regiServer.cpp

#include <iostream>
#include <sys/socket.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <pthread.h>
#include <vector>
#include <algorithm>
#include <map>
#include <unistd.h>

#define C2S_PORT 12346
#define P2P_PORT 12349
#define BUF_SIZE 1024

using namespace std;

vector<pair<char *, int>> peer_list;
map<string, pthread_t> thread_list;

// client의 socket FD와 sockaddr 구조체 정보 저장 (pthread 인자로)
struct multiArgs {
    int sock_fd;
    sockaddr_in addr;
};

void printError(const char * message)
{
    cout << message << endl;
    exit(1);
}

void sendPeerList(int clnt_fd) {
    char msg[BUF_SIZE];

    sprintf(msg, "%ld", peer_list.size());
    send(clnt_fd, msg, BUF_SIZE, 0);

    for(int i = 0; i < peer_list.size(); i++) {
        recv(clnt_fd, &msg, BUF_SIZE, 0);                               // ack 수신
        send(clnt_fd, peer_list[i].first, BUF_SIZE, 0);
        recv(clnt_fd, &msg, BUF_SIZE, 0);
        sprintf(msg, "%d", peer_list[i].second);
        send(clnt_fd, msg, BUF_SIZE, 0);
    }
}

void logOff(int clnt_fd, char *clnt_ip) {
    auto iter = find(peer_list.begin(), peer_list.end(), make_pair(clnt_ip, P2P_PORT)); 
    if(iter == peer_list.end()) {
        cout << "IP not found" << endl;
        send(clnt_fd, "IP not found", BUF_SIZE, 0);
    }
    else {
        peer_list.erase(iter);
        send(clnt_fd, "Logout Success!", BUF_SIZE, 0);
        cout << clnt_ip << " log out" << endl;


        // free resources
        close(clnt_fd);                             // close socket
        pthread_cancel(thread_list[clnt_ip]);       // terminate thread
        thread_list.erase(clnt_ip);
    }
}
 
void *newConnection(void * clientSock)
{
    int clientSocket = (*(multiArgs *)clientSock).sock_fd;
    sockaddr_in recv_from_client = (*(multiArgs *)clientSock).addr;                 // rceive한 소켓에 명시된 addr 구조체

    char *clnt_ip = inet_ntoa(recv_from_client.sin_addr);
    printf("Client Login : IP %s, Port %d\n", clnt_ip, ntohs(recv_from_client.sin_port));

    peer_list.push_back({clnt_ip, P2P_PORT});                                       // peer list에 client IP 추가
    
    char msg[BUF_SIZE];
    char send_msg[BUF_SIZE];
    int recv_len = recv(clientSocket, &msg, BUF_SIZE, 0);

    while(recv_len > 0) {
        printf("From Client : %s\n", msg);
        // send to client
        if(!strcmp(msg, "online_users")) {                                          // client가 peer list를 요청
            sendPeerList(clientSocket);
        }
        else if(!strcmp(msg, "logoff")) {
            logOff(clientSocket, clnt_ip);
        }
        recv_len = recv(clientSocket, &msg, BUF_SIZE, 0);
    }
}


int main(void) {
    int socketFd, clientSocket;
    sockaddr_in address, clientAddr;
    int addlen = sizeof(address);
    //소켓 설정
    socketFd = socket(PF_INET,SOCK_STREAM,0);
    if(socketFd == 0)
        printError("socket went wrong");
 
    //주소
    memset(&address, 0, sizeof(address));
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = 0;
    address.sin_port = htons(C2S_PORT);
 
    if(bind(socketFd, (sockaddr *)&address, addlen) < 0)
        printError("socket bind error");
 
    if(listen(socketFd, 1) < 0)
        printError("socket listen wrong");
    
    cout << "Start listening\n";
 
    pthread_t newThread;
    
    while(1) {
        clientSocket = accept(socketFd,(sockaddr *)&clientAddr, (socklen_t *)&addlen);
        if(clientSocket < 0)
            printError("client socket went wrong");
        
        cout << "Accepted" << endl;
        multiArgs pass_args = {clientSocket, clientAddr};

        pthread_create(&newThread, NULL, newConnection, (void*)&pass_args);
        // cout << newThread << endl;

        // pthread descriptor 저장
        string ip = inet_ntoa(clientAddr.sin_addr);
        thread_list[ip] = newThread;

        // for(auto iter = thread_list.begin(); iter != thread_list.end(); iter++)
        //     cout << iter->first << ", " << iter->second << endl;
    }
 
    return 0;
}