static ssize_t uinput_inject_events(struct uinput_device *udev,
const char __user *buffer, size_t count)
{
struct input_event ev;
size_t bytes = 0;
if (count != 0 && count < input_event_size())
return -EINVAL;
while (bytes + input_event_size() <= count) {
/*
* Note that even if some events were fetched successfully
* we are still going to return EFAULT instead of partial
* count to let userspace know that it got it's buffers
* all wrong.
*/
if (input_event_from_user(buffer + bytes, &ev))
return -EFAULT;
input_event(udev->dev, ev.type, ev.code, ev.value);
bytes += input_event_size();
}
return bytes;
}
static inline ssize_t uinput_inject_event(struct uinput_device *udev, const char __user *buffer, size_t count)
{
struct input_event ev;
if (count < input_event_size())
return -EINVAL;
if (input_event_from_user(buffer, &ev))
return -EFAULT;
input_event(udev->dev, ev.type, ev.code, ev.value);
return input_event_size();
}
static ssize_t uinput_read(struct file *file, char __user *buffer,
size_t count, loff_t *ppos)
{
struct uinput_device *udev = file->private_data;
ssize_t retval;
if (count != 0 && count < input_event_size())
return -EINVAL;
do {
retval = mutex_lock_interruptible(&udev->mutex);
if (retval)
return retval;
if (udev->state != UIST_CREATED)
retval = -ENODEV;
else if (udev->head == udev->tail &&
(file->f_flags & O_NONBLOCK))
retval = -EAGAIN;
else
retval = uinput_events_to_user(udev, buffer, count);
mutex_unlock(&udev->mutex);
if (retval || count == 0)
break;
if (!(file->f_flags & O_NONBLOCK))
retval = wait_event_interruptible(udev->waitq,
udev->head != udev->tail ||
udev->state != UIST_CREATED);
} while (retval == 0);
return retval;
}
static ssize_t uinput_events_to_user(struct uinput_device *udev,
char __user *buffer, size_t count)
{
struct input_event event;
size_t read = 0;
while (read + input_event_size() <= count &&
uinput_fetch_next_event(udev, &event)) {
if (input_event_to_user(buffer + read, &event))
return -EFAULT;
read += input_event_size();
}
return read;
}
static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
struct uinput_device *udev = file->private_data;
int retval = 0;
if (udev->state != UIST_CREATED)
return -ENODEV;
if (udev->head == udev->tail && (file->f_flags & O_NONBLOCK))
return -EAGAIN;
retval = wait_event_interruptible(udev->waitq,
udev->head != udev->tail || udev->state != UIST_CREATED);
if (retval)
return retval;
retval = mutex_lock_interruptible(&udev->mutex);
if (retval)
return retval;
if (udev->state != UIST_CREATED) {
retval = -ENODEV;
goto out;
}
while (udev->head != udev->tail && retval + input_event_size() <= count) {
if (input_event_to_user(buffer + retval, &udev->buff[udev->tail])) {
retval = -EFAULT;
goto out;
}
udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
retval += input_event_size();
}
out:
mutex_unlock(&udev->mutex);
return retval;
}
