104 lines
3.9 KiB
C
104 lines
3.9 KiB
C
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/*
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LUFA Library
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Copyright (C) Dean Camera, 2017.
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dean [at] fourwalledcubicle [dot] com
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www.lufa-lib.org
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*/
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/*
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Copyright 2017 Dean Camera (dean [at] fourwalledcubicle [dot] com)
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Permission to use, copy, modify, distribute, and sell this
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software and its documentation for any purpose is hereby granted
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without fee, provided that the above copyright notice appear in
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all copies and that both that the copyright notice and this
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permission notice and warranty disclaimer appear in supporting
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documentation, and that the name of the author not be used in
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advertising or publicity pertaining to distribution of the
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software without specific, written prior permission.
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The author disclaims all warranties with regard to this
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software, including all implied warranties of merchantability
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and fitness. In no event shall the author be liable for any
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special, indirect or consequential damages or any damages
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whatsoever resulting from loss of use, data or profits, whether
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in an action of contract, negligence or other tortious action,
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arising out of or in connection with the use or performance of
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this software.
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*/
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/** \file
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*
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* Common DHCP routines to manage DHCP packet data.
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*/
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#include "DHCPCommon.h"
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#if defined(ENABLE_DHCP_CLIENT) || defined(ENABLE_DHCP_SERVER) || defined(__DOXYGEN__)
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/** Sets the given DHCP option in the DHCP packet's option list. This automatically moves the
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* end of options terminator past the new option in the options list.
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*
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* \param[in,out] DHCPOptionList Pointer to the start of the DHCP packet's options list
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* \param[in] Option DHCP option to add to the list
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* \param[in] DataLen Size in bytes of the option data to add
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* \param[in] OptionData Buffer where the option's data is to be sourced from
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*
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* \return Number of bytes added to the DHCP packet
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*/
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uint8_t DHCPCommon_SetOption(uint8_t* DHCPOptionList,
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const uint8_t Option,
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const uint8_t DataLen,
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void* const OptionData)
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{
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/* Skip through the DHCP options list until the terminator option is found */
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while (*DHCPOptionList != DHCP_OPTION_END)
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DHCPOptionList += (DHCPOptionList[1] + 2);
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/* Overwrite the existing terminator with the new option, add a new terminator at the end of the list */
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DHCPOptionList[0] = Option;
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DHCPOptionList[1] = DataLen;
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memcpy(&DHCPOptionList[2], OptionData, DataLen);
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DHCPOptionList[2 + DataLen] = DHCP_OPTION_END;
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/* Calculate the total number of bytes added to the outgoing packet */
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return (2 + DataLen);
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}
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/** Retrieves the given option's data (if present) from the DHCP packet's options list.
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*
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* \param[in,out] DHCPOptionList Pointer to the start of the DHCP packet's options list
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* \param[in] Option DHCP option to retrieve to the list
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* \param[out] Destination Buffer where the option's data is to be written to if found
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*
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* \return Boolean \c true if the option was found in the DHCP packet's options list, \c false otherwise
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*/
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bool DHCPCommon_GetOption(const uint8_t* DHCPOptionList,
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const uint8_t Option,
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void* const Destination)
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{
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/* Look through the incoming DHCP packet's options list for the requested option */
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while (*DHCPOptionList != DHCP_OPTION_END)
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{
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/* Check if the current DHCP option in the packet is the one requested */
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if (DHCPOptionList[0] == Option)
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{
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/* Copy request option's data to the destination buffer */
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memcpy(Destination, &DHCPOptionList[2], DHCPOptionList[1]);
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/* Indicate that the requested option data was successfully retrieved */
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return true;
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}
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/* Skip to next DHCP option in the options list */
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DHCPOptionList += (DHCPOptionList[1] + 2);
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}
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/* Requested option not found in the incoming packet's DHCP options list */
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return false;
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}
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#endif
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