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Date: Thu, 28 Dec 2006 13:40:53 -0700 (MST)
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To: freebsd-hackers@freebsd.org, erik.udo@gmail.com, olli@lurza.secnetix.de
From: "M. Warner Losh" <imp@bsdimp.com>
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Cc: 
Subject: Re: Init.c, making it chroot
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BTW, here's a patch to test.  Since FreeBSD has kenv(2), the patch is
actually very small.

Warner


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Index: init.c
===================================================================
RCS file: /cache/ncvs/src/sbin/init/init.c,v
retrieving revision 1.62
diff -u -r1.62 init.c
--- init.c	8 Jun 2006 14:04:36 -0000	1.62
+++ init.c	28 Dec 2006 20:39:33 -0000
@@ -55,6 +55,7 @@
 #include <db.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <kenv.h>
 #include <libutil.h>
 #include <paths.h>
 #include <signal.h>
@@ -187,6 +188,7 @@
 int
 main(int argc, char *argv[])
 {
+	char init_chroot[PATH_MAX];
 	int c;
 	struct sigaction sa;
 	sigset_t mask;
@@ -239,6 +241,12 @@
 	 */
 	openlog("init", LOG_CONS|LOG_ODELAY, LOG_AUTH);
 
+	*init_chroot = '\0';
+	kenv(KENV_GET, "init_chroot", init_chroot, sizeof(init_chroot));
+	if (*init_chroot)
+		if (chdir(init_chroot) != 0 || chroot(".") != 0)
+			warning("Can't chroot to %s: %m", init_chroot);
+
 	/*
 	 * Create an initial session.
 	 */

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