Re: SSH Tunneling implementation

On Tue, Jul 10, 2012 at 2:30 PM, Ashesh Vashi <ashesh(dot)vashi(at)enterprisedb(dot)com
> wrote:

> On Tue, Jul 10, 2012 at 5:56 PM, Magnus Hagander <magnus(at)hagander(dot)net>wrote:
>
>> On Tue, Jul 10, 2012 at 2:19 PM, Akshay Joshi
>> <akshay(dot)joshi(at)enterprisedb(dot)com> wrote:
>> >
>> >
>> > On Tue, Jul 10, 2012 at 5:16 PM, Dave Page <dpage(at)pgadmin(dot)org> wrote:
>> >>
>> >>
>> >>
>> >> On Tue, Jul 10, 2012 at 12:35 PM, Ashesh Vashi
>> >> <ashesh(dot)vashi(at)enterprisedb(dot)com> wrote:
>> >>>>
>> >>>>
>> >>> Why are we talking about using the external application here?
>> >>
>> >>
>> >> Because I suggested giving it some thought in case it turns out we
>> have no
>> >> other option.
>> >>
>> >>>
>> >>> The only problem with the current implementation - is that it does use
>> >>> new APIs for tunneling.
>> >>> We can change the implementation based on the current supplied
>> libssh2 on
>> >>> most linux flavours.
>> >>> i.e. libssh2 - 1.2.7 or later
>> >>>
>> >>> I have asked Akshay to check - if we can modify the current
>> >>> implementation to use the older version of libssh2. (feasibility)
>> >>
>> >>
>> >> I've already asked him to investigate whether there is another API that
>> >> may be used that he may have missed. Only supporting old versions of
>> libssh2
>> >> is unacceptable though - we need to support current versions, and
>> ideally
>> >> older ones as well for compatibility with Ubuntu/Debian/RHEL etc.
>> >
>> >
>> > I have investigated, there are two functions
>> libssh2_session_handshake
>> > and libssh2_exit() which is not available in the older versions.
>> > libssh2_session_handshake() is replacement function to
>> > libssh2_session_startup()(deprecated) which was added in the version
>> 1.2.8
>> > and
>> > libssh2_exist() was added in the version 1.2.5. So to provide
>> backward
>> > compatibility we can perform the function check instead of configure
>> > check and will add appropriate macros to build it properly.
>> >
>> > Thought??Comments?
>>
>> Uh, I'm not sure what you mean with "function check instead of
>> configure check". You mean trying to load the function at runtime,
>> with dlopen() and friends? I guess we could, but I don't think pgadmin
>> has any functionality for that today, so it's going to bring in a fair
>> amount of platform specific code, isn't it? But if it's not too
>> complicated, it seems like a good choice.
>>
> He means to say - check function check at configuration.
> i.e.
> A lot of system does not have snprintf supported so a lot of packages
> check existence of it at configuration and define HAVE_SNPRINTF macros.
>

Oh, that's what I would've called a configure check :) In that case, +1 for
that since it's clearly the simplest way of getting it done.

--
Magnus Hagander
Me: http://www.hagander.net/
Work: http://www.redpill-linpro.com/