Visual C 实现局域网IP多播

#include <winsock2.h>

#include <ws2tcpip.h>

#include <stdio.h>

#include <stdlib.h>

#define MCASTADDR "233.0.0.1" //本例使用的多播组地址。

#define MCASTPORT 5150 //绑定的本地端口号。

#define BUFSIZE 1024 //接收数据缓冲大小。

int main( int argc,char ** argv)

{

　WSADATA wsd;

　struct sockaddr_in local,remote,from;

　SOCKET sock,sockM;

　TCHAR recvbuf[BUFSIZE];

　/*struct ip_mreq mcast; // Winsock1.0 */
　int len = sizeof( struct sockaddr_in);

　int ret;

　//初始化WinSock2.2

　if( WSAStartup( MAKEWORD(2,2),&wsd) != 0 )

　{

printf("WSAStartup() failed\n");

return -1;

　}

　/*

　创建一个SOCK_DGRAM类型的SOCKET

　其中,WSA_FLAG_MULTIPOINT_C_LEAF表示IP多播在控制面层上属于"无根"类型;

　WSA_FLAG_MULTIPOINT_D_LEAF表示IP多播在数据面层上属于"无根",有关控制面层和

　数据面层有关概念请参阅MSDN说明。

　*/

　if((sock=WSASocket(AF_INET,SOCK_DGRAM,0,NULL,0,

WSA_FLAG_MULTIPOINT_C_LEAF|WSA_FLAG_MULTIPOINT_D_LEAF|

WSA_FLAG_OVERLAPPED)) == INVALID_SOCKET)

　{

printf("socket failed with:%d\n",WSAGetLastError());

WSACleanup();

return -1;

　}

　//将sock绑定到本机某端口上。

　local.sin_family = AF_INET;

　local.sin_port = htons(MCASTPORT);

　local.sin_addr.s_addr = INADDR_ANY;

　if( bind(sock,(struct sockaddr*)&local,sizeof(local)) == SOCKET_ERROR )

　{

printf( "bind failed with:%d \n",WSAGetLastError());

closesocket(sock);

WSACleanup();

return -1;

　}

　//加入多播组

　remote.sin_family = AF_INET;

　remote.sin_port = htons(MCASTPORT);

　remote.sin_addr.s_addr = inet_addr( MCASTADDR );

　/* Winsock1.0 */

　/*

　mcast.imr_multiaddr.s_addr = inet_addr(MCASTADDR);

　mcast.imr_interface.s_addr = INADDR_ANY;

　if( setsockopt(sockM,IPPROTO_IP,IP_ADD_MEMBERSHIP,(char*)&mcast,
sizeof(mcast)) == SOCKET_ERROR)

　{

printf("setsockopt(IP_ADD_MEMBERSHIP) failed:%d\n",WSAGetLastError());

closesocket(sockM);

WSACleanup();

return -1;

　}

　*/

　/* Winsock2.0*/

　if(( sockM = WSAJoinLeaf(sock,(SOCKADDR*)&remote,sizeof(remote),
NULL,NULL,NULL,NULL,

JL_BOTH)) == INVALID_SOCKET)

　{

printf("WSAJoinLeaf() failed:%d\n",WSAGetLastError());

closesocket(sock);

WSACleanup();

return -1;

　}

　//接收多播数据，当接收到的数据为"QUIT"时退出。

　while(1)

　{

if(( ret = recvfrom(sock,recvbuf,BUFSIZE,0,
(struct sockaddr*)&from,&len)) == SOCKET_ERROR)

{

　printf("recvfrom failed with:%d\n",WSAGetLastError());

　closesocket(sockM);

　closesocket(sock);

　WSACleanup();

　return -1;

}

if( strcmp(recvbuf,"QUIT") == 0 ) break;

else {

　recvbuf[ret] = '\0';

　printf("RECV:' %s ' FROM <%s> \n",recvbuf,inet_ntoa(from.sin_addr));

}

　}
　closesocket(sockM);

　closesocket(sock);

　WSACleanup();

　return 0;

}

#include <winsock2.h>

#include <ws2tcpip.h>

#include <stdio.h>

#include <stdlib.h>

#define MCASTADDR "233.0.0.1" //本例使用的多播组地址。

#define MCASTPORT 5150 //本地端口号。

#define BUFSIZE 1024 //发送数据缓冲大小。

int main( int argc,char ** argv)

{

　WSADATA wsd;

　struct sockaddr_in remote;

　SOCKET sock,sockM;

　TCHAR sendbuf[BUFSIZE];

　int len = sizeof( struct sockaddr_in);

　//初始化WinSock2.2

　if( WSAStartup( MAKEWORD(2,2),&wsd) != 0 )

　{

printf("WSAStartup() failed\n");

return -1;

　}

　if((sock=WSASocket(AF_INET,SOCK_DGRAM,0,NULL,0,

WSA_FLAG_MULTIPOINT_C_LEAF|WSA_FLAG_MULTIPOINT_D_LEAF|

WSA_FLAG_OVERLAPPED)) == INVALID_SOCKET)

　{

printf("socket failed with:%d\n",WSAGetLastError());

WSACleanup();

return -1;

　}

　//加入多播组

　remote.sin_family = AF_INET;

　remote.sin_port = htons(MCASTPORT);

　remote.sin_addr.s_addr = inet_addr( MCASTADDR );

　if(( sockM = WSAJoinLeaf(sock,(SOCKADDR*)&remote,

sizeof(remote),NULL,NULL,NULL,NULL,

JL_BOTH)) == INVALID_SOCKET)

　{

printf("WSAJoinLeaf() failed:%d\n",WSAGetLastError());

closesocket(sock);

WSACleanup();

return -1;

　}
　//发送多播数据，当用户在控制台输入"QUIT"时退出。

　while(1)

　{

printf("SEND : ");

scanf("%s",sendbuf);

if( sendto(sockM,(char*)sendbuf,strlen(sendbuf),0,(struct sockaddr*)
&remote,sizeof(remote))==SOCKET_ERROR)

{

　printf("sendto failed with: %d\n",WSAGetLastError());

　closesocket(sockM);

　closesocket(sock);

　WSACleanup();

　return -1;

}

if(strcmp(sendbuf,"QUIT")==0) break;

Sleep(500);

　}
　closesocket(sockM);

　closesocket(sock);

　WSACleanup();

　return 0;

}