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 outdated cur_time value that was set before the call to poll(2).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).
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;
