| /******************************************************************************* |
| * 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 |
| * Ian Craggs - fix for https://bugs.eclipse.org/bugs/show_bug.cgi?id=453144 |
| *******************************************************************************/ |
| |
| #include "MQTTPacket.h" |
| #include "StackTrace.h" |
| |
| #include <string.h> |
| |
| |
| /** |
| * Determines the length of the MQTT publish packet that would be produced using the supplied parameters |
| * @param qos the MQTT QoS of the publish (packetid is omitted for QoS 0) |
| * @param topicName the topic name to be used in the publish |
| * @param payloadlen the length of the payload to be sent |
| * @return the length of buffer needed to contain the serialized version of the packet |
| */ |
| int MQTTSerialize_publishLength(int qos, MQTTString topicName, int payloadlen) |
| { |
| int len = 0; |
| |
| len += 2 + MQTTstrlen(topicName) + payloadlen; |
| if (qos > 0) |
| len += 2; /* packetid */ |
| return len; |
| } |
| |
| |
| /** |
| * Serializes the supplied publish 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 dup integer - the MQTT dup flag |
| * @param qos integer - the MQTT QoS value |
| * @param retained integer - the MQTT retained flag |
| * @param packetid integer - the MQTT packet identifier |
| * @param topicName MQTTString - the MQTT topic in the publish |
| * @param payload byte buffer - the MQTT publish payload |
| * @param payloadlen integer - the length of the MQTT payload |
| * @return the length of the serialized data. <= 0 indicates error |
| */ |
| int MQTTSerialize_publish(unsigned char* buf, int buflen, unsigned char dup, int qos, unsigned char retained, unsigned short packetid, |
| MQTTString topicName, unsigned char* payload, int payloadlen) |
| { |
| unsigned char *ptr = buf; |
| MQTTHeader header = {0}; |
| int rem_len = 0; |
| int rc = 0; |
| |
| FUNC_ENTRY; |
| if (MQTTPacket_len(rem_len = MQTTSerialize_publishLength(qos, topicName, payloadlen)) > buflen) |
| { |
| rc = MQTTPACKET_BUFFER_TOO_SHORT; |
| goto exit; |
| } |
| |
| header.bits.type = PUBLISH; |
| header.bits.dup = dup; |
| header.bits.qos = qos; |
| header.bits.retain = retained; |
| writeChar(&ptr, header.byte); /* write header */ |
| |
| ptr += MQTTPacket_encode(ptr, rem_len); /* write remaining length */; |
| |
| writeMQTTString(&ptr, topicName); |
| |
| if (qos > 0) |
| writeInt(&ptr, packetid); |
| |
| memcpy(ptr, payload, payloadlen); |
| ptr += payloadlen; |
| |
| rc = ptr - buf; |
| |
| exit: |
| FUNC_EXIT_RC(rc); |
| return rc; |
| } |
| |
| |
| |
| /** |
| * Serializes the ack packet into the supplied buffer. |
| * @param buf the buffer into which the packet will be serialized |
| * @param buflen the length in bytes of the supplied buffer |
| * @param type the MQTT packet type |
| * @param dup the MQTT dup flag |
| * @param packetid the MQTT packet identifier |
| * @return serialized length, or error if 0 |
| */ |
| int MQTTSerialize_ack(unsigned char* buf, int buflen, unsigned char packettype, unsigned char dup, unsigned short packetid) |
| { |
| MQTTHeader header = {0}; |
| int rc = 0; |
| unsigned char *ptr = buf; |
| |
| FUNC_ENTRY; |
| if (buflen < 4) |
| { |
| rc = MQTTPACKET_BUFFER_TOO_SHORT; |
| goto exit; |
| } |
| header.bits.type = packettype; |
| header.bits.dup = dup; |
| header.bits.qos = (packettype == PUBREL) ? 1 : 0; |
| writeChar(&ptr, header.byte); /* write header */ |
| |
| ptr += MQTTPacket_encode(ptr, 2); /* write remaining length */ |
| writeInt(&ptr, packetid); |
| rc = ptr - buf; |
| exit: |
| FUNC_EXIT_RC(rc); |
| return rc; |
| } |
| |
| |
| /** |
| * Serializes a puback packet into the supplied buffer. |
| * @param buf the buffer into which the packet will be serialized |
| * @param buflen the length in bytes of the supplied buffer |
| * @param packetid integer - the MQTT packet identifier |
| * @return serialized length, or error if 0 |
| */ |
| int MQTTSerialize_puback(unsigned char* buf, int buflen, unsigned short packetid) |
| { |
| return MQTTSerialize_ack(buf, buflen, PUBACK, 0, packetid); |
| } |
| |
| |
| /** |
| * Serializes a pubrel packet into the supplied buffer. |
| * @param buf the buffer into which the packet will be serialized |
| * @param buflen the length in bytes of the supplied buffer |
| * @param dup integer - the MQTT dup flag |
| * @param packetid integer - the MQTT packet identifier |
| * @return serialized length, or error if 0 |
| */ |
| int MQTTSerialize_pubrel(unsigned char* buf, int buflen, unsigned char dup, unsigned short packetid) |
| { |
| return MQTTSerialize_ack(buf, buflen, PUBREL, dup, packetid); |
| } |
| |
| |
| /** |
| * Serializes a pubrel packet into the supplied buffer. |
| * @param buf the buffer into which the packet will be serialized |
| * @param buflen the length in bytes of the supplied buffer |
| * @param packetid integer - the MQTT packet identifier |
| * @return serialized length, or error if 0 |
| */ |
| int MQTTSerialize_pubcomp(unsigned char* buf, int buflen, unsigned short packetid) |
| { |
| return MQTTSerialize_ack(buf, buflen, PUBCOMP, 0, packetid); |
| } |
| |
| |