// ブロードキャストパケットを聞く

// on FreeBSD  g++



#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <unistd.h>

#include <iostream>



int main()

{

	int sock;

	struct sockaddr_in addr;



	sock = socket(AF_INET, SOCK_DGRAM, 0);



	addr.sin_family = AF_INET;

	addr.sin_port = htons(65530);

	addr.sin_addr.s_addr = INADDR_ANY;



	int one = 1;

	

	// ブロードキャストパケットを話せるように

	setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (char *)&one, sizeof(one));



	// ソケットとアドレスのひもづけみたいなの

	bind(sock, (struct sockaddr *)&addr, sizeof(addr));

	

	char buf[100];

	memset(buf, 0, sizeof(buf));

	while(1)

	{

		sockaddr_in addr_from;

		memset(&addr_from, 0, sizeof(sockaddr_in));

		socklen_t fromlen = sizeof(addr_from);

		size_t count = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr *)&addr_from, &fromlen);

		buf[count]='\0';

		

		std::cout << "from : " << inet_ntoa(addr_from.sin_addr) << ":" << addr_from.sin_port << std::endl;

		std::cout << "data : " << buf << std::endl;

	}



	close(sock);



	return 0;

}