Fix bug "no AMF for UE"
It might happen that the RRC does not know the AMF UE NGAP ID, yet. Even
in that case, we should forward the release request to the NGAP module,
which can either forward a message to the AMF, or reply back to release
the UE. This avoids an error where the CU claims there was no AMF, when
there actually is.
One possible problematic behavior is if a UE disconnects before the gNB
receives an NGAP Initial Context Setup. In this case, the AMF UE NGAP ID
was not forwarded to the RRC (although it was known at NGAP), thus
blocking the release of the UE.
This is the main fix, the rest are minor fixes:
- store AMF UE NGAP ID as early as possible
- warn in MAC if UE unknown for UE context release command
- show TEIDs with correct endianness in GTP
- avoid NG Setup Failure+Setup log.
In the Initial Context Setup message, the NGAP forwards the AMF UE ID,
but not in the DL NAS Message, although 38.413 says, in $8.3.1.2 either
> The NG-RAN node shall use the AMF UE NGAP ID IE and RAN UE NGAP ID IE
> received in the INITIAL CONTEXT SETUP REQUEST message as identification
> of the logical connection
or in $8.6.2.2
> The NG-RAN node shall use the AMF UE NGAP ID IE and RAN UE NGAP ID IE
> received in the DOWNLINK NAS TRANSPORT message as identification of the
> logical connection
So forward in both cases for harmonization.
It might happen that the RRC does not know the AMF UE NGAP ID, yet. Even
in that case, we should forward the release request to the NGAP module,
which can either forward a message to the AMF, or reply back to release
the UE.
Reported-By: Jegor Zelenjak <jzelenjak@proton.me>
NR NGAP (N2HO) : Fix Time UE Stayed in Cell IE type and calculation
According to 3GPP TS 38.413, the 'Time UE Stayed in Cell' IE is an
integer ranging from 0 to 4095. This patch updates the data structure
to reflect the correct bit width and implements the dynamic calculation
based on the UE's residence time.
- Change time_in_cell from long to uint16_t in ngap_messages_types.h.
- Replace dummy value with real-time calculation in rrc_gNB_NGAP.c.
- Implement a ceiling of 4095 to comply with the 12-bit protocol limit.
Ref: 3GPP TS 38.413 Section 9.3.1.97
Refactor key derivation logic to properly handle Next Hop (NH) chain
synchronization according to 3GPP TS 33.501 specifications for both RRC
Reestablishment and Master Key Update procedures.
Changes in rrc_gNB.c:
- Clarify key derivation in rrc_gNB_generate_RRCReestablishment by explicitly
selecting base key (NH or KgNB) based on nh_ncc value
- Add comment explaining vertical vs horizontal derivation logic
Changes in rrc_UE.c:
Refactored the NH chain synchronization and key derivation code to match
TS 33.501 terminology:
- nr_sync_nh_chain(): Common helper to synchronize NH parameter chain per
TS 33.501 Annex A.10, supporting both Master Key Update and RRC Reestablishment
procedures
- nr_derive_kgnb_horizontal(): Derive KNG-RAN* from current KgNB when NCC values
match (horizontal derivation per TS 33.501 A.11/A.12)
- nr_derive_kgnb_vertical(): Derive KNG-RAN* from synchronized NH after NH chain
sync (vertical derivation per TS 33.501 A.11/A.12)
- nr_update_kgnb_from_ncc(): Unified function implementing TS 33.501 6.9.2.3.4
logic for updating KgNB based on received nextHopChainingCount
- Refactor as_security_key_update(): Use new nr_update_kgnb_from_ncc() helper
function for cleaner, more maintainable code
- Fix nr_rrc_ue_process_rrcReestablishment(): Properly handle received
nextHopChainingCount and update KgNB using unified helper function
- Replaced the previous nr_rrc_nh_update() helper with these functions to
improve clarity and alignment with the specification.
