This commit completes the NGAP Mobility Management procedure for N2 handover.
Upon failure on source gNB the Handover Cancel message is sent to the AMF which
in return responds with an ack.
Upon reception of NG RAN Status at the target CU-CP, send PDCP Status
via E1 Bearer Context Modification to the target CU-UP and update PDCP Count
upon reception of the message.
For the sake of simplicity, re-used and extended legacy e1_send_bearer_updates.
Further refactoring is not addressed in this commit.
Once fetched the PDCP Status from the PDCP entity over E1, the CU-CP triggers
the NG RAN Status Transfer procedure to transfer the PDCP Status to the target
CU.
This commit is also introducing the RRC callback.
* Check presence of PDCP Status Requested in Bearer Context Modification Request
* Fetch PDCP Status from PDCP entity and fill in the Bearer Context Modification Response
The E1 Bearer Context Modification Request shall send a PDCP Status Request IE
during handover, e.g. the HO context is set to source, and it is not target, i.e.
only in N2 not in F1.
The current function "e1_send_bearer_updates" used to fill the E1 Request has been
refactored only for the sake of this commit and to avoid duplicated and redundant code.
The function itself deeper analysis and eventually a refactoring that will not be addressed
in this commit.
* Introduced nr_pdcp_count_update() to apply COUNT values to the PDCP entity:
- Computes tx_next, rx_next, and rx_deliv from HFN+SN
- Handles both 12-bit and 18-bit SN modes with dynamic bitmask
* Introduced nr_pdcp_get_drb_count_values() to extract PDCP COUNT values from entity:
- Used for building UL RAN Status Transfer on source CU side
According to 4.9.1.3.3 of 3GPP TS 23.502:
> 2a. - 2c. The S-RAN sends the Uplink RAN Status Transfer message to the S-AMF,
> as specified in TS 36.300 [46] and TS 38.300 [9]. The S-RAN may omit sending
> this message if none of the radio bearers of the UE shall be treated with PDCP status preservation.
TS 38.300 says:
> For DRBs not configured with DAPS, the source gNB sends the SN STATUS TRANSFER message to the target
> gNB to convey the uplink PDCP SN receiver status and the downlink PDCP SN transmitter status of DRBs for
> which PDCP status preservation applies (i.e. for RLC AM). The uplink PDCP SN receiver status includes at
> least the PDCP SN of the first missing UL PDCP SDU and may include a bit map of the receive status of the out
> of sequence UL PDCP SDUs that the UE needs to retransmit in the target cell, if any. The downlink PDCP SN
> transmitter status indicates the next PDCP SN that the target gNB shall assign to new PDCP SDUs, not having a
> PDCP SN yet.
i.e., for DRBs for which PDCP status preservation applies (i.e. for RLC AM), which is is our case.
This commit introduces full support for NG-RAN Status Transfer message handling
(TS 38.413 §9.2.3.13-14) in CU. It enables correct state transfer of PDCP COUNT
values (SN + HFN) during mobility or recovery scenarios.
Summary of changes - NGAP:
* Added encoding/decoding support for UL/DL RAN Status Transfer message
* Defined structures for: ngap_drb_count_value_t, ngap_drb_status_t,
ngap_ran_status_container_t, ngap_ran_status_transfer_t
The pipeline is using the already existing conf files
for the source/target gNB CUs/DUs.
For the sake of simplicity, neighbour-config.conf has
been rewritten and simplified in this commit, then
adopted in this pipeline. The file was not used before.
