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@25:aedcaf7984d5, 2017-10-30 (annotated)

Committer:
Ian Craggs
Date:
Mon Oct 30 12:47:11 2017 +0000
Revision:
25:aedcaf7984d5
Parent:
17:c5bd28cc139a 
Merging mine and Jan's changes

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 */
Ian Craggs 14:c2052aee81de 34 int MQTTDeserialize_unsubscribe(unsigned char* dup, unsigned short* packetid, int maxcount, int* count, MQTTString topicFilters[],
Ian Craggs 14:c2052aee81de 35 unsigned char* buf, int len)
icraggs 0:7734401cc1b4 36 {
icraggs 17:c5bd28cc139a 37 MQTTHeader header = {0};
Ian Craggs 14:c2052aee81de 38 unsigned char* curdata = buf;
Ian Craggs 14:c2052aee81de 39 unsigned char* enddata = NULL;
icraggs 0:7734401cc1b4 40 int rc = 0;
icraggs 0:7734401cc1b4 41 int mylen = 0;
icraggs 0:7734401cc1b4 42
icraggs 0:7734401cc1b4 43 FUNC_ENTRY;
icraggs 0:7734401cc1b4 44 header.byte = readChar(&curdata);
icraggs 16:d0b3886ada32 45 if (header.bits.type != UNSUBSCRIBE)
icraggs 16:d0b3886ada32 46 goto exit;
icraggs 0:7734401cc1b4 47 *dup = header.bits.dup;
icraggs 0:7734401cc1b4 48
icraggs 0:7734401cc1b4 49 curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */
icraggs 0:7734401cc1b4 50 enddata = curdata + mylen;
icraggs 0:7734401cc1b4 51
icraggs 0:7734401cc1b4 52 *packetid = readInt(&curdata);
icraggs 0:7734401cc1b4 53
icraggs 0:7734401cc1b4 54 *count = 0;
icraggs 0:7734401cc1b4 55 while (curdata < enddata)
icraggs 0:7734401cc1b4 56 {
icraggs 0:7734401cc1b4 57 if (!readMQTTLenString(&topicFilters[*count], &curdata, enddata))
icraggs 0:7734401cc1b4 58 goto exit;
icraggs 0:7734401cc1b4 59 (*count)++;
icraggs 0:7734401cc1b4 60 }
icraggs 0:7734401cc1b4 61
icraggs 0:7734401cc1b4 62 rc = 1;
icraggs 0:7734401cc1b4 63 exit:
icraggs 0:7734401cc1b4 64 FUNC_EXIT_RC(rc);
icraggs 0:7734401cc1b4 65 return rc;
icraggs 0:7734401cc1b4 66 }
icraggs 0:7734401cc1b4 67
icraggs 0:7734401cc1b4 68
icraggs 0:7734401cc1b4 69 /**
icraggs 0:7734401cc1b4 70 * Serializes the supplied unsuback data into the supplied buffer, ready for sending
icraggs 0:7734401cc1b4 71 * @param buf the buffer into which the packet will be serialized
icraggs 0:7734401cc1b4 72 * @param buflen the length in bytes of the supplied buffer
icraggs 0:7734401cc1b4 73 * @param packetid integer - the MQTT packet identifier
icraggs 0:7734401cc1b4 74 * @return the length of the serialized data. <= 0 indicates error
icraggs 0:7734401cc1b4 75 */
Ian Craggs 14:c2052aee81de 76 int MQTTSerialize_unsuback(unsigned char* buf, int buflen, unsigned short packetid)
icraggs 0:7734401cc1b4 77 {
icraggs 17:c5bd28cc139a 78 MQTTHeader header = {0};
icraggs 0:7734401cc1b4 79 int rc = 0;
Ian Craggs 14:c2052aee81de 80 unsigned char *ptr = buf;
icraggs 0:7734401cc1b4 81
icraggs 0:7734401cc1b4 82 FUNC_ENTRY;
icraggs 0:7734401cc1b4 83 if (buflen < 2)
icraggs 0:7734401cc1b4 84 {
icraggs 0:7734401cc1b4 85 rc = MQTTPACKET_BUFFER_TOO_SHORT;
icraggs 0:7734401cc1b4 86 goto exit;
icraggs 0:7734401cc1b4 87 }
icraggs 0:7734401cc1b4 88 header.byte = 0;
icraggs 0:7734401cc1b4 89 header.bits.type = UNSUBACK;
icraggs 0:7734401cc1b4 90 writeChar(&ptr, header.byte); /* write header */
icraggs 0:7734401cc1b4 91
icraggs 0:7734401cc1b4 92 ptr += MQTTPacket_encode(ptr, 2); /* write remaining length */
icraggs 0:7734401cc1b4 93
icraggs 0:7734401cc1b4 94 writeInt(&ptr, packetid);
icraggs 0:7734401cc1b4 95
icraggs 0:7734401cc1b4 96 rc = ptr - buf;
icraggs 0:7734401cc1b4 97 exit:
icraggs 0:7734401cc1b4 98 FUNC_EXIT_RC(rc);
icraggs 0:7734401cc1b4 99 return rc;
icraggs 0:7734401cc1b4 100 }
icraggs 0:7734401cc1b4 101
icraggs 0:7734401cc1b4 102