pikascript/package/mqtt/MQTTPacket.h

/*******************************************************************************
 * Copyright (c) 2014 IBM Corp.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution.
 *
 * The Eclipse Public License is available at
 *    http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 *   http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *    Ian Craggs - initial API and implementation and/or initial
 *documentation Xiang Rong - 442039 Add makefile to Embedded C client
 *******************************************************************************/
#ifndef MQTTPACKET_H_
#define MQTTPACKET_H_

#if defined(__cplusplus) /* If this is a C++ compiler, use C linkage */
extern "C" {
#endif

#if defined(WIN32_DLL) || defined(WIN64_DLL)
#define DLLImport __declspec(dllimport)
#define DLLExport __declspec(dllexport)
#elif defined(LINUX_SO)
#define DLLImport extern
#define DLLExport __attribute__((visibility("default")))
#else
#define DLLImport
#define DLLExport
#endif

enum errors {
    MQTTPACKET_BUFFER_TOO_SHORT = -2,
    MQTTPACKET_READ_ERROR = -1,
    MQTTPACKET_READ_COMPLETE
};

enum msgTypes {
    CONNECT = 1,
    CONNACK,
    PUBLISH,
    PUBACK,
    PUBREC,
    PUBREL,
    PUBCOMP,
    SUBSCRIBE,
    SUBACK,
    UNSUBSCRIBE,
    UNSUBACK,
    PINGREQ,
    PINGRESP,
    DISCONNECT
};

/**
 * Bitfields for the MQTT header byte.
 */
typedef union {
    unsigned char byte; /**< the whole byte */
#if defined(REVERSED)
    struct {
        unsigned int type : 4;   /**< message type nibble */
        unsigned int dup : 1;    /**< DUP flag bit */
        unsigned int qos : 2;    /**< QoS value, 0, 1 or 2 */
        unsigned int retain : 1; /**< retained flag bit */
    } bits;
#else
    struct {
        unsigned int retain : 1; /**< retained flag bit */
        unsigned int qos : 2;    /**< QoS value, 0, 1 or 2 */
        unsigned int dup : 1;    /**< DUP flag bit */
        unsigned int type : 4;   /**< message type nibble */
    } bits;
#endif
} MQTTHeader;

typedef struct {
    int len;
    char* data;
} MQTTLenString;

typedef struct {
    char* cstring;
    MQTTLenString lenstring;
} MQTTString;

#define MQTTString_initializer \
    {                          \
        NULL, {                \
            0, NULL            \
        }                      \
    }

int MQTTstrlen(MQTTString mqttstring);

#include "MQTTConnect.h"
#include "MQTTFormat.h"
#include "MQTTPublish.h"
#include "MQTTSubscribe.h"
#include "MQTTUnsubscribe.h"

DLLExport int MQTTSerialize_ack(unsigned char* buf,
                                int buflen,
                                unsigned char type,
                                unsigned char dup,
                                unsigned short packetid);
DLLExport int MQTTDeserialize_ack(unsigned char* packettype,
                                  unsigned char* dup,
                                  unsigned short* packetid,
                                  unsigned char* buf,
                                  int buflen);

int MQTTPacket_len(int rem_len);
DLLExport int MQTTPacket_equals(MQTTString* a, char* b);

DLLExport int MQTTPacket_encode(unsigned char* buf, int length);
int MQTTPacket_decode(int (*getcharfn)(unsigned char*, int), int* value);
int MQTTPacket_decodeBuf(unsigned char* buf, int* value);

int readInt(unsigned char** pptr);
char readChar(unsigned char** pptr);
void writeChar(unsigned char** pptr, char c);
void writeInt(unsigned char** pptr, int anInt);
int readMQTTLenString(MQTTString* mqttstring,
                      unsigned char** pptr,
                      unsigned char* enddata);
void writeCString(unsigned char** pptr, const char* string);
void writeMQTTString(unsigned char** pptr, MQTTString mqttstring);

DLLExport int MQTTPacket_read(unsigned char* buf,
                              int buflen,
                              int (*getfn)(unsigned char*, int));

typedef struct {
    int (*getfn)(void*,
                 unsigned char*,
                 int); /* must return -1 for error, 0 for call again, or the
                          number of bytes read */
    void* sck;         /* pointer to whatever the system may use to identify the
                          transport */
    int multiplier;
    int rem_len;
    int len;
    char state;
} MQTTTransport;

int MQTTPacket_readnb(unsigned char* buf, int buflen, MQTTTransport* trp);

#ifdef __cplusplus /* If this is a C++ compiler, use C linkage */
}
#endif

#endif /* MQTTPACKET_H_ */