1 files changed, 94 insertions, 0 deletions
diff --git a/sys/kern/tty_tty.c b/sys/kern/tty_tty.c
new file mode 100644
index 0000000..07d8358
--- /dev/null
+++ b/sys/kern/tty_tty.c
@@ -0,0 +1,94 @@
+/*-
+ * Copyright (c) 2003 Poul-Henning Kamp.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/conf.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/sx.h>
+#include <sys/vnode.h>
+
+#include <fs/devfs/devfs.h>
+#include <fs/devfs/devfs_int.h>
+
+static	d_open_t	cttyopen;
+
+static struct cdevsw ctty_cdevsw = {
+	.d_version =	D_VERSION,
+	.d_open =	cttyopen,
+	.d_name =	"ctty",
+};
+
+static struct cdev *ctty;
+
+static	int
+cttyopen(struct cdev *dev, int flag, int mode, struct thread *td)
+{
+
+	return (ENXIO);
+}
+
+static void
+ctty_clone(void *arg, struct ucred *cred, char *name, int namelen,
+    struct cdev **dev)
+{
+
+	if (*dev != NULL)
+		return;
+	if (strcmp(name, "tty"))
+		return;
+	sx_sunlock(&clone_drain_lock);
+	sx_slock(&proctree_lock);
+	sx_slock(&clone_drain_lock);
+	dev_lock();
+	if (!(curthread->td_proc->p_flag & P_CONTROLT))
+		*dev = ctty;
+	else if (curthread->td_proc->p_session->s_ttyvp == NULL)
+		*dev = ctty;
+	else if (curthread->td_proc->p_session->s_ttyvp->v_type == VBAD ||
+	    curthread->td_proc->p_session->s_ttyvp->v_rdev == NULL) {
+		/* e.g. s_ttyvp was revoked */
+		*dev = ctty;
+	} else
+		*dev = curthread->td_proc->p_session->s_ttyvp->v_rdev;
+	dev_refl(*dev);
+	dev_unlock();
+	sx_sunlock(&proctree_lock);
+}
+
+static void
+ctty_drvinit(void *unused)
+{
+
+	EVENTHANDLER_REGISTER(dev_clone, ctty_clone, 0, 1000);
+	ctty = make_dev_credf(MAKEDEV_ETERNAL, &ctty_cdevsw, 0, NULL, UID_ROOT,
+	    GID_WHEEL, 0666, "ctty");
+}
+
+SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,ctty_drvinit,NULL);