From 50866e703a3338d2d43118daf6189dc6a50ce6b4 Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Mon, 18 May 2015 09:35:05 +0000
Subject: [PATCH] Add -d flag and dc capability to open devices non-blocking,
 used for the few drivers that do not support cua* so tty* must be used.

ok miod millert
---
 usr.bin/cu/cu.1 | 10 ++++++++--
 usr.bin/cu/cu.c | 24 ++++++++++++++++++------
 2 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/usr.bin/cu/cu.1 b/usr.bin/cu/cu.1
index 0535ed81ace..2f1a3c836c6 100644
--- a/usr.bin/cu/cu.1
+++ b/usr.bin/cu/cu.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: cu.1,v 1.14 2015/04/24 18:06:31 deraadt Exp $
+.\"	$OpenBSD: cu.1,v 1.15 2015/05/18 09:35:05 nicm Exp $
 .\"
 .\" Copyright (c) 1980, 1990, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -27,7 +27,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: April 24 2015 $
+.Dd $Mdocdate: May 18 2015 $
 .Dt CU 1
 .Os
 .Sh NAME
@@ -35,6 +35,7 @@
 .Nd serial terminal emulator
 .Sh SYNOPSIS
 .Nm
+.Op Fl d
 .Op Fl l Ar line
 .Op Fl s Ar speed | Fl Ar speed
 .Nm
@@ -50,6 +51,10 @@ debugging purposes.
 .Pp
 The options are as follows:
 .Bl -tag -width 4n
+.It Fl d
+Specify that the line is directly connected and
+.Nm
+should not allow the driver to block waiting for a carrier to be detected.
 .It Fl l Ar line
 Specify the line to use.
 Either of the forms like
@@ -79,6 +84,7 @@ is given,
 uses the
 .Xr remote 5
 database to retrieve the
+.Sy dc Pq directly connected ,
 .Sy dv Pq device
 and
 .Sy br Pq baud rate
diff --git a/usr.bin/cu/cu.c b/usr.bin/cu/cu.c
index 52e2f94f357..ac8ddae2d7a 100644
--- a/usr.bin/cu/cu.c
+++ b/usr.bin/cu/cu.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cu.c,v 1.21 2015/02/08 17:33:35 nicm Exp $ */
+/* $OpenBSD: cu.c,v 1.22 2015/05/18 09:35:05 nicm Exp $ */
 
 /*
  * Copyright (c) 2012 Nicholas Marriott <nicm@openbsd.org>
@@ -41,6 +41,7 @@ FILE			*record_file;
 struct termios		 saved_tio;
 struct bufferevent	*input_ev;
 struct bufferevent	*output_ev;
+int			 is_direct = -1;
 const char		*line_path = NULL;
 int			 line_speed = -1;
 int			 line_fd;
@@ -65,7 +66,7 @@ void		try_remote(const char *, const char *, const char *);
 __dead void
 usage(void)
 {
-	fprintf(stderr, "usage: %s [-l line] [-s speed | -speed]\n",
+	fprintf(stderr, "usage: %s [-d] [-l line] [-s speed | -speed]\n",
 	    __progname);
 	fprintf(stderr, "       %s [host]\n", __progname);
 	exit(1);
@@ -76,7 +77,7 @@ main(int argc, char **argv)
 {
 	const char	*errstr;
 	char		*tmp, *s, *host;
-	int		 opt, i;
+	int		 opt, i, flags;
 
 	if (isatty(STDIN_FILENO) && tcgetattr(STDIN_FILENO, &saved_tio) != 0)
 		err(1, "tcgetattr");
@@ -95,8 +96,11 @@ main(int argc, char **argv)
 			errx(1, "speed asprintf");
 	}
 
-	while ((opt = getopt(argc, argv, "l:s:")) != -1) {
+	while ((opt = getopt(argc, argv, "dl:s:")) != -1) {
 		switch (opt) {
+		case 'd':
+			is_direct = 1;
+			break;
 		case 'l':
 			line_path = optarg;
 			break;
@@ -114,7 +118,7 @@ main(int argc, char **argv)
 	if (argc != 0 && argc != 1)
 		usage();
 
-	if (line_path != NULL || line_speed != -1) {
+	if (line_path != NULL || line_speed != -1 || is_direct != -1) {
 		if (argc != 0)
 			usage();
 	} else {
@@ -139,6 +143,8 @@ main(int argc, char **argv)
 		line_path = "/dev/cua00";
 	if (line_speed == -1)
 		line_speed = 9600;
+	if (is_direct == -1)
+		is_direct = 0;
 
 	if (strchr(line_path, '/') == NULL) {
 		if (asprintf(&tmp, "%s%s", _PATH_DEV, line_path) == -1)
@@ -146,7 +152,10 @@ main(int argc, char **argv)
 		line_path = tmp;
 	}
 
-	line_fd = open(line_path, O_RDWR);
+	flags = O_RDWR;
+	if (is_direct)
+		flags |= O_NONBLOCK;
+	line_fd = open(line_path, flags);
 	if (line_fd < 0)
 		err(1, "open(\"%s\")", line_path);
 	if (ioctl(line_fd, TIOCEXCL) != 0)
@@ -347,6 +356,9 @@ try_remote(const char *host, const char *path, const char *entry)
 		}
 	}
 
+	if (is_direct == -1 && cgetcap(cp, "dc", ':') != NULL)
+		is_direct = 1;
+
 	if (line_path == NULL && cgetstr(cp, "dv", &s) >= 0)
 		line_path = s;
 
-- 
2.20.1