[NET-661] FTPSClient hang java.net.SocketInputStream.socketRead0 while doing SSL Handshake - Socket timeout not set

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.6
• Component/s: FTP
• Labels: SocketTimeout hang implicit socketRead0 ssl

Environment

Apache NET 3.6

 

#uname -a

Linux myhost 2.6.32-696.23.1.el6.x86_64 #1 SMP Sat Feb 10 11:10:31 EST 2018 x86_64 x86_64 x86_64 GNU/Linux

1. java -version

openjdk version "1.8.0_171"

OpenJDK Runtime Environment (build 1.8.0_171-b10)

OpenJDK 64-Bit Server VM (build 25.171-b10, mixed mode)

 

 

• Assignee: Unassigned
• Reporter: Dany Alain
• Created: 11/Jun/18 19:49
• Updated: 11/Jun/18 19:54

Description

In a lab with unstable connection we have our FTP client hanging forever (e.g. 36 hours -> base on our linux kernel configuration)

java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
at java.net.SocketInputStream.read(SocketInputStream.java:171)
at java.net.SocketInputStream.read(SocketInputStream.java:141)
at sun.security.ssl.InputRecord.readFully(InputRecord.java:465)
at sun.security.ssl.InputRecord.read(InputRecord.java:503)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:983)
locked <0x00000000ae243608> (a java.lang.Object)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1385)
locked <0x00000000ae243620> (a java.lang.Object)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1413)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1397)
at org.apache.commons.net.ftp.FTPSClient.sslNegotiation(FTPSClient.java:289)
at org.apache.commons.net.ftp.FTPSClient.connectAction(FTPSClient.java:220)
at org.apache.commons.net.SocketClient._connect(SocketClient.java:244)
at org.apache.commons.net.SocketClient.connect(SocketClient.java:202)
...

our code

final FTPSClient client = new FTPSClient("TLSv1.2", true);
// load the trust store& key store
client.setDataTimeout(1000);
client.setControlKeepAliveReplyTimeout(1000);
client.setControlKeepAliveTimeout(1000);
client.setDefaultTimeout(1000);
client.setConnectTimeout(1000);
client.connect(host, port); // hang randomly
client.setSoLinger(true, 10); // cannot be call before, socket is null
reply = client.getReplyCode();

After looking at the FTP, FTPSClient code and reading on internet I realize that in the case of an implicit connection the Socket is initialized with So timeout of 0 because "connectAction()" is overwritten

Socket.java

protected void connectAction() throws IOException
    socket.setSoTimeout(timeout);
    input = socket.getInputStream();
    output = socket.getOutputStream(); }

FTPSClient.java

@Override

protected void connectAction() throws IOException {

    // Implicit mode.
     if (isImplicit) {
         sslNegotiation(); // hangs at java.net.SocketInputStream.socketRead0(Native Method)
     }
     super.connectAction(); // setSoTimeout will be set here - but too late
     // Explicit mode.
     if (!isImplicit)
Unknown macro: {        execAUTH();      }
}

So workaround for now is to overwrite FTPSClient-> connectAction()

new FTPSClient(...)

Unknown macro: { @Override protected void _connectAction_() throws IOException   Unknown macro}

};