prevent log spamming with no_descriptors error

Signed-off-by: R4SAS <r4sas@i2pmail.org>

libi2pd/NTCP2.cpp

@@ -1424,16 +1424,17 @@ namespace transport
 			else
 				LogPrint (eLogError, "NTCP2: Connected from error ", ec.message ());
 		}
-		else
-		{	
-			LogPrint (eLogError, "NTCP2: Accept error ", error.message ());
-			if (error == boost::asio::error::no_descriptors)
+		else if (error == boost::asio::error::no_descriptors)
 		{
 			i2p::context.SetError (eRouterErrorNoDescriptors);
-				// TODO
-				return; 
+			if (m_NoFileExhaustTimestamp < i2p::util::GetSecondsSinceEpoch () - NTCP2_DESCRIPTORS_EXHAUST_TIMEOUT)
+			{
+				m_NoFileExhaustTimestamp = i2p::util::GetSecondsSinceEpoch ();
+				LogPrint (eLogWarning, "NTCP2: WARNING! i2pd met file descriptors exhaustion! Please check your nofile limits!");
 			}
 		}
+		else
+			LogPrint (eLogError, "NTCP2: Accept error ", error.message ());
 
 		if (error != boost::asio::error::operation_aborted)
 		{
@@ -1463,22 +1464,26 @@ namespace transport
 				}
 			}
 			else
-				LogPrint (eLogError, "NTCP2: Connected from error ", ec.message ());
+				LogPrint (eLogError, "NTCP2: Connected from ipv6 error: ", ec.message ());
 		}
-		else
-		{	
-			LogPrint (eLogError, "NTCP2: Accept ipv6 error ", error.message ());
-			if (error == boost::asio::error::no_descriptors)
+		else if (error == boost::asio::error::no_descriptors)
 		{
 			i2p::context.SetErrorV6 (eRouterErrorNoDescriptors);
-				// TODO
-				return; 
+			if (m_NoFileExhaustTimestamp < i2p::util::GetSecondsSinceEpoch () - NTCP2_DESCRIPTORS_EXHAUST_TIMEOUT)
+			{
+				m_NoFileExhaustTimestamp = i2p::util::GetSecondsSinceEpoch ();
+				LogPrint (eLogWarning, "NTCP2: WARNING! i2pd met file descriptors exhaustion! Please check your nofile limits!");
 			}
 		}
+		else
+			LogPrint (eLogError, "NTCP2: Accept ipv6 error: ", error.message ());
 
 		if (error != boost::asio::error::operation_aborted)
 		{
+			if (!conn) // connection is used, create new one
 				conn = std::make_shared<NTCP2Session> (*this);
+			else // reuse failed
+				conn->Close ();
 			m_NTCP2V6Acceptor->async_accept(conn->GetSocket (), std::bind (&NTCP2Server::HandleAcceptV6, this,
 				conn, std::placeholders::_1));
 		}

libi2pd/NTCP2.h

@@ -43,6 +43,8 @@ namespace transport
 	const int NTCP2_CLOCK_SKEW = 60; // in seconds
 	const int NTCP2_MAX_OUTGOING_QUEUE_SIZE = 500; // how many messages we can queue up
 
+	const int NTCP2_DESCRIPTORS_EXHAUST_TIMEOUT = 60; // 1 minute
+
 	enum NTCP2BlockType
 	{
 		eNTCP2BlkDateTime = 0,
@@ -286,6 +288,8 @@ namespace transport
 			std::unique_ptr<boost::asio::ip::tcp::endpoint> m_ProxyEndpoint;
 			std::shared_ptr<boost::asio::ip::tcp::endpoint> m_Address4, m_Address6, m_YggdrasilAddress;
 
+			uint64_t m_NoFileExhaustTimestamp;
+
 		public:
 
 			// for HTTP/I2PControl