TCP/IP 组播的发送和接收

/*
 * =====================================================================================
 *
 *       Filename:  client.c
 *
 *    Description:
 *
 *        Version:  1.0
 *        Created:  03/14/2013 01:48:12 PM
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  YOUR NAME (),
 *        Company:
 *
 * =====================================================================================
 */

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <strings.h>
#include <string.h>
#include <unistd.h>

#define N 256

typedef struct sockaddr SA;

int main(int argc, char *argv[])
{

    int sockfd;
    int on = 1;
    socklen_t optlen = sizeof(on);
    struct sockaddr_in broad_addr;
    char buffer[N] = {"pengdonglin\n"};


    if((sockfd = socket(PF_INET, SOCK_DGRAM, 0) ) < 0)
    {
        perror("fail to socket");
        exit(-1);
    }


    bzero(&broad_addr, sizeof(struct sockaddr_in));

    broad_addr.sin_family = PF_INET;
    broad_addr.sin_port = htons(atoi(argv[2]));
    broad_addr.sin_addr.s_addr = inet_addr(argv[1]);

    while(1)
    {
        sendto(sockfd,buffer, N, 0, (SA *)&broad_addr, sizeof(broad_addr));
        sleep(1);
    }

    return 0;
}

接收端：

/*
 * =====================================================================================
 *
 *       Filename:  client.c
 *
 *    Description:
 *
 *        Version:  1.0
 *        Created:  03/14/2013 01:48:12 PM
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  YOUR NAME (),
 *        Company:
 *
 * =====================================================================================
 */

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <strings.h>
#include <string.h>
#include <unistd.h>

#define N 256

typedef struct sockaddr SA;

int main(int argc, char *argv[])
{

    int sockfd;
    struct sockaddr_in broad_addr, peeraddr;
    socklen_t peerlen = sizeof(peeraddr);
    char buffer[N];
    struct ip_mreq mreq;


    if((sockfd = socket(PF_INET, SOCK_DGRAM, 0) ) < 0)
    {
        perror("fail to socket");
        exit(-1);
    }

    bzero(&mreq, sizeof(mreq));
    mreq.imr_multiaddr.s_addr = inet_addr("224.10.10.1");
    mreq.imr_interface.s_addr = htonl(INADDR_ANY);
    setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq));


    bzero(&broad_addr, sizeof(struct sockaddr_in));
    broad_addr.sin_family = PF_INET;
    broad_addr.sin_port = htons(atoi(argv[2]));
    broad_addr.sin_addr.s_addr = inet_addr(argv[1]);

    if(bind(sockfd, (SA *)&broad_addr, sizeof(broad_addr)) < 0)
    {
        perror("fail to bind");
        exit(-1);
    }
    while(1)
    {
        recvfrom(sockfd, buffer, N, 0, (SA *)&peeraddr, &peerlen);

        printf("%s : %d  : %s\n", inet_ntoa(peeraddr.sin_addr), ntohs(peeraddr.sin_port),buffer);
    }

    return 0;
}

运行：

发送端：

接收端：