Provide an explicit state for the flow classification process

[IvanNardi]

Application should keep calling nDPI until flow state became
NDPI_STATE_CLASSIFIED.

The main loop in the application is simplified to something like:

res = ndpi_detection_process_packet(...);
if(res->state == NDPI_STATE_CLASSIFIED) {
  /* Done: you can get finale classification and all metadata.
     nDPI doesn't need more packets for this flow */
} else {
  /* nDPI needs more packets for this flow. The provided
     classification is not final and more metadata might be
     extracted.
     If `res->state` is `NDPI_STATE_PARTIAL`, partial/initial
     classification is available in `flow->detected_protocol_stack[]`
     as usual but it can be updated later.
  */
}

/*
    Example A (QUIC flow):
     pkt 1: proto QUIC state NDPI_STATE_PARTIAL
     pkt 2: proto QUIC/Youtube  state NDPI_STATE_CLASSIFIED
    Example B (GoogleMeet call):
     pkt 1:   proto STUN state NDPI_STATE_PARTIAL
     pkt N:   proto DTLS state NDPI_STATE_PARTIAL
     pkt N+M: proto DTLS/GoogleCall state NDPI_STATE_CLASSIFIED
    Example C (standard TLS flow):
     pkt 1:   proto Unknown state NDPI_STATE_INSPECTING
     pkt 2:   proto Unknown state NDPI_STATE_INSPECTING
     pkt 3:   proto Unknown state NDPI_STATE_INSPECTING
     pkt 4:   proto TLS/Facebook state NDPI_STATE_PARTIAL
     pkt N:   proto TLS/Facebook state NDPI_STATE_CLASSIFIED
 */
}

You can take a look at ndpiReader for a slightly more complex example.

API changes:

• remove the third parameter from ndpi_detection_giveup(). If you need
  to know if the classification flow has been guessed, you can access
  flow->protocol_was_guessed
• remove ndpi_extra_dissection_possible()
• change some prototypes from accepting ndpi_protocol foo to
  ndpi_master_app_protocol bar. The update is trivial: from foo to
  foo.proto

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud