From 630222de41b8cb3b18a61d59e8fa395d533e97fe Mon Sep 17 00:00:00 2001
From: gjb <gjb@FreeBSD.org>
Date: Fri, 18 May 2018 14:57:58 +0000
Subject: MFC r315733, r315737, r315740, r330054:

 r315733 (imp):
  Impelemnt ttys onifexists in init.

  Implement a new init(8) option in /etc/ttys. If this option is present
  on the entry in /etc/ttys, the entry will be active if and only if it
  exists.  If the name starts with a '/', it will be considered an
  absolute path. If not, it will be a path relative to /dev.

  This allows one to turn off video console getty that aren't present
  (while running a getty on them even when they aren't the system
  console). Likewise with serial ports.

  It differs from onifconsole in only requiring the device exist rather
  than it be listed as one of the system consoles.

 r315737 (ngie):
  Unbreak world by adding sys/stat.h for stat(2)

 r315740 (imp):
  Simplify the code a little.

 r330054 (trasz):
  Improve missing tty handling in init(8).  This removes a check that did
  nothing - it was checking for ENXIO, which, with devfs, is no longer
  returned - and was badly placed anyway, and replaces it with similar
  one that works, and is done just before starting getty, instead of being
  done when rereading ttys(5).

  From the practical point of view, this makes init(8) handle disappearing
  terminals (eg /dev/ttyU*) gracefully, without unneccessary getty restarts
  and resulting error messages.

Reported by:	Bart Ender, Andre Albsmeier
PR:		228315
Blocks:		11.2-BETA2
Approved by:	re (marius)
Sponsored by:	The FreeBSD Foundation
---
 lib/libc/gen/getttyent.c | 32 ++++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

(limited to 'lib/libc/gen/getttyent.c')

diff --git a/lib/libc/gen/getttyent.c b/lib/libc/gen/getttyent.c
index 266f631..e0b2698 100644
--- a/lib/libc/gen/getttyent.c
+++ b/lib/libc/gen/getttyent.c
@@ -34,6 +34,7 @@ static char sccsid[] = "@(#)getttyent.c	8.1 (Berkeley) 6/4/93";
 __FBSDID("$FreeBSD$");
 
 #include <sys/types.h>
+#include <sys/stat.h>
 #include <sys/sysctl.h>
 
 #include <ctype.h>
@@ -72,11 +73,14 @@ auto_tty_status(const char *ty_name)
 {
 	size_t len;
 	char *buf, *cons, *nextcons;
+	int rv;
+
+	rv = TTY_IFCONSOLE;
 
 	/* Check if this is an enabled kernel console line */
 	buf = NULL;
 	if (sysctlbyname("kern.console", NULL, &len, NULL, 0) == -1)
-		return (0); /* Errors mean don't enable */
+		return (rv); /* Errors mean don't enable */
 	buf = malloc(len);
 	if (sysctlbyname("kern.console", buf, &len, NULL, 0) == -1)
 		goto done;
@@ -87,14 +91,32 @@ auto_tty_status(const char *ty_name)
 	nextcons = buf;
 	while ((cons = strsep(&nextcons, ",")) != NULL && strlen(cons) != 0) {
 		if (strcmp(cons, ty_name) == 0) {
-			free(buf);
-			return (TTY_ON);
+			rv |= TTY_ON;
+			break;
 		}
 	}
 
 done:
 	free(buf);
-	return (0);
+	return (rv);
+}
+
+static int
+auto_exists_status(const char *ty_name)
+{
+	struct stat sb;
+	char *dev;
+	int rv;
+
+	rv = TTY_IFEXISTS;
+	if (*ty_name == '/')
+		asprintf(&dev, "%s", ty_name);
+	else
+		asprintf(&dev, "/dev/%s", ty_name);
+	if (dev != NULL && stat(dev, &sb) == 0)
+		rv |= TTY_ON;
+	free(dev);
+	return (rv);
 }
 
 struct ttyent *
@@ -161,6 +183,8 @@ getttyent(void)
 			tty.ty_status |= TTY_ON;
 		else if (scmp(_TTYS_ONIFCONSOLE))
 			tty.ty_status |= auto_tty_status(tty.ty_name);
+		else if (scmp(_TTYS_ONIFEXISTS))
+			tty.ty_status |= auto_exists_status(tty.ty_name);
 		else if (scmp(_TTYS_SECURE))
 			tty.ty_status |= TTY_SECURE;
 		else if (scmp(_TTYS_INSECURE))
-- 
cgit v1.1