Diff: MQTT/MQTTPacket/MQTTPacket.c

Revision:

9:58eb378727d9

Parent:

8:80d49dd91542

Child:

10:0b5e0dfee08e

--- a/MQTT/MQTTPacket/MQTTPacket.c	Wed Oct 01 13:27:35 2014 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,313 +0,0 @@
-/*******************************************************************************
- * 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
- *******************************************************************************/
-
-#include "StackTrace.h"
-#include "MQTTPacket.h"
-
-#include <string.h>
-
-/**
- * Encodes the message length according to the MQTT algorithm
- * @param buf the buffer into which the encoded data is written
- * @param length the length to be encoded
- * @return the number of bytes written to buffer
- */
-int MQTTPacket_encode(unsigned char* buf, int length)
-{
-	int rc = 0;
-
-	FUNC_ENTRY;
-	do
-	{
-		char d = length % 128;
-		length /= 128;
-		/* if there are more digits to encode, set the top bit of this digit */
-		if (length > 0)
-			d |= 0x80;
-		buf[rc++] = d;
-	} while (length > 0);
-	FUNC_EXIT_RC(rc);
-	return rc;
-}
-
-
-/**
- * Decodes the message length according to the MQTT algorithm
- * @param getcharfn pointer to function to read the next character from the data source
- * @param value the decoded length returned
- * @return the number of bytes read from the socket
- */
-int MQTTPacket_decode(int (*getcharfn)(unsigned char*, int), int* value)
-{
-	unsigned char c;
-	int multiplier = 1;
-	int len = 0;
-#define MAX_NO_OF_REMAINING_LENGTH_BYTES 4
-
-	FUNC_ENTRY;
-	*value = 0;
-	do
-	{
-		int rc = MQTTPACKET_READ_ERROR;
-
-		if (++len > MAX_NO_OF_REMAINING_LENGTH_BYTES)
-		{
-			rc = MQTTPACKET_READ_ERROR;	/* bad data */
-			goto exit;
-		}
-		rc = (*getcharfn)(&c, 1);
-		if (rc != 1)
-			goto exit;
-		*value += (c & 127) * multiplier;
-		multiplier *= 128;
-	} while ((c & 128) != 0);
-exit:
-	FUNC_EXIT_RC(len);
-	return len;
-}
-
-
-int MQTTPacket_len(int rem_len)
-{
-	rem_len += 1; /* header byte */
-
-	/* now remaining_length field */
-	if (rem_len < 128)
-		rem_len += 1;
-	else if (rem_len < 16384)
-		rem_len += 2;
-	else if (rem_len < 2097151)
-		rem_len += 3;
-	else
-		rem_len += 4;
-	return rem_len;
-}
-
-
-static unsigned char* bufptr;
-
-int bufchar(unsigned char* c, int count)
-{
-	int i;
-
-	for (i = 0; i < count; ++i)
-		*c = *bufptr++;
-	return count;
-}
-
-
-int MQTTPacket_decodeBuf(unsigned char* buf, int* value)
-{
-	bufptr = buf;
-	return MQTTPacket_decode(bufchar, value);
-}
-
-
-/**
- * Calculates an integer from two bytes read from the input buffer
- * @param pptr pointer to the input buffer - incremented by the number of bytes used & returned
- * @return the integer value calculated
- */
-int readInt(unsigned char** pptr)
-{
-	unsigned char* ptr = *pptr;
-	int len = 256*(*ptr) + (*(ptr+1));
-	*pptr += 2;
-	return len;
-}
-
-
-/**
- * Reads one character from the input buffer.
- * @param pptr pointer to the input buffer - incremented by the number of bytes used & returned
- * @return the character read
- */
-char readChar(unsigned char** pptr)
-{
-	char c = **pptr;
-	(*pptr)++;
-	return c;
-}
-
-
-/**
- * Writes one character to an output buffer.
- * @param pptr pointer to the output buffer - incremented by the number of bytes used & returned
- * @param c the character to write
- */
-void writeChar(unsigned char** pptr, char c)
-{
-	**pptr = c;
-	(*pptr)++;
-}
-
-
-/**
- * Writes an integer as 2 bytes to an output buffer.
- * @param pptr pointer to the output buffer - incremented by the number of bytes used & returned
- * @param anInt the integer to write
- */
-void writeInt(unsigned char** pptr, int anInt)
-{
-	**pptr = (unsigned char)(anInt / 256);
-	(*pptr)++;
-	**pptr = (unsigned char)(anInt % 256);
-	(*pptr)++;
-}
