版权声明：This article is a blogger original article, only for study reference, reprint please indicate the source, thank you! https://blog.csdn.net/Rong_Toa/article/details/89220802
TX与RX
- TXD 发送数据 Transmit(tx) Data 的简写形式。
- RXD 接收数据 Receive(rx) Data 的简写形式。
- x没有特定的意思，就是一开始这么写，之后都这么用了，约定俗成。
PDU （协议数据单元）
- 物理层 的 PDU是数据位（bit），
- 数据链路层 的PDU是数据帧（frame），
- 网络层 的PDU是数据包（packet），
- 传输层 的 PDU是数据段（segment），
- 其他更高层次的PDU是报文（message）
pdu.h
lib\include\srslte\common 10727 4/10/2019 143
/**
*
* \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_PDU_H
#define SRSLTE_PDU_H
#include <stdint.h>
#include "srslte/common/log.h"
#include "srslte/common/interfaces_common.h"
#include <vector>
#include <stdio.h>
/* MAC PDU Packing/Unpacking functions. Section 6 of 36.321 */
class subh;
/*
PDU （协议数据单元）
物理层 的 PDU是数据位（bit），
数据链路层 的PDU是数据帧（frame），
网络层 的PDU是数据包（packet），
传输层 的 PDU是数据段（segment），
其他更高层次的PDU是报文（message）
*/
namespace srslte {
template<class SubH>
class pdu
{
public:
//初始化：构造函数
pdu(uint32_t max_subheaders_) : subheaders(max_subheaders_) {
max_subheaders = max_subheaders_;
nof_subheaders = 0;
cur_idx = -1;
pdu_len = 0;
rem_len = 0;
last_sdu_idx = -1;
pdu_is_ul = false;
buffer_tx = NULL;
total_sdu_len = 0;
}
//打印
void fprint(FILE *stream) {
fprintf(stream, "Number of Subheaders: %d\n", nof_subheaders);
for (int i=0;i<nof_subheaders;i++) {
fprintf(stream, " -- Subheader %d: ", i);
subheaders[i].fprint(stream);
}
}
/* Resets the Read/Write position and remaining PDU length */
//
void reset() {
cur_idx = -1;
last_sdu_idx = -1;
rem_len = pdu_len;
}
//RXD 接收数据 Receive(rx) Data 的简写形式
void init_rx(uint32_t pdu_len_bytes, bool is_ulsch = false) {
init_(NULL, pdu_len_bytes, is_ulsch);
}
//TXD 发送数据 Transmit(tx) Data 的简写形式。
void init_tx(uint8_t *payload, uint32_t pdu_len_bytes, bool is_ulsch = false) {
init_(payload, pdu_len_bytes, is_ulsch);
}
uint32_t nof_subh() {
return nof_subheaders;
}
bool new_subh() {
if (nof_subheaders < (int)max_subheaders - 1 && rem_len > 0) {
nof_subheaders++;
next();
return true;
} else {
return false;
}
}
bool next() {
if (cur_idx < nof_subheaders - 1) {
cur_idx++;
return true;
} else {
return false;
}
}
void del_subh() {
if (nof_subheaders > 0) {
nof_subheaders--;
}
if (cur_idx > 0) {
cur_idx--;
}
}
SubH* get() {
if (cur_idx >= 0) {
return &subheaders[cur_idx];
} else {
return NULL;
}
}
bool is_ul() {
return pdu_is_ul;
}
uint8_t* get_current_sdu_ptr() {
return &buffer_tx[total_sdu_len+sdu_offset_start];
}
void add_sdu(uint32_t sdu_sz) {
total_sdu_len += sdu_sz;
}
// Section 6.1.2 parse:解析
void parse_packet(uint8_t *ptr) {
uint8_t *init_ptr = ptr;
nof_subheaders = 0;
bool ret = false;
do {
if (nof_subheaders < (int)max_subheaders) {
ret = subheaders[nof_subheaders].read_subheader(&ptr);
nof_subheaders++;
}
} while (ret && (nof_subheaders + 1) < (int)max_subheaders);
for (int i=0;i<nof_subheaders;i++) {
subheaders[i].read_payload(&ptr);
}
}
protected:
std::vector<SubH> subheaders;
