Add CCC command support to ftplib #56348

giampaolo · 2011-05-21T18:09:00Z

BPO	12139
Nosy	@pitrou, @vstinner, @giampaolo
Files	ftplib-ccc.patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/giampaolo'
closed_at = <Date 2011-06-30.16:36:03.170>
created_at = <Date 2011-05-21.18:09:00.154>
labels = ['type-feature']
title = 'Add CCC command support to ftplib'
updated_at = <Date 2011-06-30.16:36:03.169>
user = 'https://github.com/giampaolo'

bugs.python.org fields:

activity = <Date 2011-06-30.16:36:03.169>
actor = 'giampaolo.rodola'
assignee = 'giampaolo.rodola'
closed = True
closed_date = <Date 2011-06-30.16:36:03.170>
closer = 'giampaolo.rodola'
components = []
creation = <Date 2011-05-21.18:09:00.154>
creator = 'giampaolo.rodola'
dependencies = []
files = ['22052']
hgrepos = []
issue_num = 12139
keywords = ['patch']
message_count = 10.0
messages = ['136459', '136463', '136465', '139250', '139252', '139253', '139254', '139493', '139499', '139501']
nosy_count = 4.0
nosy_names = ['pitrou', 'vstinner', 'giampaolo.rodola', 'python-dev']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue12139'
versions = ['Python 3.3']

giampaolo · 2011-05-21T18:08:59Z

In FTPS, CCC command can be used to switch back to a clear-text control connection.
This can be useful to take advantage of firewalls that know how to handle NAT with non-secure FTP without opening fixed ports.
Patch in attachment includes lib, test and doc changes.

pitrou · 2011-05-21T18:19:45Z

This can be useful to take advantage of firewalls that know how to
handle NAT with non-secure FTP without opening fixed ports.

Can you explain this a little more?

+ resp = self.voidcmd('CCC')
+ self.sock = self.sock.unwrap()
+ return resp

Should the response be checked before calling unwrap()?

giampaolo · 2011-05-21T19:08:17Z

voidcmd() expects a response code starting with "2" and automatically raises an exception otherwise.
A server succesfully accepting the CCC command is supposed to first reply with 220 and then shutdown() the SSL layer.
Client is supposed to do the same: first receive the 2xx response and then make the shutdown().

python-dev · 2011-06-27T09:17:58Z

New changeset d2eacbbdaf57 by Giampaolo Rodola' in branch 'default':
bpo-12139: add CCC command support to FTP_TLS class to revert the SSL connection back to clear-text.
http://hg.python.org/cpython/rev/d2eacbbdaf57

vstinner · 2011-06-27T09:58:00Z

http://www.python.org/dev/buildbot/all/builders/x86%20Ubuntu%20Shared%203.x/builds/4043/steps/test/logs/stdio

======================================================================
ERROR: test_ccc (test.test_ftplib.TestTLS_FTPClass)
----------------------------------------------------------------------

Traceback (most recent call last):
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/test/test_ftplib.py", line 890, in test_ccc
    self.client.sendcmd('noop')
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/ftplib.py", line 261, in sendcmd
    return self.getresp()
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/ftplib.py", line 236, in getresp
    raise error_proto(resp)
ftplib.error_proto: ��� Ôxéî¢��Ö®�º¸qh�Ñ�øcÞ�Å\³9úÓ�#ï�å200 noop ok

vstinner · 2011-06-27T09:58:22Z

http://www.python.org/dev/buildbot/all/builders/x86%20Tiger%203.x/builds/2792/steps/test/logs/stdio

======================================================================
ERROR: test_ccc (test.test_ftplib.TestTLS_FTPClass)
----------------------------------------------------------------------

Traceback (most recent call last):
  File "/Users/db3l/buildarea/3.x.bolen-tiger/build/Lib/test/test_ftplib.py", line 890, in test_ccc
    self.client.sendcmd('noop')
  File "/Users/db3l/buildarea/3.x.bolen-tiger/build/Lib/ftplib.py", line 261, in sendcmd
    return self.getresp()
  File "/Users/db3l/buildarea/3.x.bolen-tiger/build/Lib/ftplib.py", line 226, in getresp
    resp = self.getmultiline()
  File "/Users/db3l/buildarea/3.x.bolen-tiger/build/Lib/ftplib.py", line 212, in getmultiline
    line = self.getline()
  File "/Users/db3l/buildarea/3.x.bolen-tiger/build/Lib/ftplib.py", line 199, in getline
    line = self.file.readline()
  File "/Users/db3l/buildarea/3.x.bolen-tiger/build/Lib/socket.py", line 279, in readinto
    return self._sock.recv_into(b)
  File "/Users/db3l/buildarea/3.x.bolen-tiger/build/Lib/ssl.py", line 392, in recv_into
    return socket.recv_into(self, buffer, nbytes, flags)
socket.timeout: timed out

giampaolo · 2011-06-27T10:01:30Z

Hmm... Reopening. I'll look into this later.