- Add debug logging for key derivation process
Key NAS deriver utils:
- update derive_kgnb documentation and protect input keys with const attribute
Closes#857
According to 3GPP TS 38.413, the 'Time UE Stayed in Cell' IE is an
integer ranging from 0 to 4095. This patch updates the data structure
to reflect the correct bit width and implements the dynamic calculation
based on the UE's residence time.
- Change time_in_cell from long to uint16_t in ngap_messages_types.h.
- Replace dummy value with real-time calculation in rrc_gNB_NGAP.c.
- Implement a ceiling of 4095 to comply with the 12-bit protocol limit.
Ref: 3GPP TS 38.413 Section 9.3.1.97
Per TS 33.501 6.9.2.3.4 and Fig 6.9.2.1.1-1, when sending
RRCReestablishment with nextHopChainingCount, the gNB is staying at
the same NCC level (not advancing). Therefore, horizontal derivation
from the currently active KgNB must be used, not vertical derivation
from NH.
Vertical derivation (from NH) is only used when advancing to a new
NCC level, which happens during handover or masterKeyUpdate procedures.
The previous implementation incorrectly used vertical derivation from
NH whenever nh_ncc > 0, which caused key mismatch between gNB and UE
during reestablishment after handover, leading to integrity check
failures.
This fix ensures both gNB and UE use horizontal derivation when
nextHopChainingCount matches the current NCC level, aligning with the
specification's "virtual NH at NCC=0" model where:
- Horizontal derivation = derive KNG-RAN* from currently active KgNB
- Vertical derivation = derive KNG-RAN* from NH (only when advancing NCC)
These logs are very helpful to identify cell configuration
changes in MAC/PHY, for monitoring purposes, and to rapidly
signal integrity failures during re-establishment.
The RNTI from the target context was not updated after HO acknowledge
this led to a failure in the first re-establishment after HO.
This commit is introducing the function nr_rrc_apply_target_context
in nr_rrc_n2_ho_acknowledge() and also updates the cell ID for
consistency.
Refactor handover target context application logic into a reusable
function nr_rrc_apply_target_context() that updates both F1AP
associations (secondary UE and DU association) and RNTI from the
target handover context.
And apply to rrc_CU_process_ue_context_modification_response()
Per TS 33.501 6.9.2.3.4 and Fig 6.9.2.1.1-1, when sending
RRCReestablishment with nextHopChainingCount, the gNB is staying at
the same NCC level (not advancing). Therefore, horizontal derivation
from the currently active KgNB must be used, not vertical derivation
from NH.
Vertical derivation (from NH) is only used when advancing to a new
NCC level, which happens during handover or masterKeyUpdate procedures.
The previous implementation incorrectly used vertical derivation from
NH whenever nh_ncc > 0, which caused key mismatch between gNB and UE
during reestablishment after handover, leading to integrity check
failures.
This fix ensures both gNB and UE use horizontal derivation when
nextHopChainingCount matches the current NCC level, aligning with the
specification's "virtual NH at NCC=0" model where:
- Horizontal derivation = derive KNG-RAN* from currently active KgNB
- Vertical derivation = derive KNG-RAN* from NH (only when advancing NCC)
Refactor key derivation logic to properly handle Next Hop (NH) chain
synchronization according to 3GPP TS 33.501 specifications for both
RRC Reestablishment and Master Key Update procedures.
Changes in rrc_gNB.c:
- Clarify key derivation in rrc_gNB_generate_RRCReestablishment by
explicitly selecting base key (NH or KgNB) based on nh_ncc value
- Add comment explaining vertical vs horizontal derivation logic
Changes in rrc_UE.c:
- Add nr_sync_nh_chain(): Common helper to synchronize NH parameter
chain per TS 33.501 Annex A.10, supporting both Master Key Update
and RRC Reestablishment procedures
- Add nr_derive_kgnb_horizontal(): Derive KNG-RAN* from current KgNB
when NCC values match (horizontal derivation per TS 33.501 A.11/A.12)
- Add nr_derive_kgnb_vertical(): Derive KNG-RAN* from synchronized NH
after NH chain sync (vertical derivation per TS 33.501 A.11/A.12)
- Add nr_update_kgnb_from_ncc(): Unified function implementing TS 33.501
6.9.2.3.4 logic for updating KgNB based on received nextHopChainingCount
- Refactor as_security_key_update(): Use new nr_update_kgnb_from_ncc()
helper function for cleaner, more maintainable code
- Fix nr_rrc_ue_process_rrcReestablishment(): Properly handle received
nextHopChainingCount and update KgNB using unified helper function
- Add debug logging for key derivation process
Key NAS deriver utils:
- update derive_kgnb documentation and protect input keys with const attribute
NR UE: calculate TA based on SIB19 information in NTN mode, if autonomous TA is not enabled
To achieve the goal, the hyper frame number (HFN) is introduced at the NR UE
PHY, MAC and RRC layers.
