qemu/ui/input-linux.c
Ryan El Kochta 2657846fb2 input-linux: customizable grab toggle keys
This patch adds a new option to the input-linux object:

grab-toggle=[key-combo]

The key combination can be one of the following:

* ctrl-ctrl
* alt-alt
* meta-meta
* scrolllock
* ctrl-scrolllock

The user can pick any of these key combinations. The VM's grab
of the evdev device will be toggled when the key combination is
pressed.

Any invalid setting will result in an error. No setting will
result in the current default of ctrl-ctrl.

The right and left ctrl key both work for Ctrl-Scrolllock.

If scrolllock is selected as one of the grab-toggle keys, it
will be entirely disabled and not passed to the guest at all.
This is to prevent enabling it while attempting to leave or enter
the VM. On the host, scrolllock can be disabled using xmodmap.

First, find the modifier that Scroll_Lock is bound to:

$ xmodmap -pm

Then, remove Scroll_Lock from it, replacing modX with the modifier:

$ xmodmap -e 'remove modX = Scroll_Lock'

If Scroll_Lock is not bound to any modifier, it is already disabled.

To save the changes, add them to your xinitrc.

Ryan El Kochta (1):
  input-linux: customizable grab toggle keys v5

Signed-off-by: Ryan El Kochta <relkochta@gmail.com>
Message-id: 20190123214555.12712-2-relkochta@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2019-01-24 10:42:38 +01:00