* the command gets in input the neighbour PCI and the UE ID
* the telnet ci function to retrieve the UE context was extended in the process
* add function to trigger handover on the same gNB for testing purposes
Co-authored-by: batuhan duyuler <batuhan.duyuler@firecell.io>
* trigger upon reception of MasterKeyUpdate
* derive NH, store NH NCC and valid NH key in RRC
* masterKeyUpdate: derive enc/int keys after master key update
and set PDCP security for SRB1
* call nr_rrc_process_reconfiguration_v1530 before nr_rrc_ue_process_RadioBearerConfig
and move dedicatedNAS_MessageList processing at the end of the flow. The sequence
shall be (1) keys/security update (2) radioBearerConfig processing, with PDCP entity
creation, PDCP reestablishment, SDAP entity creation (3) NAS PDUs processing, which
triggers PDU Session Establishment Accept, which sets up the TUN interface.
SDAP entity is a pre-requisite, therefore the radioBearerConfig has to be processed
(in nr_rrc_ue_process_RadioBearerConfig, add_drb) early enough, or it may cause a
race condition in SDAP.
* add trigger function to (1) add the callbacks and (2) initiate
handover on the target NG-RAN
* add handover failure callback on target NG-RAN: the Handover
Failure is a procedure that belongs to the target NG-RAN and
it is different from the Handover Cancel procedure
Co-authored-by: batuhan duyuler <batuhan.duyuler@firecell.io>
This commit introduces the NG Mobility Management Procedure known as
Handover Notification. The outbound message is sent by the target NG-RAN
and is known as Handover Notify. The procedure is used to indicate to
the AMF that the UE has arrived to the target cell and the NG-based
handover has been successfully completed
* after RRCReconfiguration complete, in the N2 callback for HO success
* add NGAP encoder for the message
* RRC callback to trigger Handover Notify message
Co-authored-by: batuhan duyuler <batuhan.duyuler@firecell.io>
* add NG Handover Command message decoder
* process in RRC: encode RRCReconfiguration message
from the received HandoverCommandMessage
* trigger RRCReconfiguration for handover
Co-authored-by: batuhan duyuler <batuhan.duyuler@firecell.io>
* generate Handover Command for the source NG-RAN
to be added to the target to source transparent
container of the Handover Acknowledge message
* add Handover Acknowledge callback for N2
* send NG Handover Acknowledge to AMF
Co-authored-by: batuhan duyuler <batuhan.duyuler@firecell.io>
This commit completes the NG Mobility Management Procedure known as
Handover Resource Allocation. The outbound message is sent by the
target NG-RAN and is known as Handover Request Acknowledge.
Major changes:
* add RRC callback to trigger the generation of NG Handover
Request Acknowledge on the target NG-RAN
* add NG Handover Request Acknowledge encoder
Co-authored-by: batuhan duyuler <batuhan.duyuler@firecell.io>
This commit introduces the NG Mobility Management Procedure known as
Handover Resource Allocation. The inbound message is sent by the AMF
and is known as Handover Request.
Major changes:
(0) Add Handover Resource Allocation initiating message decoding
* add case for NGAP initiating message and unsuccessful message decoding
(1) handle Handover Request on the target NG-RAN
(2) decode NG Handover Request message
(3) process payload, e.g. create UE context,
store IDs, set UP security and trigger bearer setup
Co-authored-by: batuhan duyuler <batuhan.duyuler@firecell.io>
This message is sent from the Target NG-RAN to the AMF.
The commit introduces:
* NGAP encoding function
* N2 callback for the target gNB
* handle the failure in RRC, inform NGAP
* send NGAP message to AMF via SCTP
Note: UE context in NGAP is fetched from the amf_ue_ngap_id
Co-authored-by: batuhan duyuler <batuhan.duyuler@firecell.io>
(1) add N2 ho decision based on measurements
(2) add trigger for N2 HO on source CU
(3) generate NG Handover Preparation Information message,
including RRCReconfiguration, to be passed to the
NG Handover Required message
(4) call RRC callback for Handover Required message
Co-authored-by: batuhan duyuler <batuhan.duyuler@firecell.io>
This commit introduces the NG Mobility Management Procedure known as
Handover Preparation. The outbound message is sent by the source NG-RAN
and is known as Handover Required.
