[NNTP] 502 and 503

[Clive D.W. Feather]

Russ Allbery said:
> Clive D W Feather <clive at demon.net> writes:

>> * If the server recognizes the command but does not provide an optional
>>   feature  (for example because it does not store the required information),
>>   or only handles a subset of legitimate cases (see the HDR command for an
>>   example), the response code 503 MUST be returned.
> 
>> * If the client is not authorized to use the specified facility when
>>   the server is in its current state, then the appropriate one of the
>>   following response codes MUST be used.
>>   502: it is necessary to terminate the connection and start a new one with
>>        the appropriate authority before the command can be used.

>> To me, the meanings are:
>>   502: you made a wrong choice, disconnect and try again
>>   503: I don't do that
> 
> I really don't want to describe 502 that way.  If, for example, you
> connect to a public read-only server, POST is going to return 502 in the
> common case because the server *supports* POST, it's just been configured
> to deny that particular client access to the command.  But it's going to
> keep returning 502 forever.

I don't disagree - the "wrong choice" here is to come in from the wrong IP
address. So this is a 502. (Do I need to rephrase the definition of 502 to
include this case?)

> It's really:
>   502: permission denied, at least in this mode
>   503: command not supported

503 's not really that either; it's more "this feature of this command not
supported".

> That being said, given the above explanation, I'm okay with IHAVE in
> reader mode or POST in transit mode being 503.

502 still feels the right thing to me.

What's current practice?

-- 
Clive D.W. Feather  | Work:  <clive at demon.net>   | Tel:    +44 20 8495 6138
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