局域网小组群播

• 局域网小组群播
  • 头文件/宏定义
  • 函数1
  • 函数1
  • 主函数

头文件/宏定义

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <time.h>
#include <pthread.h>

#define MULTICAST_GROUP "223.255.255.555"
#define PORT 8888

函数1

/********************************************************************
 *
 *	name	 :  receive_thread
 *	function :
 *	argument :
 *				@n  :arg
 *
 *	retval	 :  none
 *	author	 :  [email protected]
 *	date	 :  2024年6月4日
 * 	note	 :
 *
 * *****************************************************************/
void *receive_thread(void *arg)
{
    int sockfd = *(int *)arg;
    char buffer[1024];
    struct sockaddr_in source_addr;
    socklen_t addr_len = sizeof(source_addr);

    while (1)
    {
        ssize_t len = recvfrom(sockfd, buffer, sizeof(buffer), 0, (struct sockaddr *)&source_addr, &addr_len);
        if (len < 0)
        {
            perror("接收数据失败");
            continue;
        }
        buffer[len] = '\0';

        char *source_ip = inet_ntoa(source_addr.sin_addr);

        time_t current_time;
        struct tm *time_info;
        char formatted_time[20];

        time(&current_time);
        time_info = localtime(&current_time);
        strftime(formatted_time, sizeof(formatted_time), "%Y-%m-%d %H:%M:%S", time_info);

        printf("来自 %s 的消息，时间：%s，内容：%s\n", source_ip, formatted_time, buffer);
    }

    return NULL;
}

函数1

/********************************************************************
 *
 *	name	 :  send_thread
 *	function :
 *	argument :
 *				@n  :arg
 *
 *	retval	 :  none
 *	author	 :  [email protected]
 *	date	 :  2024年6月4日
 * 	note	 :
 *
 * *****************************************************************/
void *send_thread(void *arg)
{
    int sockfd = *(int *)arg;
    char message[1024];
    struct sockaddr_in dest_addr;
    socklen_t addr_len = sizeof(dest_addr);

    memset(&dest_addr, 0, sizeof(dest_addr));
    dest_addr.sin_family = AF_INET;
    dest_addr.sin_addr.s_addr = inet_addr(MULTICAST_GROUP);
    dest_addr.sin_port = htons(PORT);

    while (1)
    {
        printf("请输入要发送的消息：");
        fgets(message, sizeof(message), stdin);
        sendto(sockfd, message, strlen(message), 0, (struct sockaddr *)&dest_addr, addr_len);
    }

    return NULL;
}

主函数

int main(int argc, char const *argv[])
{
    int sockfd;
    struct sockaddr_in addr;
    struct ip_mreq mreq;

    // 创建套接字
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd < 0)
    {
        perror("创建套接字失败");
        exit(EXIT_FAILURE);
    }

    memset(&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = htonl(INADDR_ANY);
    addr.sin_port = htons(PORT);

    // 绑定套接字
    if (bind(sockfd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
    {
        perror("绑定套接字失败");
        close(sockfd);
        exit(EXIT_FAILURE);
    }

    mreq.imr_multiaddr.s_addr = inet_addr(MULTICAST_GROUP);
    mreq.imr_interface.s_addr = htonl(INADDR_ANY);
    // 加入多播组
    if (setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
    {
        perror("加入多播组失败");
        close(sockfd);
        exit(EXIT_FAILURE);
    }

    printf("等待数据...\n");

    pthread_t receive_tid, send_tid;
    pthread_create(&receive_tid, NULL, receive_thread, &sockfd);
    pthread_create(&send_tid, NULL, send_thread, &sockfd);

    // 等待线程结束
    pthread_join(receive_tid, NULL);
    pthread_join(send_tid, NULL);

    close(sockfd);
    return 0;
}