Hi --
While testing 9.0.8 in staging, we found that when a client connects to
our Tomcat's TLS connector and doesn't send any data (not even to do
the handshake), the connection is allowed to stay open indefinitely.
We first saw this problem on Debian. We have been able to reproduce
it using the "Docker Official Image" for Tomcat.
Here is a recipe to reproduce it. First, it shows the expected
behavior (which we get with the NIO handler) and then the unexpected
behavior (which we get with the NIO2 handler).
(1) Run a tomcat docker container:
docker run -it tomcat:9.0.8 /bin/bash
(2) Install telnet
apt update
apt install telnet
(3) Generate an RSA certificate
keytool -genkey -alias tomcat -keyalg RSA
(set password to 'password' and then take the defaults)
(4) Edit /usr/local/tomcat/conf/server.xml
uncomment the SSL/TLS HTTP/1.1 Connector for port 8443 (around line
88)
set certificateKeystoreFile="/root/.keystore"
set certificateKeystorePassword="password"
(5) Start tomcat:
/usr/local/tomcat/bin/startup.sh
(6) Connect to the SSL/TLS port:
telnet 127.0.0.1 8443
(7) Note that the connection is broken in 60 seconds (that's the default
connectionTimeout).
(8) Stop tomcat:
/usr/local/tomcat/bin/shutdown.sh
(9) Edit /usr/local/tomcat/conf/server.xml to use NIO2 instead.
set protocol="org.apache.coyote.http11.Http11Nio2Protocol" (note the
*2*!)
(10) Start tomcat:
/usr/local/tomcat/bin/startup.sh
(11) Connect to the SSL/TLS port:
telnet 127.0.0.1 8443
(12) The server never appears to disconnect the connection.
Note that if the client goes through the handshake, the server will
hang up on it as expected.
(13) Make sure openssl is installed
apt install openssl
(14) openssl s_client -connect localhost:8443
(15) Note that it disconnects in about a minute.
Using docker (18.03.1-ce-mac65 (24312)) on a mid-2012 Mac Book Pro
Retina (macOs 10.13.4), I've tried this with 9.0.8 and 8.5.31. On
similar laptops and OSes we've also tried 9.0.7.
I've run it a little my Intellij IDEA with breakpoints in the code to
watch the Acceptor accept the connection and I don't see any timers
being set during the handshake phase, but i could have easily missed
them.
Is this behavior expected? Is there a configuration parameter we're
missing?
thanks,
ab
-----------------------------------------------------------------------------------
| /usr/local/tomcat/conf/server.xml from tomcat:9.0.8n with edits described
above
-----------------------------------------------------------------------------------
<?xml version="1.0" encoding="UTF-8"?>
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- Note: A "Server" is not itself a "Container", so you may not
define subcomponents such as "Valves" at this level.
Documentation at /docs/config/server.html
-->
<Server port="8005" shutdown="SHUTDOWN">
<Listener className="org.apache.catalina.startup.VersionLoggerListener" />
<!-- Security listener. Documentation at /docs/config/listeners.html
<Listener className="org.apache.catalina.security.SecurityListener" />
-->
<!--APR library loader. Documentation at /docs/apr.html -->
<Listener className="org.apache.catalina.core.AprLifecycleListener"
SSLEngine="on" />
<!-- Prevent memory leaks due to use of particular java/javax APIs-->
<Listener
className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />
<Listener
className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
<Listener
className="org.apache.catalina.core.ThreadLocalLeakPreventionListener" />
<!-- Global JNDI resources
Documentation at /docs/jndi-resources-howto.html
-->
<GlobalNamingResources>
<!-- Editable user database that can also be used by
UserDatabaseRealm to authenticate users
-->
<Resource name="UserDatabase" auth="Container"
type="org.apache.catalina.UserDatabase"
description="User database that can be updated and saved"
factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
pathname="conf/tomcat-users.xml" />
</GlobalNamingResources>
<!-- A "Service" is a collection of one or more "Connectors" that share
a single "Container" Note: A "Service" is not itself a "Container",
so you may not define subcomponents such as "Valves" at this level.