* introduce NGAP library for Mobility Management
* introduce NGAP IEs encoder functions for Handover Required and relevant common IEs
* handle RRC trigger in NGAP and Send NGAP Handover Required to the AMF
Co-authored-by: batuhan duyuler <batuhan.duyuler@firecell.io>
During the N2 HO review has been found that the HO context
was not allocated at trigger time but later in the flow. This
might lead to issues in some scenarios (e.g. in N2 HO)
and it was fixed in this commit.
During the review of the N2 HO MR it has been found that the wrong type
plmn_identity_t (S1AP) was used in RRC. Now updated to the platform type plmn_id_t.
The malloced struct is initialized to garbage and when
the IE is absent, the output "PDCP reestablishment"
member (allocated in the stack) is set to a random value.
Handle authentication not accepted by the network. The handler assumes the message
is not integrity protected, processes the received NAS message and logs whether a
EAP-failure is enclosed. The UE enters state: 5GMM-DEREGISTERED.
Not done in this commit: the UE shall performs actions as per 5.4.1.3.5 of
3GPP TS 24.501, including (1) Abort any ongoing 5GMM procedure
(2) Stop all active timers: T3510, T3516, T3517, T3519, T3520, T3521
(3) Delete stored SUCI. (4) handle EAP-failure message.
Motivation of the commit:
Previously, the RRC module on the NGAP interface directly handled ASN.1 decoding
of NGAP PDU Session Resource items, that was directly stored in pdusession_t, i.e.
in the UE context. Decode logic between Setup and Modify was also duplicated.,
e.g. fill_qos/fill_qos2. The idea behind this change is to achieve this flow:
(1) NGAP handler: decoding (2) ITTI to RRC: transfer decoded message (3) RRC
handler: process decoded message, e.g. store in UE context, etc..
The goal of this commit is to:
* improve the NGAP decoding library by adding decoding functions
* let RRC handle the already decoded data
* enhance error handling, with decode failures now consistently detected and rejected early
* have a cleaner, more maintainable code with fewer duplications and a clearer separation of modules
Changes:
* Moved all ASN.1 decode logic for PDU Session Resource items into the NGAP library
* Introduced decode functions for NGAP IEs whenever necessary, e.g. decode_TNLInformation
decode_pdusession_transfer
* Removed duplicate fill_qos functions and centralized QoS handling in NGAP
* Added function to copy from NGAP PDU Session Resource item to RRC pdusession_t: this actually
replaces decodePDUSessionResourceSetup in RRC, copying from the decoded NGAP struct to
the UE context pdusession_t
Motivation:
The previous code had overlapping and partially inconsiste definitions of
`pdusession_t` and related structures across NGAP and RRC. This struct type
was used for either the data stored in the UE context and the NGAP message
IEs holding the PDU session to setup/modify information.
This patch aims to separte the `pdusession_t` in RRC, where it logically belongs,
since RRC owns the state of the PDU sessions. NGAP should only
deal with protocol messages, i.e. enc/dec and transfer structures to RRC.
This clarifies module ownership. This also makes the code easier to maintain.
Changes:
* Moved `pdusession_t` definition from NGAP (`ngap_messages_types.h`) to RRC
(`nr_rrc_defs.h`)
* Added a simpler `pdusession_resource_item_t` structure to NGAP for use in
protocol messages
* Adjusted NGAP structures accordingly (Initial Context Setup, PDU Session
Setup Request, and PDU Session Modify Request).
* do decodePDUSessionResourceSetup to decode the NGAP IEs holding PDU session
information and store what necessary in the UE context PDU Session IE: NOTE
this changes were necessary since previously this function was acting on
the common NGAP/RRC pdu_session_t struct
Rename the struct members:
`pdusession_param` to `pdusession` in NGAP Initial Context Setup Request
`pdusession_setup_params` in `ngap_pdusession_setup_req_t`
`pdusession_modify_params` and `ngap_pdusession_modify_req_t`
Motivation:
Clarify the role of GTP tunnel endpoint IDs in PDU session handling. Previously,
the struct members (gNB_teid_N3, UPF_teid_N3, etc.) were confusingly named and
duplicated with separate transport-layer address fields.
