After a flow has been classified as RTP or RTCP, nDPI might analyse more
packets to look for STUN/DTLS packets, i.e. to try to tell if this flow
is a "pure" RTP/RTCP flow or if the RTP/RTCP packets are multiplexed with
STUN/DTLS.
Useful for proper (sub)classification when the beginning of the flows
are not captured or if there are lost packets in the the captured traffic.
Disabled by default
IRC has its best times well behind, but there are still some servers
using it.
We should try to simplify the detection logic, still based on OpenDPI
logic.
Let's start with some easy changes:
* try to detect TLS connection via standard hostname/SNI matching,
removing an old heuristic (we have never had any trace matching it);
* add some basic server names;
* once we detect that the flow is IRC, we don't have to perform
anything else;
* remove HTTP stuff; real HTTP flows never trigger that data path
* use `ndpi_memmem()` when possible
This cache was added in b6b4967aa, when there was no real Zoom support.
With 63f349319, a proper identification of multimedia stream has been
added, making this cache quite useless: any improvements on Zoom
classification should be properly done in Zoom dissector.
Tested for some months with a few 10Gbits links of residential traffic: the
cache pretty much never returned a valid hit.
P2P video player PPStream was discontinued shortly after the purchase of PPS.tv by Baidu (iQIYI) on 2013 (see https://www.techinasia.com/report-baidu-acquires-video-rival-pps)
So we remove the old `NDPI_PROTOCOL_PPSTREAM` logic and add `NDPI_PROTOCOL_IQIYI` id to handle all the iQIYI traffic, which is basically video streaming traffic.
A video hosting service, called PPS.tv, is still offered by the same company: for the time being we classified both services with the same protocol id.
* Add The Elder Scrolls Online support
* Use ndpi_memmem instead of memmem from libc
* Add protocol description
* Change selection bitmask to V4_V6
* Update protocols.rst
Enable parsing of Mapped-Address attribute for all STUN flows: that
means that STUN classification might require more packets.
Add a configuration knob to enable/disable this feature.
Note that we can have (any) STUN metadata also for flows *not*
classified as STUN (because of DTLS).
Add support for ipv6.
Restore the correct extra dissection logic for Telegram flows.
* Add detection of Gaijin Entertainment games
* Short NDPI_PROTOCOL_GAIJINENTERTAINMENT to NDPI_PROTOCOL_GAIJIN
* Add default UDP port for Gaijin Entertainment games
* Remove NDPI_PROTOCOL_CROSSOUT protocol id
Add the concept of "global context".
Right now every instance of `struct ndpi_detection_module_struct` (we
will call it "local context" in this description) is completely
independent from each other. This provide optimal performances in
multithreaded environment, where we pin each local context to a thread,
and each thread to a specific CPU core: we don't have any data shared
across the cores.
Each local context has, internally, also some information correlating
**different** flows; something like:
```
if flow1 (PeerA <-> Peer B) is PROTOCOL_X; then
flow2 (PeerC <-> PeerD) will be PROTOCOL_Y
```
To get optimal classification results, both flow1 and flow2 must be
processed by the same local context. This is not an issue at all in the far
most common scenario where there is only one local context, but it might
be impractical in some more complex scenarios.
Create the concept of "global context": multiple local contexts can use
the same global context and share some data (structures) using it.
This way the data correlating multiple flows can be read/write from
different local contexts.
This is an optional feature, disabled by default.
Obviously data structures shared in a global context must be thread safe.
This PR updates the code of the LRU implementation to be, optionally,
thread safe.
Right now, only the LRU caches can be shared; the other main structures
(trees and automas) are basically read-only: there is little sense in
sharing them. Furthermore, these structures don't have any information
correlating multiple flows.
Every LRU cache can be shared, independently from the others, via
`ndpi_set_config(ndpi_struct, NULL, "lru.$CACHE_NAME.scope", "1")`.
It's up to the user to find the right trade-off between performances
(i.e. without shared data) and classification results (i.e. with some
shared data among the local contexts), depending on the specific traffic
patterns and on the algorithms used to balance the flows across the
threads/cores/local contexts.
Add some basic examples of library initialization in
`doc/library_initialization.md`.
This code needs libpthread as external dependency. It shouldn't be a big
issue; however a configure flag has been added to disable global context
support. A new CI job has been added to test it.
TODO: we should need to find a proper way to add some tests on
multithreaded enviroment... not an easy task...
*** API changes ***
If you are not interested in this feature, simply add a NULL parameter to
any `ndpi_init_detection_module()` calls.
