MQTT / MQTTPacket

Basic C library for MQTT packet serialization and deserialization

Dependents:   MQTT MQTT MQTT MQTT ... more

Fork of MQTTPacket by MQTT

This library is part of the EclipseTM Paho project; specifically the embedded client.

A basic MQTT library in C for packet serialization and deserialization

MQTTUnsubscribeServer.c@0:7734401cc1b4, 2014-02-04 (annotated)

Committer:
icraggs
Date:
Tue Feb 04 22:31:32 2014 +0000
Revision:
0:7734401cc1b4
Child:
14:c2052aee81de
First version of MQTT library

Who changed what in which revision?

UserRevisionLine numberNew contents of line
icraggs 0:7734401cc1b4 1 /*******************************************************************************
icraggs 0:7734401cc1b4 2 * Copyright (c) 2014 IBM Corp.
icraggs 0:7734401cc1b4 3 *
icraggs 0:7734401cc1b4 4 * All rights reserved. This program and the accompanying materials
icraggs 0:7734401cc1b4 5 * are made available under the terms of the Eclipse Public License v1.0
icraggs 0:7734401cc1b4 6 * and Eclipse Distribution License v1.0 which accompany this distribution.
icraggs 0:7734401cc1b4 7 *
icraggs 0:7734401cc1b4 8 * The Eclipse Public License is available at
icraggs 0:7734401cc1b4 9 * http://www.eclipse.org/legal/epl-v10.html
icraggs 0:7734401cc1b4 10 * and the Eclipse Distribution License is available at
icraggs 0:7734401cc1b4 11 * http://www.eclipse.org/org/documents/edl-v10.php.
icraggs 0:7734401cc1b4 12 *
icraggs 0:7734401cc1b4 13 * Contributors:
icraggs 0:7734401cc1b4 14 * Ian Craggs - initial API and implementation and/or initial documentation
icraggs 0:7734401cc1b4 15 *******************************************************************************/
icraggs 0:7734401cc1b4 16
icraggs 0:7734401cc1b4 17 #include "MQTTPacket.h"
icraggs 0:7734401cc1b4 18 #include "StackTrace.h"
icraggs 0:7734401cc1b4 19
icraggs 0:7734401cc1b4 20 #include <string.h>
icraggs 0:7734401cc1b4 21
icraggs 0:7734401cc1b4 22
icraggs 0:7734401cc1b4 23 /**
icraggs 0:7734401cc1b4 24 * Deserializes the supplied (wire) buffer into unsubscribe data
icraggs 0:7734401cc1b4 25 * @param dup integer returned - the MQTT dup flag
icraggs 0:7734401cc1b4 26 * @param packetid integer returned - the MQTT packet identifier
icraggs 0:7734401cc1b4 27 * @param maxcount - the maximum number of members allowed in the topicFilters and requestedQoSs arrays
icraggs 0:7734401cc1b4 28 * @param count - number of members in the topicFilters and requestedQoSs arrays
icraggs 0:7734401cc1b4 29 * @param topicFilters - array of topic filter names
icraggs 0:7734401cc1b4 30 * @param buf the raw buffer data, of the correct length determined by the remaining length field
icraggs 0:7734401cc1b4 31 * @param buflen the length in bytes of the data in the supplied buffer
icraggs 0:7734401cc1b4 32 * @return the length of the serialized data. <= 0 indicates error
icraggs 0:7734401cc1b4 33 */
icraggs 0:7734401cc1b4 34 int MQTTDeserialize_unsubscribe(int* dup, int* packetid, int maxcount, int* count, MQTTString topicFilters[], char* buf, int len)
