stun.cxx

现在应用最广泛的一种私网穿透方式

      {
         if (verbose) clog << "received on A1:P2" << endl;
         recvAltIp = false;
         recvAltPort = true;
         ok = getMessage( info.altPortFd, msg, &msgLen, &from.addr, &from.port,verbose );
      }
      else if ( (info.altIpFd!=INVALID_SOCKET) && FD_ISSET(info.altIpFd,&fdSet))
      {
         if (verbose) clog << "received on A2:P1" << endl;
         recvAltIp = true;
         recvAltPort = false;
         ok = getMessage( info.altIpFd, msg, &msgLen, &from.addr, &from.port ,verbose);
      }
      else if ( (info.altIpPortFd!=INVALID_SOCKET) && FD_ISSET(info.altIpPortFd, &fdSet))
      {
         if (verbose) clog << "received on A2:P2" << endl;
         recvAltIp = true;
         recvAltPort = true;
         ok = getMessage( info.altIpPortFd, msg, &msgLen, &from.addr, &from.port,verbose );
      }
      else
      {
         return true;
      }

      int relayPort = 0;
      if (info.relay)
      {
         for (int i=0; i<MAX_MEDIA_RELAYS; ++i)
         {
            StunMediaRelay* relay = &info.relays[i];
            if (relay->destination.addr == from.addr && 
                relay->destination.port == from.port)
            {
               relayPort = relay->relayPort;
               relay->expireTime = time(0) + MEDIA_RELAY_TIMEOUT;
               break;
            }
         }

         if (relayPort == 0)
         {
            for (int i=0; i<MAX_MEDIA_RELAYS; ++i)
            {
               StunMediaRelay* relay = &info.relays[i];
               if (relay->fd == 0)
               {
                  if ( verbose ) clog << "Open relay port " << relay->relayPort << endl;
                  
                  relay->fd = openPort(relay->relayPort, info.myAddr.addr, verbose);
                  relay->destination.addr = from.addr;
                  relay->destination.port = from.port;
                  relay->expireTime = time(0) + MEDIA_RELAY_TIMEOUT;
                  relayPort = relay->relayPort;
                  break;
               }
            }
         }
      }
         
      if ( !ok ) 
      {
         if ( verbose ) clog << "Get message did not return a valid message" <<endl;
         return true;
      }
		
      if ( verbose ) clog << "Got a request (len=" << msgLen << ") from " << from << endl;
		
      if ( msgLen <= 0 )
      {
         return true;
      }
		
      bool changePort = false;
      bool changeIp = false;
		
      StunMessage resp;
      StunAddress4 dest;
      StunAtrString hmacPassword;  
      hmacPassword.sizeValue = 0;

      StunAddress4 secondary;
      secondary.port = 0;
      secondary.addr = 0;
               
      if (info.relay && relayPort)
      {
         secondary = from;
         
         from.addr = info.myAddr.addr;
         from.port = relayPort;
      }
      
      ok = stunServerProcessMsg( msg, msgLen, from, secondary,
                                 recvAltIp ? info.altAddr : info.myAddr,
                                 recvAltIp ? info.myAddr : info.altAddr, 
                                 &resp,
                                 &dest,
                                 &hmacPassword,
                                 &changePort,
                                 &changeIp,
                                 verbose );
		
      if ( !ok )
      {
         if ( verbose ) clog << "Failed to parse message" << endl;
         return true;
      }
		
      char buf[STUN_MAX_MESSAGE_SIZE];
      int len = sizeof(buf);
      		
      len = stunEncodeMessage( resp, buf, len, hmacPassword,verbose );
		
      if ( dest.addr == 0 )  ok=false;
      if ( dest.port == 0 ) ok=false;
		
      if ( ok )
      {
         assert( dest.addr != 0 );
         assert( dest.port != 0 );
			
         Socket sendFd;
			
         bool sendAltIp   = recvAltIp;   // send on the received IP address 
         bool sendAltPort = recvAltPort; // send on the received port
			
         if ( changeIp )   sendAltIp   = !sendAltIp;   // if need to change IP, then flip logic 
         if ( changePort ) sendAltPort = !sendAltPort; // if need to change port, then flip logic 
			
         if ( !sendAltPort )
         {
            if ( !sendAltIp )
            {
               sendFd = info.myFd;
            }
            else
            {
               sendFd = info.altIpFd;
            }
         }
         else
         {
            if ( !sendAltIp )
            {
               sendFd = info.altPortFd;
            }
            else
            {
               sendFd = info.altIpPortFd;
            }
         }
	
         if ( sendFd != INVALID_SOCKET )
         {
            sendMessage( sendFd, buf, len, dest.addr, dest.port, verbose );
         }
      }
   }
	
