Re: Anti-collide patch

[Kaspar Landsberg <kl@xxxxxxxxxxx>]

Hi,

On Fri, Jan 08, 1999 at 03:28:32PM +0100, Joern Westermann wrote:

| I've just written a patch for the 2.10.1 ircd to prevent takeovers by
| nick collides. 
|  
|  - the collide kill for the collided nick is distributed to other
| servers as before.
|  
|  - the local collided user is forced to change nick. This is done with a
| nick change command between server and client which is at least
| supported by ircII and mIRC (haven't tested others). DALNet uses this
| command to force a nick change for nicks which are registered by other
| users, so all clients usable in DALNet can be used with this patch.
| Currently a 4-digit random number is appended to the nick or replaces
| the last 4 characters of the nick (depending on previous nick length),
| e.g. nick Guenthi -> Guent6387.

the problem with the FNC (forced nick change) solution is that it can easily
result in a loop. Suppose a nick collision happens and Guenthi changes to
Guent6387. But now, there´s some guy sitting on one of your channels and
sees that you get a new nick. All he needs now is a lagged server or a
server which is currently reconnecting and he can hook up "on the other
side" a client with the same nick, resulting in a nick collision, which
makes the whole thing restart from 0 ad infinitum.

A better approach (cf. Beeth´s unique-ID proposal) would be to do the FNC to
a nick which cannot be taken from normal users like nicks starting with a
number.

Bye, Kasi

-- 
Kaspar Landsberg, <kl@xxxxxxxxxxx>