From owner-freebsd-current  Sat Feb 19 11:19:23 2000
Delivered-To: freebsd-current@freebsd.org
Received: from fw.wintelcom.net (ns1.wintelcom.net [209.1.153.20])
	by hub.freebsd.org (Postfix) with ESMTP
	id EA78737BD32; Sat, 19 Feb 2000 11:19:12 -0800 (PST)
	(envelope-from bright@fw.wintelcom.net)
Received: (from bright@localhost)
	by fw.wintelcom.net (8.9.3/8.9.3) id LAA00618;
	Sat, 19 Feb 2000 11:45:47 -0800 (PST)
Date: Sat, 19 Feb 2000 11:45:47 -0800
From: Alfred Perlstein <bright@wintelcom.net>
To: current@FreeBSD.ORG
Cc: jkh@FreeBSD.ORG
Subject: Re: "Fixing" init.
Message-ID: <20000219114547.T21720@fw.wintelcom.net>
References: <20000219022149.N21720@fw.wintelcom.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Mailer: Mutt 1.0.1i
In-Reply-To: <20000219022149.N21720@fw.wintelcom.net>; from bright@wintelcom.net on Sat, Feb 19, 2000 at 02:21:49AM -0800
Sender: owner-freebsd-current@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

* Alfred Perlstein <bright@wintelcom.net> [000219 02:22] wrote:
> I remeber being a newbie and getting burned by the need to explicitly
> turn a line 'off' in my /etc/ttys file instead of simply deleting it.
> 
> This fixes it using a trivial mark then collect sweep.
> 
> Can a couple people take a look?  I'd like to get it into 4.0 because
> it seems to follow POLA better. 
> 
> "hey i deleted and HUP'd but init keeps spawing them!"

ok, NetBSD has had this fixed for _several years_, and they use bitmasks
in the se_flags field, here's an updated patch that's essentially the
same as the old one but using NetBSD's se_flags implementation.

4.0 please? :)

thanks,
-Alfred


Index: init.c
===================================================================
RCS file: /home/ncvs/src/sbin/init/init.c,v
retrieving revision 1.37
diff -u -r1.37 init.c
--- init.c	1999/11/22 04:23:09	1.37
+++ init.c	2000/02/19 23:26:32
@@ -147,6 +147,7 @@
 	time_t	se_started;		/* used to avoid thrashing */
 	int	se_flags;		/* status of session */
 #define	SE_SHUTDOWN	0x1		/* session won't be restarted */
+#define	SE_PRESENT	0x2		/* session is in /etc/ttys */
 	int     se_nspace;              /* spacing count */
 	char	*se_device;		/* filename of port */
 	char	*se_getty;		/* what to run on that port */
@@ -964,6 +965,7 @@
 
 /*
  * Allocate a new session descriptor.
+ * Mark it SE_PRESENT.
  */
 session_t *
 new_session(sprev, session_index, typ)
@@ -982,6 +984,7 @@
 	sp = (session_t *) calloc(1, sizeof (session_t));
 
 	sp->se_index = session_index;
+	sp->se_flags |= SE_PRESENT;
 
 	sp->se_device = malloc(sizeof(_PATH_DEV) + strlen(typ->ty_name));
 	(void) sprintf(sp->se_device, "%s%s", _PATH_DEV, typ->ty_name);
@@ -1330,7 +1333,7 @@
 }
 
 /*
- * This is an n-squared algorithm.  We hope it isn't run often...
+ * This is an (n*2)+(n^2) algorithm.  We hope it isn't run often...
  */
 state_func_t
 clean_ttys()
@@ -1344,6 +1347,14 @@
 	if (! sessions)
 		return (state_func_t) multi_user;
 
+	/* 
+	 * mark all sessions for death, (!SE_PRESENT) 
+	 * as we find or create new ones they'll be marked as keepers,
+	 * we'll later nuke all the ones not found in /etc/ttys
+	 */
+	for (sp = sessions; sp != NULL; sp = sp->se_next)
+		sp->se_flags &= ~SE_PRESENT;
+
 	devlen = sizeof(_PATH_DEV) - 1;
 	while ((typ = getttyent()) != NULL) {
 		++session_index;
@@ -1353,6 +1364,8 @@
 				break;
 
 		if (sp) {
+			/* we want this one to live */
+			sp->se_flags |= SE_PRESENT;
 			if (sp->se_index != session_index) {
 				warning("port %s changed utmp index from %d to %d",
 				       sp->se_device, sp->se_index,
@@ -1402,6 +1415,17 @@
 	}
 
 	endttyent();
+
+	/*
+	 * sweep through and kill all deleted sessions
+	 * ones who's /etc/ttys line was deleted (SE_PRESENT unset)
+	 */
+	for (sp = sessions; sp != NULL; sp = sp->se_next) {
+		if ((sp->se_flags & SE_PRESENT) == 0) {
+			sp->se_flags |= SE_SHUTDOWN;
+			kill(sp->se_process, SIGHUP);
+		}
+	}
 
 	return (state_func_t) multi_user;
 }


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message