Besides this, we also implemented an orbit propagation to improve the accuracy
of N_UE_TA_adj, and a fix to keep the N_TA from RAR and MAC CE.
Fixes#981
The PDUSessionResourceReleaseResponse message was missing the mandatory
pDUSessionResourceReleaseResponseTransfer IE in each released PDU session item. This caused Open5GS to send an error indication.
Changes:
- Add encode_ngap_pdusession_release_response_transfer() function to
properly encode the transfer structure (empty since Secondary RAT Usage
Information is optional and not used, per 9.3.4.21)
- Always include the mandatory PDUSessionResourceReleasedListRelRes IE
- Always encode the pDUSessionResourceReleaseResponseTransfer for each
PDU session item
- Fix Release Command handler to decode and log Cause from command transfer:
instead of incorrectly copying command data to response: the 2 transfer
IEs in the Command and the Response messages are different and should
not be mixed
- Split Command/Response struct type definitions
- Add missing includes
1) Remove UE Context Release Response code: there is no
such thing in the specs, it is either UE Context Release Request
(NG-RAN node initiated) or UE Context Release (AMF initiated)
(3GPP TS 38.413). The former message has only the request, no
response is defined by the specs. The code in the stack had no
purpose at all and was removed.
2) The UE Context Release Request message only contains a PDU
Session Resource List (optional) of PDU Session IDs, therefore
the use of pdusession_release_t was wrong and was refactored
Fix DRB integrity failures during handover and re-establishment
This MR fixes DRB integrity protection failures that occur during N2 handover
and connection re-establishment scenarios. The issues were caused by incorrect
security key handling and ciphering configuration during these procedures with
DRB integity enabled.
See merge request !3767 for more details.
Avoid measGap configuration on handover in intra-freq scenarios
During the handover, we are incorrectly configuring the measGap, even though
neighboring cells are on the same frequency. Since gNB is not expecting this
measGap, the SRS scheduling is performed. Therefore, we are periodically
receiving these logs after the handover:
[NR_MAC] Invalid timing advance offset for RNTI 58e2
[NR_MAC] Invalid timing advance offset for RNTI 58e2
[NR_MAC] Invalid timing advance offset for RNTI 58e2
[NR_MAC] Invalid timing advance offset for RNTI 58e2
[NR_MAC] Invalid timing advance offset for RNTI 58e2
[NR_MAC] Invalid timing advance offset for RNTI 58e2
These logs occur at a time when UE is performing a MeasGap operation and not
sending the SRS, while gNB thinks it will receive the SRS, but will not receive
any SRS.
This MR resolves this issue, and after the handover, these logs no longer
appear.
Problem:
During N2 handover with integrity protection (NIA1/NIA2), the target gNB
was disabling ciphering when configuring SRB1 security, while the UE
continued using the old security context from the source gNB until it
received and processed the RRC Reconfiguration with masterKeyUpdate. The
first PDUs sent after CFRA were still ciphered with the old keys, but the
target gNB had ciphering disabled, causing it to skip deciphering and
attempt integrity verification on ciphered data, leading to MAC-I
mismatches and integrity failures.