vstinner · 2011-06-30T15:21:46Z

The test is still failing on many buildbots.

x86 Ubuntu Shared 3.x:

======================================================================
ERROR: test_ccc (test.test_ftplib.TestTLS_FTPClass)
----------------------------------------------------------------------

Traceback (most recent call last):
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/test/test_ftplib.py", line 890, in test_ccc
    self.client.sendcmd('noop')
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/ftplib.py", line 261, in sendcmd
    return self.getresp()
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/ftplib.py", line 236, in getresp
    raise error_proto(resp)
ftplib.error_proto: ��� �eÊc¯�öZÖ8N´��ýùô

"PPC Tiger 3.x", "AMD64 Leopard 3.x", "x86 FreeBSD 6.4 3.x" and "x86 Tiger 3.x":

======================================================================
ERROR: test_ccc (test.test_ftplib.TestTLS_FTPClass)
----------------------------------------------------------------------

Traceback (most recent call last):
  File "/Users/pythonbuildbot/buildarea/3.x.hansen-osx-x86-2/build/Lib/test/test_ftplib.py", line 890, in test_ccc
    self.client.sendcmd('noop')
  File "/Users/pythonbuildbot/buildarea/3.x.hansen-osx-x86-2/build/Lib/ftplib.py", line 261, in sendcmd
    return self.getresp()
  File "/Users/pythonbuildbot/buildarea/3.x.hansen-osx-x86-2/build/Lib/ftplib.py", line 226, in getresp
    resp = self.getmultiline()
  File "/Users/pythonbuildbot/buildarea/3.x.hansen-osx-x86-2/build/Lib/ftplib.py", line 212, in getmultiline
    line = self.getline()
  File "/Users/pythonbuildbot/buildarea/3.x.hansen-osx-x86-2/build/Lib/ftplib.py", line 199, in getline
    line = self.file.readline()
  File "/Users/pythonbuildbot/buildarea/3.x.hansen-osx-x86-2/build/Lib/socket.py", line 279, in readinto
    return self._sock.recv_into(b)
  File "/Users/pythonbuildbot/buildarea/3.x.hansen-osx-x86-2/build/Lib/ssl.py", line 392, in recv_into
    return socket.recv_into(self, buffer, nbytes, flags)
socket.timeout: timed out

giampaolo · 2011-06-30T16:25:26Z

The culprit here is the dummy FTP test server which does not complete the SSL shutdown procedure successfully.

I believe it's better if we remove the self.client.sendcmd('noop') line.

That's there in order to check that client and server can still "talk" after reverting the connection back to clear-text, but making the server doing this right is quite complicated, see for example:
http://code.google.com/p/pyftpdlib/source/browse/trunk/pyftpdlib/contrib/handlers.py?spec=svn868&r=861#196

I don't want to include and maintain that monster into test_ftplib.py so I think I'll just remove that line from the tests.

python-dev · 2011-06-30T16:34:53Z

New changeset 0cef8cac71c8 by Giampaolo Rodola' in branch 'default':
bpo-12139: ftplib - remove 'post CCC' test to fix various buildot failures due to dummy test server not properly handling SSL shutdown(), see http://bugs.python.org/msg139499
http://hg.python.org/cpython/rev/0cef8cac71c8

giampaolo self-assigned this May 21, 2011

giampaolo added the type-feature A feature request or enhancement label May 21, 2011

giampaolo closed this as completed Jun 27, 2011

giampaolo reopened this Jun 27, 2011

giampaolo closed this as completed Jun 30, 2011

ezio-melotti transferred this issue from another repository Apr 10, 2022

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Add CCC command support to ftplib #56348

Add CCC command support to ftplib #56348

giampaolo commented May 21, 2011

giampaolo commented May 21, 2011

pitrou commented May 21, 2011

giampaolo commented May 21, 2011

python-dev mannequin commented Jun 27, 2011

vstinner commented Jun 27, 2011

vstinner commented Jun 27, 2011

giampaolo commented Jun 27, 2011

vstinner commented Jun 30, 2011

giampaolo commented Jun 30, 2011

python-dev mannequin commented Jun 30, 2011

Add CCC command support to ftplib #56348

Add CCC command support to ftplib #56348

Comments

giampaolo commented May 21, 2011

giampaolo commented May 21, 2011

pitrou commented May 21, 2011

giampaolo commented May 21, 2011

python-dev mannequin commented Jun 27, 2011

vstinner commented Jun 27, 2011

vstinner commented Jun 27, 2011

giampaolo commented Jun 27, 2011

vstinner commented Jun 30, 2011

giampaolo commented Jun 30, 2011

python-dev mannequin commented Jun 30, 2011