termios: Added cfsetspeed function.

BSD extension to set both the input and output speed of a termios
structure.

Fixes #18220.

Change-Id: I8c4a06b4be4aa55b8ce35cb7f62552fc47a8e8d0
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6049
Reviewed-by: Jérôme Duval <[email protected]>

headers/compatibility/bsd/termios.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2023 Haiku, Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _BSD_TERMIOS_H_
+#define _BSD_TERMIOS_H_
+
+
+#include_next <termios.h>
+#include <features.h>
+
+
+#ifdef _DEFAULT_SOURCE
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern int cfsetspeed(struct termios *termios, speed_t speed);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif
+
+
+#endif  /* _BSD_TERMIOS_H_ */

src/libs/bsd/Jamfile

@@ -24,6 +24,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 			signal.c
 			string.cpp
 			stringlist.c
+			termios.c
 			unvis.c
 			usershell.c
 			vis.c

src/libs/bsd/termios.c

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2023, Haiku, inc.
+ *
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include <termios.h>
+
+
+int
+cfsetspeed(struct termios *termios, speed_t speed)
+{
+	/* Custom speed values are stored in c_ispeed and c_ospeed.
+	 * Standard values are inlined in c_cflag. */
+	if (speed > B31250) {
+		termios->c_cflag |= CBAUD;
+		termios->c_ispeed = speed;
+		termios->c_ospeed = speed;
+		return 0;
+	}
+
+	termios->c_cflag &= ~CBAUD;
+	termios->c_cflag |= speed;
+	return 0;
+}
+