Ian Craggs / MQTTSNPacket

Low level MQTTSN packet library, part of the Eclipse Paho project: http://eclipse.org/paho

Dependents:   MQTTSN sara-n200-hello-mqtt-sn MQTTSN_2

The master source for this project is held at: https://github.com/eclipse/paho.mqtt-sn.embedded-c

MQTTSNSubscribeClient.c@0:c524a894b5e8, 2015-02-26 (annotated)

Committer:
icraggs
Date:
Thu Feb 26 15:59:36 2015 +0000
Revision:
0:c524a894b5e8
Child:
1:7fa362fa563f
First version that works nicely :-)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
icraggs 0:c524a894b5e8 1 /*******************************************************************************
icraggs 0:c524a894b5e8 2 * Copyright (c) 2014 IBM Corp.
icraggs 0:c524a894b5e8 3 *
icraggs 0:c524a894b5e8 4 * All rights reserved. This program and the accompanying materials
icraggs 0:c524a894b5e8 5 * are made available under the terms of the Eclipse Public License v1.0
icraggs 0:c524a894b5e8 6 * and Eclipse Distribution License v1.0 which accompany this distribution.
icraggs 0:c524a894b5e8 7 *
icraggs 0:c524a894b5e8 8 * The Eclipse Public License is available at
icraggs 0:c524a894b5e8 9 * http://www.eclipse.org/legal/epl-v10.html
icraggs 0:c524a894b5e8 10 * and the Eclipse Distribution License is available at
icraggs 0:c524a894b5e8 11 * http://www.eclipse.org/org/documents/edl-v10.php.
icraggs 0:c524a894b5e8 12 *
icraggs 0:c524a894b5e8 13 * Contributors:
icraggs 0:c524a894b5e8 14 * Ian Craggs - initial API and implementation and/or initial documentation
icraggs 0:c524a894b5e8 15 *******************************************************************************/
icraggs 0:c524a894b5e8 16
icraggs 0:c524a894b5e8 17 #include "MQTTSNPacket.h"
icraggs 0:c524a894b5e8 18 #include "StackTrace.h"
icraggs 0:c524a894b5e8 19
icraggs 0:c524a894b5e8 20 #include <string.h>
icraggs 0:c524a894b5e8 21
icraggs 0:c524a894b5e8 22 /**
icraggs 0:c524a894b5e8 23 * Determines the length of the MQTTSN subscribe packet that would be produced using the supplied parameters,
icraggs 0:c524a894b5e8 24 * excluding length
icraggs 0:c524a894b5e8 25 * @param topicName the topic name to be used in the publish
icraggs 0:c524a894b5e8 26 * @return the length of buffer needed to contain the serialized version of the packet
icraggs 0:c524a894b5e8 27 */
icraggs 0:c524a894b5e8 28 int MQTTSNSerialize_subscribeLength(MQTTSN_topicid* topicFilter)
icraggs 0:c524a894b5e8 29 {
icraggs 0:c524a894b5e8 30 int len = 4;
icraggs 0:c524a894b5e8 31
icraggs 0:c524a894b5e8 32 if (topicFilter->type == MQTTSN_TOPIC_TYPE_NORMAL)
icraggs 0:c524a894b5e8 33 len += topicFilter->data.long_.len;
icraggs 0:c524a894b5e8 34 else if (topicFilter->type == MQTTSN_TOPIC_TYPE_SHORT || topicFilter->type == MQTTSN_TOPIC_TYPE_PREDEFINED)
icraggs 0:c524a894b5e8 35 len += 2;
icraggs 0:c524a894b5e8 36
icraggs 0:c524a894b5e8 37 return len;