uint32_t pdu_len;
uint32_t rem_len;
int cur_idx;
int nof_subheaders;
uint32_t max_subheaders;
bool pdu_is_ul;
uint8_t* buffer_tx;
uint32_t total_sdu_len;
uint32_t sdu_offset_start;
int last_sdu_idx;
/* Prepares the PDU for parsing or writing by setting the number of subheaders to 0 and the pdu length */
virtual void init_(uint8_t *buffer_tx_ptr, uint32_t pdu_len_bytes, bool is_ulsch) {
nof_subheaders = 0;
pdu_len = pdu_len_bytes;
rem_len = pdu_len;
pdu_is_ul = is_ulsch;
buffer_tx = buffer_tx_ptr;
sdu_offset_start = max_subheaders*2 + 13; // Assuming worst-case 2 bytes per sdu subheader + all possible CE
total_sdu_len = 0;
last_sdu_idx = -1;
reset();
for (uint32_t i=0;i<max_subheaders;i++) {
subheaders[i].parent = this;
subheaders[i].init();
}
}
};
typedef enum {
SCH_SUBH_TYPE = 0,
MCH_SUBH_TYPE = 1,
RAR_SUBH_TYPE = 2
} subh_type;
template<class SubH>
class subh
{
public:
subh(){}
virtual ~subh(){}
virtual bool read_subheader(uint8_t** ptr) = 0;
virtual void read_payload(uint8_t **ptr) = 0;
virtual void write_subheader(uint8_t** ptr, bool is_last) = 0;
virtual void write_payload(uint8_t **ptr) = 0;
virtual void fprint(FILE *stream) = 0;
pdu<SubH>* parent;
private:
virtual void init() = 0;
};
class sch_subh : public subh<sch_subh>
{
public:
sch_subh(subh_type type_ = SCH_SUBH_TYPE) {
lcid = 0;
nof_bytes = 0;
payload = NULL;
nof_mch_sched_ce = 0;
cur_mch_sched_ce = 0;
F_bit = false;
type = type_;
parent = NULL;
bzero(&w_payload_ce, sizeof(w_payload_ce));
}
/*
1. 作用：对象消亡时，自动被调用，用来释放对象占用的空间
2.特点:
(1) 名字与类名相同
(2) 在前面需要加上"~"
(3) 无参数，无返回值
(4) 一个类最多只有一个析构函数
(5) 不显示定义析构函数会调用缺省析构函数*/
virtual ~sch_subh(){}
typedef enum {
PHR_REPORT = 26,
CRNTI = 27,
CON_RES_ID = 28,
MTCH_MAX_LCID = 28,
TRUNC_BSR = 28,
TA_CMD = 29,
SHORT_BSR = 29,
DRX_CMD = 30,
LONG_BSR = 30,
MCH_SCHED_INFO = 30,
PADDING = 31,
SDU = 0
} cetype;
// Size of MAC CEs
const static int MAC_CE_CONTRES_LEN = 6;
// Reading functions
bool is_sdu();
bool is_var_len_ce();
cetype ce_type();
uint32_t size_plus_header();
void set_payload_size(uint32_t size);
bool read_subheader(uint8_t** ptr);
void read_payload(uint8_t **ptr);
uint32_t get_sdu_lcid();
uint32_t get_payload_size();
uint32_t get_header_size(bool is_last);
uint8_t* get_sdu_ptr();
uint16_t get_c_rnti();
uint64_t get_con_res_id();
uint8_t get_ta_cmd();
float get_phr();
int get_bsr(uint32_t buff_size[4]);
bool get_next_mch_sched_info(uint8_t *lcid, uint16_t *mtch_stop);
// Writing functions
void write_subheader(uint8_t** ptr, bool is_last);
void write_payload(uint8_t **ptr);
int set_sdu(uint32_t lcid, uint32_t nof_bytes, uint8_t *payload);
int set_sdu(uint32_t lcid, uint32_t requested_bytes, read_pdu_interface *sdu_itf);
bool set_c_rnti(uint16_t crnti);
bool set_bsr(uint32_t buff_size[4], sch_subh::cetype format);
bool set_con_res_id(uint64_t con_res_id);
bool set_ta_cmd(uint8_t ta_cmd);
bool set_phr(float phr);
void set_padding();
void set_padding(uint32_t padding_len);
void init();
