kernel: tty: implement tty input using line disciplines

include/socks/ringbuffer.h

@@ -25,6 +25,10 @@ extern size_t ringbuffer_avail(struct ringbuffer *buf);
 extern size_t ringbuffer_read(struct ringbuffer *buf, size_t size, void *buffer, socks_flags_t flags);
 extern size_t ringbuffer_write(struct ringbuffer *buf, size_t size, const void *buffer, socks_flags_t flags);
 
+/* TODO */
+//extern size_t ringbuffer_peek(struct ringbuffer *buf, size_t at, size_t size, void *buffer);
+//extern size_t ringbuffer_skip(struct ringbuffer *buf, size_t count);
+
 extern int ringbuffer_write_would_block(struct ringbuffer *buf);
 
 #endif

include/socks/tty.h

@@ -10,6 +10,9 @@
 #define TTY_DEVICE(dev) ((dev)->dev_type == DEV_TYPE_CHAR ? (dev)->chr.c_tty : NULL)
 #define TTY_DRIVER(drv) ((struct tty_driver *)((char *)drv - offsetof(struct tty_driver, tty_base)))
 
+#define TTY_EVENT_QUEUE_SIZE 4
+#define TTY_INPUT_QUEUE_SIZE 256
+
 struct kext;
 
 /* The TTY system.
@@ -56,6 +59,13 @@ enum tty_scroll_dir {
 	TTY_SCROLL_UP,
 };
 
+enum tty_modifier_key {
+	TTY_KEY_OTHER = 0x00u,
+	TTY_KEY_CTRL = 0x01u,
+	TTY_KEY_ALT = 0x02u,
+	TTY_KEY_SHIFT = 0x04u,
+};
+
 /* character attribute. this could be as simple as VGA's 16-colour palette
    plus an extra bit for bright, or a full 24-bit RGB value with bold and underline
    support, depending on what the driver supports. */
@@ -81,19 +91,35 @@ struct tty_driver {
 	struct tty_driver_ops *tty_ops;
 };
 
+struct tty_ldisc {
+	char name[OBJECT_NAME_MAX];
+	void(*process_events)(struct device *);
+};
+
 struct tty_device {
 	unsigned int tty_xcells, tty_ycells;
 	unsigned int tty_xcur, tty_ycur;
 	unsigned int tty_iflag, tty_oflag, tty_lflag;
 	tty_attrib_t tty_curattrib;
+
+	enum tty_modifier_key tty_modstate;
+
+	struct tty_ldisc *tty_ldisc;
+
+	/* raw input events sent to the TTY */
+	struct ringbuffer tty_events;
+	/* input characters processed from tty_events, returned by tty_read()  */
+	struct ringbuffer tty_input;
 };
 
 extern kern_status_t tty_bootstrap(void);
+extern struct tty_ldisc *tty_default_line_discipline(void);
 
 extern struct device *tty_device_create(void);
 extern kern_status_t tty_device_register(struct device *dev, struct tty_driver *owner, struct device *parent);
 
-extern void tty_set_printk_output(struct device *tty);
+extern void tty_set_foreground(struct device *tty);
+extern kern_status_t tty_connect_foreground_input_device(struct device *input);
 
 extern struct tty_driver *tty_driver_create(struct kext *self, const char *name);
 extern kern_status_t tty_driver_destroy(struct tty_driver *drv);
@@ -106,6 +132,7 @@ static inline struct driver *tty_driver_base(struct tty_driver *drv)
 
 extern kern_status_t tty_read(struct device *tty, void *buf, size_t max, size_t *nr_read, socks_flags_t flags);
 extern kern_status_t tty_write(struct device *tty, const void *buf, size_t len, size_t *nr_written, socks_flags_t flags);
+extern kern_status_t tty_report_event(struct device *tty, const struct input_event *ev);
 
 #ifdef __cplusplus
 }

init/main.c

@@ -21,120 +21,6 @@ extern unsigned long get_rflags(void);
 
 extern char __pstart[], __pend[];
 
