MQTTSNDeserializePublish.c

00001 /*******************************************************************************
00002  * Copyright (c) 2014 IBM Corp.
00003  *
00004  * All rights reserved. This program and the accompanying materials
00005  * are made available under the terms of the Eclipse Public License v1.0
00006  * and Eclipse Distribution License v1.0 which accompany this distribution.
00007  *
00008  * The Eclipse Public License is available at
00009  *    http://www.eclipse.org/legal/epl-v10.html
00010  * and the Eclipse Distribution License is available at
00011  *   http://www.eclipse.org/org/documents/edl-v10.php.
00012  *
00013  * Contributors:
00014  *    Ian Craggs - initial API and implementation and/or initial documentation
00015  *******************************************************************************/
00016 
00017 #include "StackTrace.h"
00018 #include "MQTTSNPacket.h"
00019 #include <string.h>
00020 
00021 #define min(a, b) ((a < b) ? 1 : 0)
00022 
00023 /**
00024   * Deserializes the supplied (wire) buffer into publish data
00025   * @param dup returned integer - the MQTT dup flag
00026   * @param qos returned integer - the MQTT QoS value
00027   * @param retained returned integer - the MQTT retained flag
00028   * @param packetid returned integer - the MQTT packet identifier
00029   * @param topicName returned MQTTSNString - the MQTT topic in the publish
00030   * @param payload returned byte buffer - the MQTT publish payload
00031   * @param payloadlen returned integer - the length of the MQTT payload
00032   * @param buf the raw buffer data, of the correct length determined by the remaining length field
00033   * @param buflen the length in bytes of the data in the supplied buffer
00034   * @return error code.  1 is success
00035   */
00036 int MQTTSNDeserialize_publish(unsigned char* dup, int* qos, unsigned char* retained, unsigned short* packetid, MQTTSN_topicid* topic,
00037         unsigned char** payload, int* payloadlen, unsigned char* buf, int buflen)
00038 {
00039     MQTTSNFlags flags;
00040     unsigned char* curdata = buf;
00041     unsigned char* enddata = NULL;
00042     int rc = 0;
00043     int mylen = 0;
00044 
00045     FUNC_ENTRY;
00046     curdata += (rc = MQTTSNPacket_decode(curdata, buflen, &mylen)); /* read length */
00047     enddata = buf + mylen;
00048     if (enddata - curdata > buflen)
00049         goto exit;
00050 
00051     if (MQTTSNPacket_readChar(&curdata) != MQTTSN_PUBLISH)
00052         goto exit;
00053 
00054     flags.all = MQTTSNPacket_readChar(&curdata);
00055     *dup = flags.bits.dup;
00056     *qos = flags.bits.QoS;
00057     *retained = flags.bits.retain;
00058 
00059     topic->type = flags.bits.topicIdType;
00060     if (topic->type == MQTTSN_TOPIC_TYPE_NORMAL && *qos == 3)
00061     {
00062         /* special arrangement for long topic names in QoS -1 publishes.  The length of the topic is in the topicid field */
00063         topic->data.long_.len = MQTTSNPacket_readInt(&curdata);
00064     }
00065     else if (topic->type == MQTTSN_TOPIC_TYPE_NORMAL || topic->type == MQTTSN_TOPIC_TYPE_PREDEFINED)
00066         topic->data.id = MQTTSNPacket_readInt(&curdata);
00067     else
00068     {
00069         topic->data.short_name[0] = MQTTSNPacket_readChar(&curdata);
00070         topic->data.short_name[1] = MQTTSNPacket_readChar(&curdata);
00071     }
00072     *packetid = MQTTSNPacket_readInt(&curdata);
00073 
00074     if (topic->type == MQTTSN_TOPIC_TYPE_NORMAL && *qos == 3)
00075     {
00076         topic->data.long_.name = (char*)curdata;
00077         curdata += topic->data.long_.len;
00078     }
00079 
00080     *payloadlen = enddata - curdata;
00081     *payload = curdata;
00082     rc = 1;
00083 exit:
00084     FUNC_EXIT_RC(rc);
00085     return rc;
00086 }
00087 
00088 
00089 int MQTTSNDeserialize_puback(unsigned short* topicid, unsigned short* packetid,
00090         unsigned char* returncode, unsigned char* buf, int buflen)
00091 {
00092     unsigned char* curdata = buf;
00093     unsigned char* enddata = NULL;
00094     int rc = 0;
00095     int mylen = 0;
00096 
00097     FUNC_ENTRY;
00098     curdata += (rc = MQTTSNPacket_decode(curdata, buflen, &mylen)); /* read length */
00099     enddata = buf + mylen;
00100     if (enddata - curdata > buflen)
00101         goto exit;
00102 
00103     if (MQTTSNPacket_readChar(&curdata) != MQTTSN_PUBACK)
00104         goto exit;