icraggs 0:7734401cc1b4 35 {
icraggs 0:7734401cc1b4 36 MQTTHeader header;
icraggs 0:7734401cc1b4 37 char* curdata = buf;
icraggs 0:7734401cc1b4 38 char* enddata = NULL;
icraggs 0:7734401cc1b4 39 int rc = 0;
icraggs 0:7734401cc1b4 40 int mylen = 0;
icraggs 0:7734401cc1b4 41
icraggs 0:7734401cc1b4 42 FUNC_ENTRY;
icraggs 0:7734401cc1b4 43 header.byte = readChar(&curdata);
icraggs 0:7734401cc1b4 44 *dup = header.bits.dup;
icraggs 0:7734401cc1b4 45
icraggs 0:7734401cc1b4 46 curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */
icraggs 0:7734401cc1b4 47 enddata = curdata + mylen;
icraggs 0:7734401cc1b4 48
icraggs 0:7734401cc1b4 49 *packetid = readInt(&curdata);
icraggs 0:7734401cc1b4 50
icraggs 0:7734401cc1b4 51 *count = 0;
icraggs 0:7734401cc1b4 52 while (curdata < enddata)
icraggs 0:7734401cc1b4 53 {
icraggs 0:7734401cc1b4 54 if (!readMQTTLenString(&topicFilters[*count], &curdata, enddata))
icraggs 0:7734401cc1b4 55 goto exit;
icraggs 0:7734401cc1b4 56 (*count)++;
icraggs 0:7734401cc1b4 57 }
icraggs 0:7734401cc1b4 58
icraggs 0:7734401cc1b4 59 rc = 1;
icraggs 0:7734401cc1b4 60 exit:
icraggs 0:7734401cc1b4 61 FUNC_EXIT_RC(rc);
icraggs 0:7734401cc1b4 62 return rc;
icraggs 0:7734401cc1b4 63 }
icraggs 0:7734401cc1b4 64
icraggs 0:7734401cc1b4 65
icraggs 0:7734401cc1b4 66 /**
icraggs 0:7734401cc1b4 67 * Serializes the supplied unsuback data into the supplied buffer, ready for sending
icraggs 0:7734401cc1b4 68 * @param buf the buffer into which the packet will be serialized
icraggs 0:7734401cc1b4 69 * @param buflen the length in bytes of the supplied buffer
icraggs 0:7734401cc1b4 70 * @param packetid integer - the MQTT packet identifier
icraggs 0:7734401cc1b4 71 * @return the length of the serialized data. <= 0 indicates error
icraggs 0:7734401cc1b4 72 */
icraggs 0:7734401cc1b4 73 int MQTTSerialize_unsuback(char* buf, int buflen, int packetid)
icraggs 0:7734401cc1b4 74 {
icraggs 0:7734401cc1b4 75 MQTTHeader header;
icraggs 0:7734401cc1b4 76 int rc = 0;
icraggs 0:7734401cc1b4 77 char *ptr = buf;
icraggs 0:7734401cc1b4 78
icraggs 0:7734401cc1b4 79 FUNC_ENTRY;
icraggs 0:7734401cc1b4 80 if (buflen < 2)
icraggs 0:7734401cc1b4 81 {
icraggs 0:7734401cc1b4 82 rc = MQTTPACKET_BUFFER_TOO_SHORT;
icraggs 0:7734401cc1b4 83 goto exit;
icraggs 0:7734401cc1b4 84 }
icraggs 0:7734401cc1b4 85 header.byte = 0;
icraggs 0:7734401cc1b4 86 header.bits.type = UNSUBACK;
icraggs 0:7734401cc1b4 87 writeChar(&ptr, header.byte); /* write header */
icraggs 0:7734401cc1b4 88
icraggs 0:7734401cc1b4 89 ptr += MQTTPacket_encode(ptr, 2); /* write remaining length */
icraggs 0:7734401cc1b4 90
icraggs 0:7734401cc1b4 91 writeInt(&ptr, packetid);
icraggs 0:7734401cc1b4 92
icraggs 0:7734401cc1b4 93 rc = ptr - buf;
icraggs 0:7734401cc1b4 94 exit:
icraggs 0:7734401cc1b4 95 FUNC_EXIT_RC(rc);
icraggs 0:7734401cc1b4 96 return rc;
icraggs 0:7734401cc1b4 97 }
icraggs 0:7734401cc1b4 98
icraggs 0:7734401cc1b4 99