This refactoring replaces these with explicit n3_incoming and n3_outgoing members using
gtpu_tunnel_t. This aligns with GTP conventions: "incoming TEID" refers to the
TEID received from the remote peer (UPF on N3), while "outgoing TEID" is the
TEID sent by the local entity (NG-RAN on N3) to the remote peer.
Benefits:
* Improves readability and clarity of the code
* Reduces redundant struct members, i.e. remove UPF_teid_N3, UPF_addr_N3
* Aligns naming with 3GPP conventions for transport layer tunnels
Changes:
* Replace gtp_addr_N3, gNB_teid_N3, gtp_teid, upf_addr with n3_incoming and n3_outgoing
* Update all related code to use the new struct members
* Aligns naming with 3GPP conventions for transport layer tunnels
This struct is used in different layers, e.g. RRC, NGAP: therefore it
has been moved to platform_types.h.
Also, the struct holds the tunnel endpoint configuration for any GTP-U
tunnel, therefore the f1u prefix is not accurate and was updated
to a more generic gtpu.
* Remove drb_is_active: function is unused and the logic will be later
added to another function to add DRBs if necessary
* Remove unused NGAP structs and empty TODO functions
* Remove unused pdusession_setup_req_t struct definition
The seq_arr_erase_it function was modifying start_it during the free_func loop,
which led to incorrectly apply the free_func on the whole array.
This commit makes sure the elements "freed" are only those in the range and not the whole seq_arr.
* Fixes the logic by introducing a temporary iterator for the free loop,
preserving start_it and end_it for correct offset calculations.
* Adds a regression test in test_seq_arr to verify that only the selected
subrange is erased and that free_func is called exactly on that range.
Corrected a logic bug in usrp_lib.cpp where the code mistakenly checked
openair0_cfg[0].clock_source instead of time_source when a time_source
was already specified in usrp_args.
Also improved the warning log to clarify that the config value is being
ignored in favor of the explicit user-provided usrp_args.
Co-authored-by: Alexandre Serio <alexandre.j.serio@altice.pt>
This 5GMM message is required for an invalid security mode command,
e.g. when the MAC integrity fails, or the wrong Security Header is set.
* Add encode/decode functions for common IEs in fgmm_lib: this library
provides encoding/decoding helpers for IEs shared across multiple
NAS messages. The goal is to avoid the legacy approach of creating
separate files per IE
* add NAS Cause enc/dec lib
* Adopted byte_array_t to handle the buffer
Co-authored-by: Eduard Vlad <eduard.vlad@rwth-aachen.de>
The mask could be present, .e.g not zero, but the selection of the AMF could
fail. This would lead to a skipping the selection of the AMF by PLMN ID,
which is the last option when no UE identity is present and/or matching.
Free memory allocated in NGAP after use in RRC.
Direct leak of 29 byte(s) in 1 object(s) allocated from:
> #0 0x7f11200b4887 in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
> #1 0x558b7fcd0137 in malloc_or_fail /n2-handover-preparation/common/utils/utils.h:86
> #2 0x558b7fcd0137 in create_byte_array /n2-handover-preparation/common/utils/ds/byte_array.c:32
> #3 0x558b7fdb7a5c in rrc_gNB_send_NGAP_NAS_FIRST_REQ /n2-handover-preparation/openair2/RRC/NR/rrc_gNB_NGAP.c:183
> #4 0x558b7fd2ab30 in rrc_gNB_process_RRCSetupComplete /n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:439
> #5 0x558b7fd2ab30 in handle_rrcSetupComplete /n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:1715
> #6 0x558b7fd63e23 in rrc_gNB_decode_dcch /n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:1851
> #7 0x558b7fd8b4c3 in rrc_gnb_task /n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:2718
> #8 0x7f111ea94ac2 in start_thread nptl/pthread_create.c:442
ASN_SEQUENCE_ADD is calling realloc which is allocating memory for the
'array' which was not freed.
