Thread: Min value for port

Is there a reason why we have set the min allowed value for port to 1,
not 1024? Given that you can't actually start postgres with a value of
<1024, shoulnd't the entry in pg_settings reference that as well?

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

On 6/27/13 6:34 AM, Magnus Hagander wrote:
> Is there a reason why we have set the min allowed value for port to 1,
> not 1024? Given that you can't actually start postgres with a value of
> <1024, shoulnd't the entry in pg_settings reference that as well?

Are you thinking of the restriction that you need to be root to use
ports <1024?  That restriction is not necessarily universal.  We can let
the kernel tell us at run time if it doesn't like our port.

On Thu, Jun 27, 2013 at 2:16 PM, Peter Eisentraut <peter_e@gmx.net> wrote:
> On 6/27/13 6:34 AM, Magnus Hagander wrote:
>> Is there a reason why we have set the min allowed value for port to 1,
>> not 1024? Given that you can't actually start postgres with a value of
>> <1024, shoulnd't the entry in pg_settings reference that as well?
>
> Are you thinking of the restriction that you need to be root to use
> ports <1024?  That restriction is not necessarily universal.  We can let
> the kernel tell us at run time if it doesn't like our port.

Yes, that's the restriction I was talking about. It's just a bit
annoying that if you look at pg_settings.min_value it doesn't actually
tell you the truth. But yeah, I believe Windows actually lets you use
a lower port number, so it'd at least have to be #ifdef'ed for that if
we wanted to change it.


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

On 27/06/13 15:11, Magnus Hagander wrote:
> On Thu, Jun 27, 2013 at 2:16 PM, Peter Eisentraut <peter_e@gmx.net> wrote:
>> On 6/27/13 6:34 AM, Magnus Hagander wrote:
>>> Is there a reason why we have set the min allowed value for port to 1,
>>> not 1024? Given that you can't actually start postgres with a value of
>>> <1024, shoulnd't the entry in pg_settings reference that as well?
>>
>> Are you thinking of the restriction that you need to be root to use
>> ports <1024?  That restriction is not necessarily universal.  We can let
>> the kernel tell us at run time if it doesn't like our port.
>
> Yes, that's the restriction I was talking about. It's just a bit
> annoying that if you look at pg_settings.min_value it doesn't actually
> tell you the truth. But yeah, I believe Windows actually lets you use
> a lower port number, so it'd at least have to be #ifdef'ed for that if
> we wanted to change it.

There's also authbind and CAP_NET_BIND_SERVICE.

Jan

On 2013-06-27 15:11:26 +0200, Magnus Hagander wrote:
> On Thu, Jun 27, 2013 at 2:16 PM, Peter Eisentraut <peter_e@gmx.net> wrote:
> > On 6/27/13 6:34 AM, Magnus Hagander wrote:
> >> Is there a reason why we have set the min allowed value for port to 1,
> >> not 1024? Given that you can't actually start postgres with a value of
> >> <1024, shoulnd't the entry in pg_settings reference that as well?
> >
> > Are you thinking of the restriction that you need to be root to use
> > ports <1024?  That restriction is not necessarily universal.  We can let
> > the kernel tell us at run time if it doesn't like our port.
> 
> Yes, that's the restriction I was talking about. It's just a bit
> annoying that if you look at pg_settings.min_value it doesn't actually
> tell you the truth. But yeah, I believe Windows actually lets you use
> a lower port number, so it'd at least have to be #ifdef'ed for that if
> we wanted to change it.

You can easily change the setting on linux as well. And you can grant
specific binaries the permission to bind to restricted ports without
being root.
I don't think the additional complexity to get a sensible value in there
is warranted.

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services