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

MQTTSNUnsubscribeClient.c@1:7fa362fa563f, 2016-01-06 (annotated)

Committer:
icraggs
Date:
Wed Jan 06 14:19:27 2016 +0000
Revision:
1:7fa362fa563f
Parent:
0:c524a894b5e8 
Internal function name changes to avoid name clashes

Who changed what in which revision?

UserRevisionLine numberNew contents of line
icraggs 1:7fa362fa563f 1 /*******************************************************************************
icraggs 1:7fa362fa563f 2 * Copyright (c) 2014 IBM Corp.
icraggs 1:7fa362fa563f 3 *
icraggs 1:7fa362fa563f 4 * All rights reserved. This program and the accompanying materials
icraggs 1:7fa362fa563f 5 * are made available under the terms of the Eclipse Public License v1.0
icraggs 1:7fa362fa563f 6 * and Eclipse Distribution License v1.0 which accompany this distribution.
icraggs 1:7fa362fa563f 7 *
icraggs 1:7fa362fa563f 8 * The Eclipse Public License is available at
icraggs 1:7fa362fa563f 9 * http://www.eclipse.org/legal/epl-v10.html
icraggs 1:7fa362fa563f 10 * and the Eclipse Distribution License is available at
icraggs 1:7fa362fa563f 11 * http://www.eclipse.org/org/documents/edl-v10.php.
icraggs 1:7fa362fa563f 12 *
icraggs 1:7fa362fa563f 13 * Contributors:
icraggs 1:7fa362fa563f 14 * Ian Craggs - initial API and implementation and/or initial documentation
icraggs 1:7fa362fa563f 15 *******************************************************************************/
icraggs 1:7fa362fa563f 16
icraggs 1:7fa362fa563f 17 #include "MQTTSNPacket.h"
icraggs 1:7fa362fa563f 18 #include "StackTrace.h"
icraggs 1:7fa362fa563f 19
icraggs 1:7fa362fa563f 20 #include <string.h>
icraggs 1:7fa362fa563f 21
icraggs 1:7fa362fa563f 22 /**
icraggs 1:7fa362fa563f 23 * Determines the length of the MQTTSN subscribe packet that would be produced using the supplied parameters,
icraggs 1:7fa362fa563f 24 * excluding length
icraggs 1:7fa362fa563f 25 * @param topicName the topic name to be used in the publish
icraggs 1:7fa362fa563f 26 * @return the length of buffer needed to contain the serialized version of the packet
icraggs 1:7fa362fa563f 27 */
icraggs 1:7fa362fa563f 28 int MQTTSNSerialize_unsubscribeLength(MQTTSN_topicid* topicFilter)
icraggs 1:7fa362fa563f 29 {
icraggs 1:7fa362fa563f 30 int len = 4;
icraggs 1:7fa362fa563f 31
icraggs 1:7fa362fa563f 32 if (topicFilter->type == MQTTSN_TOPIC_TYPE_NORMAL)
icraggs 1:7fa362fa563f 33 len += topicFilter->data.long_.len;
icraggs 1:7fa362fa563f 34 else if (topicFilter->type == MQTTSN_TOPIC_TYPE_SHORT || topicFilter->type == MQTTSN_TOPIC_TYPE_PREDEFINED)
icraggs 1:7fa362fa563f 35 len += 2;
icraggs 1:7fa362fa563f 36
icraggs 1:7fa362fa563f 37 return len;
icraggs 1:7fa362fa563f 38 }
icraggs 1:7fa362fa563f 39
icraggs 1:7fa362fa563f 40
icraggs 1:7fa362fa563f 41 int MQTTSNSerialize_unsubscribe(unsigned char* buf, int buflen, unsigned short packetid, MQTTSN_topicid* topicFilter)
icraggs 1:7fa362fa563f 42 {
icraggs 1:7fa362fa563f 43 unsigned char *ptr = buf;
icraggs 1:7fa362fa563f 44 MQTTSNFlags flags;
icraggs 1:7fa362fa563f 45 int len = 0;
icraggs 1:7fa362fa563f 46 int rc = 0;
icraggs 1:7fa362fa563f 47
icraggs 1:7fa362fa563f 48 FUNC_ENTRY;
icraggs 1:7fa362fa563f 49 if ((len = MQTTSNPacket_len(MQTTSNSerialize_unsubscribeLength(topicFilter))) > buflen)
icraggs 1:7fa362fa563f 50 {
icraggs 1:7fa362fa563f 51 rc = MQTTSNPACKET_BUFFER_TOO_SHORT;
icraggs 1:7fa362fa563f 52 goto exit;
icraggs 1:7fa362fa563f 53 }
