From 127ead92a07efd5708211fd440a4d8117a2ba75e Mon Sep 17 00:00:00 2001
From: bms <bms@FreeBSD.org>
Date: Sun, 1 Apr 2007 22:02:30 +0000
Subject: [PATCH] MFC:   Add a sysctl net.link.tap.up_on_open which defaults to
 zero; when it   is non-zero, tap(4) instances will be marked IFF_UP on
 attach.

  1.71 +6 -1 src/sys/net/if_tap.c
  1.19 +8 -1 src/share/man/man4/tap.4

PR:		110383
Requested by:	Frank Behrens
---
 share/man/man4/tap.4 | 9 ++++++++-
 sys/net/if_tap.c     | 7 ++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/share/man/man4/tap.4 b/share/man/man4/tap.4
index 98861d85b66d..86c880e4fde0 100644
--- a/share/man/man4/tap.4
+++ b/share/man/man4/tap.4
@@ -1,7 +1,7 @@
 .\" $FreeBSD$
 .\" Based on PR#2411
 .\"
-.Dd February 4, 2007
+.Dd March 19, 2007
 .Os
 .Dt TAP 4
 .Sh NAME
@@ -117,6 +117,13 @@ and is restricted to the super-user, unless the
 variable
 .Va net.link.tap.user_open
 is non-zero.
+If the
+.Xr sysctl 8
+variable
+.Va net.link.tap.up_on_open
+is non-zero, the tunnel device will be marked
+.Dq up
+when the control device is opened.
 A
 .Fn read
 call will return an error
diff --git a/sys/net/if_tap.c b/sys/net/if_tap.c
index 5b8390553664..5f55d2487ff3 100644
--- a/sys/net/if_tap.c
+++ b/sys/net/if_tap.c
@@ -149,7 +149,8 @@ static struct cdevsw	tap_cdevsw = {
  */
 static struct mtx		tapmtx;
 static int			tapdebug = 0;        /* debug flag   */
-static int			tapuopen = 0;        /* allow user open() */	     
+static int			tapuopen = 0;        /* allow user open() */
+static int			tapuponopen = 0;    /* IFF_UP on open() */
 static int			tapdclone = 1;	/* enable devfs cloning */
 static SLIST_HEAD(, tap_softc)	taphead;             /* first device */
 static struct clonedevs 	*tapclones;
@@ -163,6 +164,8 @@ SYSCTL_NODE(_net_link, OID_AUTO, tap, CTLFLAG_RW, 0,
     "Ethernet tunnel software network interface");
 SYSCTL_INT(_net_link_tap, OID_AUTO, user_open, CTLFLAG_RW, &tapuopen, 0,
 	"Allow user to open /dev/tap (based on node permissions)");
+SYSCTL_INT(_net_link_tap, OID_AUTO, up_on_open, CTLFLAG_RW, &tapuponopen, 0,
+	"Bring interface up when /dev/tap is opened");
 SYSCTL_INT(_net_link_tap, OID_AUTO, devfs_cloning, CTLFLAG_RW, &tapdclone, 0,
 	"Enably legacy devfs interface creation");
 SYSCTL_INT(_net_link_tap, OID_AUTO, debug, CTLFLAG_RW, &tapdebug, 0, "");
@@ -501,6 +504,8 @@ tapopen(struct cdev *dev, int flag, int mode, struct thread *td)
 	s = splimp();
 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
+	if (tapuponopen)
+		ifp->if_flags |= IFF_UP;
 	splx(s);
 
 	TAPDEBUG("%s is open. minor = %#x\n", ifp->if_xname, minor(dev));