cn-lab3-server

// cn-lab3-server.cpp: определяет точку входа для консольного приложения.
//

#include "stdafx.h"
#include <winsock2.h>
#include <iostream>
#include <thread>
#include <string>
#include <vector>
#include <set>

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

using namespace std;

vector<thread> clients;
set<SOCKET> open_socks;

int client_process(const SOCKET client_sock, const int client_id) {
    for (int request_id = 1;; request_id++) {
        char recv_buff[1024];
        int len = recv(client_sock, &recv_buff[0], sizeof(recv_buff) - 1, 0);
        if (len == -1) {
            cout << "Client " << client_id << " was closed" << endl;
            return 1;
        }
        recv_buff[len] = '\0';
        string s = recv_buff;
        if (s == "&close")
            break;
        cout << "Received request " << request_id << " from client " << client_id << endl;
        if (s.length() % 4 == 0)
            s = s.substr(s.length() / 2, s.length()) + s.substr(0, s.length() / 2);
        send(client_sock, s.c_str(), s.length(), 0);
        cout << "Sent answer for request " << request_id << " to client " << client_id << endl;
    }
    closesocket(client_sock);
    open_socks.erase(client_sock);
    cout << "Client " << client_id << " disconnected" << endl;
    return 0;
}

int port_listen(const SOCKET &main_sock) {
    for (int client_id = 1;; client_id++) {
        sockaddr_in addr_client;
        int client_addr_size = sizeof(addr_client);
        SOCKET client_sock = accept(main_sock, (sockaddr *)&addr_client, &client_addr_size);
        if (client_sock == INVALID_SOCKET) {
            int wsa_error = WSAGetLastError();
            if (wsa_error != 10004)
                cout << "Accept error " << wsa_error << endl;
            return 1;
        }
        cout << "Client " << client_id << " connected" << endl;
        clients.push_back(thread(client_process, client_sock, client_id));
        open_socks.insert(client_sock);
    }
    return 0;
}

int _tmain(int argc, _TCHAR* argv[])
{
    cout << "cn-lab3 var10 server start" << endl;
    WSAData wsadata;
    WSAStartup(0x0202, &wsadata);
    cout << "WinSock2 initialized" << endl;
    SOCKET main_sock;
    main_sock = socket(AF_INET, SOCK_STREAM, 0);
    if (main_sock == INVALID_SOCKET) {
        cout << "Main socket create error " << WSAGetLastError() << endl;
        WSACleanup();
        return 1;
    }
    cout << "Main socket created successfully" << endl;
    sockaddr_in addr_local;
    addr_local.sin_family = AF_INET;
    addr_local.sin_addr.S_un.S_addr = 0;
    addr_local.sin_port = htons(5001);
    if (::bind(main_sock, (sockaddr *)&addr_local, sizeof(addr_local))) {
        cout << "Bind error " << WSAGetLastError() << endl;
        closesocket(main_sock);
        WSACleanup();
        return 2;
    }
    cout << "Port " << ntohs(addr_local.sin_port) << " bound successful" << endl;
    if (listen(main_sock, 16))
    {
        cout << "Listen error " << WSAGetLastError() << endl;
        closesocket(main_sock);
        WSACleanup();
        return  3;
    }
    cout << "Listening port 5001" << endl;
    thread listen(port_listen, main_sock);
    string s;
    do {
        cin >> s;
    } while (s != "stop" && s != "exit");
    closesocket(main_sock);
    if (listen.joinable())
        listen.join();
    for (auto client_sock : open_socks) {
        send(client_sock, "&stop", sizeof("&stop"), 0);
        closesocket(client_sock);
    }
    for (unsigned int i = 0; i < clients.size(); i++)
        if (clients[i].joinable())
            clients[i].join();
    WSACleanup();
    cout << "cn-lab1 var10 server stopped" << endl;
    return 0;
}