hero123457/qtmqtt
1
0
Fork 0
mirror of https://github.com/qt/qtmqtt.git synced 2026-10-25 16:16:26 +00:00
Code Issues Projects Releases Wiki Activity

Ensure valid read buffer when parsing the fixed header

Browse Source 
Since the remaining length can be up to 4 bytes long make sure that
there are enough bytes transmitted to parse the fix header correctly.

Change-Id: I3830d3abb308c86048cac3a00a80067194caa482
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@qt.io>
This commit is contained in:
Lorenz Haas 2017-10-11 08:28:24 +02:00 committed by Maurice Kalinowski
parent 7b41e6039f
commit 460e466c3f
1 changed files with 8 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
src/mqtt/qmqttconnection.cpp
View File

@ -735,8 +735,15 @@ void QMqttConnection::processData()
m_missingData = 0;
}
if (m_readBuffer.size() == 0)
// MQTT-2.2 A fixed header of a control packet must be at least 2 bytes. If the payload is
// longer than 127 bytes the header can be up to 5 bytes long.
const int readBufferSize = m_readBuffer.size();
if (readBufferSize < 2
|| (readBufferSize == 2 && (m_readBuffer.at(1) & 128) != 0)
|| (readBufferSize == 3 && (m_readBuffer.at(2) & 128) != 0)
|| (readBufferSize == 4 && (m_readBuffer.at(3) & 128) != 0)) {
return;
}
readBuffer((char*)&m_currentPacket, 1);