Specification Reference:
According to TS 33.501 section 6.11, "the UE shall keep the K gNB used in
the source cell until the handover or a connection re-establishment has been
completed successfully". This means the UE continues using the old security
context (old KRRCint, KRRCenc) until it receives and processes the RRC
Reconfiguration with masterKeyUpdate. The target gNB must therefore enable
ciphering during handover setup to correctly decipher and verify integrity
of PDUs sent with the old security context before the UE switches to the new
keys.
Root Cause:
The code was calling nr_rrc_pdcp_config_security(UE, false) during
handover setup, which disabled ciphering. This was incorrect because:
1. The UE already has security active from the source gNB
2. The UE continues using old ciphered keys until masterKeyUpdate
3. The UE sends ciphered PDUs immediately after CFRA succeeds
4. The target gNB must be able to decipher these PDUs to verify integrity
Why it only manifested when drb_integrity = "yes":
The bug was always present, but only caused visible failures when
integrity verification was enabled. When drb_integrity = "no", the config
typically also sets integrity_algorithms to only NIA0, resulting in
UE->integrity_algorithm = 0, which causes has_integrity = 0 for SRB1,
skipping integrity verification and hiding the underlying ciphering bug.
When drb_integrity = "yes", integrity_algorithms typically includes
NIA1/NIA2, resulting in has_integrity = 1 for SRB1, causing integrity
checks to run on ciphered data and fail.
Fix:
Change nr_rrc_pdcp_config_security(UE, false) to
nr_rrc_pdcp_config_security(UE, true) during handover setup to enable
ciphering immediately, allowing the target gNB to correctly decipher and
verify integrity of PDUs sent with the old security context.
Note: This fix is specific to handover. During initial context setup,
ciphering should remain disabled until SecurityModeComplete is received,
as the UE hasn't activated ciphering yet at that point.
During re-establishment, new KgNB* is derived, requiring new UP keys (KUPint,
KUPenc) to be sent to CU-UP. When do_drb_integrity = true, CU-UP needs the
updated integrity keys to verify DRB PDUs. Without this update, CU-UP uses
old keys while the UE uses new keys, causing integrity failures.
The fix ensures security info is always sent during re-establishment,
which is critical for DRB integrity.
In case of Handover, NTNconfig sent in RRCreconfiguration triggering handover contains epoch time wrt
timing of Target cell. NTNconfig in RRC needs to be processed only after timing is acquired on the target cell
In case of Target cell, epoch time is the sfn nearest to the frame timing of the target cell.
PDU Session Release
This MR implements end-to-end PDU Session Release functionality
according to 3GPP TS 38.413 and TS 38.331 specifications.
Reason for Change Previous implementation had incomplete and wrongly
places tunnel cleanup during PDU session release. UP cleanup shall be
done at CUUP, RRCReconfiguration shall be sent after retrieval of
updated CellGroupConfig from the DU. This implies F1 and E1 exchanges
during PDU session release procedure.
Major Changes:
1. RRC PDU Session Release: DRBs and PDU session teardown in NGAP PDU
Session Release Response callback
- Helper Functions: Introduced rm_pduSession,
find_drb_by_pdusession_id and rm_drbs() helpers to locate and clean
up DRBs linked to a specific PDU session
- Targeted Cleanup: RRC PDU Session and per-session DRB removal in
rrc_gNB_send_NGAP_PDUSESSION_RELEASE_RESPONSE()
- Status Cleanup: Removed unused PDU_SESSION_STATUS_RELEASED status
2. RRC PDU Session Release: Refactor
rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND
- Any PDU session in the pdusession_release_params list that is
present in the RRC list can be set to release, regardless of its
status
- Function Signature Update: Updated function signature and other
minor changes
- Response Handling: rrc_gNB_send_NGAP_PDUSESSION_RELEASE_RESPONSE is
sent upon completion of RRCReconfiguration
3. RRC PDU Session Release: add missing procedures E1AP Integration:
- Populates E1AP Bearer Modification for each to be released session
- PDCP Enhancement: Added nr_pdcp_release_drbs() to remove all DRBs