icraggs 1:7fa362fa563f 54 ptr += MQTTSNPacket_encode(ptr, len); /* write length */
icraggs 1:7fa362fa563f 55 MQTTSNPacket_writeChar(&ptr, MQTTSN_UNSUBSCRIBE); /* write message type */
icraggs 0:c524a894b5e8 56
icraggs 1:7fa362fa563f 57 flags.all = 0;
icraggs 1:7fa362fa563f 58 flags.bits.topicIdType = topicFilter->type;
icraggs 1:7fa362fa563f 59 MQTTSNPacket_writeChar(&ptr, flags.all);
icraggs 1:7fa362fa563f 60
icraggs 1:7fa362fa563f 61 MQTTSNPacket_writeInt(&ptr, packetid);
icraggs 1:7fa362fa563f 62
icraggs 1:7fa362fa563f 63 /* now the topic id or name */
icraggs 1:7fa362fa563f 64 if (topicFilter->type == MQTTSN_TOPIC_TYPE_NORMAL) /* means long topic name */
icraggs 1:7fa362fa563f 65 {
icraggs 1:7fa362fa563f 66 memcpy(ptr, topicFilter->data.long_.name, topicFilter->data.long_.len);
icraggs 1:7fa362fa563f 67 ptr += topicFilter->data.long_.len;
icraggs 1:7fa362fa563f 68 }
icraggs 1:7fa362fa563f 69 else if (topicFilter->type == MQTTSN_TOPIC_TYPE_PREDEFINED)
icraggs 1:7fa362fa563f 70 MQTTSNPacket_writeInt(&ptr, topicFilter->data.id);
icraggs 1:7fa362fa563f 71 else if (topicFilter->type == MQTTSN_TOPIC_TYPE_SHORT)
icraggs 1:7fa362fa563f 72 {
icraggs 1:7fa362fa563f 73 MQTTSNPacket_writeChar(&ptr, topicFilter->data.short_name[0]);
icraggs 1:7fa362fa563f 74 MQTTSNPacket_writeChar(&ptr, topicFilter->data.short_name[1]);
icraggs 1:7fa362fa563f 75 }
icraggs 1:7fa362fa563f 76
icraggs 1:7fa362fa563f 77 rc = ptr - buf;
icraggs 1:7fa362fa563f 78 exit:
icraggs 1:7fa362fa563f 79 FUNC_EXIT_RC(rc);
icraggs 1:7fa362fa563f 80 return rc;
icraggs 1:7fa362fa563f 81
icraggs 1:7fa362fa563f 82 }
icraggs 1:7fa362fa563f 83
icraggs 1:7fa362fa563f 84
icraggs 1:7fa362fa563f 85 /**
icraggs 1:7fa362fa563f 86 * Deserializes the supplied (wire) buffer into unsuback data
icraggs 1:7fa362fa563f 87 * @param packetid returned - the same value as the one contained in the corresponding SUBSCRIBE
icraggs 1:7fa362fa563f 88 * @param buf the raw buffer data, of the correct length determined by the remaining length field
icraggs 1:7fa362fa563f 89 * @param buflen the length in bytes of the data in the supplied buffer
icraggs 1:7fa362fa563f 90 * @return error code. 1 is success
icraggs 1:7fa362fa563f 91 */
icraggs 1:7fa362fa563f 92 int MQTTSNDeserialize_unsuback(unsigned short* packetid, unsigned char* buf, int buflen)
icraggs 1:7fa362fa563f 93 {
icraggs 1:7fa362fa563f 94 unsigned char* curdata = buf;
icraggs 1:7fa362fa563f 95 unsigned char* enddata = NULL;
icraggs 1:7fa362fa563f 96 int rc = 0;
icraggs 1:7fa362fa563f 97 int mylen = 0;
icraggs 1:7fa362fa563f 98
icraggs 1:7fa362fa563f 99 FUNC_ENTRY;
icraggs 1:7fa362fa563f 100 curdata += (rc = MQTTSNPacket_decode(curdata, buflen, &mylen)); /* read length */
icraggs 1:7fa362fa563f 101 enddata = buf + mylen;
icraggs 1:7fa362fa563f 102 if (enddata - curdata > buflen)
icraggs 1:7fa362fa563f 103 goto exit;
icraggs 1:7fa362fa563f 104
icraggs 1:7fa362fa563f 105 if (MQTTSNPacket_readChar(&curdata) != MQTTSN_UNSUBACK)
icraggs 1:7fa362fa563f 106 goto exit;
icraggs 1:7fa362fa563f 107
icraggs 1:7fa362fa563f 108 *packetid = MQTTSNPacket_readInt(&curdata);
icraggs 1:7fa362fa563f 109
icraggs 1:7fa362fa563f 110 rc = 1;
icraggs 1:7fa362fa563f 111 exit:
icraggs 1:7fa362fa563f 112 FUNC_EXIT_RC(rc);
icraggs 1:7fa362fa563f 113 return rc;
icraggs 1:7fa362fa563f 114 }
icraggs 1:7fa362fa563f 115
icraggs 1:7fa362fa563f 116
icraggs 1:7fa362fa563f 117
icraggs 1:7fa362fa563f 118