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https://issues.apache.org/jira/browse/HTTPCORE-366?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13833852#comment-13833852
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Isaac Cruz Ballesteros commented on HTTPCORE-366:
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I'm just wondering, could it be caused by the timeout handling of the library?
Let's suppose the client is sending two packets of 16000 bytes, but due to
network issues, it sends 15000 bytes from first packet, and 1 minute later, the
remaining 1000 and the second packet.
If I'm setting CoreConnectionPNames.SO_TIMEOUT to 30 seconds, in the timeout
handler (AbstractIODispatch.timeout) the ssl session is shutdown (which is the
cause of status becoming CLOSED after 30 seconds), so the SSLEngine will no
longer decrypt data, as it's now waiting for a new handshake. This is ok except
the socket is not closed (please correct me if I'm wrong, I have not checked
the complete source but it seems so because during the infinite loop the socket
was in CLOSE_WAIT state), so it keeps calling the unwrap() to decrypt the
packet, and it will always fail even after the rest of the packet is received
(and at this point the inEncrypted buffer is full).
What do you think?
> Infinite loop when using HTTPS server + NIO
> -------------------------------------------
>
> Key: HTTPCORE-366
> URL: https://issues.apache.org/jira/browse/HTTPCORE-366
> Project: HttpComponents HttpCore
> Issue Type: Bug
> Components: HttpCore NIO
> Affects Versions: 4.2.5
> Reporter: Isaac Cruz Ballesteros
> Fix For: 4.3.1
>
> Attachments: HTTPCORE-366.patch
>
>
> This affects 4.2.5 but probably the newer versions as well.
> So I'm setting a HTTPS server using NIO to receive uploads from clients.
> Clients are using libcurl to upload.
> I've detected that sometimes (one every 2-4 days) the java process takes 100%
> cpu, and it's the "I/O dispatcher" thread which is in a infinite loop, with
> stack traces such as:
> "I/O dispatcher 1" prio=10 tid=0x00007f3e2400b000 nid=0x11c9 runnable
> [0x00007f3e3995e000]
> java.lang.Thread.State: RUNNABLE
> at
> org.apache.http.impl.nio.reactor.IOSessionImpl.getEventMask(IOSessionImpl.java:139)
> - locked <0x00000000e09f5a70> (a
> org.apache.http.impl.nio.reactor.IOSessionImpl)
> at
> org.apache.http.nio.reactor.ssl.SSLIOSession.updateEventMask(SSLIOSession.java:306)
> at
> org.apache.http.nio.reactor.ssl.SSLIOSession.inboundTransport(SSLIOSession.java:411)
> - locked <0x00000000e09f6938> (a
> org.apache.http.nio.reactor.ssl.SSLIOSession)
> at
> org.apache.http.impl.nio.reactor.AbstractIODispatch.inputReady(AbstractIODispatch.java:121)
> at
> org.apache.http.impl.nio.reactor.BaseIOReactor.validate(BaseIOReactor.java:220)
> at
> org.apache.http.impl.nio.reactor.AbstractIOReactor.execute(AbstractIOReactor.java:284)
> at
> org.apache.http.impl.nio.reactor.BaseIOReactor.execute(BaseIOReactor.java:106)
> at
> org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor$Worker.run(AbstractMultiworkerIOReactor.java:613)
> at java.lang.Thread.run(Thread.java:662)
> "I/O dispatcher 1" prio=10 tid=0x00007f01a000b000 nid=0x1f78 runnable
> [0x00007f01d1cf6000]
> java.lang.Thread.State: RUNNABLE
> at
> org.apache.http.nio.reactor.ssl.SSLIOSession.doHandshake(SSLIOSession.java:276)
> at
> org.apache.http.nio.reactor.ssl.SSLIOSession.isAppInputReady(SSLIOSession.java:381)
> - locked <0x00000000e08b5178> (a
> org.apache.http.nio.reactor.ssl.SSLIOSession)
> at
> org.apache.http.impl.nio.reactor.AbstractIODispatch.inputReady(AbstractIODispatch.java:118)
> at
> org.apache.http.impl.nio.reactor.BaseIOReactor.readable(BaseIOReactor.java:160)
> at
> org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvent(AbstractIOReactor.java:342)
> at
> org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvents(AbstractIOReactor.java:320)
> at
> org.apache.http.impl.nio.reactor.AbstractIOReactor.execute(AbstractIOReactor.java:280)
> at
> org.apache.http.impl.nio.reactor.BaseIOReactor.execute(BaseIOReactor.java:106)
> at
> org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor$Worker.run(AbstractMultiworkerIOReactor.java:613)
> at java.lang.Thread.run(Thread.java:662)
> The socket in the server side is in CLOSE_WAIT state, so the client closed
> the connection but not the server.
> I added some logs to the httpcore-nio library to try to know some details of
> when this issue happens, specifically in AbstractIODispatch.inputReady() and
> in several places in SSLIOSession, to print the SSLEngineResult after doWrap
> and doUnwrap in doHandshake() and decryptData() method, and also in
> isAppInputReady() to print bytesRead, inEncrypted buffer state, and
> HandshakeStatus.
> I'm going to explain what I found, if you want I can attach the complete
> generated logs.