-static char keycode_chars[] = {
-	[KEY_UNKNOWN]                = ' ',
-	[KEY_A]                      = 'a',
-	[KEY_B]                      = 'b',
-	[KEY_C]                      = 'c',
-	[KEY_D]                      = 'd',
-	[KEY_E]                      = 'e',
-	[KEY_F]                      = 'f',
-	[KEY_G]                      = 'g',
-	[KEY_H]                      = 'h',
-	[KEY_I]                      = 'i',
-	[KEY_J]                      = 'j',
-	[KEY_K]                      = 'k',
-	[KEY_L]                      = 'l',
-	[KEY_M]                      = 'm',
-	[KEY_N]                      = 'n',
-	[KEY_O]                      = 'o',
-	[KEY_P]                      = 'p',
-	[KEY_Q]                      = 'q',
-	[KEY_R]                      = 'r',
-	[KEY_S]                      = 's',
-	[KEY_T]                      = 't',
-	[KEY_U]                      = 'u',
-	[KEY_V]                      = 'v',
-	[KEY_W]                      = 'w',
-	[KEY_X]                      = 'x',
-	[KEY_Y]                      = 'y',
-	[KEY_Z]                      = 'z',
-	[KEY_KEY_1]                  = '1',
-	[KEY_KEY_2]                  = '2',
-	[KEY_KEY_3]                  = '3',
-	[KEY_KEY_4]                  = '4',
-	[KEY_KEY_5]                  = '5',
-	[KEY_KEY_6]                  = '6',
-	[KEY_KEY_7]                  = '7',
-	[KEY_KEY_8]                  = '8',
-	[KEY_KEY_9]                  = '9',
-	[KEY_KEY_0]                  = '0',
-	[KEY_ENTER]                  = '\n',
-	[KEY_ESCAPE]                 = 0,
-	[KEY_BACKSPACE]              = '\b',
-	[KEY_TAB]                    = ' ',
-	[KEY_SPACE]                  = ' ',
-	[KEY_MINUS]                  = '-',
-	[KEY_EQUALS]                 = '=',
-	[KEY_LEFT_BRACE]             = '[',
-	[KEY_RIGHT_BRACE]            = ']',
-	[KEY_BACKSLASH]              = '\\',
-	[KEY_NON_US_HASH]            = 0,
-	[KEY_SEMICOLON]              = ';',
-	[KEY_APOSTROPHE]             = '\'',
-	[KEY_GRAVE_ACCENT]           = 0,
-	[KEY_COMMA]                  = ',',
-	[KEY_DOT]                    = '.',
-	[KEY_SLASH]                  = '/',
-	[KEY_CAPS_LOCK]              = 0,
-	[KEY_F1]                     = 0,
-	[KEY_F2]                     = 0,
-	[KEY_F3]                     = 0,
-	[KEY_F4]                     = 0,
-	[KEY_F5]                     = 0,
-	[KEY_F6]                     = 0,
-	[KEY_F7]                     = 0,
-	[KEY_F8]                     = 0,
-	[KEY_F9]                     = 0,
-	[KEY_F10]                    = 0,
-	[KEY_F11]                    = 0,
-	[KEY_F12]                    = 0,
-	[KEY_PRINT_SCREEN]           = 0,
-	[KEY_SCROLL_LOCK]            = 0,
-	[KEY_PAUSE]                  = 0,
-	[KEY_INSERT]                 = 0,
-	[KEY_HOME]                   = 0,
-	[KEY_PAGE_UP]                = 0,
-	[KEY_DELETE]                 = 0,
-	[KEY_END]                    = 0,
-	[KEY_PAGE_DOWN]              = 0,
-	[KEY_RIGHT]                  = 0,
-	[KEY_LEFT]                   = 0,
-	[KEY_DOWN]                   = 0,
-	[KEY_UP]                     = 0,
-	[KEY_NUM_LOCK]               = 0,
-	[KEY_KEYPAD_SLASH]           = '/',
-	[KEY_KEYPAD_ASTERISK]        = '*',
-	[KEY_KEYPAD_MINUS]           = '-',
-	[KEY_KEYPAD_PLUS]            = '+',
-	[KEY_KEYPAD_ENTER]           = '\n',
-	[KEY_KEYPAD_1]               = '1',
-	[KEY_KEYPAD_2]               = '2',
-	[KEY_KEYPAD_3]               = '3',
-	[KEY_KEYPAD_4]               = '4',
-	[KEY_KEYPAD_5]               = '5',
-	[KEY_KEYPAD_6]               = '6',
-	[KEY_KEYPAD_7]               = '7',
-	[KEY_KEYPAD_8]               = '8',
-	[KEY_KEYPAD_9]               = '9',
-	[KEY_KEYPAD_0]               = '0',
-	[KEY_KEYPAD_DOT]             = '.',
-	[KEY_NON_US_BACKSLASH]       = 0,
-	[KEY_KEYPAD_EQUALS]          = '=',
-	[KEY_MENU]                   = 0,
-	[KEY_LEFT_CTRL]              = 0,
-	[KEY_LEFT_SHIFT]             = 0,
-	[KEY_LEFT_ALT]               = 0,
-	[KEY_LEFT_META]              = 0,
-	[KEY_RIGHT_CTRL]             = 0,
-	[KEY_RIGHT_SHIFT]            = 0,
-	[KEY_RIGHT_ALT]              = 0,
-	[KEY_RIGHT_META]             = 0,
-	[KEY_MEDIA_MUTE]             = 0,
-	[KEY_MEDIA_VOLUME_INCREMENT] = 0,
-	[KEY_MEDIA_VOLUME_DECREMENT] = 0,
-};
-
 void print_kernel_banner(void)
 {
 	printk("Socks kernel version " BUILD_ID);
@@ -210,7 +96,7 @@ void kernel_init(uintptr_t arg)
 	struct object *tty0;
 	status = object_get("/dev/tty/tty0", &tty0);
 	if (status == KERN_OK) {
-		tty_set_printk_output(cast_to_device(tty0));
+		tty_set_foreground(cast_to_device(tty0));
 	}
 
