UDP实现局域网内的广播

// Server
#include <stdio.h>
#include <winsock.h>
#pragma comment(lib, "wsock32.lib")
int main(int argc, char* argv[])
{
  WSADATA wsaData;
  SOCKET sockListener;
  SOCKADDR_IN sin, saUdpServ;
  BOOL fBroadcast = TRUE;
  char sendBuff[1024];
  int nSize;
  int nCount = 0;
  if (WSAStartup(MAKEWORD(1, 1), &wsaData) != 0) // initialize WinSocket
  {
    printf("Failed to initialize windows socket!/n");
    return -1;
  }
  sockListener = socket(PF_INET, SOCK_DGRAM, 0);
  setsockopt(sockListener, SOL_SOCKET, SO_BROADCAST, (CHAR*)&fBroadcast, sizeof(BOOL));
  sin.sin_family = AF_INET;
  sin.sin_port = htons(0);
  sin.sin_addr.s_addr = htonl(INADDR_ANY);
  if (bind(sockListener, (SOCKADDR*)&sin, sizeof(sin)) != 0)
  {
    printf("failed to bind socket to local port!/n");
    return -1;
  }
  saUdpServ.sin_family = AF_INET;
  saUdpServ.sin_addr.s_addr = htonl(INADDR_BROADCAST);
  saUdpServ.sin_port = htons(7001);
  nSize = sizeof(SOCKADDR_IN);
  while (true)
  {
    sprintf(sendBuff, "Message%d", nCount++);
    sendto(sockListener, sendBuff, lstrlen(sendBuff), 0, (SOCKADDR*)&saUdpServ, sizeof(SOCKADDR_IN));
    printf("%s/n", sendBuff);
  }
  return 0;
}


// client
#include <stdio.h>
#include <winsock.h>
#include <conio.h>
#pragma comment(lib, "wsock32.lib")
int main(int argc, char* argv[])
{
  WSADATA wsaData;
  SOCKET sockListener;
  SOCKADDR_IN sin, saClient;
  char cRecvBuff[1024];
  int nSize, nbSize;
  int iAddrLen = sizeof(saClient);
  if (WSAStartup(MAKEWORD(1, 1), &wsaData) != 0)
  {
    printf("Failed to initialize windows socket!/n");
    return -1;
  }
  sockListener = socket(AF_INET, SOCK_DGRAM, 0);
  sin.sin_family = AF_INET;
  sin.sin_port = htons(7001);
  sin.sin_addr.s_addr = htonl(INADDR_ANY);
  if (bind(sockListener, (SOCKADDR FAR*)&sin, sizeof(sin)) != 0)
  {
    printf("Failed to bind socket to local port!/n");
    return -1;
  }
  while (true)
  {
    nSize = sizeof(SOCKADDR_IN);
    if ((nbSize = recvfrom(sockListener, cRecvBuff, 1024, 0, 
      (SOCKADDR FAR*)&saClient, &nSize)) == SOCKET_ERROR)
    {
      printf("Receive Error!");
      break;
    }
    cRecvBuff[nbSize] = '/0';
    printf("%s/n", cRecvBuff);
  }
  return 0;
}