mc.c

一个基于linux的TCP/IP协议栈的实现

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include "my_inet.h"
#include <arpa/inet.h>

#define MAXBUF 256
#define PUERTO 5000
#define GROUP "224.0.1.1"

int main(void)
{
	int fd, n, r;
	struct sockaddr_in srv, cli;
	struct ip_mreq mreq;
	char buf[MAXBUF];
	
	srv.sin_family = MY_AF_INET;
	srv.sin_port = htons(PUERTO);
	inet_aton(GROUP, &srv.sin_addr );

	if( (fd = socket( MY_AF_INET, SOCK_DGRAM, MY_IPPROTO_UDP) ) < 0 ){
		perror("socket");
		return -1;
	}
	if( bind(fd, (struct sockaddr *)&srv, sizeof(srv)) < 0 ){
		perror("bind");
		return -1;
	}
/*
	inet_aton( GROUP, &mreq.imr_multiaddr );
	inet_aton( "172.16.48.2", &mreq.imr_interface );
	if( setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP, &mreq,sizeof(mreq)) < 0 ){
		perror("setsockopt");
		return -1;
	}

	if( setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0 ){
		perror("setsockopt");
		return -1;
	}
*/
	n = sizeof(cli);
	while(1){
		if( (r = recv(fd, buf, MAXBUF, 0)) < 0 ){
			perror("recv:");
		}else{
			buf[r] = 0;
			fprintf(stdout, "Mensaje desde: %s", buf);
		}
	}
}