#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <net/if.h>

#define MULTICAST_ADDR "239.255.0.1"
#define PORT 9123

int main() {
    int sockfd;
    struct sockaddr_in addr;
    struct ip_mreq mreq;
    struct ifreq ifr;

    // Create a UDP socket
    if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
        perror("socket creation failed");
        exit(1);
    }

    // Set up the multicast address
    memset(&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = htonl(INADDR_ANY);
    addr.sin_port = htons(PORT);

    // Bind the socket
    if (bind(sockfd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
        perror("bind failed");
        exit(1);
    }

    // Set up multicast group membership
    memset(&mreq, 0, sizeof(mreq));
    mreq.imr_multiaddr.s_addr = inet_addr(MULTICAST_ADDR);
    mreq.imr_interface.s_addr = INADDR_ANY;
    if (setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
        perror("setsockopt failed");
        exit(1);
    }

    printf("Multicast group joined successfully\n");

    // Close the socket
    close(sockfd);

    return 0;
}