> Direct leak of 32 byte(s) in 1 object(s) allocated from:
> #0 0x7ce97deb4c38 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164
> #1 0x5813fba02574 in asn_set_add /openairinterface5g/n2-handover-preparation/cmake_targets/ran_build/build/openair2/RRC/LTE/MESSAGES/asn_SET_OF.c:27
> #2 0x5813faf6c672 in createSRBlist /openairinterface5g/n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:331
> #3 0x5813faf9aa78 in rrc_gNB_generate_RRCSetup /openairinterface5g/n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:421
> #4 0x5813fafba2ee in rrc_handle_RRCSetupRequest /openairinterface5g/n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:1243
> #5 0x5813fafba2ee in rrc_gNB_process_initial_ul_rrc_message /openairinterface5g/n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:2019
> #6 0x5813fafcdc3a in rrc_gnb_task /openairinterface5g/n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:2761
> #7 0x7ce97c894ac2 in start_thread nptl/pthread_create.c:442
> Direct leak of 32 byte(s) in 1 object(s) allocated from:
> #0 0x7ce97deb4c38 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164
> #1 0x5813fba02574 in asn_set_add /openairinterface5g/n2-handover-preparation/cmake_targets/ran_build/build/openair2/RRC/LTE/MESSAGES/asn_SET_OF.c:27
> #2 0x5813faf6c672 in createSRBlist /openairinterface5g/n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:331
> #3 0x5813faf7d89d in get_RRCReconfiguration_params /openairinterface5g/n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:660
> #4 0x5813faf914b3 in rrc_gNB_generate_dedicatedRRCReconfiguration /openairinterface5g/n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:716
> #5 0x5813faf96856 in rrc_CU_process_ue_context_setup_response /openairinterface5g/n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:2190
> #6 0x5813fafcd3ed in rrc_gnb_task /openairinterface5g/n2-handover-preparation/openair2/RRC/NR/rrc_gNB.c:2796
> #7 0x7ce97c894ac2 in start_thread nptl/pthread_create.c:442
dynamically allocated memory is pushed to the seq_arr that
is doing a memcpy, so it can be either or better allocated
in the stack instead
> Direct leak of 16 byte(s) in 1 object(s) allocated from:
> #0 0x7efd8f6b4a57 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
> #1 0x577888f3457e in fill_neighbour_cell_configuration /openairinterface5g/n2-handover-preparation/openair2/GNB_APP/gnb_config.c:1914
> #2 0x577888f3457e in RCconfig_NRRRC /openairinterface5g/n2-handover-preparation/openair2/GNB_APP/gnb_config.c:2108
> #3 0x57788869a0d2 in create_gNB_tasks /openairinterface5g/n2-handover-preparation/executables/nr-softmodem.c:253
> #4 0x57788869a0d2 in main /openairinterface5g/n2-handover-preparation/executables/nr-softmodem.c:619
> #5 0x7efd8e029d8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
the dynamically allocated memory is pushed to the seq_arr that
is doing a memcpy, so it can be either or better allocated in the
stack instead
> Direct leak of 48 byte(s) in 1 object(s) allocated from:
> #0 0x7d4c934b4a57 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
> #1 0x577622a40137 in fill_neighbour_cell_configuration /openairinterface5g/n2-handover-preparation/openair2/GNB_APP/gnb_config.c:1933
> #2 0x577622a40137 in RCconfig_NRRRC /openairinterface5g/n2-handover-preparation/openair2/GNB_APP/gnb_config.c:2109
> #3 0x5776221a30f2 in create_gNB_tasks /openairinterface5g/n2-handover-preparation/executables/nr-softmodem.c:253
> #4 0x5776221a30f2 in main /openairinterface5g/n2-handover-preparation/executables/nr-softmodem.c:619
> #5 0x7d4c91e29d8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
seq_arr_push_back is doing a memcpy so locally allocated memory can be freed after.
