Bug 974940
| Summary: | Python client unexpected exception after ACL denial | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Product: | Red Hat Enterprise MRG | Reporter: | Pavel Moravec <pmoravec> | ||||||||
| Component: | python-qpid | Assignee: | Pavel Moravec <pmoravec> | ||||||||
| Status: | CLOSED ERRATA | QA Contact: | Zdenek Kraus <zkraus> | ||||||||
| Severity: | low | Docs Contact: | |||||||||
| Priority: | medium | ||||||||||
| Version: | 2.3 | CC: | jross, pmoravec, zkraus | ||||||||
| Target Milestone: | 3.1 | Keywords: | Patch, TestCaseProvided, WorkAround | ||||||||
| Target Release: | --- | ||||||||||
| Hardware: | All | ||||||||||
| OS: | All | ||||||||||
| Whiteboard: | |||||||||||
| Fixed In Version: | python-qpid-0.30-2 | Doc Type: | Bug Fix | ||||||||
| Doc Text: |
It was discovered that an repeated, unexpected exception was raised by an attempt to manipulate a session with either a (closed) session or (open) connection in Python client, after an execution exception closed the session. The exception handling is now improved in such a way that the exception is cleared after it is raised for the first time. Attempts to close the session or connection no longer re-triggers the exception.
|
Story Points: | --- | ||||||||
| Clone Of: | Environment: | ||||||||||
| Last Closed: | 2015-04-14 13:46:36 UTC | Type: | Bug | ||||||||
| Regression: | --- | Mount Type: | --- | ||||||||
| Documentation: | --- | CRM: | |||||||||
| Verified Versions: | Category: | --- | |||||||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||||||
| Embargoed: | |||||||||||
| Attachments: |
|
||||||||||
Created attachment 761952 [details]
reproducer
Created attachment 765524 [details] Simple reproducer Two types of changes were required to /usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py: A) reset session error variable in session.close as it is not further relevant: @@ -736,6 +736,7 @@ class Session(Endpoint): """ Close the session. """ + self.error = None self.sync(timeout=timeout) for link in self.receivers + self.senders: B) fixing just the above, the client / reproducer is stuck with traceback: Traceback (most recent call last): File "bz974940.py", line 19, in <module> session.close() File "<string>", line 6, in close File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 748, in close link.close(timeout=timeout) File "<string>", line 6, in close File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 1056, in close if not self.session._ewait(lambda: self.closed, timeout=timeout): File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 566, in _ewait result = self.connection._ewait(lambda: self.error or predicate(), timeout) File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 208, in _ewait result = self._wait(lambda: self.error or predicate(), timeout) File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 193, in _wait return self._waiter.wait(predicate, timeout=timeout) File "/usr/lib/python2.6/site-packages/qpid/concurrency.py", line 57, in wait self.condition.wait(3) File "/usr/lib/python2.6/site-packages/qpid/concurrency.py", line 96, in wait sw.wait(timeout) File "/usr/lib/python2.6/site-packages/qpid/compat.py", line 53, in wait ready, _, _ = select([self], [], [], timeout) As receiver on closed session is attempted to be closed. Hence the additional "if not self.session.closed:" added to both Receiver and Sender close methods Created attachment 765525 [details] Simple patch Two types of changes were required to /usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py: A) reset session error variable in session.close as it is not further relevant: @@ -736,6 +736,7 @@ class Session(Endpoint): """ Close the session. """ + self.error = None self.sync(timeout=timeout) for link in self.receivers + self.senders: B) fixing just the above, the client / reproducer is stuck with traceback: Traceback (most recent call last): File "bz974940.py", line 19, in <module> session.close() File "<string>", line 6, in close File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 748, in close link.close(timeout=timeout) File "<string>", line 6, in close File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 1056, in close if not self.session._ewait(lambda: self.closed, timeout=timeout): File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 566, in _ewait result = self.connection._ewait(lambda: self.error or predicate(), timeout) File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 208, in _ewait result = self._wait(lambda: self.error or predicate(), timeout) File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 193, in _wait return self._waiter.wait(predicate, timeout=timeout) File "/usr/lib/python2.6/site-packages/qpid/concurrency.py", line 57, in wait self.condition.wait(3) File "/usr/lib/python2.6/site-packages/qpid/concurrency.py", line 96, in wait sw.wait(timeout) File "/usr/lib/python2.6/site-packages/qpid/compat.py", line 53, in wait ready, _, _ = select([self], [], [], timeout) As receiver on closed session is attempted to be closed. Hence the additional "if not self.session.closed:" added to both Receiver and Sender close methods Resetting devel and 2.4.0 flags as both reproducer & patch is available. I'd love to accept this, especially since you've done the work for it. But