513 lines
14 KiB
C

/*
* This work is licensed under the terms of the GNU GPL, version 2 or
* (at your option) any later version. See the COPYING file in the
* top-level directory.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "qemu/config-file.h"
#include "qemu/sockets.h"
#include "sysemu/sysemu.h"
#include "ui/input.h"
#include "qom/object_interfaces.h"
#include "sysemu/iothread.h"
#include "block/aio.h"
#include <sys/ioctl.h>
#include "standard-headers/linux/input.h"
static bool linux_is_button(unsigned int lnx)
{
if (lnx < 0x100) {
return false;
}
if (lnx >= 0x160 && lnx < 0x2c0) {
return false;
}
return true;
}
#define TYPE_INPUT_LINUX "input-linux"
#define INPUT_LINUX(obj) \
OBJECT_CHECK(InputLinux, (obj), TYPE_INPUT_LINUX)
#define INPUT_LINUX_GET_CLASS(obj) \
OBJECT_GET_CLASS(InputLinuxClass, (obj), TYPE_INPUT_LINUX)
#define INPUT_LINUX_CLASS(klass) \
OBJECT_CLASS_CHECK(InputLinuxClass, (klass), TYPE_INPUT_LINUX)
typedef struct InputLinux InputLinux;
typedef struct InputLinuxClass InputLinuxClass;
struct InputLinux {
Object parent;
char *evdev;
int fd;
bool repeat;
bool grab_request;
bool grab_active;
bool grab_all;
bool keydown[KEY_CNT];
int keycount;
int wheel;
bool initialized;
bool has_rel_x;
bool has_abs_x;
int num_keys;
int num_btns;
int abs_x_min;
int abs_x_max;
int abs_y_min;
int abs_y_max;
struct input_event event;
int read_offset;
enum GrabToggleKeys grab_toggle;
QTAILQ_ENTRY(InputLinux) next;
};
struct InputLinuxClass {
ObjectClass parent_class;
};
static QTAILQ_HEAD(, InputLinux) inputs = QTAILQ_HEAD_INITIALIZER(inputs);
static void input_linux_toggle_grab(InputLinux *il)
{
intptr_t request = !il->grab_active;
InputLinux *item;
int rc;
rc = ioctl(il->fd, EVIOCGRAB, request);
if (rc < 0) {
return;
}
il->grab_active = !il->grab_active;
if (!il->grab_all) {
return;
}
QTAILQ_FOREACH(item, &inputs, next) {
if (item == il || item->grab_all) {
/* avoid endless loops */
continue;
}
if (item->grab_active != il->grab_active) {
input_linux_toggle_grab(item);
}
}
}
static bool input_linux_check_toggle(InputLinux *il)
{
switch (il->grab_toggle) {
case GRAB_TOGGLE_KEYS_CTRL_CTRL:
return il->keydown[KEY_LEFTCTRL] &&
il->keydown[KEY_RIGHTCTRL];
case GRAB_TOGGLE_KEYS_ALT_ALT:
return il->keydown[KEY_LEFTALT] &&
il->keydown[KEY_RIGHTALT];
case GRAB_TOGGLE_KEYS_META_META:
return il->keydown[KEY_LEFTMETA] &&
il->keydown[KEY_RIGHTMETA];
case GRAB_TOGGLE_KEYS_SCROLLLOCK:
return il->keydown[KEY_SCROLLLOCK];
case GRAB_TOGGLE_KEYS_CTRL_SCROLLLOCK:
return (il->keydown[KEY_LEFTCTRL] ||
il->keydown[KEY_RIGHTCTRL]) &&
il->keydown[KEY_SCROLLLOCK];
case GRAB_TOGGLE_KEYS__MAX:
/* avoid gcc error */
break;
}
return false;
}
static bool input_linux_should_skip(InputLinux *il,
struct input_event *event)
{
return (il->grab_toggle == GRAB_TOGGLE_KEYS_SCROLLLOCK ||
il->grab_toggle == GRAB_TOGGLE_KEYS_CTRL_SCROLLLOCK) &&
event->code == KEY_SCROLLLOCK;
}
static void input_linux_handle_keyboard(InputLinux *il,
struct input_event *event)
{
if (event->type == EV_KEY) {
if (event->value > 2 || (event->value > 1 && !il->repeat)) {
/*
* ignore autorepeat + unknown key events
* 0 == up, 1 == down, 2 == autorepeat, other == undefined
*/
return;
}
if (event->code >= KEY_CNT) {
/*
* Should not happen. But better safe than sorry,
* and we make Coverity happy too.
*/
return;
}
/* keep track of key state */
if (!il->keydown[event->code] && event->value) {
il->keydown[event->code] = true;
il->keycount++;
}
if (il->keydown[event->code] && !event->value) {
il->keydown[event->code] = false;
il->keycount--;
}
/* send event to guest when grab is active */
if (il->grab_active && !input_linux_should_skip(il, event)) {
