多播demo

来源：互联网发布：iroha 知乎编辑：程序博客网时间：2024/06/05 00:44

服务端：

#include <stdio.h>#include <stdlib.h>#include <sys/types.h>          /* See NOTES */#include <sys/socket.h>#include <string.h>#include <netinet/in.h>#include <arpa/inet.h>#define MCAST_PORT 8888#define MCAST_ADDR "224.0.0.101"     /*一个局部连接多播地址，路由器不进行转发*/#define MCAST_INTERVAL 5                        /*发送间隔时间*/#define BUFF_SIZE 256                           /*接收缓冲区大小*/int main(int argc, char*argv[]){      int s;                                      /*套接字文件描述符*/    struct sockaddr_in local_addr;              /*本地地址*/    int err = -1;       s = socket(AF_INET, SOCK_DGRAM, 0);     /*建立套接字*/    if (s == -1)    {        perror("socket()");        return -1;    }                                                     /*初始化地址*/    memset(&local_addr, 0, sizeof(local_addr));    local_addr.sin_family = AF_INET;    local_addr.sin_addr.s_addr = htonl(INADDR_ANY);    local_addr.sin_port = htons(MCAST_PORT);                                                   /*绑定socket*/    err = bind(s,(struct sockaddr*)&local_addr, sizeof(local_addr)) ;    if(err < 0)    {        perror("bind()");        return -2;    }                                                   /*设置回环许可*/    int loop = 1;    err = setsockopt(s,IPPROTO_IP, IP_MULTICAST_LOOP,&loop, sizeof(loop));    if(err < 0)    {        perror("setsockopt():IP_MULTICAST_LOOP");        return -3;    }       struct ip_mreq mreq;                                    /*加入多播组*/    mreq.imr_multiaddr.s_addr = inet_addr(MCAST_ADDR); /*多播地址*/    mreq.imr_interface.s_addr = htonl(INADDR_ANY); /*网络接口为默认*/                                                        /*将本机加入多播组*/    err = setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,&mreq, sizeof    (mreq));    if (err < 0)    {        perror("setsockopt():IP_ADD_MEMBERSHIP");        return -4;    }       int times = 0;    int addr_len = 0;    char buff[BUFF_SIZE];    int n = 0;                                        /*循环接收多播组的消息，5次后退出*/    for(times = 0;times<5;times++)    {        addr_len = sizeof(local_addr);        memset(buff, 0, BUFF_SIZE);                 /*清空接收缓冲区*/                                                    /*接收数据*/        n = recvfrom(s, buff, BUFF_SIZE, 0,(struct sockaddr*)&local_addr,        &addr_len);        if( n== -1)        {            perror("recvfrom()");        }                                                    /*打印信息*/        printf("Recv %dst message from server:%s\n", times, buff);        sleep(MCAST_INTERVAL);    }                                                       /*退出多播组*/    err = setsockopt(s, IPPROTO_IP, IP_DROP_MEMBERSHIP,&mreq, sizeof    (mreq));           close(s);    return 0;}

客户端：

#include <stdio.h>#include <stdlib.h>#include <sys/types.h>          /* See NOTES */#include <sys/socket.h>#include <string.h>#include <netinet/in.h>#include <arpa/inet.h>#define MCAST_PORT 8888#define MCAST_ADDR "224.0.0.100"    /*一个局部连接多播地址，路由器不进行转发*/#define MCAST_DATA "BROADCAST TEST DATA"            /*多播发送的数据*/#define MCAST_INTERVAL 5                            /*发送间隔时间*/int main(int argc, char*argv){    int s;    struct sockaddr_in mcast_addr;         s = socket(AF_INET, SOCK_DGRAM, 0);         /*建立套接字*/    if (s == -1)    {        perror("socket()");        return -1;    }       memset(&mcast_addr, 0, sizeof(mcast_addr));/*初始化IP多播地址为0*/    mcast_addr.sin_family = AF_INET;                /*设置协议族类行为AF*/    mcast_addr.sin_addr.s_addr = inet_addr(MCAST_ADDR);/*设置多播IP地址*/    mcast_addr.sin_port = htons(MCAST_PORT);        /*设置多播端口*/    while(1) {        int n = sendto(s,MCAST_DATA,sizeof(MCAST_DATA),0,(struct sockaddr*)&mcast_addr,sizeof(mcast_addr));        if( n < 0)        {            perror("sendto()");            return -2;        }                     sleep(MCAST_INTERVAL);                          /*等待一段时间*/    }       return 0;}

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