[pkg-ntp-maintainers] Bug#476193: ntpdc times out when the server monlist has over 600 clients

[Josip Rodin]

On Tue, Apr 15, 2008 at 02:44:25AM +0200, Josip Rodin wrote:
> I see the culprit in ntpd/ntp_monitor.c:
> 
> /*
>  * Limits on the number of structures allocated.  This limit is picked  
>  * with the illicit knowlege that we can only return somewhat less
>  * than 8K bytes in a mode 7 response packet, and that each structure
>  * will require about 20 bytes of space in the response.
>  *
>  * ... I don't believe the above is true anymore ... jdg
>  */
> #ifndef MAXMONMEM 
> #define MAXMONMEM       600     /* we allocate up to 600 structures */
> #endif

http://ntp.bkbits.net:8080/ntp-stable/ntpd/ntp_monitor.c?PAGE=anno&REV=4501fb5ciab3mg65AEoxeovMbL3KMg
and http://ntp.bkbits.net:8080/ntp-stable/ntpd/ntp_monitor.c?PAGE=history
seem to indicate that this code is over 9 years old (older than the initial
commit on 1999-05-25)...

http://www.eecis.udel.edu/~ntp/ntp_spool/depredated/xntp2/xntp.tar.Z
contains a copy where MAXMONMEM is 400, dated 1989-11-06.
The difference between those two versions also includes this comment:

+ * trimmed back memory consumption ... jdg 8/94

Whoa. It looks like this code could use some help. I can't remember what
could have been too much memory consumption in 1989/1994, but I'm pretty
sure that we'd all just chuckle at those numbers these days. :)

-- 
     2. That which causes joy or happiness.