Allocate in stack.
> Direct leak of 64 byte(s) in 2 object(s) allocated from:
> #0 0x7ec4bb8b4a57 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
> #1 0x55895aae1b1f in fill_measurement_configuration /openairinterface5g/n2-handover-preparation/openair2/GNB_APP/gnb_config.c:2015
> #2 0x55895aae1b1f in RCconfig_NRRRC /openairinterface5g/n2-handover-preparation/openair2/GNB_APP/gnb_config.c:2112
> #3 0x55895a246112 in create_gNB_tasks /openairinterface5g/n2-handover-preparation/executables/nr-softmodem.c:253
> #4 0x55895a246112 in main /openairinterface5g/n2-handover-preparation/executables/nr-softmodem.c:619
> #5 0x7ec4ba229d8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
Inside of passing the RRCReconfiguration buffer, call RRCReconfiguration
message generation inside the F1 callback. This will simplify the code in the
rrc_CU_process_ue_context_setup_response() function once the N2 handover case
is introduced. In rrc_CU_process_ue_context_setup_response(), with presence
of the HO context, the HO ACK callback is called only once and depending
on the type of HO it will do either RRCReconfiguration for F1 and
HandoverCommand for N2.
The byte_array reference contains the pointer to the
encoded RRC buffer to be used in the handover acknowledge
callback (e.g. in F1 to trigger RRCReconfiguration)
This is necessary because the function was re-establishing PDCP only for SRB2
however according to specs 3GPP TS 38.331 RadioBearerConfig, PDCP shall be
re-established for SRB1 and/or SRB2 whenever the security key used for the
radio bearer changes, with some exceptions for SRB1 (i.e. when resuming
an RRC connection, or at the first reconfiguration after RRC connection
reestablishment in NR, do not re-establish PDCP for SRB1).
* the input param "reestablish" is converted into a bitmap to indicate
whether PDCP should be re-established for the SRB1 and/or SRB2.
* For convenience the bitmap is 0-based, with index 1 corresponding to SRB1,
index 2 to SRB2.
This commit is keeping the legacy re-establishment, that is re-establishment
of PCDP for SRB2 only.
according to TS 38.331, RRCReconfiguration messages can be carried
in a container by different RRC messages, e.g. HandoverPreparationInformation,
HandoverCommand, RRCResume etc.. therefore before the introduction of new
RRCReconfiguration messages, e.g. for handover, a new design seems to be necessary
in order to improve modularity and maintainability of the code.
The goal of this commit is to make the generation of RRCReconfiguration
messages more modular by (1) preparing the RRCReconfiguration parameters
data in RRC (2) pass it to ASN1 for IEs allocation (3) encode to buffer
The following changes are introduced:
(1) introduce struct nr_rrc_reconfig_param_t to store the RRC parameters relevant
to encode the RRCReconfiguration IEs
(2) add RRC function get_RRCReconfiguration_params to fetch nr_rrc_reconfig_param_t
data from the UE context and
(3) pass it to the ASN1 encoder, e.g. do_RRCReconfiguration
(4) add a function build_RRCReconfiguration_IEs to allocate memory and build the
ASN1 NR_RRCReconfiguration_IEs_t and
(5) adopt it in do_RRCReconfiguration
(4) add free_RRCReconfiguration_params for memory management of nr_rrc_reconfig_param_t data
(6) add test for rrc_reconfiguration
get_RRCReconfiguration_params:
This function prepares RRCReconfigurationParams for RRC encoding.
Motivation of this change: depending on the RRCReconfiguration
message to be encoded, the ownership of ASN1 memory allocation
should belong to the ASN1 layer, therefore this function is
preparing the nr_rrc_reconfig_param_t data to pass to the
ASN1 encoder to build the ASN1 message and encode to buffer
The function is preparing the params for the IEs that are
either mandatory or shared among different RRC messages.