Documentation at /docs/config/service.html
-->
<Service name="Catalina">
<!--The connectors can use a shared executor, you can define one or
more named thread pools-->
<!--
<Executor name="tomcatThreadPool" namePrefix="catalina-exec-"
maxThreads="150" minSpareThreads="4"/>
-->
<!-- A "Connector" represents an endpoint by which requests are received
and responses are returned. Documentation at :
Java HTTP Connector: /docs/config/http.html
Java AJP Connector: /docs/config/ajp.html
APR (HTTP/AJP) Connector: /docs/apr.html
Define a non-SSL/TLS HTTP/1.1 Connector on port 8080
-->
<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
<!-- A "Connector" using the shared thread pool-->
<!--
<Connector executor="tomcatThreadPool"
port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
-->
<!-- Define a SSL/TLS HTTP/1.1 Connector on port 8443
This connector uses the NIO implementation. The default
SSLImplementation will depend on the presence of the APR/native
library and the useOpenSSL attribute of the
AprLifecycleListener.
Either JSSE or OpenSSL style configuration may be used regardless
of
the SSLImplementation selected. JSSE style configuration is used
below.
-->
<!-- -->
<Connector port="8443"
protocol="org.apache.coyote.http11.Http11Nio2Protocol"
maxThreads="150" SSLEnabled="true">
<SSLHostConfig>
<Certificate certificateKeystoreFile="/root/.keystore"
certificateKeystorePassword="password"
type="RSA" />
</SSLHostConfig>
</Connector>
<!-- -->
<!-- Define a SSL/TLS HTTP/1.1 Connector on port 8443 with HTTP/2
This connector uses the APR/native implementation which always uses
OpenSSL for TLS.
Either JSSE or OpenSSL style configuration may be used. OpenSSL
style
configuration is used below.
-->
<!--
<Connector port="8443"
protocol="org.apache.coyote.http11.Http11AprProtocol"
maxThreads="150" SSLEnabled="true" >
<UpgradeProtocol className="org.apache.coyote.http2.Http2Protocol"
/>
<SSLHostConfig>
<Certificate certificateKeyFile="conf/localhost-rsa-key.pem"
certificateFile="conf/localhost-rsa-cert.pem"
certificateChainFile="conf/localhost-rsa-chain.pem"
type="RSA" />
</SSLHostConfig>
</Connector>
-->
<!-- Define an AJP 1.3 Connector on port 8009 -->
<Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />
<!-- An Engine represents the entry point (within Catalina) that
processes
every request. The Engine implementation for Tomcat stand alone
analyzes the HTTP headers included with the request, and passes
them
on to the appropriate Host (virtual host).
Documentation at /docs/config/engine.html -->
<!-- You should set jvmRoute to support load-balancing via AJP ie :
<Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm1">
-->
<Engine name="Catalina" defaultHost="localhost">
<!--For clustering, please take a look at documentation at:
/docs/cluster-howto.html (simple how to)
/docs/config/cluster.html (reference documentation) -->
<!--
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
-->
<!-- Use the LockOutRealm to prevent attempts to guess user passwords
via a brute-force attack -->
<Realm className="org.apache.catalina.realm.LockOutRealm">
<!-- This Realm uses the UserDatabase configured in the global JNDI
resources under the key "UserDatabase". Any edits
that are performed against this UserDatabase are immediately
available for use by the Realm. -->
<Realm className="org.apache.catalina.realm.UserDatabaseRealm"
resourceName="UserDatabase"/>
</Realm>
<Host name="localhost" appBase="webapps"
unpackWARs="true" autoDeploy="true">
<!-- SingleSignOn valve, share authentication between web
applications
Documentation at: /docs/config/valve.html -->
<!--
<Valve className="org.apache.catalina.authenticator.SingleSignOn" />
-->
<!-- Access log processes all example.
Documentation at: /docs/config/valve.html
Note: The pattern used is equivalent to using pattern="common"
-->
<Valve className="org.apache.catalina.valves.AccessLogValve"
directory="logs"
prefix="localhost_access_log" suffix=".txt"
pattern="%h %l %u %t "%r" %s %b" />
</Host>
</Engine>
</Service>
</Server>
