File content as of revision 2:6c2e2cdea46a:

/**
Copyright (c) 2013, Ashley Mills.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met: 

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer. 
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution. 

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#pragma once

#include <stdint.h>

#define COAP_HDR_SIZE 4
#define COAP_OPTION_HDR_BYTE 1

// CoAP PDU format

//   0                   1                   2                   3
//  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// |Ver| T |  TKL  |      Code     |          Message ID           |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// |   Token (if any, TKL bytes) ...
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// |   Options (if any) ...
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// |1 1 1 1 1 1 1 1|    Payload (if any) ...
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

class CoapPDU {


	public:
		/// CoAP message types. Note, values only work as enum.
		enum Type {
			COAP_CONFIRMABLE=0x00,
			COAP_NON_CONFIRMABLE=0x10,
			COAP_ACKNOWLEDGEMENT=0x20,
			COAP_RESET=0x30
		};
		
		// CoAP response codes.
		enum Code {
			COAP_EMPTY=0x00,
			COAP_GET,
			COAP_POST,
			COAP_PUT,
			COAP_DELETE,
			COAP_CREATED=0x41,
			COAP_DELETED,
			COAP_VALID,
			COAP_CHANGED,
			COAP_CONTENT,
			COAP_BAD_REQUEST=0x80,
			COAP_UNAUTHORIZED,
			COAP_BAD_OPTION,
			COAP_FORBIDDEN,
			COAP_NOT_FOUND,
			COAP_METHOD_NOT_ALLOWED,
			COAP_NOT_ACCEPTABLE,
			COAP_PRECONDITION_FAILED=0x8C,
			COAP_REQUEST_ENTITY_TOO_LARGE=0x8D,
			COAP_UNSUPPORTED_CONTENT_FORMAT=0x8F,
			COAP_INTERNAL_SERVER_ERROR=0xA0,
			COAP_NOT_IMPLEMENTED,
			COAP_BAD_GATEWAY,
			COAP_SERVICE_UNAVAILABLE,
			COAP_GATEWAY_TIMEOUT,
			COAP_PROXYING_NOT_SUPPORTED,
			COAP_UNDEFINED_CODE=0xFF
		};

		/// CoAP option numbers.
		enum Option {
			COAP_OPTION_IF_MATCH=1,
			COAP_OPTION_URI_HOST=3,
			COAP_OPTION_ETAG,
			COAP_OPTION_IF_NONE_MATCH,
			COAP_OPTION_OBSERVE,
			COAP_OPTION_URI_PORT,
			COAP_OPTION_LOCATION_PATH,
			COAP_OPTION_URI_PATH=11,
			COAP_OPTION_CONTENT_FORMAT,
			COAP_OPTION_MAX_AGE=14,
			COAP_OPTION_URI_QUERY,
			COAP_OPTION_ACCEPT=17,
			COAP_OPTION_LOCATION_QUERY=20,
			COAP_OPTION_BLOCK2=23,
			COAP_OPTION_BLOCK1=27,
			COAP_OPTION_SIZE2,
			COAP_OPTION_PROXY_URI=35,
			COAP_OPTION_PROXY_SCHEME=39,
			COAP_OPTION_SIZE1=60
		};

		/// CoAP content-formats.
		enum ContentFormat {
			COAP_CONTENT_FORMAT_TEXT_PLAIN = 0,
			COAP_CONTENT_FORMAT_APP_LINK  = 40,
			COAP_CONTENT_FORMAT_APP_XML,
			COAP_CONTENT_FORMAT_APP_OCTET,
			COAP_CONTENT_FORMAT_APP_EXI   = 47,
			COAP_CONTENT_FORMAT_APP_JSON  = 50
		};

		/// Sequence of these is returned by CoapPDU::getOptions()
		struct CoapOption {
			uint16_t optionDelta;
			uint16_t optionNumber;
			uint16_t optionValueLength;
			int totalLength;
			uint8_t *optionPointer;
			uint8_t *optionValuePointer;
		};

		// construction and destruction
		CoapPDU();
		CoapPDU(uint8_t *pdu, int pduLength);
		CoapPDU(uint8_t *buffer, int bufferLength, int pduLength);
		~CoapPDU();
		int reset();
		int validate();

		// version
		int setVersion(uint8_t version);
		uint8_t getVersion();

