UDP广播

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#include <Stdio.h>
#include <WinSock.h>

 

//////////////////////////////////////////////////////////////////////////

 

struct AfxInitSocket
{
 AfxInitSocket()
 {
  WSADATA wsaData;
  WSAStartup(MAKEWORD(1, 1), &wsaData);
 }
 ~AfxInitSocket()
 {
  WSACleanup();
 }
} _AfxInitSocket;

 

//////////////////////////////////////////////////////////////////////////

 

int main(int argc, char *argv[])
{
 bool bBroadcast = true;
 SOCKET hSocket= socket(PF_INET, SOCK_DGRAM, 0);
 setsockopt(hSocket, SOL_SOCKET, SO_BROADCAST, (char *) &bBroadcast, sizeof(bBroadcast));

 SOCKADDR_IN addrUDP = { 0 };
 addrUDP.sin_family  = AF_INET;
 addrUDP.sin_port  = htons(0);
 addrUDP.sin_addr.s_addr = htonl(INADDR_ANY);
 if (bind(hSocket, (SOCKADDR *) &addrUDP, sizeof(addrUDP)) != 0) {
  return -1;
 }

 addrUDP.sin_family = AF_INET;
 addrUDP.sin_port = htons(7001);
 addrUDP.sin_addr.s_addr = htonl(INADDR_BROADCAST);

 char szSendBuffer[] = "Hello, This is Server!";
 sendto(hSocket, szSendBuffer, sizeof(szSendBuffer), 0, (SOCKADDR *) &addrUDP, sizeof(SOCKADDR_IN));
 return 0;
}

//////////////////////////////////////////////////////////////////////////

 

接收

#include <Stdio.h>
#include <Conio.h>
#include <WinSock.h>

//////////////////////////////////////////////////////////////////////////

struct AfxInitSocket
{
 AfxInitSocket()
 {
  WSADATA wsaData;
  WSAStartup(MAKEWORD(1, 1), &wsaData);
 }
 ~AfxInitSocket()
 {
  WSACleanup();
 }
} _AfxInitSocket;

//////////////////////////////////////////////////////////////////////////

int main(int argc, char *argv[])
{
 SOCKADDR_IN addrUDP = { 0 };

 addrUDP.sin_port = htons(7001);
 addrUDP.sin_family = AF_INET;
 addrUDP.sin_addr.s_addr = htonl(INADDR_ANY);

 SOCKET hSocket = socket(AF_INET, SOCK_DGRAM, 0);
 if (bind(hSocket, (SOCKADDR FAR *) &addrUDP, sizeof(addrUDP)) != 0) {
  return -1;
 }

 int nTimeout = 1000; // 设置超时一秒
 setsockopt(hSocket, SOL_SOCKET, SO_RCVTIMEO, (char *) &nTimeout, sizeof(nTimeout));
 for (int i=0; i<20; ++i) {
  int nSize = sizeof(SOCKADDR_IN);
  int nRecvLength = 0;
  char szRecvBuffer[1024] = { 0 };

  nRecvLength = recvfrom(hSocket, szRecvBuffer, sizeof(szRecvBuffer), 0, (SOCKADDR *) &addrPeer, &nSize);
  if (nRecvLength != SOCKET_ERROR) {
   szRecvBuffer[nRecvLength] = 0;
   printf("Recv --- %s/n", szRecvBuffer);
  }
  else {
   printf("Timeout/n");
  }
 }

 return 0;
}

//////////////////////////////////////////////////////////////////////////