int qcode = qemu_input_linux_to_qcode(event->code);
qemu_input_event_send_key_qcode(NULL, qcode, event->value);
}
/* hotkey -> record switch request ... */
if (input_linux_check_toggle(il)) {
il->grab_request = true;
}
/*
* ... and do the switch when all keys are lifted, so we
* confuse neither guest nor host with keys which seem to
* be stuck due to missing key-up events.
*/
if (il->grab_request && !il->keycount) {
il->grab_request = false;
input_linux_toggle_grab(il);
}
}
}
static void input_linux_event_mouse_button(int button)
{
qemu_input_queue_btn(NULL, button, true);
qemu_input_event_sync();
qemu_input_queue_btn(NULL, button, false);
qemu_input_event_sync();
}
static void input_linux_handle_mouse(InputLinux *il, struct input_event *event)
{
if (!il->grab_active) {
return;
}
switch (event->type) {
case EV_KEY:
switch (event->code) {
case BTN_LEFT:
qemu_input_queue_btn(NULL, INPUT_BUTTON_LEFT, event->value);
break;
case BTN_RIGHT:
qemu_input_queue_btn(NULL, INPUT_BUTTON_RIGHT, event->value);
break;
case BTN_MIDDLE:
qemu_input_queue_btn(NULL, INPUT_BUTTON_MIDDLE, event->value);
break;
case BTN_GEAR_UP:
qemu_input_queue_btn(NULL, INPUT_BUTTON_WHEEL_UP, event->value);
break;
case BTN_GEAR_DOWN:
qemu_input_queue_btn(NULL, INPUT_BUTTON_WHEEL_DOWN,
event->value);
break;
case BTN_SIDE:
qemu_input_queue_btn(NULL, INPUT_BUTTON_SIDE, event->value);
break;
case BTN_EXTRA:
qemu_input_queue_btn(NULL, INPUT_BUTTON_EXTRA, event->value);
break;
};
break;
case EV_REL:
switch (event->code) {
case REL_X:
qemu_input_queue_rel(NULL, INPUT_AXIS_X, event->value);
break;
case REL_Y:
qemu_input_queue_rel(NULL, INPUT_AXIS_Y, event->value);
break;
case REL_WHEEL:
il->wheel = event->value;
break;
}
break;
case EV_ABS:
switch (event->code) {
case ABS_X:
qemu_input_queue_abs(NULL, INPUT_AXIS_X, event->value,
il->abs_x_min, il->abs_x_max);
break;
case ABS_Y:
qemu_input_queue_abs(NULL, INPUT_AXIS_Y, event->value,
il->abs_y_min, il->abs_y_max);
break;
}
break;
case EV_SYN:
qemu_input_event_sync();
if (il->wheel != 0) {
input_linux_event_mouse_button((il->wheel > 0)
? INPUT_BUTTON_WHEEL_UP
: INPUT_BUTTON_WHEEL_DOWN);
il->wheel = 0;
}
break;
}
}
static void input_linux_event(void *opaque)
{
InputLinux *il = opaque;
int rc;
int read_size;
uint8_t *p = (uint8_t *)&il->event;
for (;;) {
read_size = sizeof(il->event) - il->read_offset;
rc = read(il->fd, &p[il->read_offset], read_size);
if (rc != read_size) {
if (rc < 0 && errno != EAGAIN) {
fprintf(stderr, "%s: read: %s\n", __func__, strerror(errno));
qemu_set_fd_handler(il->fd, NULL, NULL, NULL);
close(il->fd);
} else if (rc > 0) {
il->read_offset += rc;
}
break;
}
il->read_offset = 0;
if (il->num_keys) {
input_linux_handle_keyboard(il, &il->event);
}
if ((il->has_rel_x || il->has_abs_x) && il->num_btns) {
input_linux_handle_mouse(il, &il->event);
}
}
}
static void input_linux_complete(UserCreatable *uc, Error **errp)
{
InputLinux *il = INPUT_LINUX(uc);
uint8_t evtmap, relmap, absmap;
uint8_t keymap[KEY_CNT / 8], keystate[KEY_CNT / 8];
unsigned int i;
int rc, ver;
struct input_absinfo absinfo;
if (!il->evdev) {
error_setg(errp, "no input device specified");
return;
}
il->fd = open(il->evdev, O_RDWR);
if (il->fd < 0) {
error_setg_file_open(errp, errno, il->evdev);
return;
}
qemu_set_nonblock(il->fd);
rc = ioctl(il->fd, EVIOCGVERSION, &ver);
if (rc < 0) {
error_setg(errp, "%s: is not an evdev device", il->evdev);
goto err_close;
}
rc = ioctl(il->fd, EVIOCGBIT(0, sizeof(evtmap)), &evtmap);
if (rc < 0) {
error_setg(errp, "%s: failed to read event bits", il->evdev);
goto err_close;
}
if (evtmap & (1 << EV_REL)) {
relmap = 0;