Specific fields that depend on the message to be encoded are then
added afterwards in the caller. The input param to indicate
re-establishment has been split between SRBs and DRBs, since
depending on the scenario the PDCP re-establishment can vary.
This will be addressed in a later commit.
This function is also handling xid.
build_RRCReconfiguration_IE:
The long term goal is to transfer ownership of memory allocation in ASN1 encoding to
build_RRCReconfiguration_IE, then by calling ASN_STRUCT_FREE_CONTENTS_ONLY
on dl_dcch_msg, all IEs allocated in the context are freed after encoding to buffer.
In the long term, createDRBlist, createSRBlist can also be brought into the context
of build_RRCReconfiguration_IEs and free the ASN1 structure after encoding.
This improves maintability and helps preventing memory leaks.
Currently, what is not allocated in the context, is nulled and freed outside.
free_RRCReconfiguration_params:
this function frees memory allocated to build the nr_rrc_reconfig_param_t data,
including the NR_DRB_ToAddModList_t and NR_SRB_ToAddModList_t. The function
freeDRBlist has been removed since no longer necessary.
dedicated_NAS_msg_list:
dedicated_NAS_msg_list handling has also been refactored, by:
(1) fetch the NAS PDUs from the UE context in get_RRCReconfiguration_params,
which translates to (2) passing an array of dedicatedNAS-MessageList + size
to the ASN1 encoding function where (3) the ASN1 encoding logic for the
dedicated_NAS_msg_list IE has been moved
Note, 3GPP TS 38.331:
dedicatedNAS-MessageList: SEQUENCE (SIZE(1..maxDRB)) OF DedicatedNAS-Message
* differentiate the 2 functions based on the input: either NR Cell ID or PCI
* enhanced variables naming to distinguish the parameters
* add logging for debugging purposes
this commit is refactoring the function ngap_gNB_handle_nas_first_req
to (1) fill first a local instance of ngap_gNB_ue_context_t and then
(2) pass it to ngap_store_ue_context which will allocate memory
for the instance to store in ngap
This count is used to size the dynamic array lcids_bj_pos. In case
count is zero, this would lead to runtime error. With this change,
the function will indicate to the caller that no SDUs are present and
will print an error.
According to 3GPP TS 38.331 5.3.5.5.2 (Reconfiguration with sync), the UE
shall consider the target SpCell to be one with a physical cell identity
indicated by the physCellId
This function is needed also in upcoming NGAP
libraries (i.e. N2 Handover) and therefore is moved
to the NGAP utilities file. The function converts
transport_layer_addr_t data struct to BIT_STRING_t
by copying the content of its members. The naming
is also updated to tnl_to_bitstring.
* Functions added:
decode_ngap_guami
decode_ngap_UEAggregateMaximumBitRate
decode_ngap_nssai
decode_ngap_security_capabilities
decode_ngap_mobility_restriction
* Adopt these functions in the common NGAP library
GUAMI fields (Set ID, Pointer and Region ID) were decoded as Octet String,
however they are encoded as BIT STRING. Therefore, the GUAMI value was wrongly decoded.
In the AMF logs the AMF IDs are 1,1,1, however in gNB logs we had 1,64,4
Quick local test confirmed that:
---- TESTING AMF IDs = 1 ----
Region ID (OCTET STRING): 1
Region ID (BIT STRING): 1
Set ID (OCTET STRING): 64
Set ID (BIT STRING): 1
Pointer (OCTET STRING): 4
Pointer (BIT STRING): 1
The difference arises because:
- OCTET STRING treats the buffer as raw bytes, with all bits used.
