滑动窗口协议仿真（2024）

1.题目描述

滑动窗口协议以基于分组的数据传输协议为特征，该协议适用于在数据链路层以及传输层中对按 顺序传送分组的可靠性要求较高的环境。在长管道传输过程（特别是无线环境）中，相应的滑动窗口 协议可实现高效的重传恢复。附录 3 给出了一个选择性重传的滑动窗口协议的简单实现，以此为参考， 设计并实现一个滑动窗口协议的仿真，显示数据传送过程中的各项具体数据，双方帧的个数变化，帧 序号，发送和接受速度，重传提示等。

2.程序演示

?这里我们使用Socket来模拟滑动窗口协议，实现了双方帧的个数变化，帧序号，发送和接受速度控制，重传显示。

控制帧发送速度

双方帧的个数变化

丢失包

3.参考代码

接收端代码

#include <winsock2.h>
#include <iostream>
#include <list>
#include <time.h>
#include <unistd.h>
#pragma comment(lib, "ws2_32.lib")
using namespace std;

//函数说明------------------------------
DWORD WINAPI ThreadFun(LPVOID lpThreadParameter);

void init_app();

//---------------------------------------
WSADATA wd;
SOCKET Socket;
sockaddr_in addrClient;
int len = sizeof(sockaddr_in);

//变量------------------------------
struct Data {
    //消息类型定义
    int Type_ACK = 0;
    int Type_Msg = 1;
    int Type_Requst = 2;
    int Type_Retransmission=3;
    //消息内容
    int Msg_Code = 0;//消息序号
    int Msg_Type = 1;//消息类型
    int Msg_ACK=0;//是否已经ACK了
    char *Msg_Content[128];//消息内容
    int Send_WinSize = 4;//发送窗口大小
};


Data Send_Msg_Data;
Data *Get_Msg_Data;
char Get_buf[1024] = {0}, send_buf[1024] = {0};

int main() {
    //提示=======================================================================
    cout << "滑动窗口协议仿真(Socket模拟)_接收方" << endl;
    //初始化=======================================================================
    init_app();
    //==========================================================================
}

DWORD WINAPI ThreadFun(LPVOID lpThreadParameter) {
    // 接受数据
    SOCKET This_Socket = (SOCKET) lpThreadParameter;
    cout << "*连接成功" << endl;
    // 循环接收客户端数据
    int ret = 0;
    do {
        //接收
        ret = recv(This_Socket, Get_buf, sizeof(Get_buf), 0);
        Get_Msg_Data = (Data *) Get_buf;
        cout << "\n收到消息:" << endl;
        cout << "类型:" << Get_Msg_Data->Msg_Type << " 序号: " << Get_Msg_Data->Msg_Code << endl;
        //发送
        if (Get_Msg_Data->Msg_Type==3)
        {
            Send_Msg_Data.Msg_Type =3;
        } else
        {
            Send_Msg_Data.Msg_Type = 0;
        }

        Send_Msg_Data.Msg_Code = Get_Msg_Data->Msg_Code;
        memcpy(send_buf, &Send_Msg_Data, sizeof(Data));
        sleep(1);
        if (send(This_Socket, send_buf, sizeof(send_buf), 0) > 0) {
            cout << "\n回复帧:" << Send_Msg_Data.Msg_Code << " ACK" << endl;
        } else {
            cout << "\n失败回复:" << Send_Msg_Data.Msg_Code << " ACK" << endl;
        }
    } while (ret != SOCKET_ERROR && ret != 0);
    return 0;
}


void init_app() {
    if (WSAStartup(MAKEWORD(2, 2), &wd) != 0) {
        cout << "WSAStartup Error:" << WSAGetLastError() << endl;
        return;
    }
    // 创建流式套接字
    Socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (Socket == INVALID_SOCKET) {
        cout << "socket error:" << WSAGetLastError() << endl;
        return;
    }
    //绑定端口和ip
    sockaddr_in addr;
    memset(&addr, 0, sizeof(sockaddr_in));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(8000);
    addr.sin_addr.s_addr = inet_addr("127.0.0.1");
    //服务端bind绑定
    if (bind(Socket, (SOCKADDR *) &addr, len) == SOCKET_ERROR) {
        cout << "bind Error:" << WSAGetLastError() << endl;
        return;
    }
    // 监听
    listen(Socket, 5);
    //主线程循环接收客户端的连接
    while (true) {
        cout << "*等待连接..." << endl;
        // 接受成功返回与client通讯的Socket
        SOCKET Client = accept(Socket, (SOCKADDR *) &addrClient, &len);
        if (Client != INVALID_SOCKET) {
            // 创建线程，并且传入与client通讯的套接字
            HANDLE hThread = CreateThread(NULL, 0, ThreadFun, (LPVOID) Client, 0, NULL);
            CloseHandle(hThread); // 关闭对线程的引用
        }
    }
}

