client.c

STUN（RFC3489）客户端的简单实现

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>

#include "udp.h"
#include "stun.h"

#define REQ_LEN		28
#define RES_LEN		100

int main(int argc, char *argv[])
{
	if(argc != 2)
	{
		printf("Usage:%s address",argv[1]);
		exit(1);
	}
	
	Address4 addr;
	int fd,fd1;
	UInt32 ip,local_ip;
	char bufReq[REQ_LEN];
	char bufRes[RES_LEN];
	int num;
	unsigned int first_ip;
	unsigned short port,p;
	p = htons(PORT);
	ip = (UInt32)inet_addr(argv[1]);
	fd = openSocket();
	local_ip = getLocalIP(fd);
		
	if(sendMessage(bufReq,bufRes,fd,false,false,ip,p,28,&addr))
	{	
		first_ip = addr.mapped_ip;
		port = addr.mapped_port;

		if(local_ip == addr.mapped_ip)
		{
			if(sendMessage(bufReq,bufRes,fd,true,true,ip,p,28,&addr))
			{
				printf("Open Internet!\n");
			}
			else printf("Symmetric UDP firewall!\n");
		}
		else
		{
			if(sendMessage(bufReq,bufRes,fd,true,true,ip,p,28,&addr))
			{
				printf("NAT type:Full Cone!\n");
			}
			else 
			{
				
				printf("changed ip is %x\n",htonl(addr.changed_ip));
				sendMessage(bufReq,bufRes,fd,false,false,
	  			        	htonl(addr.changed_ip),htons(addr.changed_port),
							28,&addr);
				printf("mapped_ip is %x\n",htonl(addr.mapped_ip));
				if(port == addr.mapped_port)
				{
					
					if(sendMessage(bufReq,bufRes,fd,false,true,ip,p,28,&addr))
					{
						printf("NAT type:Restricted NAT\n");
					}
					else printf("NAT type:Port Restricted NAT\n");
				}
				else printf("NAT type:Symmetric NAT\n");
				
			}
		}
	}
	else printf("Firewall that blocks UDP or UDP unreachable!\n ");

	closeSocket(fd);

	return 0;
}