icraggs 0:c524a894b5e8 38 }
icraggs 0:c524a894b5e8 39
icraggs 0:c524a894b5e8 40
icraggs 0:c524a894b5e8 41 /**
icraggs 0:c524a894b5e8 42 * Serializes the supplied subscribe data into the supplied buffer, ready for sending
icraggs 0:c524a894b5e8 43 * @param buf the buffer into which the packet will be serialized
icraggs 0:c524a894b5e8 44 * @param buflen the length in bytes of the supplied buffer
icraggs 0:c524a894b5e8 45 * @param dup integer - the MQTT-SN dup flag
icraggs 0:c524a894b5e8 46 * @param qos integer - the MQTT-SN QoS value
icraggs 0:c524a894b5e8 47 * @param packetid integer - the MQTT-SN packet identifier
icraggs 0:c524a894b5e8 48 * @param topic MQTTSN_topicid - the MQTT-SN topic in the subscribe
icraggs 0:c524a894b5e8 49 * @return the length of the serialized data. <= 0 indicates error
icraggs 0:c524a894b5e8 50 */
icraggs 0:c524a894b5e8 51 int MQTTSNSerialize_subscribe(unsigned char* buf, int buflen, unsigned char dup, int qos, unsigned short packetid,
icraggs 0:c524a894b5e8 52 MQTTSN_topicid* topicFilter)
icraggs 0:c524a894b5e8 53 {
icraggs 0:c524a894b5e8 54 unsigned char *ptr = buf;
icraggs 0:c524a894b5e8 55 MQTTSNFlags flags;
icraggs 0:c524a894b5e8 56 int len = 0;
icraggs 0:c524a894b5e8 57 int rc = 0;
icraggs 0:c524a894b5e8 58
icraggs 0:c524a894b5e8 59 FUNC_ENTRY;
icraggs 0:c524a894b5e8 60 if ((len = MQTTSNPacket_len(MQTTSNSerialize_subscribeLength(topicFilter))) > buflen)
icraggs 0:c524a894b5e8 61 {
icraggs 0:c524a894b5e8 62 rc = MQTTSNPACKET_BUFFER_TOO_SHORT;
icraggs 0:c524a894b5e8 63 goto exit;
icraggs 0:c524a894b5e8 64 }
icraggs 0:c524a894b5e8 65 ptr += MQTTSNPacket_encode(ptr, len); /* write length */
icraggs 0:c524a894b5e8 66 writeChar(&ptr, MQTTSN_SUBSCRIBE); /* write message type */
icraggs 0:c524a894b5e8 67
icraggs 0:c524a894b5e8 68 flags.all = 0;
icraggs 0:c524a894b5e8 69 flags.bits.dup = dup;
icraggs 0:c524a894b5e8 70 flags.bits.QoS = qos;
icraggs 0:c524a894b5e8 71 flags.bits.topicIdType = topicFilter->type;
icraggs 0:c524a894b5e8 72 writeChar(&ptr, flags.all);
icraggs 0:c524a894b5e8 73
icraggs 0:c524a894b5e8 74 writeInt(&ptr, packetid);
icraggs 0:c524a894b5e8 75
icraggs 0:c524a894b5e8 76 /* now the topic id or name */
icraggs 0:c524a894b5e8 77 if (topicFilter->type == MQTTSN_TOPIC_TYPE_NORMAL) /* means long topic name */
icraggs 0:c524a894b5e8 78 {
icraggs 0:c524a894b5e8 79 memcpy(ptr, topicFilter->data.long_.name, topicFilter->data.long_.len);
icraggs 0:c524a894b5e8 80 ptr += topicFilter->data.long_.len;
icraggs 0:c524a894b5e8 81 }
icraggs 0:c524a894b5e8 82 else if (topicFilter->type == MQTTSN_TOPIC_TYPE_PREDEFINED)
icraggs 0:c524a894b5e8 83 writeInt(&ptr, topicFilter->data.id);
icraggs 0:c524a894b5e8 84 else if (topicFilter->type == MQTTSN_TOPIC_TYPE_SHORT)
icraggs 0:c524a894b5e8 85 {
icraggs 0:c524a894b5e8 86 writeChar(&ptr, topicFilter->data.short_name[0]);
