1 files changed, 165 insertions, 0 deletions
diff --git a/arch/um/drivers/pty.c b/arch/um/drivers/pty.c
new file mode 100644
index 000000000..39c60068c
--- /dev/null
+++ b/arch/um/drivers/pty.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <termios.h>
+#include <sys/stat.h>
+#include "chan_user.h"
+#include <os.h>
+#include <um_malloc.h>
+
+struct pty_chan {
+	void (*announce)(char *dev_name, int dev);
+	int dev;
+	int raw;
+	struct termios tt;
+	char dev_name[sizeof("/dev/pts/0123456\0")];
+};
+
+static void *pty_chan_init(char *str, int device, const struct chan_opts *opts)
+{
+	struct pty_chan *data;
+
+	data = uml_kmalloc(sizeof(*data), UM_GFP_KERNEL);
+	if (data == NULL)
+		return NULL;
+
+	*data = ((struct pty_chan) { .announce  	= opts->announce,
+				     .dev  		= device,
+				     .raw  		= opts->raw });
+	return data;
+}
+
+static int pts_open(int input, int output, int primary, void *d,
+		    char **dev_out)
+{
+	struct pty_chan *data = d;
+	char *dev;
+	int fd, err;
+
+	fd = get_pty();
+	if (fd < 0) {
+		err = -errno;
+		printk(UM_KERN_ERR "open_pts : Failed to open pts\n");
+		return err;
+	}
+
+	if (data->raw) {
+		CATCH_EINTR(err = tcgetattr(fd, &data->tt));
+		if (err)
+			goto out_close;
+
+		err = raw(fd);
+		if (err)
+			goto out_close;
+	}
+
+	dev = ptsname(fd);
+	sprintf(data->dev_name, "%s", dev);
+	*dev_out = data->dev_name;
+
+	if (data->announce)
+		(*data->announce)(dev, data->dev);
+
+	return fd;
+
+out_close:
+	close(fd);
+	return err;
+}
+
+static int getmaster(char *line)
+{
+	struct stat buf;
+	char *pty, *bank, *cp;
+	int master, err;
+
+	pty = &line[strlen("/dev/ptyp")];
+	for (bank = "pqrs"; *bank; bank++) {
+		line[strlen("/dev/pty")] = *bank;
+		*pty = '0';
+		/* Did we hit the end ? */
+		if ((stat(line, &buf) < 0) && (errno == ENOENT))
+			break;
+
+		for (cp = "0123456789abcdef"; *cp; cp++) {
+			*pty = *cp;
+			master = open(line, O_RDWR);
+			if (master >= 0) {
+				char *tp = &line[strlen("/dev/")];
+
+				/* verify slave side is usable */
+				*tp = 't';
+				err = access(line, R_OK | W_OK);
+				*tp = 'p';
+				if (!err)
+					return master;
+				close(master);
+			}
+		}
+	}
+
+	printk(UM_KERN_ERR "getmaster - no usable host pty devices\n");
+	return -ENOENT;
+}
+
+static int pty_open(int input, int output, int primary, void *d,
+		    char **dev_out)
+{
+	struct pty_chan *data = d;
+	int fd, err;
+	char dev[sizeof("/dev/ptyxx\0")] = "/dev/ptyxx";
+
+	fd = getmaster(dev);
+	if (fd < 0)
+		return fd;
+
+	if (data->raw) {
+		err = raw(fd);
+		if (err) {
+			close(fd);
+			return err;
+		}
+	}
+
+	if (data->announce)
+		(*data->announce)(dev, data->dev);
+
+	sprintf(data->dev_name, "%s", dev);
+	*dev_out = data->dev_name;
+
+	return fd;
+}
+
+const struct chan_ops pty_ops = {
+	.type		= "pty",
+	.init		= pty_chan_init,
+	.open		= pty_open,
+	.close		= generic_close,
+	.read		= generic_read,
+	.write		= generic_write,
+	.console_write	= generic_console_write,
+	.window_size	= generic_window_size,
+	.free		= generic_free,
+	.winch		= 0,
+};
+
+const struct chan_ops pts_ops = {
+	.type		= "pts",
+	.init		= pty_chan_init,
+	.open		= pts_open,
+	.close		= generic_close,
+	.read		= generic_read,
+	.write		= generic_write,
+	.console_write	= generic_console_write,
+	.window_size	= generic_window_size,
+	.free		= generic_free,
+	.winch		= 0,
+};