[ovs-dev] [PATCH] system-traffic: Use NC_EOF_OPT in truncate tests.

[Joe Stringer]

On 11 July 2016 at 12:37, Guru Shetty <guru at ovn.org> wrote:
> On 11 July 2016 at 11:50, Andy Zhou <azhou at ovn.org> wrote:
>
>> On Mon, Jul 11, 2016 at 11:44 AM, Guru Shetty <guru at ovn.org> wrote:
>>
>> >
>> >
>> > On 11 July 2016 at 11:41, Andy Zhou <azhou at ovn.org> wrote:
>> >
>> >>
>> >>
>> >> On Mon, Jul 11, 2016 at 11:28 AM, Guru Shetty <guru at ovn.org> wrote:
>> >>
>> >>> On 11 July 2016 at 10:29, Joe Stringer <joe at ovn.org> wrote:
>> >>>
>> >>> > NC_EOF_OPT should always be passed to netcat in system-traffic tests
>> >>> > when invoking netcat to send a single packet that does not expect a
>> >>> > response. While on typical fedora/RH based distributions the default
>> >>> > behaviour is to send the packet then return, there are multiple other
>> >>> > implementations of netcat that do not do this (for example, those
>> used
>> >>> > by Debian and Ubuntu by default). For these alternative
>> >>> implementations,
>> >>> > we provide $NC_EOF_OPT to ensure that netcat simply sends the packet
>> >>> > then returns immediately.
>> >>> >
>> >>> > Signed-off-by: Joe Stringer <joe at ovn.org>
>> >>> >
>> >>>
>> >>> I did notice the "hang" without this patch. But with this patch, those
>> >>> tests fail now with:
>> >>> +nc: invalid option -- 'q'
>> >>> +Try `nc --help' for more information.
>> >>>
>> >>> My nc --version says:
>> >>>
>> >>> nc --version
>> >>> netcat (The GNU Netcat) 0.7.1
>> >>> Copyright (C) 2002 - 2003  Giovanni Giacobbi
>> >>>
>> >>> This program comes with NO WARRANTY, to the extent permitted by law.
>> >>> You may redistribute copies of this program under the terms of
>> >>> the GNU General Public License.
>> >>> For more information about these matters, see the file named COPYING.
>> >>>
>> >>> Original idea and design by Avian Research <hobbit at avian.org>,
>> >>> Written by Giovanni Giacobbi <giovanni at giacobbi.net>.
>> >>>
>> >>
>> >> On my ubuntu 14.04.2LTS system. There are two possible packages that
>> >> installs nc,
>> >> netcat-tradition or netcat-openbsd.  Both versions accepts the -q
>> option,
>> >> and do not
>> >> accept --version option. Did you install nc from source by chance?
>> >>
>> >
>> > Yeah. I was trying out different nc versions to get out of the hang and
>> > ended up compiling from sources. I guess, that is not useful as
>> apparently
>> > no body uses GNU netcat.
>> >
>>
>> That version was released by Jan 2004. and is more than 10 years old. Not
>> sure how important it is to catch or support this version.
>>
>
> I don't think it is important to support it.

Thanks a lot for the review and testing it out. For now I'll leave it
as is, if we find out that a popular distribution ships this netcat
then we can always fix it in a subsequent patch.

I pushed the patch to master.