| /******************************************************************************* |
| * 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 "MQTTPacket.h" |
| #include "StackTrace.h" |
| |
| #include <string.h> |
| |
| /** |
| * Determines the length of the MQTT subscribe packet that would be produced using the supplied parameters |
| * @param count the number of topic filter strings in topicFilters |
| * @param topicFilters the array of topic filter strings to be used in the publish |
| * @return the length of buffer needed to contain the serialized version of the packet |
| */ |
| int MQTTSerialize_subscribeLength(int count, MQTTString topicFilters[]) |
| { |
| int i; |
| int len = 2; /* packetid */ |
| |
| for (i = 0; i < count; ++i) |
| len += 2 + MQTTstrlen(topicFilters[i]) + 1; /* length + topic + req_qos */ |
| return len; |
| } |
| |
| |
| /** |
| * Serializes the supplied subscribe 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 bufferr |
| * @param dup integer - the MQTT dup flag |
| * @param packetid integer - the MQTT packet identifier |
| * @param count - number of members in the topicFilters and reqQos arrays |
| * @param topicFilters - array of topic filter names |
| * @param requestedQoSs - array of requested QoS |
| * @return the length of the serialized data. <= 0 indicates error |
| */ |
| int MQTTSerialize_subscribe(unsigned char* buf, int buflen, unsigned char dup, unsigned short packetid, int count, |
| MQTTString topicFilters[], int requestedQoSs[]) |
| { |
| unsigned char *ptr = buf; |
| MQTTHeader header = {0}; |
| int rem_len = 0; |
| int rc = 0; |
| int i = 0; |
| |
| FUNC_ENTRY; |
| if (MQTTPacket_len(rem_len = MQTTSerialize_subscribeLength(count, topicFilters)) > buflen) |
| { |
| rc = MQTTPACKET_BUFFER_TOO_SHORT; |
| goto exit; |
| } |
| |
| header.byte = 0; |
| header.bits.type = SUBSCRIBE; |
| header.bits.dup = dup; |
| header.bits.qos = 1; |
| writeChar(&ptr, header.byte); /* write header */ |
| |
| ptr += MQTTPacket_encode(ptr, rem_len); /* write remaining length */; |
| |
| writeInt(&ptr, packetid); |
| |
| for (i = 0; i < count; ++i) |
| { |
| writeMQTTString(&ptr, topicFilters[i]); |
| writeChar(&ptr, requestedQoSs[i]); |
| } |
| |
| rc = ptr - buf; |
| exit: |
| FUNC_EXIT_RC(rc); |
| return rc; |
| } |
| |
| |
| |
| /** |
| * Deserializes the supplied (wire) buffer into suback data |
| * @param packetid returned integer - the MQTT packet identifier |
| * @param maxcount - the maximum number of members allowed in the grantedQoSs array |
| * @param count returned integer - number of members in the grantedQoSs array |
| * @param grantedQoSs returned array of integers - the granted qualities of service |
| * @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, 0 is failure |
| */ |
| int MQTTDeserialize_suback(unsigned short* packetid, int maxcount, int* count, int grantedQoSs[], unsigned char* buf, int buflen) |
| { |
| MQTTHeader header = {0}; |
| unsigned char* curdata = buf; |
| unsigned char* enddata = NULL; |
| int rc = 0; |
| int mylen; |
| |
| FUNC_ENTRY; |
| header.byte = readChar(&curdata); |
| if (header.bits.type != SUBACK) |
| goto exit; |
| |
| curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */ |
| enddata = curdata + mylen; |
| if (enddata - curdata < 2) |
| goto exit; |
| |
| *packetid = readInt(&curdata); |
| |
| *count = 0; |
| while (curdata < enddata) |
| { |
| if (*count > maxcount) |
| { |
| rc = -1; |
| goto exit; |
| } |
| grantedQoSs[(*count)++] = readChar(&curdata); |
| } |
| |
| rc = 1; |
| exit: |
| FUNC_EXIT_RC(rc); |
| return rc; |
| } |
| |
| |