WIP: NGAP ran node N3IWF handling

• Validated NGAP setup request with Free5gc N3IWF ngap_setup_with_n3iwf.pcapng

  • Quick test

git clone -b non-3gpp https://gitlab.eurecom.fr/oai/cn5g/oai-cn5g-fed.git && cd oai-cn5g-fed/docker-compose
oai-cn5g-fed/docker-compose$ docker-compose -f docker-compose-basic-nrf.yaml up -d

• We assume the ran node type as Gnb during sctp association, and coundn't verify node type at this stage, so here we tranfser gnb information (context/association id) to new node context n3iwf.

• Following states are not yet validated or addressed.

  • NGAP RESET for N3IWF
  • NGAP SHUTDOWN for N3IWF (but it works since we keep original gnb context pointer)