On Wed, Jul 11, 2001 at 07:43:14AM -0700, [EMAIL PROTECTED] wrote:
>
> APR doesn't really handle signals, for a very good reason. They are
> incredibly non-portable, and very difficult to deal with. Having said
> that, there are some APR functions for dealing with signals.
>
> 1) apr_signal. Just like signal, only portable and predictable
>
> 2) apr_signal_thread puts a single thread into sigwait. Whenever ANY
> signal is received that thread is woken up, and a function is called. The
> function is passed in to the setup_signal_thread function.
>
> 3) You can get a list of signals understood by the machine. I can't
> remember the function, but it is there.
>
> Most of Apache specifically tries to avoid any signals, although the
> parent still relies on SIGWINCH, SIGTERM, and SIGHUP. And the children
> rely on SIGTERM and sometimes on SIGINT.
okay... so... what you are saying, effectively, is that apache is
vulnerable to a SIGPIPE DOS attack, amongst others.
for xvl, i think... i think what i will do is simply rip all of the
signal handling / fault / blocking etc. code out. xvl doesn't
use apr_signal_thread() - it doesn't use threads [yet :)]
when this issue has been addressed [DOS attacks possible via
signals], i'll follow suit.
all best,
luke
