NetWork/Program

最新推荐文章于 2024-09-18 23:03:36 发布

转载最新推荐文章于 2024-09-18 23:03:36 发布 · 333 阅读

文章标签：

#socket #struct #null #server #interface #c

本文提供了一个使用Winsock在Windows环境下实现组播通信的C语言程序示例。该示例展示了如何设置发送者和接收者，配置组播地址、端口及接口，并通过命令行参数来定制通信行为。

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#include <winsock2.h>
#include <ws2tcpip.h>

#include <stdio.h>
#include <stdlib.h>

#pragma comment( lib, "ws2_32.lib" )

#define MCASTADDR "234.0.0.5"
#define MCASTPORT 7000

#define BUFSIZE 1024
#define DEFAULT_COUNT 500

BOOL bSender = FALSE,
bLoopBack = FALSE;

DWORD dwInterface,dwMulticastGroup,dwCount;
short iPort;

void usage(char *progname)
{
printf("usage: %s -s -m:str -p:int -i:str -l -n:int/n",progname);
printf(" -s Act as server (send data);otherwise/n");
printf("    receive data./n");
printf(" -m:str Dotted decimal multicast IP address to join/n");
printf("   The default group is: %s/n",MCASTADDR);
printf(" -p:int Port number to use/n");
printf("   The default port is: %d/n",MCASTPORT);
printf(" -i:str Local interface to bind to; by default/n");
printf("    use INADDRY_ANY/n");
printf(" -l Disable loopback/n");
printf(" -n:int Number of messages to send/receive/n");
ExitProcess(-1);
}

void ValidateArgs(int argc,char** argv)
{
int i;

dwInterface = INADDR_ANY;
dwMulticastGroup = inet_addr(MCASTADDR);
iPort = MCASTPORT;
dwCount = DEFAULT_COUNT;

for(i = 1; i < argc; i++)
{
  if(( argv[i][0] == '-') || (argv[i][0] == '/'))
  {
   switch(tolower(argv[i][1]))
   {
   case 's':
    bSender = TRUE;
    break;
   case 'm':
    if( strlen(argv[i]) > 3 )
     dwMulticastGroup = inet_addr(&argv[i][3]);
    break;
   case 'i':
    if( strlen(argv[i]) > 3)
     dwInterface = inet_addr(&argv[i][3]);
    break;
   case 'p':
    if ( strlen(argv[i]) > 3)
     iPort = atoi(&argv[i][3]);
    break;
   case 'l':
    bLoopBack = TRUE;
    break;
   case 'n':
    dwCount = atoi(&argv[i][3]);
    break;
   default:
    usage(argv[0]);
    break;
   }
  }
}
return;
}

int main(int argc,char **argv)
{
WSADATA wsd;
struct sockaddr_in local,remote,from;
SOCKET sock,sockM;
char   recvbuf[BUFSIZE],sendbuf[BUFSIZE];
int    len = sizeof(struct sockaddr_in),optval,ret;
DWORD   i = 0;

ValidateArgs(argc,argv);

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;
}

local.sin_family = AF_INET;
local.sin_port = htons(iPort);
local.sin_addr.s_addr = dwInterface;

if( bind(sock,(struct sockaddr * )&local,sizeof(local) ) == SOCKET_ERROR)
{
  printf("bind failed with: %d/n",WSAGetLastError());
  closesocket(sock);
  WSACleanup();
  return -1;
}

remote.sin_family = AF_INET;
remote.sin_port = htons(iPort);
remote.sin_addr.s_addr = dwMulticastGroup;

optval = 8;
if( setsockopt(sock,IPPROTO_IP,IP_MULTICAST_TTL,
  (char*)&optval,sizeof(int)) == SOCKET_ERROR)
{
  printf("setsockopt(IP_MULTICAST_TTL) failed: %d/n",WSAGetLastError());
  closesocket(sock);
  WSACleanup();
  return -1;
}

if( bLoopBack )
{
  optval = 0;
  if( setsockopt(sock,IPPROTO_IP,IP_MULTICAST_LOOP,
   (char*)& optval,sizeof(optval)) == SOCKET_ERROR)
  {
   printf("setsockopt(IP_MULTICAST_LOOP) failed: %d/n",WSAGetLastError());
   closesocket(sock);
   WSACleanup();
   return -1;
  }
}

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;
}

if(!bSender)
{
  for(i = 0; i < dwCount; i++)
  {
   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;
   }
   recvbuf[ret] = 0;
   printf("RECV: '%s' from <%s>/n",recvbuf,inet_ntoa(from.sin_addr));
  }
}
else
{
  for(i = 0; i < dwCount; i ++)
  {
   sprintf(sendbuf,"server 1:This is a test:%d",i);
   if(sendto(sock,(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;
   }
   printf("send out!/n");
   Sleep(500);
  }
}

closesocket(sock);
WSACleanup();
return -1;
}