Reliable process tracking

[Jilles Tjoelker]

On Fri, Aug 09, 2013 at 10:42:09AM +0200, Edward Tomasz Napierała wrote:
> Wiadomość napisana przez Jilles Tjoelker <jilles at stack.nl> w dniu 7 sie 2013, o godz. 22:19:
> > On Mon, Aug 05, 2013 at 01:13:10PM +0200, Edward Tomasz Napierała wrote:
> >> Wiadomość napisana przez Jilles Tjoelker <jilles at stack.nl> w dniu 4 sie 2013, o godz. 15:46:
> >>> When shutting down a service or requesting status, rc.subr currently
> >>> uses a combination of pidfiles and process names. This is fairly but not
> >>> completely reliable once it is set up correctly (which can take a lot of
> >>> work and possibly patching the daemon to use pidfile(3) from our
> >>> libutil). It is also incapable of killing multiprocess daemons such as
> >>> CGI web servers without cooperation of the daemon.

> >>> I think what is needed here is a facility that marks a process and all
> >>> of its descendants. Removing the mark should be a privileged or at least
> >>> an unusual operation; no unprivileged function specified by POSIX such
> >>> as setsid() should do this.

> >> I've actually thought about that when I added setloginclass(2).  It's
> >> trivial to modify rc.subr to use su(8) to set login class for each
> >> service.  It should be trivial to modify pkill(1) and killall(1) to
> >> add "-c" option to kill all processes in a given login class.

> > There are some problems with su -c:

> > * It refuses to set a login class name that is not in /etc/login.conf.
> >  Given that multiple instances of a service should each have their own
> >  kernel login class, it may make sense to allow specifying the
> >  login.conf entry separate from the kernel login class.

> Indeed.  I'll try to figure out something.

> FWIW, I've just committed a patch that adds "-c" flag to pkill.

On another note, init(8) does not set the kernel login class for /etc/rc
to daemon as might be expected from the /etc/login.conf entry used. I
use this patch:

Index: sbin/init/init.c
===================================================================
--- sbin/init/init.c	(revision 253911)
+++ sbin/init/init.c	(working copy)
@@ -1729,7 +1729,8 @@
 	login_cap_t *lc;
 	if ((lc = login_getclassbyname(cname, NULL)) != NULL) {
 		setusercontext(lc, (struct passwd*)NULL, 0,
-		    LOGIN_SETPRIORITY | LOGIN_SETRESOURCES);
+		    LOGIN_SETPRIORITY | LOGIN_SETRESOURCES |
+		    LOGIN_SETLOGINCLASS);
 		login_close(lc);
 	}
 }

Should I commit this?

-- 
Jilles Tjoelker