Peter Ferland / Cayenne-MQTT-mbed-MTSAS

The Cayenne MQTT mbed Library provides functions to easily connect to the Cayenne IoT project builder.

Fork of Cayenne-MQTT-mbed by myDevicesIoT

src/MQTTCommon/MQTTSubscribeClient.c@0:09ef59d2d0f7, 2016-10-07 (annotated)

Committer:
jburhenn
Date:
Fri Oct 07 17:21:45 2016 +0000
Revision:
0:09ef59d2d0f7
Child:
22:0dbabcc6e7b2
Initial commit.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jburhenn 0:09ef59d2d0f7 1 /*******************************************************************************
jburhenn 0:09ef59d2d0f7 2 * Copyright (c) 2014 IBM Corp.
jburhenn 0:09ef59d2d0f7 3 *
jburhenn 0:09ef59d2d0f7 4 * All rights reserved. This program and the accompanying materials
jburhenn 0:09ef59d2d0f7 5 * are made available under the terms of the Eclipse Public License v1.0
jburhenn 0:09ef59d2d0f7 6 * and Eclipse Distribution License v1.0 which accompany this distribution.
jburhenn 0:09ef59d2d0f7 7 *
jburhenn 0:09ef59d2d0f7 8 * The Eclipse Public License is available at
jburhenn 0:09ef59d2d0f7 9 * http://www.eclipse.org/legal/epl-v10.html
jburhenn 0:09ef59d2d0f7 10 * and the Eclipse Distribution License is available at
jburhenn 0:09ef59d2d0f7 11 * http://www.eclipse.org/org/documents/edl-v10.php.
jburhenn 0:09ef59d2d0f7 12 *
jburhenn 0:09ef59d2d0f7 13 * Contributors:
jburhenn 0:09ef59d2d0f7 14 * Ian Craggs - initial API and implementation and/or initial documentation
jburhenn 0:09ef59d2d0f7 15 *******************************************************************************/
jburhenn 0:09ef59d2d0f7 16
jburhenn 0:09ef59d2d0f7 17 #include "MQTTPacket.h"
jburhenn 0:09ef59d2d0f7 18
jburhenn 0:09ef59d2d0f7 19 #include <string.h>
jburhenn 0:09ef59d2d0f7 20
jburhenn 0:09ef59d2d0f7 21 /**
jburhenn 0:09ef59d2d0f7 22 * Determines the length of the MQTT subscribe packet that would be produced using the supplied parameters
jburhenn 0:09ef59d2d0f7 23 * @param count the number of topic filter strings in topicFilters
jburhenn 0:09ef59d2d0f7 24 * @param topicFilters the array of topic filter strings to be used in the publish
jburhenn 0:09ef59d2d0f7 25 * @return the length of buffer needed to contain the serialized version of the packet
jburhenn 0:09ef59d2d0f7 26 */
jburhenn 0:09ef59d2d0f7 27 int MQTTSerialize_subscribeLength(int count, MQTTString topicFilters[])
jburhenn 0:09ef59d2d0f7 28 {
jburhenn 0:09ef59d2d0f7 29 int i;
jburhenn 0:09ef59d2d0f7 30 int len = 2; /* packetid */
jburhenn 0:09ef59d2d0f7 31
jburhenn 0:09ef59d2d0f7 32 for (i = 0; i < count; ++i)
jburhenn 0:09ef59d2d0f7 33 len += 2 + MQTTstrlen(topicFilters[i]) + 1; /* length + topic + req_qos */
jburhenn 0:09ef59d2d0f7 34 return len;
jburhenn 0:09ef59d2d0f7 35 }
jburhenn 0:09ef59d2d0f7 36
jburhenn 0:09ef59d2d0f7 37
jburhenn 0:09ef59d2d0f7 38 /**
jburhenn 0:09ef59d2d0f7 39 * Serializes the supplied subscribe data into the supplied buffer, ready for sending
jburhenn 0:09ef59d2d0f7 40 * @param buf the buffer into which the packet will be serialized
jburhenn 0:09ef59d2d0f7 41 * @param buflen the length in bytes of the supplied bufferr
jburhenn 0:09ef59d2d0f7 42 * @param dup integer - the MQTT dup flag
jburhenn 0:09ef59d2d0f7 43 * @param packetid integer - the MQTT packet identifier
jburhenn 0:09ef59d2d0f7 44 * @param count - number of members in the topicFilters and reqQos arrays
jburhenn 0:09ef59d2d0f7 45 * @param topicFilters - array of topic filter names
jburhenn 0:09ef59d2d0f7 46 * @param requestedQoSs - array of requested QoS
jburhenn 0:09ef59d2d0f7 47 * @return the length of the serialized data. <= 0 indicates error
jburhenn 0:09ef59d2d0f7 48 */
jburhenn 0:09ef59d2d0f7 49 int MQTTSerialize_subscribe(unsigned char* buf, int buflen, unsigned char dup, unsigned short packetid, int count,
jburhenn 0:09ef59d2d0f7 50 MQTTString topicFilters[], int requestedQoSs[])
jburhenn 0:09ef59d2d0f7 51 {
jburhenn 0:09ef59d2d0f7 52 unsigned char *ptr = buf;
jburhenn 0:09ef59d2d0f7 53 MQTTHeader header = {0};
