Version 0.4.3 (the real one): fix Gentoo ip config failures and crashes

This version fixes problems with locating the 'ip' command on Gentoo
and possibly other Linux systems, and a problem that could cause a
crash if EthernetTap was unable to locate one of the commands it
invokes to configure IP information on tap devices.

The code also now builds on Windows. It doesn't run yet, but it's a
step. Windows port is in full swing.

Finally, the multicast rate limit defaults were raised a little. More
testing is needed here, and real world measurments.

node/Constants.hpp

@@ -284,22 +284,22 @@ error_no_ZT_ARCH_defined;
 /**
  * Default bytes per second limit for multicasts per peer on a network
  */
-#define ZT_MULTICAST_DEFAULT_BYTES_PER_SECOND 50.0
+#define ZT_MULTICAST_DEFAULT_BYTES_PER_SECOND 100.0
 
 /**
  * Default balance preload for multicast rate limiters on a network
  */
-#define ZT_MULTICAST_DEFAULT_RATE_PRELOAD 20000.0
+#define ZT_MULTICAST_DEFAULT_RATE_PRELOAD 25000.0
 
 /**
  * Default maximum balance for multicast rate limiters
  */
-#define ZT_MULTICAST_DEFAULT_RATE_MAX_BALANCE 20000.0
+#define ZT_MULTICAST_DEFAULT_RATE_MAX_BALANCE 25000.0
 
 /**
  * Default minimum balance for multicast rate limiters (max debt)
  */
-#define ZT_MULTICAST_DEFAULT_RATE_MIN_BALANCE -10000.0
+#define ZT_MULTICAST_DEFAULT_RATE_MIN_BALANCE -5000.0
 
 /**
  * Delay between scans of the topology active peer DB for peers that need ping

node/RateLimiter.hpp

@@ -135,6 +135,15 @@ public:
 		return allow;
 	}
 
+	/**
+	 * @return Current balance
+	 */
+	inline double balance() const
+		throw()
+	{
+		return _balance;
+	}
+
 private:
 	double _lastTime;
 	double _balance;

selftest.cpp

@@ -33,6 +33,7 @@
 #include <string>
 #include <vector>
 
+#include "node/Constants.hpp"
 #include "node/InetAddress.hpp"
 #include "node/EllipticCurveKey.hpp"
 #include "node/EllipticCurveKeyPair.hpp"
@@ -46,6 +47,7 @@
 #include "node/Condition.hpp"
 #include "node/NodeConfig.hpp"
 #include "node/Dictionary.hpp"
+#include "node/RateLimiter.hpp"
 
 #include <openssl/rand.h>
 
@@ -366,6 +368,32 @@ static int testOther()
 	return 0;
 }
 
+static int testRateLimiter()
+{
+	RateLimiter limiter;
+	RateLimiter::Limit limit;
+
+	std::cout << "[ratelimiter] preload: 10000.0, rate: 1000.0/sec, max: 15000.0, min: -7500.0" << std::endl;
+	limit.bytesPerSecond = 1000.0;
+	limit.maxBalance = 15000.0;
+	limit.minBalance = -7500.0;
+	limiter.init(10000.0);
+	for(int i=0;i<25;++i) {
+		Thread::sleep(100);
+		std::cout << "[ratelimiter] delayed 0.1s, gate(1000.0): " << (limiter.gate(limit,1000.0) ? "OK" : "BLOCK");
+		std::cout << " (new balance afterwords: " << limiter.balance() << ")" << std::endl;
+	}
+	std::cout << "[ratelimiter] delaying 15s..." << std::endl;
+	Thread::sleep(15000);
+	for(int i=0;i<20;++i) {
+		Thread::sleep(1000);
+		std::cout << "[ratelimiter] delayed 1s, gate(2000.0): " << (limiter.gate(limit,2000.0) ? "OK" : "BLOCK");
+		std::cout << " (new balance afterwords: " << limiter.balance() << ")" << std::endl;
+	}
+
+	return 0;
+}
+
 int main(int argc,char **argv)
 {
 	int r = 0;
@@ -377,6 +405,7 @@ int main(int argc,char **argv)
 	r |= testPacket();
 	r |= testOther();
 	r |= testIdentity();
+	r |= testRateLimiter();
 
 	if (r)
 		std::cout << std::endl << "SOMETHING FAILED!" << std::endl;