ietf-nntp Generic response codes

[Clive D.W. Feather]

Some time ago I made a proposal for "generic response codes". For example,
I noted that:

> In practice, many commands use 502 to mean "not permitted at present"
> and 503 to mean "not supported in this implementation". There's also a
> need for generic codes for "service about to break", "can't provide this
> right now", and "something went wrong in the server".

The proposal didn't receive any objections that I recall, and at least one
other person liked the idea. My generic list was:

    400 service temporarily unavailable (TCP connection is then closed)
    401 service about to shut down temporarily
    403 facility temporarily unavailable
    500 unrecognised command
    501 syntax error in command
    502 not authorised
    503 optional feature not supported

Russ wrote:
> I think I agree with this suggestion (although I've not done my promised
> audit of INN yet).

[Did you ?]

I proposed the following wording to be added as a new section 4.1.1. Is
there any reason to not adopt it ?

+ 4.1.1 Generic response codes
+
+ The server MUST respond to any command with the appropriate one of the
+ following generic responses if it represents the situation.
+
+ If there is a syntax error in the arguments of a recognised command, the
+ response code 501 MUST be returned.
+ 
+ If the client is not authorised to use the specified facility when the
+ server is in its current state, the response code 502 MUST be returned.
+ A different command MIGHT change the server state and permit the command
+ if retried.  
+
+ If the server does not provide an optional feature, then the response
+ code 403 MUST be returned if the omission is temporary (e.g. because a
+ necessary facility is unavailable) and the code 503 if it is permanent
+ (e.g. because the server does not store the required information).
+ 
+ If the server has to terminate the connection for some reason, it MUST
+ give a 400 response code to the next command and then immediately close
+ the TCP connection. It MAY give a 401 response code to any command
+ indicate that termination is imminent (following a 401 response, it MUST
+ NOT close the TCP connection immediately). 

-- 
Clive D.W. Feather  | Work:  <clive at demon.net>   | Tel:  +44 20 8371 1138
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