MQTTSubscribeServer.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 "MQTTPacket.h"
00018 #include "StackTrace.h"
00019 
00020 #include <string.h>
00021 
00022 
00023 /**
00024   * Deserializes the supplied (wire) buffer into subscribe data
00025   * @param dup integer returned - the MQTT dup flag
00026   * @param packetid integer returned - the MQTT packet identifier
00027   * @param maxcount - the maximum number of members allowed in the topicFilters and requestedQoSs arrays
00028   * @param count - number of members in the topicFilters and requestedQoSs arrays
00029   * @param topicFilters - array of topic filter names
00030   * @param requestedQoSs - array of requested QoS
00031   * @param buf the raw buffer data, of the correct length determined by the remaining length field
00032   * @param buflen the length in bytes of the data in the supplied buffer
00033   * @return the length of the serialized data.  <= 0 indicates error
00034   */
00035 int MQTTDeserialize_subscribe(unsigned char* dup, unsigned short* packetid, int maxcount, int* count, MQTTString topicFilters[],
00036     int requestedQoSs[], unsigned char* buf, int buflen)
00037 {
00038     MQTTHeader header = {0};
00039     unsigned char* curdata = buf;
00040     unsigned char* enddata = NULL;
00041     int rc = -1;
00042     int mylen = 0;
00043 
00044     FUNC_ENTRY;
00045     header.byte = readChar(&curdata);
00046     if (header.bits.type != SUBSCRIBE)
00047         goto exit;
00048     *dup = header.bits.dup;
00049 
00050     curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */
00051     enddata = curdata + mylen;
00052 
00053     *packetid = readInt(&curdata);
00054 
00055     *count = 0;
00056     while (curdata < enddata)
00057     {
00058         if (!readMQTTLenString(&topicFilters[*count], &curdata, enddata))
00059             goto exit;
00060         if (curdata >= enddata) /* do we have enough data to read the req_qos version byte? */
00061             goto exit;
00062         requestedQoSs[*count] = readChar(&curdata);
00063         (*count)++;
00064     }
00065 
00066     rc = 1;
00067 exit:
00068     FUNC_EXIT_RC(rc);
00069     return rc;
00070 }
00071 
00072 
00073 /**
00074   * Serializes the supplied suback data into the supplied buffer, ready for sending
00075   * @param buf the buffer into which the packet will be serialized
00076   * @param buflen the length in bytes of the supplied buffer
00077   * @param packetid integer - the MQTT packet identifier
00078   * @param count - number of members in the grantedQoSs array
00079   * @param grantedQoSs - array of granted QoS
00080   * @return the length of the serialized data.  <= 0 indicates error
00081   */
00082 int MQTTSerialize_suback(unsigned char* buf, int buflen, unsigned short packetid, int count, int* grantedQoSs)
00083 {
00084     MQTTHeader header = {0};
00085     int rc = -1;
00086     unsigned char *ptr = buf;
00087     int i;
00088 
00089     FUNC_ENTRY;
00090     if (buflen < 2 + count)
00091     {
00092         rc = MQTTPACKET_BUFFER_TOO_SHORT;
00093         goto exit;
00094     }
00095     header.byte = 0;
00096     header.bits.type = SUBACK;
00097     writeChar(&ptr, header.byte); /* write header */
00098 
00099     ptr += MQTTPacket_encode(ptr, 2 + count); /* write remaining length */
00100 
00101     writeInt(&ptr, packetid);
00102 
00103     for (i = 0; i < count; ++i)
00104         writeChar(&ptr, grantedQoSs[i]);
00105 
00106     rc = ptr - buf;
00107 exit:
00108     FUNC_EXIT_RC(rc);
00109     return rc;
00110 }
00111 
00112