		// message type
		void setType(CoapPDU::Type type);
		CoapPDU::Type getType();

		// tokens
		int setTokenLength(uint8_t tokenLength);
		int getTokenLength();
		uint8_t* getTokenPointer();
		int setToken(uint8_t *token, uint8_t tokenLength);

		// message code
		void setCode(CoapPDU::Code code);
		CoapPDU::Code getCode();
		CoapPDU::Code httpStatusToCode(int httpStatus);

		// message ID
		int setMessageID(uint16_t messageID);
		uint16_t getMessageID();

		// options
		int addOption(uint16_t optionNumber, uint16_t optionLength, uint8_t *optionValue);
		// gets a list of all options
		CoapOption* getOptions();
		int getNumOptions();
		// shorthand helpers
		int setURI(char *uri);
		int setURI(char *uri, int urilen);
		int getURI(char *dst, int dstlen, int *outLen);
		int addURIQuery(char *query);

		// content format helper
		int setContentFormat(CoapPDU::ContentFormat format);

		// payload
		uint8_t* mallocPayload(int bytes);
		int setPayload(uint8_t *value, int len);
		uint8_t* getPayloadPointer();
		int getPayloadLength();
		uint8_t* getPayloadCopy();

		// pdu
		int getPDULength();
		uint8_t* getPDUPointer();
		void setPDULength(int len);

		// debugging
		static void printBinary(uint8_t b);
		void print();
		void printBin();
		void printHex();
		void printOptionHuman(uint8_t *option);
		void printHuman();
		void printPDUAsCArray();

	private:
		// variables
		uint8_t *_pdu;
		int _pduLength;

		int _constructedFromBuffer;
		int _bufferLength;

		uint8_t *_payloadPointer;
		int _payloadLength;

		int _numOptions;
		uint16_t _maxAddedOptionNumber;

		// functions
		void shiftPDUUp(int shiftOffset, int shiftAmount);
		void shiftPDUDown(int startLocation, int shiftOffset, int shiftAmount);
		uint8_t codeToValue(CoapPDU::Code c);

		// option stuff
		int findInsertionPosition(uint16_t optionNumber, uint16_t *prevOptionNumber);
		int computeExtraBytes(uint16_t n);
		int insertOption(int insertionPosition, uint16_t optionDelta, uint16_t optionValueLength, uint8_t *optionValue);
		uint16_t getOptionDelta(uint8_t *option);
		void setOptionDelta(int optionPosition, uint16_t optionDelta);
		uint16_t getOptionValueLength(uint8_t *option);
		
};

/*
#define COAP_CODE_EMPTY 0x00

// method codes 0.01-0.31
#define COAP_CODE_GET 	0x01
#define COAP_CODE_POST 	0x02
#define COAP_CODE_PUT 	0x03
#define COAP_CODE_DELETE 0x04

// Response codes 2.00 - 5.31
// 2.00 - 2.05
#define COAP_CODE_CREATED 0x41 
#define COAP_CODE_DELETED 0x42
#define COAP_CODE_VALID   0x43
#define COAP_CODE_CHANGED 0x44
#define COAP_CODE_CONTENT 0x45

// 4.00 - 4.15
#define COAP_CODE_BAD_REQUEST                0x80
#define COAP_CODE_UNAUTHORIZED               0x81
#define COAP_CODE_BAD_OPTION                 0x82
#define COAP_CODE_FORBIDDEN                  0x83
#define COAP_CODE_NOT_FOUND                  0x84
#define COAP_CODE_METHOD_NOT_ALLOWED         0x85
#define COAP_CODE_NOT_ACCEPTABLE             0x86
#define COAP_CODE_PRECONDITION_FAILED        0x8C
#define COAP_CODE_REQUEST_ENTITY_TOO_LARGE   0x8D
#define COAP_CODE_UNSUPPORTED_CONTENT_FORMAT 0x8F

// 5.00 - 5.05
#define COAP_CODE_INTERNAL_SERVER_ERROR      0xA0
#define COAP_CODE_NOT_IMPLEMENTED            0xA1
#define COAP_CODE_BAD_GATEWAY                0xA2
#define COAP_CODE_SERVICE_UNAVAILABLE        0xA3
#define COAP_CODE_GATEWAY_TIMEOUT            0xA4
#define COAP_CODE_PROXYING_NOT_SUPPORTED     0xA5
*/