Preparation Work for N2 Handover
This MR introduces preliminary improvements to support !3334.
Refactored utility NGAP functions
- Moved allocAddrCopy to NGAP utilities
Decoding Functions for NGAP IEs:
- Added common decoding functions (decode_ngap_guami,
decode_ngap_UEAggregateMaximumBitRate, decode_ngap_nssai, etc.)
- Adopted these functions across the NGAP stack
Improvements to RRC and Handover Handling:
- Enhanced get_neighbour_cell_information and get_neighbour_config to
differentiate input parameters (cell by NR Cell ID vs. gNB by PCI)
- Used byte_array_t in nr_initiate_handover
- Introduced RRCReconfigurationParams_t to structure RRCReconfiguration
IEs
- Added a function to build NR_RRCReconfiguration_IEs_t
- Adopted this approach in do_RRCReconfiguration and refactored the
function
- Refactored the handling of Dedicated NAS message list
- Add masterKeyUpdate handling in RRCReconfiguration generation
PDCP Re-Establishment Improvements:
- Enabled PDCP re-establishment for SRB1/SRB2 based on a bitmap in
createSRBlist (3GPP TS 38.331 RadioBearerConfig)
NH & KgNB Key Management:
- Added NH derivation function as per 3GPP TS 33.501 A.10
- Moved KgNB derivation function to key_nas_deriver utilities
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
Integration: `2025.w23`
Closes#962, #956, and #801
See merge request oai/openairinterface5g!3464
* !3302 Enhance UE identity management in Initial UE Message and other NGAP improvements
* !3400 T bugfix: check input data a bit better
* !3459 Improvements in NR band tables according to Rel.17
* !3465 Fix checking that amf_ip_address section is not set.
* !3463 Move RRC radio parameters file to DU
* CI: Use host network mode in NSA-B200 pipeline
* !3389 Relax NR_UE_CAPABILITY_SLOT_RX_TO_TX asserts
* !3417 Imscope updates
* !3443 Fix data race in NR UE MSG3 scheduling
* !3467 remove dead globals
Fix data race in NR UE MSG3 scheduling
Fixed a data race between DL processing of RAR and UL scheduler, which might
result in dropping MSG3.
It was possible that the UL scheduler for the UL slot which RAR indicates as
MSG3 slot was already run by the time the RAR was decoded.
Therefore when DCI for RAR is decoded, assume worst case and halt UL scheduler
for next slot until RAR is decoded solving the data race. This also in turn
halts all later scheduling due to sequential nature of the UL scheduler calls.
Closes#962
imscope updates
- Add CSV export button to imscope
- Add extra cache for IQ data in imscope record thread so that UE time domain
data can be kept until PDSCH is decoded.
- Add metadata to UE time domain samples scope
- Add UE pdsch pre-compensation IQ and PDSCH channel estimates
Move RRC radio parameters file to DU
A number of radio-related RRC parameters, e.g., CellGroupConfig, "originate" at
the DU and are sent to the CU for forwarding to the UE only. Similarly, there
are additional parameters, e.g., RLC-BearerConfig (part of CellGroupConfig),
that originate at the DU.
Hence, the DU decides about these parameters, depending on the MAC state and
capabilities. To clarify this, move the existing
openair2/RRC/NR/nr_rrc_config.{c,h} => openair2/LAYER2/NR_MAC_gNB/nr_radio_config.{c,h}
So that developers know that while those are RRC parameters, they originate at
the DU.
In other words, the CU/RRC is not supposed to use any of these functions in
the RRC. Correspondingly, includes of this file have been cleaned up (and when
they are not necessary at the MAC as well)
Fixed a data race between DL processing of RAR and UL scheduler, which
might result in dropping MSG3.
It was possible that the UL scheduler for the UL slot which RAR
indicates as MSG3 slot was already run by the time the RAR was decoded.
Therefore when DCI for RAR is decoded, assume worst case and halt the
earliest corresponding UL scheduler call until RAR is decoded solving
the data race. This also in turn halts all later scheduling due to
sequential nature of the UL scheduler calls.
Following a power cycle of the CI machines in the NSA-B200 setup, the gNB
machine encountered a networking issue. Although packets were observed leaving
and returning to the host of gNB, they failed to reach the container.
Debugging steps taken:
- upgraded the gNB machine
- reinstalled Docker
- reviewed and verified IP rules and routing settings
Setting the container to use host network mode resolved the issue.
Enhance UE identity management in Initial UE Message and other NGAP improvements
This MR improves the Initial UE Message procedures by supporting simultaneous
presence of both 5G-S-TMSI and GUAMI. Previously, only one identity could be
used, leading to potential AMF selection failures. Now the presenceMask allows
both identities. The AMF selection is prioritizing GUAMI first, then falling
back to 5G-S-TMSI, and finally using PLMN or highest capacity.
Also, fix handling of selected PLMN identity in NGAP.
Refactoring:
- Select the AMF based on (1) absence of UE Identity (2) Presence of GUAMI
(3) Presence of 5G-S-TMSI
- Also refactored the AMF selection logic for better readability and reliability.
- Refactor and cleanup rrc_gNB_send_NGAP_NAS_FIRST_REQ
- Replace ngap_pdu_t with byte_array_t
- Add guami_t to ngran_types.h: refactor NGAP and RRC code to use one common
GUAMI type instead of two identical ones
Also:
- Bugfix in ngap_gNB_handle_ng_setup_response: use correct count for PLMNSupportList
Closes issue #801
A number of radio-related RRC parameters, e.g., CellGroupConfig,
"originate" at the DU and are sent to the CU for forwarding to the UE
only. Similarly, there are additional parameters, e.g., RLC-BearerConfig
(part of CellGroupConfig), that originate at the DU.
Hence, the DU decides about these parameters, depending on the MAC state
and capabilities. To clarify this, move the existing
openair2/RRC/NR/nr_rrc_config.{c,h} => openair2/LAYER2/NR_MAC_gNB/nr_radio_config.{c,h}
So that developers know that while those are RRC parameters, they
originate at the DU.
In other words, the CU/RRC is not supposed to use any of these functions
in the RRC. Correspondingly, includes of this file have been cleaned up
(and when they are not necessary at the MAC as well).
Robert Schmidt