1 files changed, 630 insertions, 0 deletions

diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
new file mode 100644
index 000000000..fade7fcf6
--- /dev/null
+++ b/drivers/hid/hidraw.c
@@ -0,0 +1,630 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * HID raw devices, giving access to raw HID events.
+ *
+ * In comparison to hiddev, this device does not process the
+ * hid events at all (no parsing, no lookups). This lets applications
+ * to work on raw hid events as they want to, and avoids a need to
+ * use a transport-specific userspace libhid/libusb libraries.
+ *
+ *  Copyright (c) 2007-2014 Jiri Kosina
+ */
+
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/cdev.h>
+#include <linux/poll.h>
+#include <linux/device.h>
+#include <linux/major.h>
+#include <linux/slab.h>
+#include <linux/hid.h>
+#include <linux/mutex.h>
+#include <linux/sched/signal.h>
+#include <linux/string.h>
+
+#include <linux/hidraw.h>
+
+static int hidraw_major;
+static struct cdev hidraw_cdev;
+static struct class *hidraw_class;
+static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
+static DEFINE_MUTEX(minors_lock);
+
+static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
+{
+	struct hidraw_list *list = file->private_data;
+	int ret = 0, len;
+	DECLARE_WAITQUEUE(wait, current);
+
+	mutex_lock(&list->read_mutex);
+
+	while (ret == 0) {
+		if (list->head == list->tail) {
+			add_wait_queue(&list->hidraw->wait, &wait);
+			set_current_state(TASK_INTERRUPTIBLE);
+
+			while (list->head == list->tail) {
+				if (signal_pending(current)) {
+					ret = -ERESTARTSYS;
+					break;
+				}
+				if (!list->hidraw->exist) {
+					ret = -EIO;
+					break;
+				}
+				if (file->f_flags & O_NONBLOCK) {
+					ret = -EAGAIN;
+					break;
+				}
+
+				/* allow O_NONBLOCK to work well from other threads */
+				mutex_unlock(&list->read_mutex);
+				schedule();
+				mutex_lock(&list->read_mutex);
+				set_current_state(TASK_INTERRUPTIBLE);
+			}
+
+			set_current_state(TASK_RUNNING);
+			remove_wait_queue(&list->hidraw->wait, &wait);
+		}
+
+		if (ret)
+			goto out;
+
+		len = list->buffer[list->tail].len > count ?
+			count : list->buffer[list->tail].len;
+
+		if (list->buffer[list->tail].value) {
+			if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
+				ret = -EFAULT;
+				goto out;
+			}
+			ret = len;
+		}
+
+		kfree(list->buffer[list->tail].value);
+		list->buffer[list->tail].value = NULL;
+		list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
+	}
+out:
+	mutex_unlock(&list->read_mutex);
+	return ret;
+}
+
+/*
+ * The first byte of the report buffer is expected to be a report number.
+ */
+static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
+{
+	unsigned int minor = iminor(file_inode(file));
+	struct hid_device *dev;
+	__u8 *buf;
+	int ret = 0;
+
+	lockdep_assert_held(&minors_lock);
+
+	if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	dev = hidraw_table[minor]->hid;
+
+	if (count > HID_MAX_BUFFER_SIZE) {
+		hid_warn(dev, "pid %d passed too large report\n",
+			 task_pid_nr(current));
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (count < 2) {
+		hid_warn(dev, "pid %d passed too short report\n",
+			 task_pid_nr(current));
+		ret = -EINVAL;
+		goto out;
+	}
+
+	buf = memdup_user(buffer, count);
+	if (IS_ERR(buf)) {
+		ret = PTR_ERR(buf);
+		goto out;
+	}
+
+	if ((report_type == HID_OUTPUT_REPORT) &&
+	    !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) {
+		ret = hid_hw_output_report(dev, buf, count);
+		/*
+		 * compatibility with old implementation of USB-HID and I2C-HID:
+		 * if the device does not support receiving output reports,
+		 * on an interrupt endpoint, fallback to SET_REPORT HID command.
+		 */
+		if (ret != -ENOSYS)
+			goto out_free;
+	}
+
+	ret = hid_hw_raw_request(dev, buf[0], buf, count, report_type,
+				HID_REQ_SET_REPORT);
+
+out_free:
+	kfree(buf);
+out:
+	return ret;
+}
+
+static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
+{
+	ssize_t ret;
+	mutex_lock(&minors_lock);
+	ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);
+	mutex_unlock(&minors_lock);
+	return ret;
+}
+
+
+/*
+ * This function performs a Get_Report transfer over the control endpoint
+ * per section 7.2.1 of the HID specification, version 1.1.  The first byte
+ * of buffer is the report number to request, or 0x0 if the defice does not
+ * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT
+ * or HID_INPUT_REPORT.
