[NET-470] DataConnection-Socket hangs on InputStream.read()

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.0, 3.0.1, 3.1
• Component/s: FTP

Environment

Windows 7 (x86), Netbeans 7, JDK 1.6 and JDK 1.7

• Assignee: Unassigned
• Reporter: Alexander Schuetz
• Created: 13/Jun/12 08:45
• Updated: 19/May/14 15:22

Description

I'm using ftps (SSL/implicit) and passive mode. connect(), login() and cwd() commands work well.

But if I have to open a data connection (for example for LIST) the socket is opened successfully using one of the desired "dataports". The underlying InputStream is created as well without any Exception.
But then every attempt to read from the InputStream will eventually time out or hang forever (depending on the DataTimeout-value).

If I use the FileZilla client, everything works successfully and fast. FileZilla issues the following commands:

C: SYST
A: 215 UNIX Type: L8
C: FEAT
A: 211-Extensions supported
A: SIZE
A: REST
A: MDTM
A: MFMT YYYYMMDDHHMMSS filename
A: MDTM YYYYMMDDHHMMSS filename
A: MDTM YYYYMMDDHHMMSS[+-TZ] filename
A: XCRC filename
A: XMD5 filename
A: AUTH TLS
A: AUTH SSL
A: MODE Z
A: PBSZ
A: PROT
A: 211 End of FEAT
C: USER ********
A: 331 Password required for ********
C: PASS ********
A: 230 User ******** logged in
C: PBSZ 0
A: 200 PBSZ 0 successful
C: PROT P
A: 200 Data connection set to: Private
C: TYPE I
A: 200 TYPE set to BINARY
C: PASV
A: 227 Entering passive mode (217,70,161,93,39,15)
C: LIST
A: 150 Opening ASCII mode data connection
A: 226 Directory send OK

Issueing the commands "PBSZ 0" and "PROT P" before and calling enterLocalPassiveMode() and setFileType(FTP.BINARY_FILE_TYPE) will produce the same commandsequence (without SYST and FEAT), but with the error described above.

On top of that: disconnect() will block forever, originating from socket.close() which is blocking. The only way to avoid this is calling logout() (even if login() wasn't issued). Then disconnect will return as expected.