 	create_kernel_thread(background_thread);
@@ -220,31 +106,8 @@ void kernel_init(uintptr_t arg)
 	run_all_tests();
 
 	status = object_get("/dev/input/input0", &kbd);
-	if (status != KERN_OK) {
+	if (status == KERN_OK) {
-		printk("no keyboard available");
+		tty_connect_foreground_input_device(cast_to_device(kbd));
-		hang();
-	}
-
-	while (1) {
-		struct input_event ev;
-		size_t r;
-		status = object_read(kbd, &ev, sizeof ev, &r, 0);
-
-		if (status != KERN_OK || r != sizeof ev) {
-			printk("keyboard read error: %s", kern_status_string(status));
-			break;
-		}
-
-		if (ev.ev_type != INPUT_TYPE_KEY || ev.ev_key.state != INPUT_KEYSTATE_DOWN) {
-			continue;
-		}
-
-		char c = keycode_chars[ev.ev_key.key];
-		if (c == 0) {
-			continue;
-		}
-
-		putchar(c);
 	}
 
 	hang();

kernel/tty/device.c

@@ -1,6 +1,7 @@
 #include <socks/tty.h>
 #include <socks/device.h>
 #include <socks/console.h>
+#include <socks/input.h>
 #include <socks/libc/stdio.h>
 
 static struct char_device_ops tty_ops = {
@@ -8,12 +9,32 @@ static struct char_device_ops tty_ops = {
 	.write = tty_write,
 };
 
