tty: reading input from a tty is now handled by the line discipline

kernel/tty/ldisc.c

@@ -3,6 +3,7 @@
 #include <socks/libc/ctype.h>
 
 static void default_ldisc_write(struct device *, const struct input_event *);
+static kern_status_t default_ldisc_read(struct device *tty, void *buf, size_t max, size_t *nr_read, socks_flags_t flags);
 
 static char keycode_chars[] = {
 	[KEY_UNKNOWN]                = ' ',
@@ -234,6 +235,7 @@ static char keycode_chars_shift[] = {
 
 static struct tty_ldisc default_ldisc = {
 	.name = "n_tty",
+	.read = default_ldisc_read,
 	.write = default_ldisc_write,
 };
 
@@ -254,6 +256,34 @@ static enum tty_modifier_key get_modifier_key(const struct input_event *ev)
 	}
 }
 
+static bool is_arrow_key(const struct input_event *ev, char *ch)
+{
+	bool ret = false;
+	switch (ev->ev_key.key) {
+	case KEY_UP:
+		ret = true;
+		*ch = 'A';
+		break;
+	case KEY_DOWN:
+		ret = true;
+		*ch = 'B';
+		break;
+	case KEY_RIGHT:
+		ret = true;
+		*ch = 'C';
+		break;
+	case KEY_LEFT:
+		ret = true;
+		*ch = 'D';
+		break;
+	default:
+		ret = false;
+		break;
+	}
+
+	return ret;
+}
+
 static void handle_modifier_keys(struct device *tty, enum tty_modifier_key modkey, const struct input_event *ev)
 {
 	struct tty_device *ttydev = TTY_DEVICE(tty);
@@ -273,13 +303,13 @@ static void convert_ev_to_chars(struct device *tty, const struct input_event *ev
 
 	struct tty_device *ttydev = TTY_DEVICE(tty);
 
-	char echo[2];
+	char echo[4];
 	int echo_len = 0;
 
+	char data[4];
+	int data_len = 0;
+
 	char c = keycode_chars[ev->ev_key.key];
-	if (c == 0) {
-		return;
-	}
 
 	if (ttydev->tty_modstate & TTY_KEY_CTRL) {
 		if (!isalpha(c)) {
@@ -293,24 +323,67 @@ static void convert_ev_to_chars(struct device *tty, const struct input_event *ev
 		c = tolower(c);
 		c -= 97;
 		c++;
+		data[0] = c;
+		data_len = 1;
 	} else if (ttydev->tty_modstate & TTY_KEY_SHIFT) {
 		c = keycode_chars_shift[ev->ev_key.key];
 		echo[0] = c;
 		echo_len = 1;
-	} else {
+		data[0] = c;
+		data_len = 1;
+	} else if (is_arrow_key(ev, &c)) {
+		echo[0] = '^';
+		echo[1] = '[';
+		echo[2] = '[';
+		echo[3] = c;
+		echo_len = 4;
+
+		data[0] = 0x1b;
+		data[1] = '[';
+		data[2] = c;
+		data_len = 3;
+	} else if (c != 0) {
 		echo[0] = c;
 		echo_len = 1;
+		data[0] = c;
+		data_len = 1;
 	}
 
-	if (c == 0) {
+	if (data_len == 0) {
 		return;
 	}
 
-	ringbuffer_write(&ttydev->tty_input, sizeof c, &c, S_NOBLOCK);
+	ringbuffer_write(&ttydev->tty_input, data_len, data, S_NOBLOCK);
 	size_t nr_written;
 	tty_write(tty, echo, echo_len, &nr_written, S_NOBLOCK);
 }
 
+static kern_status_t canonical_read(struct device *tty, void *buf, size_t max, size_t *nr_read, socks_flags_t flags)
+{
+	//struct tty_device *ttydev = TTY_DEVICE(tty);
+	//struct termios backup = ttydev
+	//char *linebuf = ttydev->tty_linebuf;
+	//unsigned int pos = 0, len = 0;
+	return KERN_OK;
+}
+
+static kern_status_t non_canonical_read(struct device *tty, void *buf, size_t max, size_t *nr_read, socks_flags_t flags)
+{
+	return KERN_OK;
+}
+
+static kern_status_t default_ldisc_read(struct device *tty, void *buf, size_t max, size_t *nr_read, socks_flags_t flags)
+{
+	struct tty_device *ttydev = TTY_DEVICE(tty);
+	if (ttydev->tty_config.c_lflag & ICANON) {
+		return canonical_read(tty, buf, max, nr_read, flags);
+	} else {
+		return non_canonical_read(tty, buf, max, nr_read, flags);
+	}
+
+	return KERN_OK;
+}
+
 static void default_ldisc_write(struct device *tty, const struct input_event *ev)
 {
 	enum tty_modifier_key modkeys = get_modifier_key(ev);

kernel/tty/tty.c

@@ -75,8 +75,14 @@ static void putchar(struct device *tty, int c)
 
 kern_status_t tty_read(struct device *tty, void *buf, size_t max, size_t *nr_read, socks_flags_t flags)
 {
-	printk("tty_read");
-	return KERN_OK;
+	kern_status_t status = KERN_UNSUPPORTED;
+	struct tty_device *ttydev = TTY_DEVICE(tty);
+
+	if (ttydev->tty_ldisc || ttydev->tty_ldisc->read) {
+		status = ttydev->tty_ldisc->read(tty, buf, max, nr_read, flags);
+	}
+
+	return status;
 }
 
 kern_status_t tty_write(struct device *tty, const void *buf, size_t len, size_t *nr_written, socks_flags_t flags)