/** * * \section COPYRIGHT * * Copyright 2013-2015 Software Radio Systems Limited * * \section LICENSE * * This file is part of the srsUE library. * * srsUE is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of * the License, or (at your option) any later version. * * srsUE is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * A copy of the GNU Affero General Public License can be found in * the LICENSE file in the top-level directory of this distribution * and at http://www.gnu.org/licenses/. * */ #ifndef SRSLTE_RLC_AM_H #define SRSLTE_RLC_AM_H #include "srslte/common/buffer_pool.h" #include "srslte/common/log.h" #include "srslte/common/common.h" #include "srslte/interfaces/ue_interfaces.h" #include "srslte/upper/rlc_tx_queue.h" #include "srslte/common/timeout.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; 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; 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; }; class rlc_am : public rlc_common { public: rlc_am(uint32_t queue_len = 16); ~rlc_am(); void init(log *rlc_entity_log_, uint32_t lcid_, srsue::pdcp_interface_rlc *pdcp_, srsue::rrc_interface_rlc *rrc_, mac_interface_timers *mac_timers); bool configure(srslte_rlc_config_t cnfg); void reestablish(); void stop(); void empty_queue(); rlc_mode_t get_mode(); uint32_t get_bearer(); // PDCP interface void write_sdu(byte_buffer_t *sdu); void write_sdu_nb(byte_buffer_t *sdu); // MAC interface uint32_t get_buffer_state(); uint32_t get_total_buffer_state(); int read_pdu(uint8_t *payload, uint32_t nof_bytes); void write_pdu(uint8_t *payload, uint32_t nof_bytes); uint32_t get_num_tx_bytes(); uint32_t get_num_rx_bytes(); void reset_metrics(); private: byte_buffer_pool *pool; srslte::log *log; uint32_t lcid; srsue::pdcp_interface_rlc *pdcp; srsue::rrc_interface_rlc *rrc; // TX SDU buffers rlc_tx_queue tx_sdu_queue; byte_buffer_t *tx_sdu; // PDU being resegmented rlc_amd_tx_pdu_t tx_pdu_segments; // Tx and Rx windows std::map tx_window; std::deque retx_queue; std::map rx_window; std::map rx_segments; // RX SDU buffers byte_buffer_t *rx_sdu; // Mutexes pthread_mutex_t mutex; bool tx_enabled; bool poll_received; bool do_status; rlc_status_pdu_t status; // Metrics uint32_t num_tx_bytes; uint32_t num_rx_bytes; /**************************************************************************** * Configurable parameters * Ref: 3GPP TS 36.322 v10.0.0 Section 7 ***************************************************************************/ srslte_rlc_am_config_t cfg; /**************************************************************************** * State variables and counters * Ref: 3GPP TS 36.322 v10.0.0 Section 7 ***************************************************************************/ // Tx state variables uint32_t vt_a; // ACK state. SN of next PDU in sequence to be ACKed. Low edge of tx window. uint32_t vt_ms; // Max send state. High edge of tx window. vt_a + window_size. uint32_t vt_s; // Send state. SN to be assigned for next PDU. uint32_t poll_sn; // Poll send state. SN of most recent PDU txed with poll bit set. // Tx counters uint32_t pdu_without_poll; uint32_t byte_without_poll; // Rx state variables uint32_t vr_r; // Receive state. SN following last in-sequence received PDU. Low edge of rx window uint32_t vr_mr; // Max acceptable receive state. High edge of rx window. vr_r + window size. uint32_t vr_x; // t_reordering state. SN following PDU which triggered t_reordering. uint32_t vr_ms; // Max status tx state. Highest possible value of SN for ACK_SN in status PDU. uint32_t vr_h; // Highest rx state. SN following PDU with highest SN among rxed PDUs. /**************************************************************************** * Timers * Ref: 3GPP TS 36.322 v10.0.0 Section 7 ***************************************************************************/ timeout poll_retx_timeout; timeout reordering_timeout; timeout status_prohibit_timeout; static const int reordering_timeout_id = 1; static const int poll_periodicity = 8; // After how many data PDUs a status PDU shall be requested // Timer checks bool status_prohibited(); bool poll_retx(); void check_reordering_timeout(); // Helpers bool poll_required(); int prepare_status(); 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 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 handle_control_pdu(uint8_t *payload, uint32_t nof_bytes); void reassemble_rx_sdus(); bool inside_tx_window(uint16_t sn); bool inside_rx_window(uint16_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); int required_buffer_size(rlc_amd_retx_t retx); bool retx_queue_has_sn(uint32_t sn); }; /**************************************************************************** * 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_control_pdu(byte_buffer_t *pdu); bool rlc_am_is_control_pdu(uint8_t *payload); bool rlc_am_is_pdu_segment(uint8_t *payload); std::string rlc_am_to_string(rlc_status_pdu_t *status); 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_H