-static struct device *tty_printk_output = NULL;
+static spin_lock_t foreground_lock;
+static struct device *foreground = NULL;
+static struct device *foreground_input = NULL;
+
+static void tty_input_hook_callback(struct device *dev, struct input_event *ev, enum input_event_hook_flags *flags, void *arg)
+{
+	struct device *fg_tty = foreground;
+
+	if (!fg_tty) {
+		return;
+	}
+
+	tty_report_event(fg_tty, ev);
+	*flags = 0;
+}
+
+static struct input_event_hook foreground_input_hook = {
+	.hook_callback = tty_input_hook_callback,
+};
 
 static void tty_console_write(struct console *con, const char *s, unsigned int len)
 {
-	size_t nr_written;
+	if (foreground) {
-	tty_write(tty_printk_output, s, len, &nr_written, 0);
+		size_t nr_written;
+		tty_write(foreground, s, len, &nr_written, 0);
+	}
 }
 
 static struct console tty_console = {
@@ -30,10 +51,27 @@ struct device *tty_device_create(void)
 
 	struct tty_device *tty_dev = kmalloc(sizeof *tty_dev, VM_NORMAL);
 	if (!tty_dev) {
-		/* TODO destroy cdev */
+		object_deref(char_device_object(cdev));
 		return NULL;
 	}
 
+	kern_status_t status = ringbuffer_init(&tty_dev->tty_events, TTY_EVENT_QUEUE_SIZE * sizeof(struct input_event));
+	if (status != KERN_OK) {
+		kfree(tty_dev);
+		object_deref(char_device_object(cdev));
+		return NULL;
+	}
+
+	status = ringbuffer_init(&tty_dev->tty_input, TTY_INPUT_QUEUE_SIZE * sizeof(char));
+	if (status != KERN_OK) {
+		ringbuffer_deinit(&tty_dev->tty_events);
+		kfree(tty_dev);
+		object_deref(char_device_object(cdev));
+		return NULL;
+	}
+
+	tty_dev->tty_ldisc = tty_default_line_discipline();
+
 	cdev->c_ops = &tty_ops;
 	cdev->c_tty = tty_dev;
 
@@ -62,16 +100,47 @@ kern_status_t tty_device_register(struct device *dev, struct tty_driver *owner,
 	return object_namespace_create_link(global_namespace(), link_path, &dev->dev_base);
 }
 
-void tty_set_printk_output(struct device *tty)
+void tty_set_foreground(struct device *tty)
 {
 	bool console_init = false;
-	if (tty_printk_output) {
+	if (foreground) {
 		console_init = true;
 	}
 
-	tty_printk_output = tty;
+	foreground = tty;
 
 	if (!console_init) {
 		console_register(&tty_console);
 	}
 }
+
+kern_status_t tty_connect_foreground_input_device(struct device *input)
+{
+	struct input_device *inputdev = INPUT_DEVICE(input);
+	if (!inputdev) {
+		return KERN_INVALID_ARGUMENT;
+	}
+
+	unsigned long flags;
+	spin_lock_irqsave(&foreground_lock, &flags);
+
+	if (foreground_input) {
+		struct device *prev = foreground_input;
+		foreground_input = NULL;
+
+		device_lock(prev);
+		input_device_remove_hook(prev, &foreground_input_hook);
+		device_unlock(prev);
+		object_deref(&prev->dev_base);
+	}
+
+	object_ref(&input->dev_base);
+	foreground_input = input;
+	device_lock(input);
+	input_device_add_hook(input, &foreground_input_hook);
+	device_unlock(input);
+
+	spin_unlock_irqrestore(&foreground_lock, flags);
+
+	return KERN_OK;
+}

