From 5406ce65400c07e6fd37cecc42209411acc350be Mon Sep 17 00:00:00 2001
From: Michael Friedrich <michael.friedrich@icinga.com>
Date: Mon, 29 Oct 2018 12:57:24 +0100
Subject: [PATCH] Ensure that API/JSON-RPC messages in the same session are
 processed and not stalled

This basically drops the "corked" implementation which just stalled the
TLS IO polling after some requests. If you need sort of rate limiting
for these events, use an external TLS proxy which terminates that in front
of Icinga.

fixes #6635
---
 lib/base/stream.cpp                 | 10 ----------
 lib/base/stream.hpp                 |  5 -----
 lib/base/tlsstream.cpp              | 22 +++-------------------
 lib/base/tlsstream.hpp              |  2 --
 lib/remote/httpserverconnection.cpp |  5 -----
 lib/remote/jsonrpcconnection.cpp    |  4 ----
 6 files changed, 3 insertions(+), 45 deletions(-)

diff --git a/lib/base/stream.cpp b/lib/base/stream.cpp
index 8e1258d75..f41bc52a2 100644
--- a/lib/base/stream.cpp
+++ b/lib/base/stream.cpp
@@ -91,16 +91,6 @@ bool Stream::WaitForData(int timeout)
 	return IsDataAvailable() || IsEof();
 }
 
-void Stream::SetCorked(bool corked)
-{
-	m_Corked = corked;
-}
-
-bool Stream::IsCorked() const
-{
-	return m_Corked;
-}
-
 static void StreamDummyCallback()
 { }
 
diff --git a/lib/base/stream.hpp b/lib/base/stream.hpp
index 0a7bf5fd0..72da2ba9a 100644
--- a/lib/base/stream.hpp
+++ b/lib/base/stream.hpp
@@ -127,9 +127,6 @@ public:
 	bool WaitForData();
 	bool WaitForData(int timeout);
 
-	virtual void SetCorked(bool corked);
-	bool IsCorked() const;
-
 	virtual bool SupportsWaiting() const;
 
 	virtual bool IsDataAvailable() const;
@@ -146,8 +143,6 @@ private:
 
 	boost::mutex m_Mutex;
 	boost::condition_variable m_CV;
-
-	bool m_Corked{false};
 };
 
 }
diff --git a/lib/base/tlsstream.cpp b/lib/base/tlsstream.cpp
index b771b3622..f57af8d5e 100644
--- a/lib/base/tlsstream.cpp
+++ b/lib/base/tlsstream.cpp
@@ -153,16 +153,12 @@ void TlsStream::OnEvent(int revents)
 	char buffer[64 * 1024];
 
 	if (m_CurrentAction == TlsActionNone) {
-		bool corked = IsCorked();
-		if (!corked && (revents & (POLLIN | POLLERR | POLLHUP)))
+		if (revents & (POLLIN | POLLERR | POLLHUP))
 			m_CurrentAction = TlsActionRead;
 		else if (m_SendQ->GetAvailableBytes() > 0 && (revents & POLLOUT))
 			m_CurrentAction = TlsActionWrite;
 		else {
-			if (corked)
-				ChangeEvents(0);
-			else
-				ChangeEvents(POLLIN);
+			ChangeEvents(POLLIN);
 
 			return;
 		}
@@ -289,7 +285,7 @@ void TlsStream::OnEvent(int revents)
 
 		lock.unlock();
 
-		while (!IsCorked() && m_RecvQ->IsDataAvailable() && IsHandlingEvents())
+		while (m_RecvQ->IsDataAvailable() && IsHandlingEvents())
 			SignalDataAvailable();
 	}
 
@@ -441,18 +437,6 @@ bool TlsStream::IsDataAvailable() const
 	return m_RecvQ->GetAvailableBytes() > 0;
 }
 
-void TlsStream::SetCorked(bool corked)
-{
-	Stream::SetCorked(corked);
-
-	boost::mutex::scoped_lock lock(m_Mutex);
-
-	if (corked)
-		m_CurrentAction = TlsActionNone;
-	else
-		ChangeEvents(POLLIN | POLLOUT);
-}
-
 Socket::Ptr TlsStream::GetSocket() const
 {
 	return m_Socket;
diff --git a/lib/base/tlsstream.hpp b/lib/base/tlsstream.hpp
index e58d5995d..8e4ceb08e 100644
--- a/lib/base/tlsstream.hpp
+++ b/lib/base/tlsstream.hpp
@@ -70,8 +70,6 @@ public:
 	bool SupportsWaiting() const override;
 	bool IsDataAvailable() const override;
 
-	void SetCorked(bool corked) override;
-
 	bool IsVerifyOK() const;
 	String GetVerifyError() const;
 
diff --git a/lib/remote/httpserverconnection.cpp b/lib/remote/httpserverconnection.cpp
index 301d5ba5f..356a0ffba 100644
--- a/lib/remote/httpserverconnection.cpp
+++ b/lib/remote/httpserverconnection.cpp
@@ -344,7 +344,6 @@ void HttpServerConnection::ProcessMessageAsync(HttpRequest& request, HttpRespons
 
 	response.Finish();
 	m_PendingRequests--;
-	m_Stream->SetCorked(false);
 }
 
 void HttpServerConnection::DataAvailableHandler()
@@ -354,8 +353,6 @@ void HttpServerConnection::DataAvailableHandler()
 	if (!m_Stream->IsEof()) {
 		boost::recursive_mutex::scoped_lock lock(m_DataHandlerMutex);
 
-		m_Stream->SetCorked(true);
-
 		try {
 			while (ProcessMessage())
 				; /* empty loop body */
@@ -366,8 +363,6 @@ void HttpServerConnection::DataAvailableHandler()
 			close = true;
 		}
 
-		m_RequestQueue.Enqueue(std::bind(&Stream::SetCorked, m_Stream, false));
-
 		/* Request finished, decide whether to explicitly close the connection. */
 		if (m_CurrentRequest.ProtocolVersion == HttpVersion10 ||
 			m_CurrentRequest.Headers->Get("connection") == "close") {
diff --git a/lib/remote/jsonrpcconnection.cpp b/lib/remote/jsonrpcconnection.cpp
index 099d28723..b9a9ceee2 100644
--- a/lib/remote/jsonrpcconnection.cpp
+++ b/lib/remote/jsonrpcconnection.cpp
@@ -276,8 +276,6 @@ void JsonRpcConnection::DataAvailableHandler()
 	if (!m_Stream->IsEof()) {
 		boost::mutex::scoped_lock lock(m_DataHandlerMutex);
 
-		m_Stream->SetCorked(true);
-
 		try {
 			while (ProcessMessage())
 				; /* empty loop body */
@@ -290,8 +288,6 @@ void JsonRpcConnection::DataAvailableHandler()
 
 			return;
 		}
-
-		l_JsonRpcConnectionWorkQueues[m_ID % l_JsonRpcConnectionWorkQueueCount].Enqueue(std::bind(&Stream::SetCorked, m_Stream, false));
 	} else
 		close = true;
 
-- 
2.40.0