Re: flexfax: y2k problem in faxcron/recvstats/xferstats

[Dmitry Bely <dbely@mail.ru>]

"Frans E. van Dorsselaer" <frans@bia-bv.demon.nl> writes:

> I use hylafax 4.0pl2 on Suse Linux 6.1, but the problem
> appears to be present in the current CVS as well.
> Since 1/1/2000 faxcron reports _all_ faxes ever sent in
> the receive stats, transmission stats, and error log report.
> 
> The receive/transmit stats are done in scripts called
> recvstats and xferstats respectively, I fixed those (patch attached).
> The problem is due to calculation of the age based on
> YY * 365 + ..., where YY is a 2-digit year representation.
> Fix includes YY < 70 check.
> 
> The error reports are filtered from faxcron itself, using
> awk.  I'm not good at awk, and I haven't tracked down the
> problem further.
> 
> Bye,
> 
> Frans van Dorsselaer
> frans@bia-bv.demon.nl
> 
> 
> --- orig.recvstats      Mon Jan  3 00:11:45 2000
> +++ recvstats   Mon Jan  3 00:12:20 2000
> @@ -157,7 +157,10 @@
>  #
>  function cvtDateTime(s)
>  {
> -    yday = substr(s,7,2)*365 + substr(s,4,2) - 1;
> +    yday = substr(s,7,2);
> +    if (yday < 70)
> +        yday += 100;
> +    yday = yday*365 + substr(s,4,2) - 1;
>      mon = substr(s,0,2) + 0;
>      for (i = 0; i < mon; i++)
>         yday += daysInMonth[i];
> --- orig.xferstats      Mon Jan  3 00:03:55 2000
> +++ xferstats   Mon Jan  3 00:11:08 2000
> @@ -186,7 +186,10 @@
>  #
>  function cvtDateTime(s)
>  {
> -    yday = substr(s,7,2)*365 + substr(s,4,2) - 1;
> +    yday = substr(s,7,2);
> +    if (yday < 70)
> +       yday += 100;
> +    yday = yday*365 + substr(s,4,2) - 1;
>      mon = substr(s,0,2) + 0;
>      for (i = 0; i < mon; i++)
>         yday += daysInMonth[i];

It seems that you run Alpha or other 64-bit box :-) On the 32-bit
processors the above code gives incorrect result due to an overflow. And
it also contains an older bug : substr(s,0,2) instead of substr(s,1,2). It
means that xferstats/recvstats _never_ generated correct results. I wonder
why nobody noticed that before.

So, here is the function with my fixes applied:

function cvtDateTime(s)
{
    yday = substr(s,7,2);
    if (yday < 70)
	yday += 30;
    else
	yday -= 70;
    yday = yday*365 + substr(s,4,2) - 1;
    mon = substr(s,1,2) + 0;
    for (i = 0; i < mon; i++)
	yday += daysInMonth[i];
    return yday*FULLDAY + cvtTime(substr(s,10) ":00");
}

Hope to hear from you soon,
Dmitry