Bot udp_server, C

udp_server.c

//server.cpp
 
//header.h
 
# include <stdio.h>
# include <string.h>
# include <stdlib.h>
# include <netinet/in.h>
# include <sys/socket.h>
# include <arpa/inet.h>
# include <unistd.h>
 
# define PORT 20162
# define BUFFER_SIZE 4096 // 서버에 이용
# define BUFF_SIZE 100 // 클라이언트에 이용
 
//                                                       This source code Copyright belongs to Crocus
//   


int main(int argc, char *argv[])
{
    char readBuff[BUFFER_SIZE];
    char sendBuff[BUFFER_SIZE];
    struct sockaddr_in serverAddress, clientAddress;
    int server_fd, client_fd;
    int client_addr_size;
    ssize_t receivedBytes;
    ssize_t sentBytes;
 
    /*
    if (argc != 2)
    {
    printf("사용법 : ./filename 포트번호 \n");
    exit(0);
    }
    */
 
    socklen_t clientAddressLength = 0;
 
    memset(&serverAddress, 0, sizeof(serverAddress));
    memset(&clientAddress, 0, sizeof(clientAddress));
 
    serverAddress.sin_family = AF_INET;
    serverAddress.sin_addr.s_addr = htonl(INADDR_ANY);
    serverAddress.sin_port = htons(20162);
 
 
    // 서버 소켓 생성 및 서버 주소와 bind
 
    // 서버 소켓 생성(UDP니 SOCK_DGRAM이용)
    if ((server_fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) // SOCK_DGRAM : UDP
    {
        printf("Sever : can not Open Socket\n");
        exit(0);
    }
 
    // bind 과정
    if (bind(server_fd, (struct sockaddr *)&serverAddress, sizeof(serverAddress)) < 0)
    {
        printf("Server : can not bind local address");
        exit(0);
    }
 
 
    printf("Server: waiting connection request.\n");
 
    while (1)
    {
 
        // 클라이언트 IP 확인
        struct sockaddr_in connectSocket;
        socklen_t connectSocketLength = sizeof(connectSocket);
        getpeername(client_fd, (struct sockaddr*)&clientAddress, &connectSocketLength);
        char clientIP[sizeof(clientAddress.sin_addr) + 1] = { 0 };
        sprintf(clientIP, "%s", inet_ntoa(clientAddress.sin_addr));
        // 접속이 안되었을 때는 while에서 출력 x
        if(strcmp(clientIP,"0.0.0.0") != 0)
            printf("\nClient : %s\n", clientIP);
 
 
        //채팅 프로그램 제작
        client_addr_size = sizeof(clientAddress);
 
        receivedBytes = recvfrom(server_fd, readBuff, BUFF_SIZE, 0, (struct sockaddr*)&clientAddress, &client_addr_size);
        printf("%lu bytes read\n", receivedBytes);
        readBuff[receivedBytes] = '\0';
        fputs(readBuff, stdout);
        fflush(stdout);
 
        sprintf(sendBuff, "%s", readBuff);
        sentBytes = sendto(server_fd, sendBuff, strlen(sendBuff), 0, (struct sockaddr*)&clientAddress, sizeof(clientAddress));
    }
 
    // 서버 소켓 close
    close(server_fd);
 
    return 0;
}
 
//                                                       This source code Copyright belongs to Crocus
//      


//출처: https://www.crocus.co.kr/444 [Crocus]