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Linux组播代码

时间:2020-04-07 19:02来源:linux.it.net.cn 作者:IT
Ubuntu组播

在真机上没有问题,但是放到虚拟机里面,使用桥接方式,就接收不到组播包了,需要手动添加组播路由:

sudo add -net 239.255.255.0 netmask 255.255.255.0 dev eth0

相应代码:

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <arpa/inet.h>
#include <net/if.h>


#define BUFSIZ 1024
#define PORT 37020
#define GROUP "239.255.255.250"

int main(int argc, char *argv[])
{
    struct sockaddr_in localaddr, from;
    int confd;
    ssize_t len, addr_len;
    char buf[BUFSIZ];

    struct ip_mreqn group;                                                  /*组播结构体*/
    confd = socket(AF_INET, SOCK_DGRAM, 0);
    bzero(&localaddr, sizeof(localaddr));                                   /* 初始化*/
    localaddr.sin_family = AF_INET;
    inet_pton(AF_INET, "0.0.0.0" , &localaddr.sin_addr.s_addr);
    localaddr.sin_port = htons(PORT);

    bind(confd, (struct sockaddr *)&localaddr, sizeof(localaddr));

    inet_pton(AF_INET, GROUP, &group.imr_multiaddr);                        /* 设置组播组地址*/
    inet_pton(AF_INET, "0.0.0.0", &group.imr_address);                      /*使用本地任意IP添加到组播组*/
    group.imr_ifindex = if_nametoindex("eth0");                             /* 设置网卡名 编号 ip ad */   
    setsockopt(confd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &group, sizeof(group));/* 将client加入组播组*/
    while (1) {
        len = recvfrom(confd, buf, sizeof(buf), 0, (struct sockaddr *)&from, &addr_len);
        write(STDOUT_FILENO, buf, len);
  sprintf(buf, "good to see you.");
  len = sendto(confd, buf, strlen(buf), 0, (struct sockaddr *)&from, sizeof(from));
    }
    close(confd);
    return 0;
}





(责任编辑:IT)
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