MQTTSNSearchServer.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 "MQTTSNPacket.h"
00018 #include "StackTrace.h"
00019 
00020 #include <string.h>
00021 
00022 
00023 /**
00024   * Serializes the supplied advertise data into the supplied buffer, ready for sending
00025   * @param buf the buffer into which the packet will be serialized
00026   * @param buflen the length in bytes of the supplied buffer
00027   * @param radius the broadcast radius of this message
00028   * @param duration - the time interval until the next advertise will be sent
00029   * @return the length of the serialized data.  <= 0 indicates error
00030   */
00031 int MQTTSNSerialize_advertise(unsigned char* buf, int buflen, unsigned char gatewayid, unsigned short duration)
00032 {
00033     unsigned char *ptr = buf;
00034     int len = 0;
00035     int rc = 0;
00036 
00037     FUNC_ENTRY;
00038     if ((len = MQTTSNPacket_len(4)) > buflen)
00039     {
00040         rc = MQTTSNPACKET_BUFFER_TOO_SHORT;
00041         goto exit;
00042     }
00043     ptr += MQTTSNPacket_encode(ptr, len);   /* write length */
00044     MQTTSNPacket_writeChar(&ptr, MQTTSN_ADVERTISE);      /* write message type */
00045 
00046     MQTTSNPacket_writeChar(&ptr, gatewayid);
00047     MQTTSNPacket_writeInt(&ptr, duration);
00048 
00049     rc = ptr - buf;
00050 exit:
00051     FUNC_EXIT_RC(rc);
00052     return rc;
00053 }
00054 
00055 
00056 /**
00057   * Deserializes the supplied (wire) buffer into searchgw data
00058   * @param radius the returned broadcast radius of this message
00059   * @param buf the raw buffer data, of the correct length determined by the remaining length field
00060   * @param buflen the length in bytes of the data in the supplied buffer
00061   * @return error code.  1 is success
00062   */
00063 int MQTTSNDeserialize_searchgw(unsigned char* radius, unsigned char* buf, int buflen)
00064 {
00065     unsigned char* curdata = buf;
00066     unsigned char* enddata = NULL;
00067     int rc = 0;
00068     int mylen = 0;
00069 
00070     FUNC_ENTRY;
00071     curdata += (rc = MQTTSNPacket_decode(curdata, buflen, &mylen)); /* read length */
00072     enddata = buf + mylen;
00073     if (enddata - curdata > buflen)
00074         goto exit;
00075 
00076     if (MQTTSNPacket_readChar(&curdata) != MQTTSN_SEARCHGW)
00077         goto exit;
00078 
00079     *radius = MQTTSNPacket_readChar(&curdata);
00080 
00081     rc = 1;
00082 exit:
00083     FUNC_EXIT_RC(rc);
00084     return rc;
00085 }
00086 
00087 
00088 /**
00089   * Serializes the supplied gwinfo data into the supplied buffer, ready for sending
00090   * @param buf the buffer into which the packet will be serialized
00091   * @param buflen the length in bytes of the supplied buffer
00092   * @param gatewayid the gateway id
00093   * @param gatewayaddress_len the optional length of the gateway address (0 if none)
00094   * @param gatewayaddress the optional gateway address (NULL if none)
00095   * @return the length of the serialized data.  <= 0 indicates error
00096   */
00097 int MQTTSNSerialize_gwinfo(unsigned char* buf, int buflen, unsigned char gatewayid, unsigned short gatewayaddress_len,
00098         unsigned char* gatewayaddress)
00099 {
00100     unsigned char *ptr = buf;
00101     int len = 0;
00102     int rc = 0;
00103 
00104     FUNC_ENTRY;
00105     if ((len = MQTTSNPacket_len(2 + gatewayaddress_len)) > buflen)
00106     {
00107         rc = MQTTSNPACKET_BUFFER_TOO_SHORT;
00108         goto exit;
00109     }
00110     ptr += MQTTSNPacket_encode(ptr, len);   /* write length */
00111     MQTTSNPacket_writeChar(&ptr, MQTTSN_GWINFO);      /* write message type */
00112 
00113     MQTTSNPacket_writeChar(&ptr, gatewayid);
00114     if (gatewayaddress_len > 0 && gatewayaddress != NULL)
00115     {
00116         memcpy(ptr, gatewayaddress, gatewayaddress_len);
00117         ptr += gatewayaddress_len;
00118     }
00119 
00120     rc = ptr - buf;
00121 exit:
00122     FUNC_EXIT_RC(rc);
00123     return rc;
00124 
00125 }
00126 
00127 
00128 
00129