linked to a given PDU session in CUUP
- GTP-U Cleanup: GTP tunnel teardown handled in CUUP
e1_bearer_context_modif() using correct F1 or N3 GTP instance
4. NR PDCP/GTP:
- Enhanced Tunnel Deletion Logic: Separate handling for N3 tunnels (1
per PDU session) and F1-U tunnels (1 per DRB)
- New PDCP API Function: Added nr_pdcp_get_drb_ids_for_pdusession()
function to retrieve all DRB IDs associated with a specific PDU
session
5. RRC PDU Session Release: F1AP-based UE Context Modification:
- Replaced direct RRC message transfer with F1AP UE Context
Modification Request for proper retrieval from DU
- Cell Group Configuration: handling of updated CellGroupConfig from
DU ensures DRB release at CU
6. Docs and testing:
- Added PDU session add/remove test cases to 25 PRB RFSIM pipeline
- Documentation: Added PDU Session Release sequence diagram
- Telnet Commands: Added ci command to trigger NGAP PDU Session
Release and ciUE command to trigger establishment of a new PDU
Session
7. Additional fixes:
- UE RLC Management: ensure release of RLC entities
- Unify NG delay control before calling the RRC NGAP handler, for both
Setup and Release
8. Code Cleanup: Cleaned up unused GTP teardown functions.
Closes#867
- Add delayed_action_state_t in the UE context for ongoing delayed action
- Move delay check and timer re-enqueue to rrc thread in rrc_gNB.c (rrc_delay_transaction)
- Call delay before NGAP setup/release handlers; remove local delay logic from rrc_gNB_NGAP.c
- Clear on RRCReconfigurationComplete (reset_delayed_action)
Closes#960
We need to keep PDU sessions and DRBs in list until the NGAP PDU Session Release Response is sent.
* Introduced find_drb() and remove_drbs_by_pdu_session() helpers to locate
and clean up DRBs linked to a specific PDU session
* Targeted per-session DRB removal in rrc_gNB_send_NGAP_PDUSESSION_RELEASE_RESPONSE()
* Ensures DRBs for unaffected PDU sessions remain intact
* Remove unused PDU_SESSION_STATUS_RELEASED status: keeping this status is no longer relevant
since the PDU sessions are effectively removed from the RRC lists
Closes#867
Also, refactor rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND
3GPP TS 38.413 8.2.2 PDU Session Resource Release says:
> upon reception the NG-RAN node shall execute the release of the requested PDU sessions.
> For each PDU session to be released the NG-RAN node shall release the corresponding
> resources over Uu and over NG, if any.
Therefore, any PDU session in the pdusession_release_params list that is
also present in the RRC list can be set to release, regardless of its status.
The function signature was also updated along with other minor changes.
This commit implements proper PDU Session Release handling across
RRC, PDCP, F1AP, E1AP to ensure clean resource cleanup when
a PDU session is terminated.
Key changes:
NGAP:
In `rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND()`:
* Populates E1AP Bearer Modification for each released session
* If a CU-UP is connected, triggers `bearer_context_mod()` for PDU teardown
PDCP:
* Added `nr_pdcp_release_drbs()` to remove all DRBs linked to a given PDU session
* Called from `e1_bearer_context_modif()` for correct clean-up during session release
F1AP UE Context Modification:
Replace direct RRC message transfer with F1AP UE Context Modification Request
to properly handle PDU session release according to 3GPP TS 38.331.
3GPP TS 38.331 `5.3.5.6.4 DRB release` says: whether or not the RLC and MAC entities associated
with a PDCP entity are reset or released is determined by the CellGroupConfig. Thus,
updated CellGroupConfig needs to be received by the UE. This has to be retrieved by CUCP
from the DU. Therefore:
After receiving an NGAP_PDUSESSION_RELEASE_COMMAND, the CUCP shall:
1) forward (store for later) the NAS PDU to the UE, if present as per 3GPP TS 38.413, and
2) send a UE Context Modification to the DU with the list of DRBs to release
and the RRC container (RRCReconfiguration with NAS PDU)
After reception of UE Context Modification Response, the list of drbs to release
is prepared based on PDU session status PDU_SESSION_STATUS_TORELEASE
in rrc_gNB_generate_dedicatedRRCReconfiguration and then encoded
in drb_ToReleaseList for a new RRCReconfiguration with the new cellGroupConfig.