+ */
+static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)
+{
+	unsigned int minor = iminor(file_inode(file));
+	struct hid_device *dev;
+	__u8 *buf;
+	int ret = 0, len;
+	unsigned char report_number;
+
+	lockdep_assert_held(&minors_lock);
+
+	if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	dev = hidraw_table[minor]->hid;
+
+	if (!dev->ll_driver->raw_request) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	if (count > HID_MAX_BUFFER_SIZE) {
+		hid_warn(dev, "pid %d passed too large report\n",
+			task_pid_nr(current));
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (count < 2) {
+		hid_warn(dev, "pid %d passed too short report\n",
+			task_pid_nr(current));
+		ret = -EINVAL;
+		goto out;
+	}
+
+	buf = kmalloc(count, GFP_KERNEL);
+	if (!buf) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * Read the first byte from the user. This is the report number,
+	 * which is passed to hid_hw_raw_request().
+	 */
+	if (copy_from_user(&report_number, buffer, 1)) {
+		ret = -EFAULT;
+		goto out_free;
+	}
+
+	ret = hid_hw_raw_request(dev, report_number, buf, count, report_type,
+				 HID_REQ_GET_REPORT);
+
+	if (ret < 0)
+		goto out_free;
+
+	len = (ret < count) ? ret : count;
+
+	if (copy_to_user(buffer, buf, len)) {
+		ret = -EFAULT;
+		goto out_free;
+	}
+
+	ret = len;
+
+out_free:
+	kfree(buf);
+out:
+	return ret;
+}
+
+static __poll_t hidraw_poll(struct file *file, poll_table *wait)
+{
+	struct hidraw_list *list = file->private_data;
+	__poll_t mask = EPOLLOUT | EPOLLWRNORM; /* hidraw is always writable */
+
+	poll_wait(file, &list->hidraw->wait, wait);
+	if (list->head != list->tail)
+		mask |= EPOLLIN | EPOLLRDNORM;
+	if (!list->hidraw->exist)
+		mask |= EPOLLERR | EPOLLHUP;
+	return mask;
+}
+
+static int hidraw_open(struct inode *inode, struct file *file)
+{
+	unsigned int minor = iminor(inode);
+	struct hidraw *dev;
+	struct hidraw_list *list;
+	unsigned long flags;
+	int err = 0;
+
+	if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	mutex_lock(&minors_lock);
+	if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
+		err = -ENODEV;
+		goto out_unlock;
+	}
+
+	dev = hidraw_table[minor];
+	if (!dev->open++) {
+		err = hid_hw_power(dev->hid, PM_HINT_FULLON);
+		if (err < 0) {
+			dev->open--;
+			goto out_unlock;
+		}
+
+		err = hid_hw_open(dev->hid);
+		if (err < 0) {
+			hid_hw_power(dev->hid, PM_HINT_NORMAL);
+			dev->open--;
+			goto out_unlock;
+		}
+	}
+
+	list->hidraw = hidraw_table[minor];
+	mutex_init(&list->read_mutex);
+	spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
+	list_add_tail(&list->node, &hidraw_table[minor]->list);
+	spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
+	file->private_data = list;
+out_unlock:
+	mutex_unlock(&minors_lock);
+out:
+	if (err < 0)
+		kfree(list);
+	return err;
+
+}
+
+static int hidraw_fasync(int fd, struct file *file, int on)
+{
+	struct hidraw_list *list = file->private_data;
+
+	return fasync_helper(fd, file, on, &list->fasync);
+}
+
+static void drop_ref(struct hidraw *hidraw, int exists_bit)
+{
+	if (exists_bit) {
+		hidraw->exist = 0;
+		if (hidraw->open) {
+			hid_hw_close(hidraw->hid);
+			wake_up_interruptible(&hidraw->wait);
+		}
+		device_destroy(hidraw_class,
+			       MKDEV(hidraw_major, hidraw->minor));
+	} else {
+		--hidraw->open;
+	}
+	if (!hidraw->open) {
+		if (!hidraw->exist) {
+			hidraw_table[hidraw->minor] = NULL;
+			kfree(hidraw);
+		} else {
+			/* close device for last reader */
+			hid_hw_close(hidraw->hid);
+			hid_hw_power(hidraw->hid, PM_HINT_NORMAL);
+		}
+	}
+}
+
+static int hidraw_release(struct inode * inode, struct file * file)
+{
+	unsigned int minor = iminor(inode);
+	struct hidraw_list *list = file->private_data;
+	unsigned long flags;
+	int i;
+
+	mutex_lock(&minors_lock);
+
+	spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
+	for (i = list->tail; i < list->head; i++)
+		kfree(list->buffer[i].value);
+	list_del(&list->node);
+	spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
+	kfree(list);
+
+	drop_ref(hidraw_table[minor], 0);
+
+	mutex_unlock(&minors_lock);
+	return 0;
+}
+
+static long hidraw_ioctl(struct file *file, unsigned int cmd,
+							unsigned long arg)
+{
+	struct inode *inode = file_inode(file);
+	unsigned int minor = iminor(inode);
