IP address given to it by the device. + */ + +#include "DHCP.h" + +/** Processes a DHCP packet inside an Ethernet frame, and writes the appropriate response + *  to the output Ethernet frame if the host is requesting or accepting an IP address. + * + *  \param[in] IPHeaderInStart     Pointer to the start of the incoming packet's IP header + *  \param[in] DHCPHeaderInStart   Pointer to the start of the incoming packet's DHCP header + *  \param[out] DHCPHeaderOutStart  Pointer to the start of the outgoing packet's DHCP header + * + *  \return The number of bytes written to the out Ethernet frame if any, NO_RESPONSE otherwise + */ +int16_t DHCP_ProcessDHCPPacket(void* IPHeaderInStart, +                               void* DHCPHeaderInStart, +                               void* DHCPHeaderOutStart) +{ +	IP_Header_t*   IPHeaderIN    = (IP_Header_t*)IPHeaderInStart; +	DHCP_Header_t* DHCPHeaderIN  = (DHCP_Header_t*)DHCPHeaderInStart; +	DHCP_Header_t* DHCPHeaderOUT = (DHCP_Header_t*)DHCPHeaderOutStart; + +	uint8_t* DHCPOptionsINStart  = ((uint8_t*)DHCPHeaderInStart  + sizeof(DHCP_Header_t)); +	uint8_t* DHCPOptionsOUTStart = ((uint8_t*)DHCPHeaderOutStart + sizeof(DHCP_Header_t)); + +	DecodeDHCPHeader(DHCPHeaderInStart); + +	/* Zero out the response DHCP packet, as much of it is legacy and left at 0 */ +	memset(DHCPHeaderOUT, 0, sizeof(DHCP_Header_t)); + +	/* Fill out the response DHCP packet */ +	DHCPHeaderOUT->HardwareType          = DHCPHeaderIN->HardwareType; +	DHCPHeaderOUT->Operation             = DHCP_OP_BOOTREPLY; +	DHCPHeaderOUT->HardwareAddressLength = DHCPHeaderIN->HardwareAddressLength; +	DHCPHeaderOUT->Hops                  = 0; +	DHCPHeaderOUT->TransactionID         = DHCPHeaderIN->TransactionID; +	DHCPHeaderOUT->ElapsedSeconds        = 0; +	DHCPHeaderOUT->Flags                 = DHCPHeaderIN->Flags; +	DHCPHeaderOUT->YourIP                = ClientIPAddress; +	memmove(&DHCPHeaderOUT->ClientHardwareAddress, &DHCPHeaderIN->ClientHardwareAddress, sizeof(MAC_Address_t)); +	DHCPHeaderOUT->Cookie                = SwapEndian_32(DHCP_MAGIC_COOKIE); + +	/* Alter the incoming IP packet header so that the corrected IP source and destinations are used - this means that +	   when the response IP header is generated, it will use the corrected addresses and not the null/broatcast addresses */ +	IPHeaderIN->SourceAddress      = ClientIPAddress; +	IPHeaderIN->DestinationAddress = ServerIPAddress; + +	/* Process the incoming DHCP packet options */ +	while (DHCPOptionsINStart[0] != DHCP_OPTION_END) +	{ +		/* Find the Message Type DHCP option, to determine the type of DHCP packet */ +		if (DHCPOptionsINStart[0] == DHCP_OPTION_MESSAGETYPE) +		{ +			if ((DHCPOptionsINStart[2] == DHCP_MESSAGETYPE_DISCOVER) || (DHCPOptionsINStart[2] == DHCP_MESSAGETYPE_REQUEST)) +			{ +				/* Fill out the response DHCP packet options for a DHCP OFFER or ACK response */ + +				*(DHCPOptionsOUTStart++) = DHCP_OPTION_MESSAGETYPE; +				*(DHCPOptionsOUTStart++) = 1; +				*(DHCPOptionsOUTStart++) = (DHCPOptionsINStart[2] == DHCP_MESSAGETYPE_DISCOVER) ? DHCP_MESSAGETYPE_OFFER +																								: DHCP_MESSAGETYPE_ACK; + +				*(DHCPOptionsOUTStart++) = DHCP_OPTION_SUBNETMASK; +				*(DHCPOptionsOUTStart++) = sizeof(IP_Address_t); +				*(DHCPOptionsOUTStart++) = 0xFF; +				*(DHCPOptionsOUTStart++) = 0xFF; +				*(DHCPOptionsOUTStart++) = 0xFF; +				*(DHCPOptionsOUTStart++) = 0x00; + +				*(DHCPOptionsOUTStart++) = DHCP_OPTION_LEASETIME; +				*(DHCPOptionsOUTStart++) = sizeof(uint32_t); +				/* Lease Time 86400s (ONE_DAY) */ +				*(DHCPOptionsOUTStart++) = 0x00; +				*(DHCPOptionsOUTStart++) = 0x01; +				*(DHCPOptionsOUTStart++) = 0x51; +				*(DHCPOptionsOUTStart++) = 0x80; + +				*(DHCPOptionsOUTStart++) = DHCP_OPTION_DHCPSERVER; +				*(DHCPOptionsOUTStart++) = sizeof(IP_Address_t); +				memcpy(DHCPOptionsOUTStart, &ServerIPAddress, sizeof(IP_Address_t)); +				DHCPOptionsOUTStart     += sizeof(IP_Address_t); + +				*(DHCPOptionsOUTStart++) = DHCP_OPTION_END; + +				return (sizeof(DHCP_Header_t) + 18 + sizeof(IP_Address_t)); +			} +		} + +		/* Go to the next DHCP option - skip one byte if option is a padding byte, else skip the complete option's size */ +		DHCPOptionsINStart += ((DHCPOptionsINStart[0] == DHCP_OPTION_PAD) ? 1 : (DHCPOptionsINStart[1] + 2)); +	} + +	return NO_RESPONSE; +} + | 