icraggs 0:c524a894b5e8 87 writeChar(&ptr, topicFilter->data.short_name[1]);
icraggs 0:c524a894b5e8 88 }
icraggs 0:c524a894b5e8 89
icraggs 0:c524a894b5e8 90 rc = ptr - buf;
icraggs 0:c524a894b5e8 91 exit:
icraggs 0:c524a894b5e8 92 FUNC_EXIT_RC(rc);
icraggs 0:c524a894b5e8 93 return rc;
icraggs 0:c524a894b5e8 94
icraggs 0:c524a894b5e8 95 }
icraggs 0:c524a894b5e8 96
icraggs 0:c524a894b5e8 97
icraggs 0:c524a894b5e8 98 /**
icraggs 0:c524a894b5e8 99 * Deserializes the supplied (wire) buffer into suback data
icraggs 0:c524a894b5e8 100 * @param qos the returned qos
icraggs 0:c524a894b5e8 101 * @param topicid returned if "accepted" the value which will be used by the gateway in subsequent PUBLISH packets
icraggs 0:c524a894b5e8 102 * @param packetid returned - the same value as the one contained in the corresponding SUBSCRIBE
icraggs 0:c524a894b5e8 103 * @param returncode returned - "accepted" or rejection reason
icraggs 0:c524a894b5e8 104 * @param buf the raw buffer data, of the correct length determined by the remaining length field
icraggs 0:c524a894b5e8 105 * @param buflen the length in bytes of the data in the supplied buffer
icraggs 0:c524a894b5e8 106 * @return error code. 1 is success
icraggs 0:c524a894b5e8 107 */
icraggs 0:c524a894b5e8 108 int MQTTSNDeserialize_suback(int* qos, unsigned short* topicid, unsigned short* packetid,
icraggs 0:c524a894b5e8 109 unsigned char* returncode, unsigned char* buf, int buflen)
icraggs 0:c524a894b5e8 110 {
icraggs 0:c524a894b5e8 111 MQTTSNFlags flags;
icraggs 0:c524a894b5e8 112 unsigned char* curdata = buf;
icraggs 0:c524a894b5e8 113 unsigned char* enddata = NULL;
icraggs 0:c524a894b5e8 114 int rc = 0;
icraggs 0:c524a894b5e8 115 int mylen = 0;
icraggs 0:c524a894b5e8 116
icraggs 0:c524a894b5e8 117 FUNC_ENTRY;
icraggs 0:c524a894b5e8 118 curdata += (rc = MQTTSNPacket_decode(curdata, buflen, &mylen)); /* read length */
icraggs 0:c524a894b5e8 119 enddata = buf + mylen;
icraggs 0:c524a894b5e8 120 if (enddata - curdata > buflen)
icraggs 0:c524a894b5e8 121 goto exit;
icraggs 0:c524a894b5e8 122
icraggs 0:c524a894b5e8 123 if (readChar(&curdata) != MQTTSN_SUBACK)
icraggs 0:c524a894b5e8 124 goto exit;
icraggs 0:c524a894b5e8 125
icraggs 0:c524a894b5e8 126 flags.all = readChar(&curdata);
icraggs 0:c524a894b5e8 127 *qos = flags.bits.QoS;
icraggs 0:c524a894b5e8 128
icraggs 0:c524a894b5e8 129 *topicid = readInt(&curdata);
icraggs 0:c524a894b5e8 130 *packetid = readInt(&curdata);
icraggs 0:c524a894b5e8 131 *returncode = readChar(&curdata);
icraggs 0:c524a894b5e8 132
icraggs 0:c524a894b5e8 133 rc = 1;
icraggs 0:c524a894b5e8 134 exit:
icraggs 0:c524a894b5e8 135 FUNC_EXIT_RC(rc);
icraggs 0:c524a894b5e8 136 return rc;
icraggs 0:c524a894b5e8 137 }
icraggs 0:c524a894b5e8 138
icraggs 0:c524a894b5e8 139
icraggs 0:c524a894b5e8 140
icraggs 0:c524a894b5e8 141