+++ /dev/null
-/*
- LUFA Library
- Copyright (C) Dean Camera, 2021.
-
- dean [at] fourwalledcubicle [dot] com
- www.lufa-lib.org
-*/
-
-/*
- Copyright 2021 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;
-}
-
projects / pub / lufa.git / blobdiff