/** * Copyright 2013-2021 Software Radio Systems Limited * * This file is part of srsRAN. * * srsRAN 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. * * srsRAN 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 SRSRAN_RLC_COMMON_H #define SRSRAN_RLC_COMMON_H #include "srsran/adt/circular_buffer.h" #include "srsran/interfaces/rlc_interface_types.h" #include "srsran/upper/bearer_mem_pool.h" #include "srsran/upper/rlc_metrics.h" #include namespace srsran { /**************************************************************************** * Structs and Defines * Ref: 3GPP TS 36.322 v10.0.0 ***************************************************************************/ #define RLC_AM_WINDOW_SIZE 512 #define RLC_MAX_SDU_SIZE ((1 << 11) - 1) // Length of LI field is 11bits #define RLC_AM_MIN_DATA_PDU_SIZE (3) // AMD PDU with 10 bit SN (length of LI field is 11 bits) (No LI) typedef enum { RLC_FI_FIELD_START_AND_END_ALIGNED = 0, RLC_FI_FIELD_NOT_END_ALIGNED, RLC_FI_FIELD_NOT_START_ALIGNED, RLC_FI_FIELD_NOT_START_OR_END_ALIGNED, RLC_FI_FIELD_N_ITEMS, } rlc_fi_field_t; static const char rlc_fi_field_text[RLC_FI_FIELD_N_ITEMS][32] = {"Start and end aligned", "Not end aligned", "Not start aligned", "Not start or end aligned"}; enum class rlc_nr_si_field_t : unsigned { full_sdu = 0b00, first_segment = 0b01, last_segment = 0b10, neither_first_nor_last_segment = 0b11, nulltype }; inline std::string to_string(const rlc_nr_si_field_t& si) { constexpr static const char* options[] = {"Data field contains full SDU", "Data field contains first segment of SDU", "Data field contains last segment of SDU", "Data field contains neither first nor last segment of SDU"}; return enum_to_text(options, (uint32_t)rlc_nr_si_field_t::nulltype, (uint32_t)si); } inline std::string to_string_short(const rlc_nr_si_field_t& si) { constexpr static const char* options[] = {"full", "first", "last", "middle"}; return enum_to_text(options, (uint32_t)rlc_nr_si_field_t::nulltype, (uint32_t)si); } static inline uint8_t operator&(rlc_nr_si_field_t lhs, int rhs) { return static_cast(static_cast::type>(lhs) & static_cast::type>(rhs)); } enum class rlc_am_nr_control_pdu_type_t : unsigned { status_pdu = 0b000, nulltype }; inline std::string to_string(const rlc_am_nr_control_pdu_type_t& type) { constexpr static const char* options[] = {"Control PDU"}; return enum_to_text(options, (uint32_t)rlc_am_nr_control_pdu_type_t::nulltype, (uint32_t)type); } typedef enum { RLC_DC_FIELD_CONTROL_PDU = 0, RLC_DC_FIELD_DATA_PDU, RLC_DC_FIELD_N_ITEMS, } rlc_dc_field_t; static const char rlc_dc_field_text[RLC_DC_FIELD_N_ITEMS][20] = {"Control PDU", "Data PDU"}; // UMD PDU Header typedef struct { uint8_t fi; // Framing info rlc_umd_sn_size_t sn_size; // Sequence number size (5 or 10 bits) uint16_t sn; // Sequence number uint32_t N_li; // Number of length indicators uint16_t li[RLC_AM_WINDOW_SIZE]; // Array of length indicators } rlc_umd_pdu_header_t; typedef struct { rlc_nr_si_field_t si; // Segmentation info rlc_um_nr_sn_size_t sn_size; // Sequence number size (6 or 12 bits) uint16_t sn; // Sequence number uint16_t so; // Segment offset } rlc_um_nr_pdu_header_t; // AMD PDU Header class rlc_amd_pdu_header_t { public: rlc_amd_pdu_header_t() = default; rlc_amd_pdu_header_t(const rlc_amd_pdu_header_t& h) { copy(h); } rlc_amd_pdu_header_t(rlc_amd_pdu_header_t&& h) noexcept { copy(h); } rlc_amd_pdu_header_t& operator=(const rlc_amd_pdu_header_t& h) { if (this == &h) { return *this; } copy(h); return *this; } rlc_amd_pdu_header_t& operator=(rlc_amd_pdu_header_t&& h) noexcept { copy(h); return *this; } void copy(const rlc_amd_pdu_header_t& h) { dc = h.dc; rf = h.rf; p = h.p; fi = h.fi; sn = h.sn; lsf = h.lsf; so = h.so; N_li = h.N_li; for (uint32_t i = 0; i < h.N_li; i++) { li[i] = h.li[i]; } } rlc_dc_field_t dc = RLC_DC_FIELD_CONTROL_PDU; // Data or control uint8_t rf = 0; // Resegmentation flag uint8_t p = 0; // Polling bit uint8_t fi = RLC_FI_FIELD_START_AND_END_ALIGNED; // Framing info uint16_t sn = 0; // Sequence number uint8_t lsf = 0; // Last segment flag uint16_t so = 0; // Segment offset uint32_t