On Wed, May 15, 2013 at 10:29:22AM +0200, Gerhard Roth wrote:
> On Wed, 15 May 2013 10:15:54 +0200
> Gerhard Roth <gr...@genua.de> wrote:
>
> > In dhcpd, variable cur_time is set only once per dispatch loop.
> > Unfortunately, this is done before the poll(2) call. Since poll(2)
> > may sleep for an arbitrary amount of time, the value of cur_time
> > might refer to some long ago point in time. When message dispatching
> > is done, timeouts and lease ends are calculated based on this
> > outdated cur_time value that was set before the call to poll(2).
> >
> > It's fine to set cur_time only once per loop, but we should do it after
> > the blocking poll(2) syscall so that its value is more accurate.
> >
> > ok?
> >
> > Gerhard
> >
>
>
> Sorry, the previous version will break timeout handling when there
> are no incoming packets. I notice the moment that I sent the mail.
>
> So let's keep all the old code and just add another update of cur_time
> after poll(2).
ok with me,
-Otto
>
> Gerhard
>
>
> Index: usr.sbin/dhcpd/dispatch.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/dhcpd/dispatch.c,v
> retrieving revision 1.30
> diff -u -p -r1.30 dispatch.c
> --- usr.sbin/dhcpd/dispatch.c 19 Apr 2013 21:25:39 -0000 1.30
> +++ usr.sbin/dhcpd/dispatch.c 15 May 2013 08:26:49 -0000
> @@ -360,6 +360,7 @@ another:
> case 0:
> continue; /* no packets */
> }
> + time(&cur_time);
>
> for (i = 0, l = protocols; l; l = l->next) {
> struct interface_info *ip = l->local;
