1 files changed, 80 insertions, 18 deletions

diff --git a/node/Peer.hpp b/node/Peer.hpp
index 2e64fb4d..1ae239bc 100644
--- a/node/Peer.hpp
+++ b/node/Peer.hpp
@@ -312,7 +312,7 @@ public:
 	/**
 	 * @return 256-bit secret symmetric encryption key
 	 */
-	inline const unsigned char *key() const throw() { return _key; }
+	inline const unsigned char *key() const { return _key; }
 
 	/**
 	 * Set the currently known remote version of this peer's client
@@ -330,25 +330,22 @@ public:
 		_vRevision = (uint16_t)vrev;
 	}
 
-	inline unsigned int remoteVersionProtocol() const throw() { return _vProto; }
-	inline unsigned int remoteVersionMajor() const throw() { return _vMajor; }
-	inline unsigned int remoteVersionMinor() const throw() { return _vMinor; }
-	inline unsigned int remoteVersionRevision() const throw() { return _vRevision; }
+	inline unsigned int remoteVersionProtocol() const { return _vProto; }
+	inline unsigned int remoteVersionMajor() const { return _vMajor; }
+	inline unsigned int remoteVersionMinor() const { return _vMinor; }
+	inline unsigned int remoteVersionRevision() const { return _vRevision; }
 
-	inline bool remoteVersionKnown() const throw() { return ((_vMajor > 0)||(_vMinor > 0)||(_vRevision > 0)); }
+	inline bool remoteVersionKnown() const { return ((_vMajor > 0)||(_vMinor > 0)||(_vRevision > 0)); }
 
 	/**
-	 * Update direct path push stats and return true if we should respond
-	 *
-	 * This is a circuit breaker to make VERB_PUSH_DIRECT_PATHS not particularly
-	 * useful as a DDOS amplification attack vector. Otherwise a malicious peer
-	 * could send loads of these and cause others to bombard arbitrary IPs with
-	 * traffic.
-	 *
-	 * @param now Current time
-	 * @return True if we should respond
+	 * @return True if peer has received a trust established packet (e.g. common network membership) in the past ZT_TRUST_EXPIRATION ms
+	 */
+	inline bool trustEstablished(const uint64_t now) const { return ((now - _lastTrustEstablishedPacketReceived) < ZT_TRUST_EXPIRATION); }
+
+	/**
+	 * Rate limit gate for VERB_PUSH_DIRECT_PATHS
 	 */
-	inline bool shouldRespondToDirectPathPush(const uint64_t now)
+	inline bool rateGatePushDirectPaths(const uint64_t now)
 	{
 		if ((now - _lastDirectPathPushReceive) <= ZT_PUSH_DIRECT_PATHS_CUTOFF_TIME)
 			++_directPathPushCutoffCount;
@@ -358,6 +355,66 @@ public:
 	}
 
 	/**
+	 * Rate limit gate for VERB_NETWORK_CREDENTIALS
+	 */
+	inline bool rateGateCredentialsReceived(const uint64_t now)
+	{
+		if ((now - _lastCredentialsReceived) <= ZT_PEER_CREDENTIALS_CUTOFF_TIME)
+			++_credentialsCutoffCount;
+		else _credentialsCutoffCount = 0;
+		_lastCredentialsReceived = now;
+		return (_directPathPushCutoffCount < ZT_PEER_CREDEITIALS_CUTOFF_LIMIT);
+	}
+
+	/**
+	 * Rate limit gate for sending of ERROR_NEED_MEMBERSHIP_CERTIFICATE
+	 */
+	inline bool rateGateRequestCredentials(const uint64_t now)
+	{
+		if ((now - _lastCredentialRequestSent) >= ZT_PEER_GENERAL_RATE_LIMIT) {
+			_lastCredentialRequestSent = now;
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * Rate limit gate for inbound WHOIS requests
+	 */
+	inline bool rateGateInboundWhoisRequest(const uint64_t now)
+	{
+		if ((now - _lastWhoisRequestReceived) >= ZT_PEER_GENERAL_RATE_LIMIT) {
+			_lastWhoisRequestReceived = now;
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * Rate limit gate for inbound ECHO requests
+	 */
+	inline bool rateGateEchoRequest(const uint64_t now)
+	{
+		if ((now - _lastEchoRequestReceived) >= ZT_PEER_GENERAL_RATE_LIMIT) {
+			_lastEchoRequestReceived = now;
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * Rate gate requests for network COM
+	 */
+	inline bool rateGateComRequest(const uint64_t now)
+	{
+		if ((now - _lastComRequestReceived) >= ZT_PEER_GENERAL_RATE_LIMIT) {
+			_lastComRequestReceived = now;
+			return true;
+		}
+		return false;
+	}
+
+	/**
 	 * Find a common set of addresses by which two peers can link, if any
 	 *
 	 * @param a Peer A
@@ -378,8 +435,6 @@ public:
 	}
 
 private:
-	bool _pushDirectPaths(const SharedPtr<Path> &path,uint64_t now);
-
 	inline uint64_t _pathScore(const unsigned int p,const uint64_t now) const
 	{
 		uint64_t s = ZT_PEER_PING_PERIOD + _paths[p].lastReceive + (uint64_t)(_paths[p].path->preferenceRank() * (ZT_PEER_PING_PERIOD / ZT_PATH_MAX_PREFERENCE_RANK));
@@ -415,6 +470,12 @@ private:
 	uint64_t _lastMulticastFrame;
 	uint64_t _lastDirectPathPushSent;
 	uint64_t _lastDirectPathPushReceive;
+	uint64_t _lastCredentialRequestSent;
+	uint64_t _lastWhoisRequestReceived;
+	uint64_t _lastEchoRequestReceived;
+	uint64_t _lastComRequestReceived;
+	uint64_t _lastCredentialsReceived;
+	uint64_t _lastTrustEstablishedPacketReceived;
 	const RuntimeEnvironment *RR;
 	uint32_t _remoteClusterOptimal4;
 	uint16_t _vProto;
@@ -433,6 +494,7 @@ private:
 	unsigned int _numPaths;
 	unsigned int _latency;
 	unsigned int _directPathPushCutoffCount;
+	unsigned int _credentialsCutoffCount;
 
 	AtomicCounter __refCount;
 };