发送端代码

#include<winsock2.h>//winsock2的头文件
#include<iostream>
#include <list>
#include <ctime>

#pragma comment(lib, "ws2_32.lib")

using namespace std;

//定义========================
void Init_Socket();

void *SendMsg(void *pVoid);

int getRand(int min, int max);

void Sycn();

void Send_Win_Move();

void Retransmission(int Num);

//发送的数据=======================
struct Data {
    //消息类型定义
    int Type_ACK = 0;
    int Type_Msg = 1;
    int Type_Requst = 2;
    int Type_Retransmission = 3;
    //消息内容
    int Msg_Code = 0;//消息序号
    int Msg_Type = 1;//消息类型
    int Msg_ACK = 0;//是否已经ACK了
    char *Msg_Content[128];//消息内容
    int Send_WinSize = 4;//发送窗口大小
};

//默认参数=======================
int Rand_Num = 5;//随机概率1/5
int Receiver_WinSize = 10;
int Send_WinSize = 5;
int Send_Size = 10;
int ACK_OutTime = 10;
int Send_Num = 100;
char *Send_Msg = "0123456789";
SOCKET Socket;
int Win_Now_Size = 0;


//消息列表=======================
list<Data> MSG_Win_List;
Data Send_Msg_Data;
Data *Get_Msg_Data;
Data *Temp_Msg_Data;
int Num = 0;
char send_buf[1024] = {0}, Get_buf[1024] = {0};

void init_data() {
    char auto_data;
    //提示=======================================================================
    cout << "*====滑动窗口协议仿真(Socket模拟)_发送方====*\n";
    cout << "\n-------------------------------\n";
    cout << " 请输入必要参数(y/n):";
    cin >> auto_data;
    if (auto_data == 'n') {
        cout << " 发送窗口: ", cout << Send_WinSize << endl;
        cout << " 消息帧数: ", cout << Send_Num << endl;
//        cout << " 发送内容: ", cout << Send_Msg << endl;
    } else {
        cout << " 发送窗口: ", cin >> Send_WinSize;
        cout << " 消息帧数: ", cin >> Send_Num;
    }
    cout << "-------------------------------" << endl;
    system("pause");

}

int main() {
    init_data();
    Init_Socket();
    //接收服务端的消息
    pthread_t tids;
    pthread_create(&tids, NULL, SendMsg, &Socket);
    //随时给服务端发消息
    do {
        int ret = 0;
        do {
            ret = recv(Socket, Get_buf, sizeof(Get_buf), 0);
            Get_Msg_Data = (Data *) Get_buf;
            if (ret != SOCKET_ERROR && ret != 0) {
                cout << "\n\n\t==>收到帧:" << " ACK: " << Get_Msg_Data->Msg_Code << endl;
                list<Data>::iterator iter;
                for (iter = MSG_Win_List.begin(); iter != MSG_Win_List.end(); iter++) {
                    if (Get_Msg_Data->Msg_Code == iter->Msg_Code) {
                        (*iter).Msg_ACK = 1;

                        if (Get_Msg_Data->Msg_Type == 3) {
                            cout << "\n\t重传删除了一个" << endl;
                            Win_Now_Size--;
                            MSG_Win_List.erase(iter);
                        }
                        break;
                    }
                }
                Sycn();
            }
        } while (ret != SOCKET_ERROR && ret != 0);
    } while (true);
    //关闭监听套接字
    closesocket(Socket);
    WSACleanup();

