Claus, Having looked a bit more at the commons-net code it's becoming clear to me that you probably can't just reconnect an FTPSClient once it has entered secure communication mode. I can't find a way to re-initialise an FTPSClient. I tried the disconnect() method (in the super class FTPClient) but it didn't get the FTPSClient out of secure communication mode.
To be safe I think we should always start with a newly instantiated FTPSClient when we try to connect. Today the FTPSClient is created by the FtpsEndpoint. I don't think it has to. It could just get all the righ configuration parameters and pass it to FtpsOperations which would then instantiate a new FTPSClient at every connect attempt. If we do it this way for ftps I guess it would make sense with the same setup for plain ftp. What do you think? /Bengt 2010/6/17 Bengt Rodehav <[email protected]> > Claus, > > Yeah, maybe this is a commons-net issue. As always I find it surprising > that no one else has encountered this problem. > > As I started writing an email on the commons user list, I took another look > at the code in commons-net. It turns out that the FTPSSocketFactory class > actually does override the createSocket() methods in SocketFactory. A > similar work-around that I was talking about but on the factory class > instead of in the SocketClient class. FTPSSocketFactory delegates the > createSocket() calls to its SSLContect's socket factory. > > So why then are we initially able to connect but not after we have called > execProt() and thus changed the connection factory? > > Moving back to the FTPSClient class now. When the initial connection is up, > the _connectAction() method is called. It in turn calls sslNegotiation() > which in turn sets up the secure socket. In the sslNegotiation() method, an > SSLSocketFactory is not instantiated directly. It is given by the > SSLContext's getSocketFactory() method. This connection factory obviously > works otherwise the secure connection wouldn't work even initially. > > Compare this with what's being done in the execProt() method. Here the > FTPSSocketFactory is instantiated directly with the SSLContext passed as a > constructor argument. Obviously this factory does NOT work... > > Another question that comes to mind is why the socket factory created in > the sslNegotiation() method is NOT set as the SocketClient's socket factory > but the one created in the execProt() method is? It turns out that > execProt() calls a generic sendCommand() method that sends the command and > if the reply is OK, then sets the socket factory to null! One wonders why > (and there is also a comment in the code: "Check this - is this necessary at > all?"). Anyway, this is probably the reason why execProt() needs to "reset" > the connection factory. > > Still sounds like a commons-net problem though. I'll try to post this at > their user mailing list. > > Just one thought. Do we need to reuse the FTPSClient instance? Can't we > just create a fresh new instance everytime we need to connect? > > /Bengt > > > > 2010/6/17 Claus Ibsen <[email protected]> > > Hi Bengt >> >> I think the issue should be created as a ticket for Apache Commons >> Net. Then at least the people there can take a look, and maybe they >> got some ideas. And can fix it in a future release. >> >> Bengt fell free to experiment yourself with the subclassing, as it >> sounds like a good workaround. >> >> I assume the FTPSClient doesn't offer other methods to re connect >> which can recover this error? >> >> >> On Wed, Jun 16, 2010 at 2:44 PM, Bengt Rodehav <[email protected]> wrote: >> > I have mentioned this problem in a previous conversation but after >> > investigating the subject further I decided to start a new thread for >> this. >> > >> > If some kind of problem is encountered while using ftps (I tested this >> using >> > Filezilla server by copying a file that already existed which Filezilla >> does >> > not allow), then at the next attempt to connect to the ftps server, I >> get >> > the following exception in my logfile: >> > >> > 13:03:27,606 | ERROR | %7Bfile%3Aext%7D | GenericFileOnCompletion >> | >> > rg.apache.camel.processor.Logger 248 | Caused by: >> > [org.apache.camel.component.file.GenericFileOperationFailedException - >> File >> > operation failed: null Unconnected sockets not implemented. Code: 221] >> > org.apache.camel.component.file.GenericFileOperationFailedException: >> File >> > operation failed: null Unconnected sockets not implemented. Code: 221 >> > at >> > >> org.apache.camel.component.file.remote.FtpOperations.connect(FtpOperations.java:108)[76:org.apache.camel.camel-ftp:2.4.0.SNAPSHOT] >> > at >> > >> org.apache.camel.component.file.remote.FtpsOperations.connect(FtpsOperations.java:40)[76:org.apache.camel.camel-ftp:2.4.0.SNAPSHOT] >> > at >> > >> org.apache.camel.component.file.remote.RemoteFileProducer.connectIfNecessary(RemoteFileProducer.java:170)[76:org.apache.camel.camel-ftp:2.4.0.SNAPSHOT] >> > at >> > >> org.apache.camel.component.file.remote.RemoteFileProducer.preWriteCheck(RemoteFileProducer.java:123)[76:org.apache.camel.camel-ftp:2.4.0.SNAPSHOT] >> > at >> > >> org.apache.camel.component.file.GenericFileProducer.processExchange(GenericFileProducer.java:75)[65:org.apache.camel.camel-core:2.4.0.SNAPSHOT] >> > at >> > >> org.apache.camel.component.file.remote.RemoteFileProducer.process(RemoteFileProducer.java:49)[76:org.apache.camel.camel-ftp:2.4.0.SNAPSHOT] >> > at >> > >> org.apache.camel.processor.SendProcessor$1.doInProducer(SendProcessor.java:91)[65:org.apache.camel.camel-core:2.4.0.SNAPSHOT] >> > >> > I added some logging to see the actual stack trace which is: >> > >> > java.net.SocketException: Unconnected sockets not implemented >> > at javax.net.SocketFactory.createSocket(SocketFactory.java:104) >> > at >> > org.apache.commons.net.SocketClient.connect(SocketClient.java:175) >> > at >> > >> org.apache.camel.component.file.remote.FtpOperations.connect(FtpOperations.java:91) >> > at >> > >> org.apache.camel.component.file.remote.FtpsOperations.connect(FtpsOperations.java:40) >> > at >> > >> org.apache.camel.component.file.remote.RemoteFileProducer.connectIfNecessary(RemoteFileProducer.java:170) >> > at >> > >> org.apache.camel.component.file.remote.RemoteFileProducer.preWriteCheck(RemoteFileProducer.java:99) >> > at >> > >> org.apache.camel.component.file.GenericFileProducer.processExchange(GenericFileProducer.java:75) >> > at >> > >> org.apache.camel.component.file.remote.RemoteFileProducer.process(RemoteFileProducer.java:49) >> > >> > commons-net SocketClient class tries to call the socket factory's >> > createSocket() method (with no parameters): >> > >> > _socket_= _socketFactory_.createSocket(); >> > _socket_.connect(new InetSocketAddress(hostname, port), >> > connectTimeout); >> > >> > Then intention is to create an "unconnected socket" (hence the error >> > message) and then subsequently connect it. In my case, the connection >> > factory being used is an FTPSSocketFactory >> > (package org.apache.commons.net.ftp) that inherits from >> > SocketFactory(package javax.net). The SocketFactory class implements >> the >> > createSocket() method but throws the exception ("Unconnected sockets not >> > implemented"). >> > >> > The reason why this happens is that after having executed the >> > FTPSClient.execPROT() method (package org.apache.commons.net.ftp), with >> any >> > other parameter than "C" (in my case I used "P"), the socket factory is >> set >> > to an FTPSSocketFactory as follows: >> > >> > setSocketFactory(new FTPSSocketFactory(context)); >> > >> > After this, no connection attempt will succeed. This problem has been >> > introduced recently when Claus (on my initiative) added support for >> secure >> > data channel in ftps. I'm thus to blame... >> > >> > I'm not sure how this should be fixed. >> > >> > It's a bit strange that all the connect methods >> > in org.apache.commons.net.SocketClient (which is the ultimate base class >> of >> > FTPSClient) always try to create an unconnected socket first and then >> > connects it. If commons-net uses this pattern, then it should make sure >> that >> > all its connection factor's support unconnected sockets but the >> > FTPSSocketFactory dosn't. This sounds like a bug in commons-net. >> > >> > Knowing that commons-net doesn't release very frequently I think we need >> a >> > workaround for this. I guess it would be possible to subclass the >> FTPClient >> > class and override all the connect methods to make sure that no attempt >> is >> > made to create unconnected sockets. We would then change the >> > createFtpClient() method in the FtpsEndpoint class to instantiate our >> own >> > subclass instead of an FTPSClient. Doesn't sound like a nice clean >> solution >> > though. >> > >> > Any ideas? >> > >> > /Bengt >> > >> >> >> >> -- >> Claus Ibsen >> Apache Camel Committer >> >> Author of Camel in Action: http://www.manning.com/ibsen/ >> Open Source Integration: http://fusesource.com >> Blog: http://davsclaus.blogspot.com/ >> Twitter: http://twitter.com/davsclaus >> > >
