Re: [PATCH] svcgss: reply AUTH_BADCRED to RPCSEC_GSS with unkown services

Wei Yongjun
2009-08-28T00:56:32Z

J. Bruce Fields wrote:
> On Thu, Aug 27, 2009 at 12:26:23PM -0400, bfields wrote:
>
>> On Thu, Aug 27, 2009 at 10:23:39AM +0800, Wei Yongjun wrote:
>>
>>> Hi J. Bruce Fields,
>>>
>>> J. Bruce Fields wrote:
>>>
>>>> On Wed, Aug 26, 2009 at 08:34:39AM +0800, Wei Yongjun wrote:
>>>>
>>>>
>>>>> J. Bruce Fields wrote:
>>>>>
>>>>>
>>>>>> On Tue, Aug 04, 2009 at 05:27:52PM +0800, Wei Yongjun wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>> When RPC messages is received with RPCSEC_GSS, and if the RPCSEC_GSS
>>>>>>> include unkown services (not RPC_GSS_SVC_NONE, RPC_GSS_SVC_INTEGRITY
>>>>>>> and RPC_GSS_SVC_PRIVACY), the response is considered as AUTH_BADCRED
>>>>>>> in svcauth_gss_accept(), but the response be drop by
>>>>>>> svcauth_gss_release(). I think response with AUTH_BADCRED is correct
>>>>>>> one. So this patch fixed it.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> Thanks! How did you find this? (And how did you test the result?)
>>>>>>
>>>>>>
>>>>>>
>>>>> I test this used newpynfs, the GSS8 item test for this.
>>>>> #./testserver.py nfsserver:/ --security=krb5 GSS8
>>>>>
>>>>>
>>>> Oh, OK--I thought I'd been running the pynfs gss tests, but now I see
>>>> that I haven't been; I've fixed my test scripts.... Thanks!--b.
>>>>
>>>>
>>> Did you test the test case for write? In the old kernel, there was only one
>>> test case WRT5 is FAILURE, but in current kernel, the test cases after
>>> WRT5 are all fail, the result like the following:
>>> WRT1 st_write.testSimpleWrite : PASS
>>> WRT1b st_write.testSimpleWrite2 : PASS
>>> WRT2 st_write.testStateidOne : PASS
>>> WRT3 st_write.testWithOpen : PASS
>>> WRT4 st_write.testNoData : PASS
>>> WRT5 st_write.testLargeData : FAILURE
>>> timed out
>>>
>> I'm not seeing exactly this, but am seeing timeouts in other tests now
>> that I'm running pynfs tests over gss--it may have the same root cause.
>> Unfortunately, your patch doesn't seem to fix the failures I'm seeing.
>>
>>
>>> WRT6a st_write.testLink : FAILURE
>>> timed out
>>> WRT6c st_write.testChar : FAILURE
>>> timed out
>>> WRT6d st_write.testDir : FAILURE
>>> timed out
>>> WRT6f st_write.testFifo : FAILURE
>>> timed out
>>> WRT6s st_write.testSocket : FAILURE
>>> timed out
>>> WRT7 st_write.testNoFh : FAILURE
>>> timed out
>>> WRT8 st_write.testOpenMode : FAILURE
>>> timed out
>>> WRT9 st_write.testShareDeny : FAILURE
>>> timed out
>>> WRT10 st_write.testBadStateid : FAILURE
>>> timed out
>>> WRT11 st_write.testStaleStateid : FAILURE
>>> timed out
>>> WRT12 st_write.testOldStateid : FAILURE
>>> timed out
>>>
>>> Case WRT5 fail because the RPC TCP fragment issue. But the rest test
>>> cases are fail seems after this patch:
>>> svc: Move close processing to a single place
>>>
>>> http://git.kernel.org/?p=linux/kernel/git/davem/net-2.6.git;a=commitdiff;h=d7979ae4a050a45b78af51832475001b68263d2a
>>>
>>> Old kernel will close the xprt after receive error. But new code is
>>> check before
>>> receive, and can nerver enter the check for CLOSE state.
>>>
>>> Can you have a look at this patch?
>>>
>> OK, thanks, that makes sense. I won't to investigate a little more
>> before applying, though.
>>
>
> Bah, it looks like I was just seeing a disagreement between pynfs and
> nfsd about whether the sequence number should be incremented in the case
> of an otherwise correct packet with a bad gss_service, which means that
> after running GSS8, any subsequent requests with the same context are
> dropped (and time out).
>
> Since this sitaution is of no practical interest whatsoever (I can't
> see why we'd ever see a request that was broken in this particular way),
> I think the correct solution is to just stop running GSS8....
>

When I test, I just fixed the GSS8 with this patch:

diff --git a/lib/nfs4/servertests/st_gss.py b/lib/nfs4/servertests/st_gss.py
index 6ad3e3e..dfff598 100644
--- a/lib/nfs4/servertests/st_gss.py
+++ b/lib/nfs4/servertests/st_gss.py
@@ -330,4 +330,5 @@ def testBadService(t, env):
"should return AUTH_BADCRED, instead got %s" %
(service, e))
finally:
+ orig.gss_seq_num = c.security.gss_seq_num
c.security = orig

I am not have a test of all the case with --security=krb5, just test
the gss. This is because the krb server does not always works well.^_^

> (This is the problem with spending a lot of time on pynfs tests.
> They've been useful for catching regressions, but there's a risk of
> spending too much time tracking down "problems" that won't actually show
> up in real situations. Time would usually be better spent on bugs
> (and/or performance problems) found in actual use.)
>