00105 
00106     *topicid = MQTTSNPacket_readInt(&curdata);
00107     *packetid = MQTTSNPacket_readInt(&curdata);
00108     *returncode = MQTTSNPacket_readChar(&curdata);
00109 
00110     rc = 1;
00111 exit:
00112     FUNC_EXIT_RC(rc);
00113     return rc;
00114 }
00115 
00116 
00117 /**
00118   * Deserializes the supplied (wire) buffer into an ack
00119   * @param packettype returned integer - the MQTT packet type
00120   * @param packetid returned integer - the MQTT packet identifier
00121   * @param buf the raw buffer data, of the correct length determined by the remaining length field
00122   * @param buflen the length in bytes of the data in the supplied buffer
00123   * @return error code.  1 is success, 0 is failure
00124   */
00125 int MQTTSNDeserialize_ack(unsigned char* type, unsigned short* packetid, unsigned char* buf, int buflen)
00126 {
00127     unsigned char* curdata = buf;
00128     unsigned char* enddata = NULL;
00129     int rc = 0;
00130     int mylen = 0;
00131 
00132     FUNC_ENTRY;
00133     curdata += (rc = MQTTSNPacket_decode(curdata, buflen, &mylen)); /* read length */
00134     enddata = buf + mylen;
00135     if (enddata - curdata > buflen)
00136         goto exit;
00137 
00138     *type = MQTTSNPacket_readChar(&curdata);
00139     if (*type != MQTTSN_PUBREL && *type != MQTTSN_PUBREC && *type != MQTTSN_PUBCOMP)
00140         goto exit;
00141 
00142     *packetid = MQTTSNPacket_readInt(&curdata);
00143 
00144     rc = 1;
00145 exit:
00146     FUNC_EXIT_RC(rc);
00147     return rc;
00148 }
00149 
00150 
00151 /**
00152   * Deserializes the supplied (wire) buffer into register data
00153   * @param topicid returned topic id
00154   * @param packetid returned integer - the MQTT packet identifier
00155   * @param topicName returned MQTTSNString - the MQTT topic in the register
00156   * @param buf the raw buffer data, of the correct length determined by the remaining length field
00157   * @param buflen the length in bytes of the data in the supplied buffer
00158   * @return error code.  1 is success
00159   */
00160 int MQTTSNDeserialize_register(unsigned short* topicid, unsigned short* packetid, MQTTSNString* topicname,
00161         unsigned char* buf, int buflen)
00162 {
00163     unsigned char* curdata = buf;
00164     unsigned char* enddata = NULL;
00165     int rc = 0;
00166     int mylen = 0;
00167 
00168     FUNC_ENTRY;
00169     curdata += (rc = MQTTSNPacket_decode(curdata, buflen, &mylen)); /* read length */
00170     enddata = buf + mylen;
00171     if (enddata - curdata > buflen)
00172         goto exit;
00173 
00174     if (MQTTSNPacket_readChar(&curdata) != MQTTSN_REGISTER)
00175         goto exit;
00176 
00177     *topicid = MQTTSNPacket_readInt(&curdata);
00178     *packetid = MQTTSNPacket_readInt(&curdata);
00179 
00180     topicname->lenstring.data = (char*)curdata;
00181     topicname->lenstring.len = enddata - curdata;
00182     topicname->cstring = NULL;
00183 
00184     rc = 1;
00185 exit:
00186     FUNC_EXIT_RC(rc);
00187     return rc;
00188 }
00189 
00190 
00191 /**
00192   * Deserializes the supplied (wire) buffer into register data
00193   * @param topicid returned topic id
00194   * @param packetid returned integer - the MQTT packet identifier
00195   * @param return_code returned integer return code
00196   * @param buf the raw buffer data, of the correct length determined by the remaining length field
00197   * @param buflen the length in bytes of the data in the supplied buffer
00198   * @return error code.  1 is success
00199   */
00200 int MQTTSNDeserialize_regack(unsigned short* topicid, unsigned short* packetid, unsigned char* return_code,
00201         unsigned char* buf, int buflen)
00202 {
00203     unsigned char* curdata = buf;
00204     unsigned char* enddata = NULL;
00205     int rc = 0;
00206     int mylen = 0;
00207 
00208     FUNC_ENTRY;
00209     curdata += (rc = MQTTSNPacket_decode(curdata, buflen, &mylen)); /* read length */
00210     enddata = buf + mylen;
00211     if (enddata - curdata > buflen)
00212         goto exit;
00213 
00214     if (MQTTSNPacket_readChar(&curdata) != MQTTSN_REGACK)
00215         goto exit;
00216 
00217     *topicid = MQTTSNPacket_readInt(&curdata);
00218     *packetid = MQTTSNPacket_readInt(&curdata);
00219     *return_code = MQTTSNPacket_readChar(&curdata);
00220 
00221     rc = 1;
00222 exit:
00223     FUNC_EXIT_RC(rc);
00224     return rc;
00225 }
00226