   return true;
}

int 
stunFindLocalInterfaces(UInt32* addresses,int maxRet)
{
#if defined(WIN32) || defined(__sparc__)
   return 0;
#else
   struct ifconf ifc;
	
   int s = socket( AF_INET, SOCK_DGRAM, 0 );
   int len = 100 * sizeof(struct ifreq);
	
   char buf[ len ];
	
   ifc.ifc_len = len;
   ifc.ifc_buf = buf;
	
   int e = ioctl(s,SIOCGIFCONF,&ifc);
   char *ptr = buf;
   int tl = ifc.ifc_len;
   int count=0;
	
   while ( (tl > 0) && ( count < maxRet) )
   {
      struct ifreq* ifr = (struct ifreq *)ptr;
		
      int si = sizeof(ifr->ifr_name) + sizeof(struct sockaddr);
      tl -= si;
      ptr += si;
      //char* name = ifr->ifr_ifrn.ifrn_name;
      //cerr << "name = " << name << endl;
		
      struct ifreq ifr2;
      ifr2 = *ifr;
		
      e = ioctl(s,SIOCGIFADDR,&ifr2);
      if ( e == -1 )
      {
         break;
      }
		
      //cerr << "ioctl addr e = " << e << endl;
		
      struct sockaddr a = ifr2.ifr_addr;
      struct sockaddr_in* addr = (struct sockaddr_in*) &a;
		
      UInt32 ai = ntohl( addr->sin_addr.s_addr );
      if (int((ai>>24)&0xFF) != 127)
      {
         addresses[count++] = ai;
      }
		
#if 0
      cerr << "Detected interface "
           << int((ai>>24)&0xFF) << "." 
           << int((ai>>16)&0xFF) << "." 
           << int((ai>> 8)&0xFF) << "." 
           << int((ai    )&0xFF) << endl;
#endif
   }
	
   closesocket(s);
	
   return count;
#endif
}


void
stunBuildReqSimple( StunMessage* msg,
                    const StunAtrString& username,
                    bool changePort, bool changeIp, unsigned int id )
{
   assert( msg );
   memset( msg , 0 , sizeof(*msg) );
	
   msg->msgHdr.msgType = BindRequestMsg;
	
   for ( int i=0; i<16; i=i+4 )
   {
      assert(i+3<16);
      int r = stunRand();
      msg->msgHdr.id.octet[i+0]= r>>0;
      msg->msgHdr.id.octet[i+1]= r>>8;
      msg->msgHdr.id.octet[i+2]= r>>16;
      msg->msgHdr.id.octet[i+3]= r>>24;
   }
	
   if ( id != 0 )
   {
      msg->msgHdr.id.octet[0] = id; 
   }
	
   msg->hasChangeRequest = true;
   msg->changeRequest.value =(changeIp?ChangeIpFlag:0) | 
      (changePort?ChangePortFlag:0);
	
   if ( username.sizeValue > 0 )
   {
      msg->hasUsername = true;
      msg->username = username;
   }
}


static void 
stunSendTest( Socket myFd, StunAddress4& dest, 
              const StunAtrString& username, const StunAtrString& password, 
              int testNum, bool verbose )
{ 
   assert( dest.addr != 0 );
   assert( dest.port != 0 );
	
   bool changePort=false;
   bool changeIP=false;
   bool discard=false;
	
   switch (testNum)
   {
      case 1:
      case 10:
      case 11:
         break;
      case 2:
         //changePort=true;
         changeIP=true;
         break;
      case 3:
         changePort=true;
         break;
      case 4:
         changeIP=true;
         break;
      case 5:
         discard=true;
         break;
      default:
         cerr << "Test " << testNum <<" is unkown\n";
         assert(0);
   }
	
   StunMessage req;
   memset(&req, 0, sizeof(StunMessage));
	
   stunBuildReqSimple( &req, username, 
                       changePort , changeIP , 
                       testNum );
	
   char buf[STUN_MAX_MESSAGE_SIZE];
   int len = STUN_MAX_MESSAGE_SIZE;
	
   len = stunEncodeMessage( req, buf, len, password,verbose );
	
   if ( verbose )
   {
      clog << "About to send msg of len " << len << " to " << dest << endl;
   }
	
   sendMessage( myFd, buf, len, dest.addr, dest.port, verbose );
	
   // add some delay so the packets don't get sent too quickly 
#ifdef WIN32 // !cj! TODO - should fix this up in windows
		 clock_t now = clock();
		 assert( CLOCKS_PER_SEC == 1000 );
		 while ( clock() <= now+10 ) { };
#else
		 usleep(10*1000);
#endif

