/** * * \section COPYRIGHT * * Copyright 2013-2020 Software Radio Systems Limited * * By using this file, you agree to the terms and conditions set * forth in the LICENSE file which can be found at the top level of * the distribution. * */ #ifndef SRSLTE_RLC_AM_LTE_H #define SRSLTE_RLC_AM_LTE_H #include "srslte/adt/accumulators.h" #include "srslte/common/buffer_pool.h" #include "srslte/common/common.h" #include "srslte/common/log.h" #include "srslte/common/timeout.h" #include "srslte/interfaces/ue_interfaces.h" #include "srslte/upper/byte_buffer_queue.h" #include "srslte/upper/rlc_am_base.h" #include "srslte/upper/rlc_common.h" #include #include #include namespace srslte { #undef RLC_AM_BUFFER_DEBUG struct rlc_amd_rx_pdu_t { rlc_amd_pdu_header_t header; unique_byte_buffer_t buf; }; struct rlc_amd_rx_pdu_segments_t { std::list segments; }; struct rlc_amd_tx_pdu_t { rlc_amd_pdu_header_t header; unique_byte_buffer_t buf; uint32_t retx_count; bool is_acked; }; struct rlc_amd_retx_t { uint32_t sn; bool is_segment; uint32_t so_start; uint32_t so_end; }; struct rlc_sn_info_t { uint32_t sn; bool is_acked; }; struct pdcp_sdu_info_t { uint32_t sn; bool fully_txed; // Boolean indicating if the SDU is fully transmitted. bool fully_acked; // Boolean indicating if the SDU is fully acked. This is only necessary temporarely to avoid // duplicate removal from the queue while processing the status report std::vector rlc_sn_info_list; // List of RLC PDUs in transit and whether they have been acked or not. }; class rlc_am_lte : public rlc_common { public: rlc_am_lte(srslte::log_ref log_, uint32_t lcid_, srsue::pdcp_interface_rlc* pdcp_, srsue::rrc_interface_rlc* rrc_, srslte::timer_handler* timers_); bool configure(const rlc_config_t& cfg_); void reestablish(); void stop(); void empty_queue(); rlc_mode_t get_mode(); uint32_t get_bearer(); // PDCP interface void write_sdu(unique_byte_buffer_t sdu); void discard_sdu(uint32_t pdcp_sn); bool sdu_queue_is_full(); // MAC interface bool has_data(); uint32_t get_buffer_state(); int read_pdu(uint8_t* payload, uint32_t nof_bytes); void write_pdu(uint8_t* payload, uint32_t nof_bytes); rlc_bearer_metrics_t get_metrics(); void reset_metrics(); void set_bsr_callback(bsr_callback_t callback); private: // Transmitter sub-class class rlc_am_lte_tx : public timer_callback { public: rlc_am_lte_tx(rlc_am_lte* parent_); ~rlc_am_lte_tx(); bool configure(const rlc_config_t& cfg_); void empty_queue(); void reestablish(); void stop(); int write_sdu(unique_byte_buffer_t sdu); int read_pdu(uint8_t* payload, uint32_t nof_bytes); void discard_sdu(uint32_t discard_sn); bool sdu_queue_is_full(); bool has_data(); uint32_t get_buffer_state(); // Timeout callback interface void timer_expired(uint32_t timeout_id); // Interface for Rx subclass void handle_control_pdu(uint8_t* payload, uint32_t nof_bytes); void set_bsr_callback(bsr_callback_t callback); private: int build_status_pdu(uint8_t* payload, uint32_t nof_bytes); int build_retx_pdu(uint8_t* payload, uint32_t nof_bytes); int build_segment(uint8_t* payload, uint32_t nof_bytes, rlc_amd_retx_t retx); int build_data_pdu(uint8_t* payload, uint32_t nof_bytes); void update_notification_ack_info(const rlc_amd_tx_pdu_t& tx_pdu, std::vector& notify_info_vec); void debug_state(); bool retx_queue_has_sn(uint32_t sn); int required_buffer_size(rlc_amd_retx_t retx); void retransmit_pdu(); // Helpers bool poll_required(); bool do_status(); rlc_am_lte* parent = nullptr; byte_buffer_pool* pool = nullptr; srslte::log_ref log; /**************************************************************************** * Configurable parameters * Ref: 3GPP TS 36.322 v10.0.0 Section 7 ***************************************************************************/ rlc_am_config_t cfg = {}; // TX SDU buffers byte_buffer_queue tx_sdu_queue; unique_byte_buffer_t tx_sdu; bool tx_enabled = false; /**************************************************************************** * State variables and counters * Ref: 3GPP TS 36.322 v10.0.0 Section 7 ***************************************************************************/ // Tx state variables uint32_t vt_a = 0; // ACK state. SN of next PDU in sequence to be ACKed. Low edge of tx window. uint32_t vt_ms = RLC_AM_WINDOW_SIZE; // Max send state. High edge of tx window. vt_a + window_size. uint32_t vt_s = 0; // Send state. SN to be assigned for next PDU. uint32_t poll_sn = 0; // Poll send state. SN of most recent PDU txed with poll bit set. // Tx counters uint32_t pdu_without_poll = 0; uint32_t byte_without_poll = 0; rlc_status_pdu_t tx_status; /**************************************************************************** * Timers * Ref: 3GPP TS 36.322 v10.0.0 Section 7 ***************************************************************************/ srslte::timer_handler::unique_timer poll_retx_timer; srslte::timer_handler::unique_timer status_prohibit_timer; // SDU info for PDCP notifications uint32_t pdcp_info_queue_capacity = 512; std::map undelivered_sdu_info_queue = {}; // Callback function for buffer status report bsr_callback_t bsr_callback; // Tx windows std::map tx_window; std::deque retx_queue; // Mutexes pthread_mutex_t mutex; }; // Receiver sub-class class rlc_am_lte_rx : public timer_callback { public: rlc_am_lte_rx(rlc_am_lte* parent_); ~rlc_am_lte_rx(); bool configure(rlc_am_config_t cfg_); void reestablish(); void stop(); void write_pdu(uint8_t* payload, uint32_t nof_bytes); uint32_t get_rx_buffered_bytes(); // returns sum of PDUs in rx_window uint32_t get_sdu_rx_latency_ms(); // Timeout callback interface void timer_expired(uint32_t timeout_id); // Functions needed by Tx subclass to query rx state int get_status_pdu_length(); int get_status_pdu(rlc_status_pdu_t* status, const uint32_t nof_bytes); bool get_do_status(); void reset_status(); // called when status PDU has been sent private: void handle_data_pdu(uint8_t* payload, uint32_t nof_bytes, rlc_amd_pdu_header_t& header); void handle_data_pdu_segment(uint8_t* payload, uint32_t nof_bytes, rlc_amd_pdu_header_t& header); void reassemble_rx_sdus(); bool inside_rx_window(const int16_t sn); void debug_state(); void print_rx_segments(); bool add_segment_and_check(rlc_amd_rx_pdu_segments_t* pdu, rlc_amd_rx_pdu_t* segment); rlc_am_lte* parent = nullptr; byte_buffer_pool* pool = nullptr; srslte::log_ref log; /**************************************************************************** * Configurable parameters * Ref: 3GPP TS 36.322 v10.0.0 Section 7 ***************************************************************************/ rlc_am_config_t cfg = {}; // RX SDU buffers unique_byte_buffer_t rx_sdu; /**************************************************************************** * State variables and counters * Ref: 3GPP TS 36.322 v10.0.0 Section 7 ***************************************************************************/ // Rx state variables uint32_t vr_r = 0; // Receive state. SN following last in-sequence received PDU. Low edge of rx window uint32_t vr_mr = RLC_AM_WINDOW_SIZE; // Max acceptable receive state. High edge of rx window. vr_r + window size. uint32_t vr_x = 0; // t_reordering state. SN following PDU which triggered t_reordering. uint32_t vr_ms = 0; // Max status tx state. Highest possible value of SN for ACK_SN in status PDU. uint32_t vr_h = 0; // Highest rx state. SN following PDU with highest SN among rxed PDUs. // Mutexes pthread_mutex_t mutex; // Rx windows std::map rx_window; std::map rx_segments; bool poll_received = false; bool do_status = false; /**************************************************************************** * Timers * Ref: 3GPP TS 36.322 v10.0.0 Section 7 ***************************************************************************/ srslte::timer_handler::unique_timer reordering_timer; srslte::rolling_average sdu_rx_latency_ms; }; // Common variables needed/provided by parent class srsue::rrc_interface_rlc* rrc = nullptr; srslte::log_ref log; srsue::pdcp_interface_rlc* pdcp = nullptr; srslte::timer_handler* timers = nullptr; uint32_t lcid = 0; rlc_config_t cfg = {}; std::string rb_name; static const int poll_periodicity = 8; // After how many data PDUs a status PDU shall be requested // Rx and Tx objects rlc_am_lte_tx tx; rlc_am_lte_rx rx; rlc_bearer_metrics_t metrics = {}; }; /**************************************************************************** * Header pack/unpack helper functions * Ref: 3GPP TS 36.322 v10.0.0 Section 6.2.1 ***************************************************************************/ void rlc_am_read_data_pdu_header(byte_buffer_t* pdu, rlc_amd_pdu_header_t* header); void rlc_am_read_data_pdu_header(uint8_t** payload, uint32_t* nof_bytes, rlc_amd_pdu_header_t* header); void rlc_am_write_data_pdu_header(rlc_amd_pdu_header_t* header, byte_buffer_t* pdu); void rlc_am_write_data_pdu_header(rlc_amd_pdu_header_t* header, uint8_t** payload); void rlc_am_read_status_pdu(byte_buffer_t* pdu, rlc_status_pdu_t* status); void rlc_am_read_status_pdu(uint8_t* payload, uint32_t nof_bytes, rlc_status_pdu_t* status); void rlc_am_write_status_pdu(rlc_status_pdu_t* status, byte_buffer_t* pdu); int rlc_am_write_status_pdu(rlc_status_pdu_t* status, uint8_t* payload); uint32_t rlc_am_packed_length(rlc_amd_pdu_header_t* header); uint32_t rlc_am_packed_length(rlc_status_pdu_t* status); uint32_t rlc_am_packed_length(rlc_amd_retx_t retx); bool rlc_am_is_valid_status_pdu(const rlc_status_pdu_t& status); bool rlc_am_is_pdu_segment(uint8_t* payload); std::string rlc_am_undelivered_sdu_info_to_string(const std::map& info_queue); std::string rlc_am_status_pdu_to_string(rlc_status_pdu_t* status); std::string rlc_amd_pdu_header_to_string(const rlc_amd_pdu_header_t& header); bool rlc_am_start_aligned(const uint8_t fi); bool rlc_am_end_aligned(const uint8_t fi); bool rlc_am_is_unaligned(const uint8_t fi); bool rlc_am_not_start_aligned(const uint8_t fi); } // namespace srslte #endif // SRSLTE_RLC_AM_LTE_H