1 files changed, 114 insertions, 0 deletions
diff --git a/lib/libc/stdlib/ptsname.c b/lib/libc/stdlib/ptsname.c
new file mode 100644
index 000000000000..adbf0e1692a4
--- /dev/null
+++ b/lib/libc/stdlib/ptsname.c
@@ -0,0 +1,114 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Portions of this software were developed under sponsorship from Snow
+ * B.V., the Netherlands.
+ *
+ * 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 "namespace.h"
+#include <sys/param.h>
+#include <sys/ioctl.h>
+
+#include <errno.h>
+#include <paths.h>
+#include <stdlib.h>
+#include <string.h>
+#include "un-namespace.h"
+
+/*
+ * __isptmaster():  return whether the file descriptor refers to a
+ *                  pseudo-terminal master device.
+ */
+static int
+__isptmaster(int fildes)
+{
+
+	if (_ioctl(fildes, TIOCPTMASTER) == 0)
+		return (0);
+
+	if (errno != EBADF)
+		errno = EINVAL;
+
+	return (-1);
+}
+
+/*
+ * In our implementation, grantpt() and unlockpt() don't actually have
+ * any use, because PTY's are created on the fly and already have proper
+ * permissions upon creation.
+ *
+ * Just make sure `fildes' actually points to a real PTY master device.
+ */
+__strong_reference(__isptmaster, grantpt);
+__strong_reference(__isptmaster, unlockpt);
+
+/*
+ * ptsname_r(): return the pathname of the slave pseudo-terminal device
+ *              associated with the specified master.
+ */
+int
+__ptsname_r(int fildes, char *buffer, size_t buflen)
+{
+
+	if (buflen <= sizeof(_PATH_DEV)) {
+		errno = ERANGE;
+		return (-1);
+	}
+
+	/* Make sure fildes points to a master device. */
+	if (__isptmaster(fildes) != 0)
+		return (-1);
+
+	memcpy(buffer, _PATH_DEV, sizeof(_PATH_DEV));
+	buffer += sizeof(_PATH_DEV) - 1;
+	buflen -= sizeof(_PATH_DEV) - 1;
+
+	if (fdevname_r(fildes, buffer, buflen) == NULL) {
+		if (errno == EINVAL)
+			errno = ERANGE;
+		return (-1);
+	}
+
+	return (0);
+}
+
+__strong_reference(__ptsname_r, ptsname_r);
+
+/*
+ * ptsname():  return the pathname of the slave pseudo-terminal device
+ *             associated with the specified master.
+ */
+char *
+ptsname(int fildes)
+{
+	static char pt_slave[sizeof(_PATH_DEV) + SPECNAMELEN];
+
+	if (__ptsname_r(fildes, pt_slave, sizeof(pt_slave)) == 0)
+		return (pt_slave);
+
+	return (NULL);
+}