jburhenn 0:09ef59d2d0f7 54 int rem_len = 0;
jburhenn 0:09ef59d2d0f7 55 int rc = 0;
jburhenn 0:09ef59d2d0f7 56 int i = 0;
jburhenn 0:09ef59d2d0f7 57
jburhenn 0:09ef59d2d0f7 58 if (MQTTPacket_len(rem_len = MQTTSerialize_subscribeLength(count, topicFilters)) > buflen)
jburhenn 0:09ef59d2d0f7 59 {
jburhenn 0:09ef59d2d0f7 60 rc = MQTTPACKET_BUFFER_TOO_SHORT;
jburhenn 0:09ef59d2d0f7 61 goto exit;
jburhenn 0:09ef59d2d0f7 62 }
jburhenn 0:09ef59d2d0f7 63
jburhenn 0:09ef59d2d0f7 64 header.byte = 0;
jburhenn 0:09ef59d2d0f7 65 header.bits.type = SUBSCRIBE_MSG;
jburhenn 0:09ef59d2d0f7 66 header.bits.dup = dup;
jburhenn 0:09ef59d2d0f7 67 header.bits.qos = 1;
jburhenn 0:09ef59d2d0f7 68 writeChar(&ptr, header.byte); /* write header */
jburhenn 0:09ef59d2d0f7 69
jburhenn 0:09ef59d2d0f7 70 ptr += MQTTPacket_encode(ptr, rem_len); /* write remaining length */;
jburhenn 0:09ef59d2d0f7 71
jburhenn 0:09ef59d2d0f7 72 writeInt(&ptr, packetid);
jburhenn 0:09ef59d2d0f7 73
jburhenn 0:09ef59d2d0f7 74 for (i = 0; i < count; ++i)
jburhenn 0:09ef59d2d0f7 75 {
jburhenn 0:09ef59d2d0f7 76 writeMQTTString(&ptr, topicFilters[i]);
jburhenn 0:09ef59d2d0f7 77 writeChar(&ptr, requestedQoSs[i]);
jburhenn 0:09ef59d2d0f7 78 }
jburhenn 0:09ef59d2d0f7 79
jburhenn 0:09ef59d2d0f7 80 rc = ptr - buf;
jburhenn 0:09ef59d2d0f7 81 exit:
jburhenn 0:09ef59d2d0f7 82 return rc;
jburhenn 0:09ef59d2d0f7 83 }
jburhenn 0:09ef59d2d0f7 84
jburhenn 0:09ef59d2d0f7 85
jburhenn 0:09ef59d2d0f7 86
jburhenn 0:09ef59d2d0f7 87 /**
jburhenn 0:09ef59d2d0f7 88 * Deserializes the supplied (wire) buffer into suback data
jburhenn 0:09ef59d2d0f7 89 * @param packetid returned integer - the MQTT packet identifier
jburhenn 0:09ef59d2d0f7 90 * @param maxcount - the maximum number of members allowed in the grantedQoSs array
jburhenn 0:09ef59d2d0f7 91 * @param count returned integer - number of members in the grantedQoSs array
jburhenn 0:09ef59d2d0f7 92 * @param grantedQoSs returned array of integers - the granted qualities of service
jburhenn 0:09ef59d2d0f7 93 * @param buf the raw buffer data, of the correct length determined by the remaining length field
jburhenn 0:09ef59d2d0f7 94 * @param buflen the length in bytes of the data in the supplied buffer
jburhenn 0:09ef59d2d0f7 95 * @return error code. 1 is success, 0 is failure
jburhenn 0:09ef59d2d0f7 96 */
jburhenn 0:09ef59d2d0f7 97 int MQTTDeserialize_suback(unsigned short* packetid, int maxcount, int* count, int grantedQoSs[], unsigned char* buf, int buflen)
jburhenn 0:09ef59d2d0f7 98 {
jburhenn 0:09ef59d2d0f7 99 MQTTHeader header = {0};
jburhenn 0:09ef59d2d0f7 100 unsigned char* curdata = buf;
jburhenn 0:09ef59d2d0f7 101 unsigned char* enddata = NULL;
jburhenn 0:09ef59d2d0f7 102 int rc = 0;
jburhenn 0:09ef59d2d0f7 103 int mylen;
jburhenn 0:09ef59d2d0f7 104
jburhenn 0:09ef59d2d0f7 105 header.byte = readChar(&curdata);
jburhenn 0:09ef59d2d0f7 106 if (header.bits.type != SUBACK_MSG)
jburhenn 0:09ef59d2d0f7 107 goto exit;
jburhenn 0:09ef59d2d0f7 108
jburhenn 0:09ef59d2d0f7 109 curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */
jburhenn 0:09ef59d2d0f7 110 enddata = curdata + mylen;
jburhenn 0:09ef59d2d0f7 111 if (enddata - curdata < 2)
jburhenn 0:09ef59d2d0f7 112 goto exit;
jburhenn 0:09ef59d2d0f7 113
jburhenn 0:09ef59d2d0f7 114 *packetid = readInt(&curdata);
jburhenn 0:09ef59d2d0f7 115
jburhenn 0:09ef59d2d0f7 116 *count = 0;
jburhenn 0:09ef59d2d0f7 117 while (curdata < enddata)
jburhenn 0:09ef59d2d0f7 118 {
jburhenn 0:09ef59d2d0f7 119 if (*count > maxcount)
jburhenn 0:09ef59d2d0f7 120 {
jburhenn 0:09ef59d2d0f7 121 rc = -1;
jburhenn 0:09ef59d2d0f7 122 goto exit;
jburhenn 0:09ef59d2d0f7 123 }
jburhenn 0:09ef59d2d0f7 124 grantedQoSs[(*count)++] = readChar(&curdata);
jburhenn 0:09ef59d2d0f7 125 }
jburhenn 0:09ef59d2d0f7 126
jburhenn 0:09ef59d2d0f7 127 rc = 1;
jburhenn 0:09ef59d2d0f7 128 exit:
jburhenn 0:09ef59d2d0f7 129 return rc;
jburhenn 0:09ef59d2d0f7 130 }
jburhenn 0:09ef59d2d0f7 131
jburhenn 0:09ef59d2d0f7 132