Key changes:
* rrc_gNB_generate_dedicatedRRCReconfiguration_release() now uses F1AP UE Context
Modification Request instead of direct RRC transfer
* Only DRBs to be released are now added to the list.
* The ASN.1 memory allocation is entirely done in build_RRCReconfiguration_IEs
* No longer needed to store ASN1 struct in UE context
GTP-U:
* Previous implementation had incomplete tunnel cleanup during PDU session release
- Missing distinction between N3 (PDU session level) and F1-U (DRB level) tunnels
- Lack of proper DRB identification for F1-U tunnel deletion
Major Changes:
* GTP tunnel teardown now handled in `e1_bearer_context_modif()` using the correct
F1 or N3 GTP instance (`newGtpuDeleteOneTunnel()`)
* Enhanced Tunnel Deletion Logic (cucp_cuup_handler.c):
- Separate handling for N3 tunnels (1 per PDU session) and F1-U tunnels (1 per DRB)
- Added proper DRB identification for F1-U tunnel cleanup
- Improved error handling with detailed logging for each tunnel deletion
- Enhanced logging to distinguish between N3 and F1-U tunnel operations
* New PDCP API Function (nr_pdcp_oai_api.c/h):
- Added nr_pdcp_get_drb_ids_for_pdusession() function
- Enables retrieval of all DRB IDs associated with a specific PDU session
- Supports proper F1-U tunnel cleanup by providing DRB identifiers in CUUP
* Enhanced GTP Interface (gtp_itf.cpp/h):
- Modified newGtpuDeleteOneTunnel() to accept tunnel_type parameter
- Improved logging to distinguish between PDU session and DRB tunnel types
- Better error messages for tunnel deletion failures
- Enhanced debugging information for remaining tunnels
Clean-up:
* Ensured xid tracking works consistently between PDU Session Establishment (with NAS PDU)
and dedicated RRCReconfiguration
* Add function to release GTP-U tunnel in Bearer Context Modification Request handler
* Do not send rrc_gNB_send_NGAP_PDUSESSION_RELEASE_RESPONSE when no PDU session are to
be released: it is sent upon completion of the RRCReconfiguration and needs to contain
released PDU Sessions (mandatory IE), therefore it is no necessary to send it in case
there is no PDU session to release.
Related to #867
Co-authored-by: rmagueta <rmagueta@allbesmart.pt>
Refactor SDAP adaptation work for QoS
This MR is an adaptation of the code introduced in !2703.
The goal is a cleanup and functional refactor of the SDAP/PDCP
integration, that is:
- centralize SDAP configuration logic
- simplify entity creation
- improve robustness of role-based SDAP handling
- prepare the codebase for clean support of DRB reconfiguration and
teardown flows
More concretely:
1. New sdap_config_t and get_sdap_Config()
- Introduced an internal struct sdap_config_t to abstract SDAP config
input
- Centralized SDAP config parsing into new get_sdap_Config() function
that translates ASN.1 NR_SDAP_Config into this internal
representation. This is called during RRC triggered
(re)configuration procedures.
- Enable mapping of number of QoS flows > 1
2. Unified role handling with bitmasks
- Added a bitmask-based entity_role field to track SDAP directions:
SDAP_UL_RX, SDAP_UL_TX, SDAP_DL_RX, SDAP_DL_TX: header presence was
determined by simple direction (UE vs gNB) and individual
is_sdap_rx/tx() checks, however nr_sdap_rx_entity behaves
differently depending on the direction of the RX entity (DL/UL),
therefore this change can help enable a more accurate SDAP header
handling across directions and node types.
