For a lot of protocols, reduce the number of packets after which the
protocols dissector gives up.
The values are quite arbitary, tring to not impact on classification
This piece of code has multiple problems:
* nDPI is able to detect some TCP protocols even with mid-flows (i.e.
without the initial packets of the session); TLS is the most
significative example
* since e6b332aa4a it is perfectly valid
to not pass the TCP Handshake packets to nDPI
* in any case, we shouldn't call `ndpi_detection_giveup()`. That
function is usually called by the application and we end up calling it
twice in some cases.
The simple solution is to completely remove that code: process these
kinds of flows like everyone else.
Note that the application can always avoid to pass to nDPI any TCP flows
without the initial handshake; the flow managemnt is always up to the
application.
Looking at the CI results, some rare flows are now processed significantly
longer. As a follow-up we could look into that.
In some networks, there are some anomalous TCP flows where the smallest
ACK packets have some kind of zero padding.
It looks like the IP and TCP headers in those frames wrongly consider the
0x00 Ethernet padding bytes as part of the TCP payload.
While this kind of packets is perfectly valid per-se, in some conditions
they might be treated by the TCP reassembler logic as (partial) overlaps,
deceiving the classification engine.
Add an heuristic to detect these packets and to ignore them, allowing
correct detection/classification.
This heuristic is configurable. Default value:
* in the library, it is disabled
* in `ndpiReader` and in the fuzzers, it is enabled (to ease testing)
Credit to @vel21ripn for the initial patch.
Close#1946
Extend internal unit tests to handle multiple configurations.
As some examples, add tests about:
* disabling some protocols
* disabling Ookla aggressiveness
Every configurations data is stored in a dedicated directory under
`tests\cfgs`
