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.
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.
When switching to (D)TLS dissector from the STUN one, we need to clear
any flow risks set from the latter (because we don't have anymore
`NDPI_PROTOCOL_STUN` in the classification results)
Keep demultiplexing STUN/RTP/RTCP packets after DTLS ones.
We might end up processing the session a little longer, because we will
process the STUN/RTP/RTCP packets after the DTLS handshake.
Try to have a faster classification, on first packet; use standard extra
dissection data path for sub-classification, metadata extraction and
monitoring.
STUN caches:
* use the proper confidence value
* lookup into the caches only once per flow, after having found a proper
STUN classification
Add identification of Telegram VoIP calls.