kernel/tty/ldisc.c

@@ -0,0 +1,339 @@
+#include <socks/tty.h>
+#include <socks/input.h>
+#include <socks/libc/ctype.h>
+
+static void process_events(struct device *tty);
+
+static char keycode_chars[] = {
+	[KEY_UNKNOWN]                = ' ',
+	[KEY_A]                      = 'a',
+	[KEY_B]                      = 'b',
+	[KEY_C]                      = 'c',
+	[KEY_D]                      = 'd',
+	[KEY_E]                      = 'e',
+	[KEY_F]                      = 'f',
+	[KEY_G]                      = 'g',
+	[KEY_H]                      = 'h',
+	[KEY_I]                      = 'i',
+	[KEY_J]                      = 'j',
+	[KEY_K]                      = 'k',
+	[KEY_L]                      = 'l',
+	[KEY_M]                      = 'm',
+	[KEY_N]                      = 'n',
+	[KEY_O]                      = 'o',
+	[KEY_P]                      = 'p',
+	[KEY_Q]                      = 'q',
+	[KEY_R]                      = 'r',
+	[KEY_S]                      = 's',
+	[KEY_T]                      = 't',
+	[KEY_U]                      = 'u',
+	[KEY_V]                      = 'v',
+	[KEY_W]                      = 'w',
+	[KEY_X]                      = 'x',
+	[KEY_Y]                      = 'y',
+	[KEY_Z]                      = 'z',
+	[KEY_KEY_1]                  = '1',
+	[KEY_KEY_2]                  = '2',
+	[KEY_KEY_3]                  = '3',
+	[KEY_KEY_4]                  = '4',
+	[KEY_KEY_5]                  = '5',
+	[KEY_KEY_6]                  = '6',
+	[KEY_KEY_7]                  = '7',
+	[KEY_KEY_8]                  = '8',
+	[KEY_KEY_9]                  = '9',
+	[KEY_KEY_0]                  = '0',
+	[KEY_ENTER]                  = '\n',
+	[KEY_ESCAPE]                 = 0,
+	[KEY_BACKSPACE]              = '\b',
+	[KEY_TAB]                    = ' ',
+	[KEY_SPACE]                  = ' ',
+	[KEY_MINUS]                  = '-',
+	[KEY_EQUALS]                 = '=',
+	[KEY_LEFT_BRACE]             = '[',
+	[KEY_RIGHT_BRACE]            = ']',
+	[KEY_BACKSLASH]              = '\\',
+	[KEY_NON_US_HASH]            = 0,
+	[KEY_SEMICOLON]              = ';',
+	[KEY_APOSTROPHE]             = '\'',
+	[KEY_GRAVE_ACCENT]           = 0,
+	[KEY_COMMA]                  = ',',
+	[KEY_DOT]                    = '.',
+	[KEY_SLASH]                  = '/',
+	[KEY_CAPS_LOCK]              = 0,
+	[KEY_F1]                     = 0,
+	[KEY_F2]                     = 0,
+	[KEY_F3]                     = 0,
+	[KEY_F4]                     = 0,
+	[KEY_F5]                     = 0,
+	[KEY_F6]                     = 0,
+	[KEY_F7]                     = 0,
+	[KEY_F8]                     = 0,
+	[KEY_F9]                     = 0,
+	[KEY_F10]                    = 0,
+	[KEY_F11]                    = 0,
+	[KEY_F12]                    = 0,
+	[KEY_PRINT_SCREEN]           = 0,
+	[KEY_SCROLL_LOCK]            = 0,
+	[KEY_PAUSE]                  = 0,
+	[KEY_INSERT]                 = 0,
+	[KEY_HOME]                   = 0,
+	[KEY_PAGE_UP]                = 0,
+	[KEY_DELETE]                 = 0,
+	[KEY_END]                    = 0,
+	[KEY_PAGE_DOWN]              = 0,
+	[KEY_RIGHT]                  = 0,
+	[KEY_LEFT]                   = 0,
+	[KEY_DOWN]                   = 0,
+	[KEY_UP]                     = 0,
+	[KEY_NUM_LOCK]               = 0,
+	[KEY_KEYPAD_SLASH]           = '/',
+	[KEY_KEYPAD_ASTERISK]        = '*',
+	[KEY_KEYPAD_MINUS]           = '-',
+	[KEY_KEYPAD_PLUS]            = '+',
+	[KEY_KEYPAD_ENTER]           = '\n',
+	[KEY_KEYPAD_1]               = '1',
+	[KEY_KEYPAD_2]               = '2',
+	[KEY_KEYPAD_3]               = '3',
+	[KEY_KEYPAD_4]               = '4',
