Move utmpx handling out of init(8).

This has the following advantages:

- During boot, the BOOT_TIME record is now written right after the file
  systems become writable, but before users are allowed to log in. This
  means that they can't cause `hidden logins' by logging in right before
  init(8) kicks in.

- The pututxline(3) function may potentially block on file locking,
  though this is very rare to occur. By placing it in an rc script, the
  user can still kill it with ^C if needed.

- Most importantly: jails don't use init(8). This means that a force
  reboot of a system running jails will leave stale entries in the
  accounting database of the jails individually.

etc/rc.d/Makefile

@@ -144,6 +144,7 @@ FILES=	DAEMON \
 	tmp \
 	${_ubthidhci} \
 	ugidfw \
+	${_utx} \
 	var \
 	virecover \
 	watchdogd \
@@ -177,6 +178,10 @@ _nscd=		nscd
 _ubthidhci=	ubthidhci
 .endif
 
+.if ${MK_UTMPX} != "no"
+_utx=		utx
+.endif
+
 FILESDIR=	/etc/rc.d
 FILESMODE=	${BINMODE}
 

etc/rc.d/cleanvar

@@ -58,8 +58,6 @@ cleanvar_start ()
 {
 	if [ -d /var/run -a ! -f /var/run/clean_var ]; then
 		purgedir /var/run
-		# And an initial utmpx active session file
-		(cd /var/run && cp /dev/null utx.active && chmod 644 utx.active)
 		>/var/run/clean_var
 	fi
 	if [ -d /var/spool/lock -a ! -f /var/spool/lock/clean_var ]; then

etc/rc.d/utx

@@ -0,0 +1,18 @@
+#!/bin/sh
+#
+# $FreeBSD$
+#
+
+# PROVIDE: utx
+# REQUIRE: DAEMON cleanvar
+# BEFORE:  LOGIN
+# KEYWORD: shutdown
+
+. /etc/rc.subr
+
+name="utx"
+start_cmd="utx boot"
+stop_cmd="utx shutdown"
+
+load_rc_config $name
+run_rc_command "$1"

sbin/init/init.8

@@ -31,7 +31,7 @@
 .\"     @(#)init.8	8.3 (Berkeley) 4/18/94
 .\" $FreeBSD$
 .\"
-.Dd January 23, 2011
+.Dd February 11, 2012
 .Dt INIT 8
 .Os
 .Sh NAME
@@ -146,14 +146,7 @@ executes a shell for that user.
 When this shell
 dies, either because the user logged out
 or an abnormal termination occurred (a signal),
-.Nm login
-records the logout in the user accounting
-database (see
-.Xr getutxent 3)
-and terminates.
-The cycle is
-then restarted by
-.Nm
+the cycle is restarted by
 executing a new
 .Nm getty
 for the line.

sbin/init/init.c

@@ -66,7 +66,6 @@ static const char rcsid[] =
 #include <time.h>
 #include <ttyent.h>
 #include <unistd.h>
-#include <utmpx.h>
 #include <sys/reboot.h>
 #include <err.h>
 
@@ -181,8 +180,6 @@ static void setprocresources(const char *);
 #endif
 static int clang;
 
-static void clear_session_logs(session_t *);
-
 static int start_session_db(void);
 static void add_session(session_t *);
 static void del_session(session_t *);
@@ -566,20 +563,6 @@ transition(state_t s)
 		current_state = (state_t) (*current_state)();
 }
 
-/*
- * Close out the accounting files for a login session.
- * NB: should send a message to the session logger to avoid blocking.
- */
-static void
-clear_session_logs(session_t *sp __unused)
-{
-
-	/*
-	 * XXX: Use getutxline() and call pututxline() for each entry.
-	 * Is this safe to do this here?  Is it really required anyway?
-	 */
-}
-
 /*
  * Start a session and allocate a controlling terminal.
  * Only called by children of init after forking.
@@ -780,17 +763,12 @@ single_user(void)
 static state_func_t
 runcom(void)
 {
-	struct utmpx utx;
 	state_func_t next_transition;
 
 	if ((next_transition = run_script(_PATH_RUNCOM)) != 0)
 		return next_transition;
 
 	runcom_mode = AUTOBOOT;		/* the default */
-	/* NB: should send a message to the session logger to avoid blocking. */
-	utx.ut_type = BOOT_TIME;
-	gettimeofday(&utx.ut_tv, NULL);
-	pututxline(&utx);
 	return (state_func_t) read_ttys;
 }
 
@@ -1119,8 +1097,6 @@ read_ttys(void)
 	 * There shouldn't be any, but just in case...
 	 */
 	for (sp = sessions; sp; sp = snext) {
-		if (sp->se_process)
-			clear_session_logs(sp);
 		snext = sp->se_next;
 		free_session(sp);
 	}
@@ -1274,7 +1250,6 @@ collect_child(pid_t pid)
 	if (! (sp = find_session(pid)))
 		return;
 
-	clear_session_logs(sp);
 	del_session(sp);
 	sp->se_process = 0;
 
@@ -1504,14 +1479,8 @@ alrm_handler(int sig)
 static state_func_t
 death(void)
 {
-	struct utmpx utx;
 	session_t *sp;
 
-	/* NB: should send a message to the session logger to avoid blocking. */
-	utx.ut_type = SHUTDOWN_TIME;
-	gettimeofday(&utx.ut_tv, NULL);
-	pututxline(&utx);
-
 	/*
 	 * Also revoke the TTY here.  Because runshutdown() may reopen
 	 * the TTY whose getty we're killing here, there is no guarantee