Refactor SDAP adaptation work for QoS

Guido Casatirequested to merge
sdap-qos-improvements into develop

This MR is an adaptation of the code introduced in !2703 (closed).

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

Namely:

  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
  1. 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
  1. 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
  1. 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

Merge request reports