+	[KEY_KEYPAD_5]               = '5',
+	[KEY_KEYPAD_6]               = '6',
+	[KEY_KEYPAD_7]               = '7',
+	[KEY_KEYPAD_8]               = '8',
+	[KEY_KEYPAD_9]               = '9',
+	[KEY_KEYPAD_0]               = '0',
+	[KEY_KEYPAD_DOT]             = '.',
+	[KEY_NON_US_BACKSLASH]       = 0,
+	[KEY_KEYPAD_EQUALS]          = '=',
+	[KEY_MENU]                   = 0,
+	[KEY_LEFT_CTRL]              = 0,
+	[KEY_LEFT_SHIFT]             = 0,
+	[KEY_LEFT_ALT]               = 0,
+	[KEY_LEFT_META]              = 0,
+	[KEY_RIGHT_CTRL]             = 0,
+	[KEY_RIGHT_SHIFT]            = 0,
+	[KEY_RIGHT_ALT]              = 0,
+	[KEY_RIGHT_META]             = 0,
+	[KEY_MEDIA_MUTE]             = 0,
+	[KEY_MEDIA_VOLUME_INCREMENT] = 0,
+	[KEY_MEDIA_VOLUME_DECREMENT] = 0,
+};
+
+static char keycode_chars_shift[] = {
+	[KEY_UNKNOWN]                = ' ',
+	[KEY_A]                      = 'A',
+	[KEY_B]                      = 'B',
+	[KEY_C]                      = 'C',
+	[KEY_D]                      = 'D',
+	[KEY_E]                      = 'E',
+	[KEY_F]                      = 'F',
+	[KEY_G]                      = 'G',
+	[KEY_H]                      = 'H',
+	[KEY_I]                      = 'I',
+	[KEY_J]                      = 'J',
+	[KEY_K]                      = 'K',
+	[KEY_L]                      = 'L',
+	[KEY_M]                      = 'M',
+	[KEY_N]                      = 'N',
+	[KEY_O]                      = 'O',
+	[KEY_P]                      = 'P',
+	[KEY_Q]                      = 'Q',
+	[KEY_R]                      = 'R',
+	[KEY_S]                      = 'S',
+	[KEY_T]                      = 'T',
+	[KEY_U]                      = 'U',
+	[KEY_V]                      = 'V',
+	[KEY_W]                      = 'W',
+	[KEY_X]                      = 'X',
+	[KEY_Y]                      = 'Y',
+	[KEY_Z]                      = 'Z',
+	[KEY_KEY_1]                  = '!',
+	[KEY_KEY_2]                  = '"',
+	[KEY_KEY_3]                  = 0,
+	[KEY_KEY_4]                  = '$',
+	[KEY_KEY_5]                  = '%',
+	[KEY_KEY_6]                  = '^',
+	[KEY_KEY_7]                  = '&',
+	[KEY_KEY_8]                  = '*',
+	[KEY_KEY_9]                  = '(',
+	[KEY_KEY_0]                  = ')',
+	[KEY_ENTER]                  = '\n',
+	[KEY_ESCAPE]                 = 0,
+	[KEY_BACKSPACE]              = '\b',
+	[KEY_TAB]                    = ' ',
+	[KEY_SPACE]                  = ' ',
+	[KEY_MINUS]                  = '_',
+	[KEY_EQUALS]                 = '+',
+	[KEY_LEFT_BRACE]             = '{',
+	[KEY_RIGHT_BRACE]            = '}',
+	[KEY_BACKSLASH]              = '|',
+	[KEY_NON_US_HASH]            = 0,
+	[KEY_SEMICOLON]              = ':',
+	[KEY_APOSTROPHE]             = '@',
+	[KEY_GRAVE_ACCENT]           = 0,
+	[KEY_COMMA]                  = '<',
+	[KEY_DOT]                    = '>',
+	[KEY_SLASH]                  = '?',
+	[KEY_CAPS_LOCK]              = 0,
+	[KEY_F1]                     = 0,
+	[KEY_F2]                     = 0,
+	[KEY_F3]                     = 0,
+	[KEY_F4]                     = 0,
+	[KEY_F5]                     = 0,
+	[KEY_F6]                     = 0,
+	[KEY_F7]                     = 0,
+	[KEY_F8]                     = 0,
+	[KEY_F9]                     = 0,
+	[KEY_F10]                    = 0,
+	[KEY_F11]                    = 0,
+	[KEY_F12]                    = 0,
+	[KEY_PRINT_SCREEN]           = 0,
+	[KEY_SCROLL_LOCK]            = 0,
+	[KEY_PAUSE]                  = 0,
+	[KEY_INSERT]                 = 0,
+	[KEY_HOME]                   = 0,
+	[KEY_PAGE_UP]                = 0,
+	[KEY_DELETE]                 = 0,
