If the UE continuously attempts to Attach while changing PDN Type,
it will cause the wrong IP to be assigned.
(e.g PDU-Type : IPv4v6 -> IPv4 -> IPv4v6)
This is because we use two variables at the same time,
one to read and store the Static IP from the Subscriber DB and
one to store the IP assigned from SMF, called session->paa.
When the UE attaches with PDN-Type set to IPv4v6,
MME saves the allocated IP in session->paa.
However, MME thinks it has been assigned a static IP based on the information
in session->paa, so changing the PDN-Type may result in the wrong IP
being assigned.
To solve this problem, I separated the variable(session->paa) that stores
the allocated IP received from SMF and the variable(session->ue_ip) that stores
the Static IP read from the Subscriber DB.
Therefore, the information read from the Subscriber DB
(session->session_type and session->ue_ip) should not be modified.
First of all, it crashes when creating a Dedicated Bearer
on the default Session that is created for the first time.
This behavior should be possible, so the related ASSERT is removed.
Next, the InitialContextRequest is modified
during the Attach Request to include the first Bearer.
Finally, there was an issue where trying to create a Dedicated Bearer
with SGsAP enabled resulted in an InitialContextSetupRequest message
with a PTI of zero. This is because MME initializes the PTI to 0
upon receiving the Create Bearer Request while processing SGsAP.
All of these issues has been fixed.
1. According to ETSI TS 129 118 4.1, if the Network Access Mode (NAM) is set
to "Packet only," no SGs association should be established.
2. If the NAM is set to "Packet and Circuit," and the SGs association is
rejected by the CS core, this rejection should only impact
the SGs association itself and not result in a UE attach rejection
for a UE with a valid HSS account.
o Generate the private key as below.
$ openssl genpkey -algorithm X25519 -out /etc/open5gs/hnet/curve25519-1.key
$ openssl ecparam -name prime256v1 -genkey -conv_form compressed -out /etc/open5gs/hnet/secp256r1-2.key
o The private and public keys can be viewed with the command.
The public key is used when creating the SIM.
$ openssl pkey -in /etc/open5gs/hnet/curve25519-1.key -text
$ openssl ec -in /etc/open5gs/hnet/secp256r1-2.key -conv_form compressed -text
In ausf/udm.yaml
hnet:
o Home network public key identifier(PKI) value : 1
Protection scheme identifier : ECIES scheme profile A
- id: 1
scheme: 1
key: /etc/open5gs/hnet/curve25519-1.key
o Home network public key identifier(PKI) value : 2
Protection scheme identifier : ECIES scheme profile B
- id: 2
scheme: 2
key: /etc/open5gs/hnet/secp256r1-2.key
o Home network public key identifier(PKI) value : 3
Protection scheme identifier : ECIES scheme profile A
- id: 3
scheme: 1
key: /etc/open5gs/hnet/curve25519-1.key
o Home network public key identifier(PKI) value : 4
Protection scheme identifier : ECIES scheme profile B
- id: 4
scheme: 2
key: /etc/open5gs/hnet/secp256r1-2.key
Related to #1779
In the past only GTPv2C was supported, and had the "gtp" generic prefix.
Later on, GTPv1C support was added, and "gtp1" prefix was used.
Let's move GTPv2C specific bits to have "gtp2" prefix too, and leave
"gtp" prefix for generic stuff among different GTP versions.