N_li = 0; // Number of length indicators uint16_t li[RLC_AM_WINDOW_SIZE] = {0}; // Array of length indicators }; // NACK helper (for LTE and NR) struct rlc_status_nack_t { uint32_t nack_sn; bool has_so; uint16_t so_start; uint16_t so_end; rlc_status_nack_t() { has_so = false; nack_sn = 0; so_start = 0; so_end = 0; } }; // STATUS PDU struct rlc_status_pdu_t { uint16_t ack_sn; // SN of the next not received RLC Data PDU uint32_t N_nack; rlc_status_nack_t nacks[RLC_AM_WINDOW_SIZE]; rlc_status_pdu_t() { N_nack = 0; ack_sn = 0; } }; /** RLC AM NR structs */ ///< AM NR PDU header typedef struct { rlc_dc_field_t dc; ///< Data/Control (D/C) field uint8_t p; ///< Polling bit rlc_nr_si_field_t si; ///< Segmentation info rlc_am_nr_sn_size_t sn_size; ///< Sequence number size (12 or 18 bits) uint32_t sn; ///< Sequence number uint16_t so; ///< Sequence offset } rlc_am_nr_pdu_header_t; ///< AM NR Status PDU header (perhaps merge with LTE version) typedef struct { rlc_am_nr_control_pdu_type_t cpt; uint32_t ack_sn; ///< SN of the next not received RLC Data PDU uint16_t N_nack; ///< number of NACKs uint8_t nack_range; ///< number of consecutively lost RLC SDUs starting from and including NACK_SN rlc_status_nack_t nacks[RLC_AM_WINDOW_SIZE]; } rlc_am_nr_status_pdu_t; typedef std::function bsr_callback_t; /**************************************************************************** * RLC Common interface * Common interface for all RLC entities ***************************************************************************/ class rlc_common { public: virtual ~rlc_common() = default; virtual bool configure(const rlc_config_t& cnfg) = 0; virtual void stop() = 0; virtual void reestablish() = 0; virtual void empty_queue() = 0; bool suspend() { if (suspended) { return false; } suspended = true; return true; } // Pops all PDUs from queue and calls write_pdu() method for the bearer type bool resume() { if (!suspended) { return false; } pdu_t p; // Do not block while (rx_pdu_resume_queue.try_pop(p)) { write_pdu(p.payload, p.nof_bytes); free(p.payload); } unique_byte_buffer_t s; while (tx_sdu_resume_queue.try_pop(s)) { write_sdu(std::move(s)); } suspended = false; return true; } void write_pdu_s(uint8_t* payload, uint32_t nof_bytes) { if (suspended) { queue_rx_pdu(payload, nof_bytes); } else { write_pdu(payload, nof_bytes); } } void write_sdu_s(unique_byte_buffer_t sdu) { if (suspended) { queue_tx_sdu(std::move(sdu)); } else { write_sdu(std::move(sdu)); } } virtual rlc_mode_t get_mode() = 0; virtual uint32_t get_bearer() = 0; virtual rlc_bearer_metrics_t get_metrics() = 0; virtual void reset_metrics() = 0; // PDCP interface virtual void write_sdu(unique_byte_buffer_t sdu) = 0; virtual void discard_sdu(uint32_t discard_sn) = 0; virtual bool sdu_queue_is_full() = 0; // MAC interface virtual bool has_data() = 0; bool is_suspended() { return suspended; }; virtual uint32_t get_buffer_state() = 0; virtual int read_pdu(uint8_t* payload, uint32_t nof_bytes) = 0; virtual void write_pdu(uint8_t* payload, uint32_t nof_bytes) = 0; virtual void set_bsr_callback(bsr_callback_t callback) = 0; void* operator new(size_t sz) { return allocate_rlc_bearer(sz); } void operator delete(void* p) { return deallocate_rlc_bearer(p); } private: bool suspended = false; // Enqueues the Rx PDU in the resume queue void queue_rx_pdu(uint8_t* payload, uint32_t nof_bytes) { pdu_t p = {}; p.nof_bytes = nof_bytes; p.payload = (uint8_t*)malloc(nof_bytes); memcpy(p.payload, payload, nof_bytes); // Do not block ever if (!rx_pdu_resume_queue.try_push(p)) { srslog::fetch_basic_logger("RLC").warning("Dropping SDUs while bearer suspended."); return; } } // Enqueues the Tx SDU in the resume queue void queue_tx_sdu(unique_byte_buffer_t sdu) { // Do not block ever if (not tx_sdu_resume_queue.try_push(std::move(sdu))) { srslog::fetch_basic_logger("RLC").warning("Dropping SDUs while bearer suspended."); return; } } typedef struct { uint8_t* payload; uint32_t nof_bytes; } pdu_t; static_blocking_queue rx_pdu_resume_queue; static_blocking_queue tx_sdu_resume_queue; }; } // namespace srsran #endif // SRSRAN_RLC_COMMON_H