+	[KEY_END]                    = 0,
+	[KEY_PAGE_DOWN]              = 0,
+	[KEY_RIGHT]                  = 0,
+	[KEY_LEFT]                   = 0,
+	[KEY_DOWN]                   = 0,
+	[KEY_UP]                     = 0,
+	[KEY_NUM_LOCK]               = 0,
+	[KEY_KEYPAD_SLASH]           = '/',
+	[KEY_KEYPAD_ASTERISK]        = '*',
+	[KEY_KEYPAD_MINUS]           = '-',
+	[KEY_KEYPAD_PLUS]            = '+',
+	[KEY_KEYPAD_ENTER]           = '\n',
+	[KEY_KEYPAD_1]               = '1',
+	[KEY_KEYPAD_2]               = '2',
+	[KEY_KEYPAD_3]               = '3',
+	[KEY_KEYPAD_4]               = '4',
+	[KEY_KEYPAD_5]               = '5',
+	[KEY_KEYPAD_6]               = '6',
+	[KEY_KEYPAD_7]               = '7',
+	[KEY_KEYPAD_8]               = '8',
+	[KEY_KEYPAD_9]               = '9',
+	[KEY_KEYPAD_0]               = '0',
+	[KEY_KEYPAD_DOT]             = '.',
+	[KEY_NON_US_BACKSLASH]       = 0,
+	[KEY_KEYPAD_EQUALS]          = '=',
+	[KEY_MENU]                   = 0,
+	[KEY_LEFT_CTRL]              = 0,
+	[KEY_LEFT_SHIFT]             = 0,
+	[KEY_LEFT_ALT]               = 0,
+	[KEY_LEFT_META]              = 0,
+	[KEY_RIGHT_CTRL]             = 0,
+	[KEY_RIGHT_SHIFT]            = 0,
+	[KEY_RIGHT_ALT]              = 0,
+	[KEY_RIGHT_META]             = 0,
+	[KEY_MEDIA_MUTE]             = 0,
+	[KEY_MEDIA_VOLUME_INCREMENT] = 0,
+	[KEY_MEDIA_VOLUME_DECREMENT] = 0,
+};
+
+static struct tty_ldisc default_ldisc = {
+	.name = "n_tty",
+	.process_events = process_events,
+};
+
+static enum tty_modifier_key get_modifier_key(struct input_event *ev)
+{
+	switch (ev->ev_key.key) {
+	case KEY_LEFT_CTRL:
+	case KEY_RIGHT_CTRL:
+		return TTY_KEY_CTRL;
+	case KEY_LEFT_ALT:
+	case KEY_RIGHT_ALT:
+		return TTY_KEY_ALT;
+	case KEY_LEFT_SHIFT:
+	case KEY_RIGHT_SHIFT:
+		return TTY_KEY_SHIFT;
+	default:
+		return TTY_KEY_OTHER;
+	}
+}
+
+static void handle_modifier_keys(struct device *tty, enum tty_modifier_key modkey, struct input_event *ev)
+{
+	struct tty_device *ttydev = TTY_DEVICE(tty);
+
+	if (ev->ev_key.state == INPUT_KEYSTATE_DOWN) {
+		ttydev->tty_modstate |= modkey;
+	} else {
+		ttydev->tty_modstate &= ~modkey;
+	}
+}
+
+static void convert_ev_to_chars(struct device *tty, struct input_event *ev)
+{
+	if (ev->ev_key.state == INPUT_KEYSTATE_UP) {
+		return;
+	}
+
+	struct tty_device *ttydev = TTY_DEVICE(tty);
+
+	char echo[2];
+	int echo_len = 0;
+
+	char c = keycode_chars[ev->ev_key.key];
+	if (c == 0) {
+		return;
+	}
+
+	if (ttydev->tty_modstate & TTY_KEY_CTRL) {
+		if (!isalpha(c)) {
+			return;
+		}
+
+		echo[0] = '^';
+		echo[1] = toupper(c);
+		echo_len = 2;
+
+		c = tolower(c);
+		c -= 97;
+		c++;
+	} else if (ttydev->tty_modstate & TTY_KEY_SHIFT) {
+		c = keycode_chars_shift[ev->ev_key.key];
+		echo[0] = c;
+		echo_len = 1;
+	} else {
+		echo[0] = c;
+		echo_len = 1;
+	}
+
+	if (c == 0) {
+		return;
+	}
+
+	ringbuffer_write(&ttydev->tty_input, sizeof c, &c, S_NOBLOCK);
+	size_t nr_written;
+	tty_write(tty, echo, echo_len, &nr_written, S_NOBLOCK);
+}
+
+void process_events(struct device *tty)
+{
+	struct tty_device *ttydev = TTY_DEVICE(tty);
+	struct ringbuffer *events = &ttydev->tty_events;
+
+	struct input_event ev;
+
+	size_t w = ringbuffer_read(events, sizeof ev, &ev, S_NOBLOCK);
+
+	if (w != sizeof ev || ev.ev_type != INPUT_TYPE_KEY) {
+		return;
+	}
+
+	enum tty_modifier_key modkeys = get_modifier_key(&ev);
+
+	if (modkeys != TTY_KEY_OTHER) {
+		handle_modifier_keys(tty, modkeys, &ev);
+	} else {
+		convert_ev_to_chars(tty, &ev);
+	}
+}
+
+struct tty_ldisc *tty_default_line_discipline(void)
+{
+	return &default_ldisc;
+}