- Replaces old helpers is_sdap_rx() / is_sdap_tx() with internal
checks against the role bitfield
- QFI-to-DRB mapping is now annotated with direction for both data and
control PDUs
3. Simplified DRB and SDAP setup
- add_drb() in PDCP API now delegates SDAP config processing cleanly
- new_nr_sdap_entity() is used consistently to register a fresh SDAP
context for the UE and PDU session.
- Also, re-use and reconfigure existing SDAP entity if already
exists.
- logging has been added to trace mapped QFIs from RRC and resulting
table entries
4. Improved QFI-to-DRB management
- Refactored nr_sdap_qfi2drb_map_update() to register QFIs based on
parsed config
- Ensures control PDUs are correctly routed even after reconfiguration
- Extended nr_sdap_ue_qfi2drb_config: perform UL QoS flow to DRB
mapping configuration for a SDAP entity has already been established
according to TS 37.324, 5.3 QoS flow to DRB Mapping, 5.3.1
Configuration Procedures. Handle both UL QoS Flows mapping rules to
add and to remove. QFIs will now be properly unmapped if specified
via mappedQoS_FlowsToRelease, this might prevent stale QFI mappings
from being used incorrectly.
- nr_sdap_qfi2drb() and sdap_map_ctrl_pdu() now strictly fallback to
default_drb only if a QFI mapping is missing. Missing default DRB
now triggers LOG_E() (previously silent or misrouted to DRB 0).
5. Other cleanup
- Remove dependencies from legacy rb_id_t
This commit refactors the SDAP entity QoS flow to DRB mapping functionality
to improve code organization and enhance maintainability.
Key changes:
- Split nr_sdap_qfi2drb_map_update into focused functions:
* nr_sdap_add_qos_flows_to_drb: handles QFI addition to DRB
* nr_sdap_rm_qos_flows_from_drb: handles QFI removal from DRB
* nr_sdap_ue_control_pdu_config: handles UE control PDU generation
- Consolidate add/modify logic into reusable nr_sdap_addmod_entity function
- Remove entity existence checking and updating from new_nr_sdap_entity:
this function should only add SDAP entities
- Improve function separation of concerns: do SDAP entity add or update
separately and improve modularity by splitting operations in self
contained functions
- At SDAP creation, do only add of QFI to DRB mapping
- rename new_nr_sdap_entity to nr_sdap_add_entity for function naming consinstency
* use get_sdap_Config to process sdap_Config
* move SDAP config logic to the scope where it is relevant
* add SDAP entity direcly in RRC, not from PDCP
* replaced nr_pdcp_add_drbs with single add_drb call: it was no longer
efficient to keep it in the new logic. The addMod list can be looped directly in RRC.
* add specific function to add bearers from addMod list in E1, NSA, and UE
Initialize NCC=0 on NGAP Initial Context Setup (3GPP TS 33.501 §6.9.2.1.1)
The nhcc should be initialized to 0 upon Initial Context Setup.
Also, remove unused kgnb_ncc: nh_ncc is already there.
Closes#1008
Prevent assertion in ngap_gNB_nas_uplink() due to uninitialized selected_plmn_identity:
the selected_plmn_identity field was not being set during N2 handover,
causing the assertion ((plmn->mnc_digit_length == 3) || (plmn->mnc_digit_length == 2))
to fail when processing subsequent NAS messages. The issue is that the Serving PLMN
is not stored by RRC. During N2 mobility, RRC can get this info from GUAMI.
When receiving the Handover Request the target gNB knows from GUAMI
which serving PLMN is the AMF belonging to. In current design, allowed PLMNs
are stored in rrc.configuration. The incoming PLMN needs to be validate
against the PLMNs in the list, then stored in the UE context as Serving PLMN.
This change adds PLMN validation when processing handover requests from the source gNB.
The validation is needed because:
- Target gNB must verify that the PLMN from the GUAMI in the handover request
is allowed by its configuration before accepting the handover to prevent handover
to unsupported PLMNs.
- When PLMN validation fails, the target gNB now properly sends NGAP_HANDOVER_FAILURE
- UE Context must store serving PLMN for later use
Robert Schmidt