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
Diff: MQTTSNSubscribeServer.c
- Revision:
- 0:c524a894b5e8
- Child:
- 1:7fa362fa563f
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MQTTSNSubscribeServer.c Thu Feb 26 15:59:36 2015 +0000 @@ -0,0 +1,120 @@ +/******************************************************************************* + * Copyright (c) 2014 IBM Corp. + * + * All rights reserved. This program and the accompanying materials + * are made available under the terms of the Eclipse Public License v1.0 + * and Eclipse Distribution License v1.0 which accompany this distribution. + * + * The Eclipse Public License is available at + * http://www.eclipse.org/legal/epl-v10.html + * and the Eclipse Distribution License is available at + * http://www.eclipse.org/org/documents/edl-v10.php. + * + * Contributors: + * Ian Craggs - initial API and implementation and/or initial documentation + *******************************************************************************/ + +#include "StackTrace.h" +#include "MQTTSNPacket.h" +#include <string.h> + + +/** + * Deserializes the supplied (wire) buffer into subscribe data + * @param dup the returned MQTT-SN dup flag + * @param qos the returned qos + * @param packetid returned - the same value as the one contained in the corresponding SUBSCRIBE + * @param topicFilter returned - the topic filter - normal, predefined or short + * @param buf the raw buffer data, of the correct length determined by the remaining length field + * @param buflen the length in bytes of the data in the supplied buffer + * @return error code. 1 is success + */ +int MQTTSNDeserialize_subscribe(unsigned char* dup, int* qos, unsigned short* packetid, + MQTTSN_topicid* topicFilter, unsigned char* buf, int buflen) +{ + MQTTSNFlags flags = {0}; + unsigned char* curdata = buf; + unsigned char* enddata = NULL; + int rc = 0; + int mylen = 0; + + FUNC_ENTRY; + curdata += (rc = MQTTSNPacket_decode(curdata, buflen, &mylen)); /* read length */ + enddata = buf + mylen; + if (enddata - curdata > buflen) + goto exit; + + if (readChar(&curdata) != MQTTSN_SUBSCRIBE) + goto exit; + + flags.all = readChar(&curdata); + *dup = flags.bits.dup; + *qos = flags.bits.QoS; + + *packetid = readInt(&curdata); + + topicFilter->type = flags.bits.topicIdType; + + if (topicFilter->type == MQTTSN_TOPIC_TYPE_NORMAL) + { + topicFilter->data.long_.len = enddata - curdata; + topicFilter->data.long_.name = (char*)curdata; + } + else if (topicFilter->type == MQTTSN_TOPIC_TYPE_PREDEFINED) + topicFilter->data.id = readInt(&curdata); + else if (topicFilter->type == MQTTSN_TOPIC_TYPE_SHORT) + { + topicFilter->data.short_name[0] = readChar(&curdata); + topicFilter->data.short_name[1] = readChar(&curdata); + } + + rc = 1; +exit: + FUNC_EXIT_RC(rc); + return rc; +} + + +/** + * Serializes the supplied suback data into the supplied buffer, ready for sending + * @param buf the buffer into which the packet will be serialized + * @param buflen the length in bytes of the supplied buffer + * @param qos integer - the MQTT-SN QoS value + * @param topicid if "accepted" the value which will be used by the gateway in subsequent PUBLISH packets + * @param packetid integer - the MQTT-SN packet identifier + * @param returncode returned - "accepted" or rejection reason + * @return the length of the serialized data. <= 0 indicates error + */ +int MQTTSNSerialize_suback(unsigned char* buf, int buflen, int qos, unsigned short topicid, unsigned short packetid, + unsigned char returncode) +{ + MQTTSNFlags flags = {0}; + unsigned char *ptr = buf; + int len = 0; + int rc = 0; + + FUNC_ENTRY; + if ((len = MQTTSNPacket_len(7)) > buflen) + { + rc = MQTTSNPACKET_BUFFER_TOO_SHORT; + goto exit; + } + ptr += MQTTSNPacket_encode(ptr, len); /* write length */ + writeChar(&ptr, MQTTSN_SUBACK); /* write message type */ + + flags.all = 0; + flags.bits.QoS = qos; + writeChar(&ptr, flags.all); + + writeInt(&ptr, topicid); + writeInt(&ptr, packetid); + writeChar(&ptr, returncode); + + rc = ptr - buf; +exit: + FUNC_EXIT_RC(rc); + return rc; +} + + +