kernel/tty/tty.c

@@ -1,4 +1,5 @@
 #include <socks/tty.h>
+#include <socks/input.h>
 #include <socks/printk.h>
 
 static void newline(struct device *tty)
@@ -90,3 +91,36 @@ kern_status_t tty_write(struct device *tty, const void *buf, size_t len, size_t
 	*nr_written = r;
 	return KERN_OK;
 }
+
+static void process_events(struct device *tty)
+{
+	struct tty_device *ttydev = TTY_DEVICE(tty);
+
+	if (!ttydev->tty_ldisc || !ttydev->tty_ldisc->process_events) {
+		struct input_event ev;
+		while (ringbuffer_unread(&ttydev->tty_events)) {
+			ringbuffer_read(&ttydev->tty_events, sizeof ev, &ev, S_NOBLOCK);
+		}
+
+		return;
+	}
+
+	ttydev->tty_ldisc->process_events(tty);
+}
+
+kern_status_t tty_report_event(struct device *tty, const struct input_event *ev)
+{
+	struct tty_device *ttydev = TTY_DEVICE(tty);
+	size_t w = ringbuffer_write(&ttydev->tty_events, sizeof *ev, ev, S_NOBLOCK);
+
+	if (w != sizeof *ev) {
+		return KERN_WOULD_BLOCK;
+	}
+
+	if (ringbuffer_unread(&ttydev->tty_events) > 0) {
+		process_events(tty);
+
+	}
+
+	return KERN_OK;
+}