-
-
-/**
- * Writes a "UTF" string to an output buffer.  Converts C string to length-delimited.
- * @param pptr pointer to the output buffer - incremented by the number of bytes used & returned
- * @param string the C string to write
- */
-void writeCString(unsigned char** pptr, const char* string)
-{
-	int len = strlen(string);
-	writeInt(pptr, len);
-	memcpy(*pptr, string, len);
-	*pptr += len;
-}
-
-
-int getLenStringLen(char* ptr)
-{
-	int len = 256*((unsigned char)(*ptr)) + (unsigned char)(*(ptr+1));
-	return len;
-}
-
-
-void writeMQTTString(unsigned char** pptr, MQTTString mqttstring)
-{
-	if (mqttstring.lenstring.len > 0)
-	{
-		writeInt(pptr, mqttstring.lenstring.len);
-		memcpy(*pptr, mqttstring.lenstring.data, mqttstring.lenstring.len);
-		*pptr += mqttstring.lenstring.len;
-	}
-	else if (mqttstring.cstring)
-		writeCString(pptr, mqttstring.cstring);
-	else
-		writeInt(pptr, 0);
-}
-
-
-/**
- * @param mqttstring the MQTTString structure into which the data is to be read
- * @param pptr pointer to the output buffer - incremented by the number of bytes used & returned
- * @param enddata pointer to the end of the data: do not read beyond
- * @return 1 if successful, 0 if not
- */
-int readMQTTLenString(MQTTString* mqttstring, unsigned char** pptr, unsigned char* enddata)
-{
-	int rc = 0;
-
-	FUNC_ENTRY;
-	/* the first two bytes are the length of the string */
-	if (enddata - (*pptr) > 1) /* enough length to read the integer? */
-	{
-		mqttstring->lenstring.len = readInt(pptr); /* increments pptr to point past length */
-		if (&(*pptr)[mqttstring->lenstring.len] <= enddata)
-		{
-			mqttstring->lenstring.data = (char*)*pptr;
-			*pptr += mqttstring->lenstring.len;
-			rc = 1;
-		}
-	}
-	mqttstring->cstring = NULL;
-	FUNC_EXIT_RC(rc);
-	return rc;
-}
-
-
-/**
- * Return the length of the MQTTstring - C string if there is one, otherwise the length delimited string
- * @param mqttstring the string to return the length of
- * @return the length of the string
- */
-int MQTTstrlen(MQTTString mqttstring)
-{
-	int rc = 0;
-
-	if (mqttstring.cstring)
-		rc = strlen(mqttstring.cstring);
-	else
-		rc = mqttstring.lenstring.len;
-	return rc;
-}
-
-
-/**
- * Compares an MQTTString to a C string
- * @param a the MQTTString to compare
- * @param bptr the C string to compare
- * @return boolean - equal or not
- */
-int MQTTPacket_equals(MQTTString* a, char* bptr)
-{
-	int alen = 0,
-		blen = 0;
-	char *aptr;
-	
-	if (a->cstring)
-	{
-		aptr = a->cstring;
-		alen = strlen(a->cstring);
-	}
-	else
-	{
-		aptr = a->lenstring.data;
-		alen = a->lenstring.len;
-	}
-	blen = strlen(bptr);
-	
-	return (alen == blen) && (strncmp(aptr, bptr, alen) == 0);
-}
-
-
-/**
- * Helper function to read packet data from some source into a buffer
- * @param buf the buffer into which the packet will be serialized
- * @param buflen the length in bytes of the supplied buffer
- * @param getfn pointer to a function which will read any number of bytes from the needed source
- * @return integer MQTT packet type, or -1 on error
- */
-int MQTTPacket_read(unsigned char* buf, int buflen, int (*getfn)(unsigned char*, int))
-{
-	int rc = -1;
-	MQTTHeader header = {0};
-	int len = 0;
-	int rem_len = 0;
-
-	/* 1. read the header byte.  This has the packet type in it */
-	if ((*getfn)(buf, 1) != 1)
-		goto exit;
-
-	len = 1;
-	/* 2. read the remaining length.  This is variable in itself */
-	MQTTPacket_decode(getfn, &rem_len);
-	len += MQTTPacket_encode(buf + 1, rem_len); /* put the original remaining length back into the buffer */
-
-	/* 3. read the rest of the buffer using a callback to supply the rest of the data */
-	if ((*getfn)(buf + len, rem_len) != rem_len)
-		goto exit;
-
-	header.byte = buf[0];
-	rc = header.bits.type;
-exit:
-	return rc;
-}
-