server_test1.c

#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>

int main(int argc, char *argv[])
{
    int sockfd;
    struct sockaddr_in serv_addr, cli_addr;
    struct iovec iov[1];
    struct msghdr message;
    struct msghdr message1;
    char buffer[1024];
    int bytes_received;
    socklen_t cli_len;
    
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd < 0) {
        perror("Error creating socket");
        return 1;
    }

    // memset(&serv_addr, 0, sizeof(serv_addr));
    // serv_addr.sin_family = AF_INET;
    // serv_addr.sin_port = htons(8090);
    // serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    
    // if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) {
    //     perror("Error binding socket to address");
    //     return 1;
    // }

    for (;;) {        
        cli_len = sizeof(cli_addr);
        memset(&cli_addr, 0, sizeof(cli_addr));
        cli_addr.sin_family = AF_INET;
        cli_addr.sin_port = htons(8060);
        cli_addr.sin_addr.s_addr = htonl(INADDR_ANY);
        iov[0].iov_base = buffer;
        iov[0].iov_len = sizeof(buffer);
        message.msg_name = &cli_addr;
        message.msg_namelen = cli_len;
        message.msg_iov = iov;
        message.msg_iovlen = 1;
        message.msg_control = NULL;
        message.msg_controllen = 0;
        bytes_received = recvmsg(sockfd, &message, 0);

        // print the address from which the message was received
        printf("Received message from addr: %s, port: %d", inet_ntoa(cli_addr.sin_addr), ntohs(cli_addr.sin_port));

        if (bytes_received < 0) {
            perror("Error receiving message");
            return 1;
        }
        printf("Received %d bytes from %s: %.*s\n", bytes_received,
               inet_ntoa(cli_addr.sin_addr), bytes_received, buffer);
               

        if (sendmsg(sockfd, &message, 0) < 0) {
            perror("Error sending response");
            return 1;
        }
    }
    
    close(sockfd);

    return 0;
}