We only try to parse a small subset of what is possible in
RFB. Currently we only understand some standard auth schemes
and stop parsing when the server-client handshake is complete.
Since in IPS mode returning an error from the parser causes
drops that are likely uncalled for, we do not want to return
errors when we simply do not understand what happens in the
traffic. This addresses Redmine #5912.
Bug: #5912.
Common /usr/share/suricata/rules or /usr/local/share/suricata/rules.
The rules provided by the distribution are installed here as part
of the Suricata install process so will always be installed, even
without the use of install-rules.
Decode Modbus request and response messages, and extracts
MODBUS Application Protocol header and the code function.
In case of read/write function, extracts message contents
(read/write address, quantity, count, data to write).
Links request and response messages in a transaction according to
Transaction Identifier (transaction management based on DNS source code).
MODBUS Messaging on TCP/IP Implementation Guide V1.0b
(http://www.modbus.org/docs/Modbus_Messaging_Implementation_Guide_V1_0b.pdf)
MODBUS Application Protocol Specification V1.1b3
(http://www.modbus.org/docs/Modbus_Application_Protocol_V1_1b3.pdf)
Based on DNS source code.
Signed-off-by: David DIALLO <diallo@et.esia.fr>