}


void 
stunGetUserNameAndPassword(  const StunAddress4& dest, 
                             StunAtrString* username,
                             StunAtrString* password)
{ 
   // !cj! This is totally bogus - need to make TLS connection to dest and get a
   // username and password to use 
   stunCreateUserName(dest, username);
   stunCreatePassword(*username, password);
}


void 
stunTest( StunAddress4& dest, int testNum, bool verbose, StunAddress4* sAddr )
{ 
   assert( dest.addr != 0 );
   assert( dest.port != 0 );
	
   int port = randomPort();
   UInt32 interfaceIp=0;
   if (sAddr)
   {
      interfaceIp = sAddr->addr;
      if ( sAddr->port != 0 )
      {
        port = sAddr->port;
      }
   }
   Socket myFd = openPort(port,interfaceIp,verbose);
	
   StunAtrString username;
   StunAtrString password;
	
   username.sizeValue = 0;
   password.sizeValue = 0;
	
#ifdef USE_TLS
   stunGetUserNameAndPassword( dest, username, password );
#endif
	
   stunSendTest( myFd, dest, username, password, testNum, verbose );
    
   char msg[STUN_MAX_MESSAGE_SIZE];
   int msgLen = STUN_MAX_MESSAGE_SIZE;
	
   StunAddress4 from;
   getMessage( myFd,
               msg,
               &msgLen,
               &from.addr,
               &from.port,verbose );
	
   StunMessage resp;
   memset(&resp, 0, sizeof(StunMessage));
	
   if ( verbose ) clog << "Got a response" << endl;
   bool ok = stunParseMessage( msg,msgLen, resp,verbose );
	
   if ( verbose )
   {
      clog << "\t ok=" << ok << endl;
      clog << "\t id=" << resp.msgHdr.id << endl;
      clog << "\t mappedAddr=" << resp.mappedAddress.ipv4 << endl;
      clog << "\t changedAddr=" << resp.changedAddress.ipv4 << endl;
      clog << endl;
   }
	
   if (sAddr)
   {
      sAddr->port = resp.mappedAddress.ipv4.port;
      sAddr->addr = resp.mappedAddress.ipv4.addr;
   }
}


NatType
stunNatType( StunAddress4& dest, 
             bool verbose,
             bool* preservePort, // if set, is return for if NAT preservers ports or not
             bool* hairpin,  // if set, is the return for if NAT will hairpin packets
             int port, // port to use for the test, 0 to choose random port
             StunAddress4* sAddr // NIC to use 
   )
{ 
   assert( dest.addr != 0 );
   assert( dest.port != 0 );
	
   if ( hairpin ) 
   {
      *hairpin = false;
   }
	
   if ( port == 0 )
   {
      port = randomPort();
   }
   UInt32 interfaceIp=0;
   if (sAddr)
   {
      interfaceIp = sAddr->addr;
   }
   Socket myFd1 = openPort(port,interfaceIp,verbose);
   Socket myFd2 = openPort(port+1,interfaceIp,verbose);

   if ( ( myFd1 == INVALID_SOCKET) || ( myFd2 == INVALID_SOCKET) )
   {
        cerr << "Some problem opening port/interface to send on" << endl;
       return StunTypeFailure; 
   }

   assert( myFd1 != INVALID_SOCKET );
   assert( myFd2 != INVALID_SOCKET );
    
   bool respTestI=false;
   bool isNat=true;
   StunAddress4 testIchangedAddr;
   StunAddress4 testImappedAddr;
   bool respTestI2=false; 
   bool mappedIpSame = true;
   StunAddress4 testI2mappedAddr;
   StunAddress4 testI2dest=dest;
   bool respTestII=false;
   bool respTestIII=false;

   bool respTestHairpin=false;
	
   memset(&testImappedAddr,0,sizeof(testImappedAddr));
	
   StunAtrString username;
   StunAtrString password;
	
   username.sizeValue = 0;
   password.sizeValue = 0;
	
#ifdef USE_TLS 
   stunGetUserNameAndPassword( dest, username, password );
#endif
	
   //stunSendTest( myFd1, dest, username, password, 1, verbose );
   int count=0;
   while ( count < 7 )
   {
      struct timeval tv;
      fd_set fdSet; 
#ifdef WIN32
      unsigned int fdSetSize;
#else
      int fdSetSize;
#endif
      FD_ZERO(&fdSet); fdSetSize=0;
      FD_SET(myFd1,&fdSet); fdSetSize = (myFd1+1>fdSetSize) ? myFd1+1 : fdSetSize;
      FD_SET(myFd2,&fdSet); fdSetSize = (myFd2+1>fdSetSize) ? myFd2+1 : fdSetSize;
      tv.tv_sec=0;