Random failure while communicating with KDC

[Russ Allbery]

sowmya <sowmya_ambale at yahoo.com> writes:

> We are seeing this also but only when communicating with an IPv6 KDC.
> In our case, is a Windows 2008 and client is linux x86_64.

> I enabled some tracing and found that inside service_tcp_fd, it gets to 

> case WRITING and I see the following prints:

> trying to writev 2 (194 bytes) to fd 13
> wrote 194 bytes
> switching fd 13 to READING

> Then in service_fds function, where service_tcp_fd gets invoked again,
> ssflags is set to 5.  And the exception returned is

> socket error on exception fd for fd 13: Operation now in progress

> We are using krb5-1.10.3 which is what comes with fedora 18.

The function is returning EINPROGRESS.

That's kind of a weird error for read to return.  Normally it would return
EAGAIN or EWOULDBLOCK.  Usually EINPROGRESS is returned by connect.  Maybe
it's actually connecting, not reading?  Then that error would make more
sense.

Regardless, the answer is that the network operation hasn't completed yet.

Are you driving the Kerberos operation using the lower-level functions
using file descriptors that you've provided?  This is the sort of behavior
that I'd expect if you were doing that using file descriptors that you'd
set to non-blocking.

-- 
Russ Allbery (eagle at eyrie.org)              <http://www.eyrie.org/~eagle/>