we're short on QE time, so we'll have to take it for a later release, unless you have some other reason to elevate its priority. (In reply to Pavel Moravec from comment #4) > Resetting devel and 2.4.0 flags as both reproducer & patch is available. automated tests found one failing test, see https://reviews.apache.org/r/14466/. Committed upstream in r1534643. Tested on RHEL 6.6 i686 and x86_64 with following packages: python-qpid-0.30-2 python-qpid-qmf-0.30-2 qpid-cpp-client-0.30-4 qpid-cpp-client-devel-0.30-4 qpid-cpp-client-devel-docs-0.30-4 qpid-cpp-debuginfo-0.30-4 qpid-cpp-server-0.30-4 qpid-cpp-server-devel-0.30-4 qpid-cpp-server-linearstore-0.30-4 qpid-cpp-server-xml-0.30-4 qpid-java-client-0.30-3 qpid-java-common-0.30-3 qpid-java-example-0.30-3 qpid-jca-0.22-2 qpid-jca-xarecovery-0.22-2 qpid-proton-c-0.8-1 qpid-qmf-0.30-2 qpid-tools-0.30-3 Fix works as expected. -> VERIFIED Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHEA-2015-0805.html |
Description of problem: After ACL denies a command from qpid Python client, an attempt to close either session or connection raises unexpected exception (relevant to ACL, though). While at that time, session is properly closed and connection is working fine. Version-Release number of selected component (if applicable): python-qpid-0.18-4.el6.noarch How reproducible: 100% Steps to Reproduce: 1. Have ACL file: acl deny all consume all acl allow all all 2. Run attached script. Actual results: ---------------------------------------------------------------------------------------------------- Create receiver failed with exception Traceback (most recent call last): File "ACL_denial_session-hang.py", line 13, in <module> recv = session.receiver('testQ; {create:always}') File "<string>", line 6, in receiver File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 616, in receiver receiver._ewait(lambda: receiver.linked) File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 973, in _ewait result = self.session._ewait(lambda: self.error or predicate(), timeout) File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 567, in _ewait self.check_error() File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 556, in check_error raise self.error UnauthorizedAccess: unauthorized-access: ACL denied Queue subscribe request from guest@QPID (qpid/broker/SessionAdapter.cpp:399)(403) ---------------------------------------------------------------------------------------------------- Session close failed with exception Traceback (most recent call last): File "ACL_denial_session-hang.py", line 19, in <module> session.close() File "<string>", line 6, in close File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 739, in close self.sync(timeout=timeout) File "<string>", line 6, in sync File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 731, in sync if not self._ewait(lambda: not self.outgoing and not self.acked, timeout=timeout): File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 567, in _ewait self.check_error() File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 556, in check_error raise self.error UnauthorizedAccess: unauthorized-access: ACL denied Queue subscribe request from guest@QPID (qpid/broker/SessionAdapter.cpp:399)(403) ---------------------------------------------------------------------------------------------------- Connection close failed with exception Traceback (most recent call last): File "ACL_denial_session-hang.py", line 25, in <module> connection.close() File "<string>", line 6, in close File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 316, in close ssn.close(timeout=timeout) File "<string>", line 6, in close File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 739, in close self.sync(timeout=timeout) File "<string>", line 6, in sync File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 731, in sync if not self._ewait(lambda: not self.outgoing and not self.acked, timeout=timeout): File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 567, in _ewait self.check_error() File "/usr/lib/python2.6/site-packages/qpid/messaging/endpoints.py", line 556, in check_error raise self.error UnauthorizedAccess: unauthorized-access: ACL denied Queue subscribe request from guest@QPID (qpid/broker/SessionAdapter.cpp:399)(403) Expected results: Just the first exception is printed - when the "session.receiver" fails due to ACL. Additional info: Some hints for fixing it: - session object is properly closed. Just an attempt to close it again raises that exception. When trying to close a closed session without an ACL deny, no exception is raised - connection object is properly working and closing it really closes the AMQP connection. And the connection object can be normally used later on. - it seems to me like: a) exception raised and stored somewhere b) program catches it c) Python library should delete it from the stored place / variable but it does not do so d) any action on affected session/connection first checks for the stored exception, finds it so re-raises it Workaround: try: # this should fail - ACL does not allow this recv = session.receiver('testQ; {create:always}') except Exception as e1: try: session.close() except Exception as e2: "if e2 is ACL exception, then:" session = connection.session() .. "else close connection"