}

void Init_Socket() {
    WSADATA wd;
    //加载winsock2的环境
    if (WSAStartup(MAKEWORD(2, 2), &wd) != 0) {
        cout << "WSAStartup  error：" << GetLastError() << endl;
        return;
    }
    //创建流式套接字
    Socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (Socket == INVALID_SOCKET) {
        cout << "socket  error：" << GetLastError() << endl;
        return;
    }
    //连接服务器
    sockaddr_in addr;
    addr.sin_family = AF_INET;
    addr.sin_port = htons(8000);
    addr.sin_addr.s_addr = inet_addr("127.0.0.1");
    int len = sizeof(sockaddr_in);
    if (connect(Socket, (SOCKADDR *) &addr, len) == SOCKET_ERROR) {
        cout << "connect  error：" << GetLastError() << endl;
        return;
    }
}

void *SendMsg(void *pVoid) {
    do {
        Send_Win_Move();
        Sycn();
        system("pause");
        Send_Msg_Data.Msg_Code = Num;
        Send_Msg_Data.Msg_Type = 1;
        memcpy(send_buf, &Send_Msg_Data, sizeof(Data));
        if (Win_Now_Size == Send_WinSize) {
            list<Data>::iterator iter;
            for (iter = MSG_Win_List.begin(); iter != MSG_Win_List.end(); iter++) {
                if (iter->Msg_ACK == 0) {
                    Send_Msg_Data.Msg_Code = iter->Msg_Code;
                    Send_Msg_Data.Msg_Type = 3;
                    memcpy(send_buf, &Send_Msg_Data, sizeof(Data));
                    if (send(Socket, send_buf, sizeof(send_buf), 0) > 0) {
                        cout << "\n\t<==发送重传帧:" << iter->Msg_Code << endl;
                    } else {
                        cout << "\n\t<==失败发送重传帧:" << iter->Msg_Code << endl;
                    }

                    break;
                }
            }
            continue;
        }
        if (getRand(1, Rand_Num) == Rand_Num)//随机丢失
        {
            cout << "\n\t<=xxxx=随机丢失帧:" << Num++ << endl;
        } else {
            if (send(Socket, send_buf, sizeof(send_buf), 0) > 0) {
                cout << "\n\t<==发送帧:" << Num++ << endl;
            } else {
                cout << "\n\t<<==失败发送帧:" << Num++ << endl;
            }
        }
        Win_Now_Size++;
        Send_Num--;
        MSG_Win_List.push_back(Send_Msg_Data);
    } while (Send_Num > 0);
}

void Send_Win_Move() {

    if (MSG_Win_List.begin()->Msg_ACK == 0) return;
    list<Data>::iterator iter=MSG_Win_List.begin();
    while (iter->Msg_ACK==1)
    {
        MSG_Win_List.erase(iter);
        Win_Now_Size--;
        iter=MSG_Win_List.begin();
    }
    cout << "\n\t窗口移动了" << endl;
}

int getRand(int min, int max) {
    return (rand() % (max - min + 1)) + min;
}

void Sycn() {

    cout << "\n\t------------------------------" << endl;
    cout << "\t当前发送窗口:" << Send_WinSize << "\t可用窗口大小:" << Send_WinSize - Win_Now_Size << endl;
    list<Data>::iterator iter;
    for (iter = MSG_Win_List.begin(); iter != MSG_Win_List.end(); iter++) {
        cout << "\t#帧序号:" << iter->Msg_Code << "\t#是否ACK:" << iter->Msg_ACK << endl;
    }
    cout << "\t------------------------------" << endl;
}

?4.导入ws2_32库到Clion?:

导入ws2_32库到Clion项目-CSDN博客

?

?2024 HNUST计算机网络课程设计-(????)?芒果酱-参考文章

（代码可以参考，?? ? ? ? ?? 但同学们要认真编写哦）
-------------------------------------------------------------------------
1、网络聊天程序的设计与实现
C++ Socket 多线程 网络聊天室 支持用户端双向交流(2023)-CSDN博客
2、Tracert 与 Ping 程序设计与实现
Tracert 与 Ping 程序设计与实现（2024）-CSDN博客
3、滑动窗口协议仿真
滑动窗口协议仿真（2024）-CSDN博客
4、OSPF 路由协议原型系统设计与实现
OSPF 路由协议原型系统设计与实现-CSDN博客
5、基于 IP 多播的网络会议程序
基于 IP 多播的网络会议程序（2024）-CSDN博客
6、编程模拟 NAT 网络地址转换
编程模拟 NAT 网络地址转换(2024)-CSDN博客
7、网络嗅探器的设计与实现
网络嗅探器的设计与实现(2024)-转载-CSDN博客
8、网络报文分析程序的设计与实现
网络报文分析程序的设计与实现（2024）-CSDN博客
9、简单 Web Server 程序的设计与实现
简单 Web Server 程序的设计与实现 (2024)-CSDN博客
10、路由器查表过程模拟

计算机网络 - 路由器查表过程模拟 C++(2024)-CSDN博客

?