void fprint(FILE *stream);
bool set_next_mch_sched_info(uint8_t lcid, uint16_t mtch_stop);
protected:
static const int MAX_CE_PAYLOAD_LEN = 8;
uint32_t lcid;
int nof_bytes;
uint8_t* payload;
uint8_t w_payload_ce[64];
uint8_t nof_mch_sched_ce;
uint8_t cur_mch_sched_ce;
bool F_bit;
subh_type type;
private:
uint32_t sizeof_ce(uint32_t lcid, bool is_ul);
static uint8_t buff_size_table(uint32_t buffer_size);
static uint8_t phr_report_table(float phr_value);
};
class sch_pdu : public pdu<sch_subh>
{
public:
sch_pdu(uint32_t max_subh): pdu(max_subh) {}
void parse_packet(uint8_t *ptr);
uint8_t* write_packet();
uint8_t* write_packet(srslte::log *log_h);
bool has_space_ce(uint32_t nbytes, bool var_len=false);
bool has_space_sdu(uint32_t nbytes);
int get_pdu_len();
int rem_size();
int get_sdu_space();
static uint32_t size_header_sdu(uint32_t nbytes);
bool update_space_ce(uint32_t nbytes, bool var_len=false);
bool update_space_sdu(uint32_t nbytes);
void fprint(FILE *stream);
};
class rar_subh : public subh<rar_subh>
{
public:
rar_subh() {
bzero(&grant, sizeof(grant));
ta = 0;
temp_rnti = 0;
preamble = 0;
parent = NULL;
}
static const uint32_t RAR_GRANT_LEN = 20;
// Reading functions
bool read_subheader(uint8_t** ptr);
void read_payload(uint8_t** ptr);
uint32_t get_rapid();
uint32_t get_ta_cmd();
uint16_t get_temp_crnti();
void get_sched_grant(uint8_t grant[RAR_GRANT_LEN]);
// Writing functoins
void write_subheader(uint8_t** ptr, bool is_last);
void write_payload(uint8_t** ptr);
void set_rapid(uint32_t rapid);
void set_ta_cmd(uint32_t ta);
void set_temp_crnti(uint16_t temp_rnti);
void set_sched_grant(uint8_t grant[RAR_GRANT_LEN]);
void init();
void fprint(FILE *stream);
private:
uint8_t grant[RAR_GRANT_LEN];
uint32_t ta;
uint16_t temp_rnti;
uint32_t preamble;
};
class rar_pdu : public pdu<rar_subh>
{
public:
rar_pdu(uint32_t max_rars = 16);
void set_backoff(uint8_t bi);
bool has_backoff();
uint8_t get_backoff();
bool write_packet(uint8_t* ptr);
void fprint(FILE *stream);
private:
bool has_backoff_indicator;
uint8_t backoff_indicator;
};
class mch_subh : public sch_subh
{
public:
mch_subh():sch_subh(MCH_SUBH_TYPE){}
// Size of MAC CEs
const static int MAC_CE_CONTRES_LEN = 6;
};
class mch_pdu : public sch_pdu
{
public:
mch_pdu(uint32_t max_subh) : sch_pdu(max_subh) {}
private:
/* Prepares the PDU for parsing or writing by setting the number of subheaders to 0 and the pdu length */
virtual void init_(uint8_t *buffer_tx_ptr, uint32_t pdu_len_bytes, bool is_ulsch) {
nof_subheaders = 0;
pdu_len = pdu_len_bytes;
rem_len = pdu_len;
pdu_is_ul = is_ulsch;
buffer_tx = buffer_tx_ptr;
sdu_offset_start = max_subheaders*2 + 13; // Assuming worst-case 2 bytes per sdu subheader + all possible CE
total_sdu_len = 0;
last_sdu_idx = -1;
reset();
for (uint32_t i=0;i<max_subheaders;i++) {
mch_subh mch_subh1;
subheaders[i] = mch_subh1;
subheaders[i].parent = this;
subheaders[i].init();
}
}
};
} // namespace srsue
#endif // MACPDU_H