> So after handshake and some data exchange, we start receiving data from
> client, and we keep getting a BUFFER_UNDERFLOW until the inEncrypted buffer
> is complete:
> 2013-11-26 02:59:37,914 [I/O dispatcher 1] ssl.SSLIOSession: bytesRead from
> socket: 1346, inEncrypted: java.nio.HeapByteBuffer[pos=16665 lim=16665
> cap=16665]
> 2013-11-26 02:59:37,915 [I/O dispatcher 1] ssl.SSLIOSession: result from
> unwrap: Status = OK HandshakeStatus = NOT_HANDSHAKING
> bytesConsumed = 16421 bytesProduced = 16384
> We produce 16384 bytes of user data, and from here we start receiving more
> data:
> 2013-11-26 02:59:37,915 [I/O dispatcher 1] ssl.SSLIOSession: bytesRead from
> socket: 34, inEncrypted: java.nio.HeapByteBuffer[pos=278 lim=16665 cap=16665]
> 2013-11-26 02:59:37,948 [I/O dispatcher 1] ssl.SSLIOSession: bytesRead from
> socket: 1380, inEncrypted: java.nio.HeapByteBuffer[pos=1658 lim=16665
> cap=16665]
> 2013-11-26 02:59:37,982 [I/O dispatcher 1] ssl.SSLIOSession: bytesRead from
> socket: 1380, inEncrypted: java.nio.HeapByteBuffer[pos=3038 lim=16665
> cap=16665]
> 2013-11-26 02:59:38,017 [I/O dispatcher 1] ssl.SSLIOSession: bytesRead from
> socket: 1380, inEncrypted: java.nio.HeapByteBuffer[pos=4418 lim=16665
> cap=16665]
> 2013-11-26 02:59:38,051 [I/O dispatcher 1] ssl.SSLIOSession: bytesRead from
> socket: 1380, inEncrypted: java.nio.HeapByteBuffer[pos=5798 lim=16665
> cap=16665]
> 2013-11-26 02:59:38,391 [I/O dispatcher 1] ssl.SSLIOSession: bytesRead from
> socket: 4140, inEncrypted: java.nio.HeapByteBuffer[pos=9938 lim=16665
> cap=16665]
> 2013-11-26 02:59:38,440 [I/O dispatcher 1] ssl.SSLIOSession: bytesRead from
> socket: 5520, inEncrypted: java.nio.HeapByteBuffer[pos=15458 lim=16665
> cap=16665]
> Between all these recvs we always get a BUFFER_UNDERFLOW from unwrap()
> From that time (note that the inEncrypted buffer is still not full) we stop
> receiving any data. For some reason there's a call to isAppInputReady() every
> second, which always do the same: bytesRead = 0, buffer_underflow. I don't
> know why this is called even though this channel hasn't been "selected" by
> select(), I think it comes from the validate() call in AbstractIOReactor line
> 284:
> // Validate active channels
> validate(this.selector.keys());
> But anyway, this isn't very important.
> The point is after 30 seconds from last packet sent, the client closes
> connection. This is probably a timeout, not sure, and I also don't understand
> why the server thinks it needs more data to decrypt, and why the client does
> not send more data if that's true.... In any case, after 30 seconds this is
> what happens:
> 2013-11-26 03:00:07,481 [I/O dispatcher 1] nio.DefaultHttpServerIODispatch:
> inputReady on 192.168.100.40:9443<->75.37.10.219:40186[ACTIVE][r:r]
> 2013-11-26 03:00:07,481 [I/O dispatcher 1] ssl.SSLIOSession: bytesRead from
> socket: 0, inEncrypted: java.nio.HeapByteBuffer[pos=15458 lim=16665 cap=16665]
> 2013-11-26 03:00:07,481 [I/O dispatcher 1] ssl.SSLIOSession: handshake
> status: NOT_HANDSHAKING
> 2013-11-26 03:00:07,481 [I/O dispatcher 1] ssl.SSLIOSession: result from
> unwrap: Status = BUFFER_UNDERFLOW HandshakeStatus = NOT_HANDSHAKING
> 2013-11-26 03:00:08,483 [I/O dispatcher 1] nio.DefaultHttpServerIODispatch:
> inputReady on 192.168.100.40:9443<->75.37.10.219:40186[ACTIVE][rw:r]
> 2013-11-26 03:00:08,483 [I/O dispatcher 1] ssl.SSLIOSession: bytesRead from
> socket: 0, inEncrypted: java.nio.HeapByteBuffer[pos=15458 lim=16665 cap=16665]
> 2013-11-26 03:00:08,483 [I/O dispatcher 1] ssl.SSLIOSession: result from
> wrap: Status = CLOSED HandshakeStatus = NEED_UNWRAP
> bytesConsumed = 0 bytesProduced = 37
> 2013-11-26 03:00:08,483 [I/O dispatcher 1] ssl.SSLIOSession: handshake
> status: NEED_UNWRAP
> From here it starts an infinite loop: it's calling continuously the
> inputReady() method, but it never closes the socket, it keeps getting status
> = BUFFER_UNDERFLOW when calling unwrap() and handshake status = NEED_UNWRAP
> (as the client has closed SSL session)
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