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/*
* Copyright 2013-2019 Software Radio Systems Limited
*
* This file is part of srsLTE.
*
* srsLTE 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.
*
* srsLTE 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_COMMON_H
#define SRSLTE_RLC_COMMON_H
#include "srslte/common/block_queue.h"
#include "srslte/upper/rlc_metrics.h"
#include <stdlib.h>
namespace srslte {
/****************************************************************************
* 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
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<uint8_t>(static_cast<std::underlying_type<rlc_nr_si_field_t>::type>(lhs) &
static_cast<std::underlying_type<rlc_nr_si_field_t>::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
struct rlc_amd_pdu_header_t{
rlc_dc_field_t dc; // Data or control
uint8_t rf; // Resegmentation flag
uint8_t p; // Polling bit
uint8_t fi; // Framing info
uint16_t sn; // Sequence number
uint8_t lsf; // Last segment flag
uint16_t so; // Segment offset
uint32_t N_li; // Number of length indicators
uint16_t li[RLC_AM_WINDOW_SIZE]; // Array of length indicators
rlc_amd_pdu_header_t(){
dc = RLC_DC_FIELD_CONTROL_PDU;
rf = 0;
p = 0;
fi = 0;
sn = 0;
lsf = 0;
so = 0;
N_li=0;
for(int i=0;i<RLC_AM_WINDOW_SIZE;i++)
li[i] = 0;
}
rlc_amd_pdu_header_t(const rlc_amd_pdu_header_t& h)
{
copy(h);
}
rlc_amd_pdu_header_t& operator= (const rlc_amd_pdu_header_t& h)
{
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];
}
}
};
// 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;
/****************************************************************************
* RLC Common interface
* Common interface for all RLC entities
***************************************************************************/
class rlc_common
{
public:
// Size of the Uplink buffer in number of PDUs
const static int RLC_BUFFER_NOF_PDU = 128;
virtual ~rlc_common() {}
virtual bool configure(rlc_config_t cnfg) = 0;
virtual void stop() = 0;
virtual void reestablish() = 0;
virtual void empty_queue() = 0;
bool suspend()
{
if (is_suspended) {
return false;
}
is_suspended = true;
return true;
}
// Pops all PDUs from queue and calls write_pdu() method for the bearer type
bool resume()
{
if (!is_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);
}
is_suspended = false;
return true;
}
void write_pdu_s(uint8_t* payload, uint32_t nof_bytes)
{
if (is_suspended) {
queue_pdu(payload, nof_bytes);
} else {
write_pdu(payload, nof_bytes);
}
}
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, bool blocking) = 0;
virtual void discard_sdu(uint32_t discard_sn) = 0;
// MAC interface
virtual bool has_data() = 0;
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;
private:
bool is_suspended = false;
// Enqueues the PDU in the resume queue
void queue_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)) {
fprintf(stderr, "Error dropping PDUs while bearer suspended. Queue should be unbounded\n");
return;
}
}
typedef struct {
uint8_t* payload;
uint32_t nof_bytes;
} pdu_t;
block_queue<pdu_t> rx_pdu_resume_queue;
};
} // namespace srslte
#endif // SRSLTE_RLC_COMMON_H