rc = ioctl(il->fd, EVIOCGBIT(EV_REL, sizeof(relmap)), &relmap);
if (relmap & (1 << REL_X)) {
il->has_rel_x = true;
}
}
if (evtmap & (1 << EV_ABS)) {
absmap = 0;
rc = ioctl(il->fd, EVIOCGBIT(EV_ABS, sizeof(absmap)), &absmap);
if (absmap & (1 << ABS_X)) {
il->has_abs_x = true;
rc = ioctl(il->fd, EVIOCGABS(ABS_X), &absinfo);
il->abs_x_min = absinfo.minimum;
il->abs_x_max = absinfo.maximum;
rc = ioctl(il->fd, EVIOCGABS(ABS_Y), &absinfo);
il->abs_y_min = absinfo.minimum;
il->abs_y_max = absinfo.maximum;
}
}
if (evtmap & (1 << EV_KEY)) {
memset(keymap, 0, sizeof(keymap));
rc = ioctl(il->fd, EVIOCGBIT(EV_KEY, sizeof(keymap)), keymap);
rc = ioctl(il->fd, EVIOCGKEY(sizeof(keystate)), keystate);
for (i = 0; i < KEY_CNT; i++) {
if (keymap[i / 8] & (1 << (i % 8))) {
if (linux_is_button(i)) {
il->num_btns++;
} else {
il->num_keys++;
}
if (keystate[i / 8] & (1 << (i % 8))) {
il->keydown[i] = true;
il->keycount++;
}
}
}
}
qemu_set_fd_handler(il->fd, input_linux_event, NULL, il);
if (il->keycount) {
/* delay grab until all keys are released */
il->grab_request = true;
} else {
input_linux_toggle_grab(il);
}
QTAILQ_INSERT_TAIL(&inputs, il, next);
il->initialized = true;
return;
err_close:
close(il->fd);
return;
}
static void input_linux_instance_finalize(Object *obj)
{
InputLinux *il = INPUT_LINUX(obj);
if (il->initialized) {
QTAILQ_REMOVE(&inputs, il, next);
close(il->fd);
}
g_free(il->evdev);
}
static char *input_linux_get_evdev(Object *obj, Error **errp)
{
InputLinux *il = INPUT_LINUX(obj);
return g_strdup(il->evdev);
}
static void input_linux_set_evdev(Object *obj, const char *value,
Error **errp)
{
InputLinux *il = INPUT_LINUX(obj);
if (il->evdev) {
error_setg(errp, "evdev property already set");
return;
}
il->evdev = g_strdup(value);
}
static bool input_linux_get_grab_all(Object *obj, Error **errp)
{
InputLinux *il = INPUT_LINUX(obj);
return il->grab_all;
}
static void input_linux_set_grab_all(Object *obj, bool value,
Error **errp)
{
InputLinux *il = INPUT_LINUX(obj);
il->grab_all = value;
}
static bool input_linux_get_repeat(Object *obj, Error **errp)
{
InputLinux *il = INPUT_LINUX(obj);
return il->repeat;
}
static void input_linux_set_repeat(Object *obj, bool value,
Error **errp)
{
InputLinux *il = INPUT_LINUX(obj);
il->repeat = value;
}
static int input_linux_get_grab_toggle(Object *obj, Error **errp)
{
InputLinux *il = INPUT_LINUX(obj);
return il->grab_toggle;
}
static void input_linux_set_grab_toggle(Object *obj, int value,
Error **errp)
{
InputLinux *il = INPUT_LINUX(obj);
il->grab_toggle = value;
}
static void input_linux_instance_init(Object *obj)
{
object_property_add_str(obj, "evdev",
input_linux_get_evdev,
input_linux_set_evdev, NULL);
object_property_add_bool(obj, "grab_all",
input_linux_get_grab_all,
input_linux_set_grab_all, NULL);
object_property_add_bool(obj, "repeat",
input_linux_get_repeat,
input_linux_set_repeat, NULL);
object_property_add_enum(obj, "grab-toggle", "GrabToggleKeys",
&GrabToggleKeys_lookup,
input_linux_get_grab_toggle,
input_linux_set_grab_toggle, NULL);
}
static void input_linux_class_init(ObjectClass *oc, void *data)
{
UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
ucc->complete = input_linux_complete;
}
static const TypeInfo input_linux_info = {
.name = TYPE_INPUT_LINUX,
.parent = TYPE_OBJECT,
.class_size = sizeof(InputLinuxClass),
.class_init = input_linux_class_init,
.instance_size = sizeof(InputLinux),
.instance_init = input_linux_instance_init,
.instance_finalize = input_linux_instance_finalize,
.interfaces = (InterfaceInfo[]) {
{ TYPE_USER_CREATABLE },
{ }
}
};
static void register_types(void)
{
type_register_static(&input_linux_info);
}
type_init(register_types);