- BIT STRING includes a `bits_unused` field, which tells how many padding bits
are present in the least significant end. This is especially important in
3GPP ASN.1 definitions like AMF Set ID (10 bits), AMF Region ID (8 bits),
AMF Pointer (6 bits), where the full byte(s) may contain unused bits that
must be masked out.
selectedPLMN-Identity IE in RRCSetupComplete is an Index (long) of the PLMN selected
by the UE from the plmn-IdentityInfoList (SIB1) (see 3GPP TS 38.331)
while
Selected PLMN Identity in NGAP INITIAL UE MESSAGE Indicates the selected PLMN
id for the non-3GPP access (PLMN Identity ID carrying MNC, MCC and MNC size,
9.2.5.1 3GPP TS 38.413)
The legacy code was setting Selected PLMN Identity in the latter to an ID
value as the former, however in NGAP the IE to be encoded is PLMN Identity 9.3.3.5
therefore:
* set plmn type plmn_id_t in ngap_nas_first_req_t
* check whether received selectedPLMN-Identity is within bounds
* select PLMN from gNB_RrcConfigurationReq by selectedPLMN-Identity ID
note: this commit is assuming that the plmn-IdentityInfoList in SIB1
is matching the PLMN list in gNB_RrcConfigurationReq
* in NGAP: store the PLMN in the NGAP UE context, no need to fetch the PLMN
in the NGAP instance since the UE context already tells what PLMN
was selected
Closes#801
* use bitmask to select presence of either 5G-S-TMSI or GUAMI
* select the AMF based on
(1) absence of UE Identity (2) Presence of GUAMI (3) Presence of 5G-S-TMSI
Related to #801
* add function to process AMF Identifier
* add function to select AMF
* set const parameters in utility nnsf functions
* adopt utilities for memory allocation
* improve readability and maintainability
* improve logging
ngap_pdu_t has the same definition as byte_array_t, so it is
replaced by the latter. This simplify the stack and reduces
duplicated code.
Also, add function create_byte_array to copy from an
existing buffer to a new byte_array_t and replaced
allocCopy with create_byte_array, and adopted
OCTET_STRING_fromBuf whenever possible.
The UE shall use the currently stored UL NAS count to derive the
KgNB. Hardcoding the UL count to 0 is wrong, if there is a reset
to be done it should be explicitly done elsewhere.
Closes#832
The Security Mode Command is the only NAS message sending a security header
type "integrity protected with new 5G NAS security context". Such header
type is indicating that there is no valid security context and it is
indicating the current one configured by the AMF.
When receiving a Security Mode Command the "AMF shall reset the downlink NAS COUNT"
and use it to integrity protect the initial Security Mode Command. "The AMF shall
send the SECURITY MODE COMMAND message unciphered, but shall integrity protect [...]
The AMF shall set the security header type of the message to
"integrity protected with new 5G NAS security context".
See 5.4.2.2 3GPP TS 24.501.
This commit is ensuring the NAS DL count is reset when the relevant security header
is received. Also, the security container is deleted since no more valid and
NAS_SECURITY_NO_SECURITY_CONTEXT is returned. The setup of the new security context
is done by "handle_security_mode_command",
NAS 3GPP TS 24.501 clause 4.4.4.2 specify which NAS messages
are an exception to the integrity protection. All the other
scenarios are expected to be integrity protected. The
nas_security_rx_process function is returning:
1) NAS_SECURITY_NO_SECURITY_CONTEXT if no security context is established
2) NAS_SECURITY_UNPROTECTED for the messages listed in 4.4.4.2
3) NAS_SECURITY_INTEGRITY_PASSED if the integrity check is successful
These 3 results can be all considered successful. The other not.
Also, add a function to check whether a message is allowed to be
integrity unprotected, as per clause 4.2.2.2.
* trigger Identity Response callback from the handler
* process decoded message
According to 4.4.4.2 3GPP TS 24.501, Identity Request
with Identity Type SUCI is not expected to be
integrity protected.
The information about the payload carried by NAS DOWNLINK is helpful
in the logging and also for debugging purposes, therefore it was
added in this commit by enabling the already existing relevant function.
Guido Casati