+	long ret = 0;
+	struct hidraw *dev;
+	void __user *user_arg = (void __user*) arg;
+
+	mutex_lock(&minors_lock);
+	dev = hidraw_table[minor];
+	if (!dev || !dev->exist) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	switch (cmd) {
+		case HIDIOCGRDESCSIZE:
+			if (put_user(dev->hid->rsize, (int __user *)arg))
+				ret = -EFAULT;
+			break;
+
+		case HIDIOCGRDESC:
+			{
+				__u32 len;
+
+				if (get_user(len, (int __user *)arg))
+					ret = -EFAULT;
+				else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
+					ret = -EINVAL;
+				else if (copy_to_user(user_arg + offsetof(
+					struct hidraw_report_descriptor,
+					value[0]),
+					dev->hid->rdesc,
+					min(dev->hid->rsize, len)))
+					ret = -EFAULT;
+				break;
+			}
+		case HIDIOCGRAWINFO:
+			{
+				struct hidraw_devinfo dinfo;
+
+				dinfo.bustype = dev->hid->bus;
+				dinfo.vendor = dev->hid->vendor;
+				dinfo.product = dev->hid->product;
+				if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
+					ret = -EFAULT;
+				break;
+			}
+		default:
+			{
+				struct hid_device *hid = dev->hid;
+				if (_IOC_TYPE(cmd) != 'H') {
+					ret = -EINVAL;
+					break;
+				}
+
+				if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
+					int len = _IOC_SIZE(cmd);
+					ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
+					break;
+				}
+				if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
+					int len = _IOC_SIZE(cmd);
+					ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
+					break;
+				}
+
+				/* Begin Read-only ioctls. */
+				if (_IOC_DIR(cmd) != _IOC_READ) {
+					ret = -EINVAL;
+					break;
+				}
+
+				if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
+					int len = strlen(hid->name) + 1;
+					if (len > _IOC_SIZE(cmd))
+						len = _IOC_SIZE(cmd);
+					ret = copy_to_user(user_arg, hid->name, len) ?
+						-EFAULT : len;
+					break;
+				}
+
+				if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) {
+					int len = strlen(hid->phys) + 1;
+					if (len > _IOC_SIZE(cmd))
+						len = _IOC_SIZE(cmd);
+					ret = copy_to_user(user_arg, hid->phys, len) ?
+						-EFAULT : len;
+					break;
+				}
+
+				if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWUNIQ(0))) {
+					int len = strlen(hid->uniq) + 1;
+					if (len > _IOC_SIZE(cmd))
+						len = _IOC_SIZE(cmd);
+					ret = copy_to_user(user_arg, hid->uniq, len) ?
+						-EFAULT : len;
+					break;
+				}
+			}
+
+		ret = -ENOTTY;
+	}
+out:
+	mutex_unlock(&minors_lock);
+	return ret;
+}
+
+static const struct file_operations hidraw_ops = {
+	.owner =        THIS_MODULE,
+	.read =         hidraw_read,
+	.write =        hidraw_write,
+	.poll =         hidraw_poll,
+	.open =         hidraw_open,
+	.release =      hidraw_release,
+	.unlocked_ioctl = hidraw_ioctl,
+	.fasync =	hidraw_fasync,
+	.compat_ioctl   = compat_ptr_ioctl,
+	.llseek =	noop_llseek,
+};
+
+int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
+{
+	struct hidraw *dev = hid->hidraw;
+	struct hidraw_list *list;
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->list_lock, flags);
+	list_for_each_entry(list, &dev->list, node) {
+		int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
+
+		if (new_head == list->tail)
+			continue;
+
+		if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
+			ret = -ENOMEM;
+			break;
+		}
+		list->buffer[list->head].len = len;
+		list->head = new_head;
+		kill_fasync(&list->fasync, SIGIO, POLL_IN);
+	}
+	spin_unlock_irqrestore(&dev->list_lock, flags);
+
+	wake_up_interruptible(&dev->wait);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hidraw_report_event);
+
+int hidraw_connect(struct hid_device *hid)
+{
+	int minor, result;
+	struct hidraw *dev;
+
+	/* we accept any HID device, all applications */
+
+	dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	result = -EINVAL;
+
+	mutex_lock(&minors_lock);
+
+	for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
+		if (hidraw_table[minor])
+			continue;
+		hidraw_table[minor] = dev;
+		result = 0;
+		break;
+	}
+
+	if (result) {
+		mutex_unlock(&minors_lock);
+		kfree(dev);
+		goto out;
+	}
+
+	dev->dev = device_create(hidraw_class, &hid->dev, MKDEV(hidraw_major, minor),
+				 NULL, "%s%d", "hidraw", minor);
+
+	if (IS_ERR(dev->dev)) {
+		hidraw_table[minor] = NULL;
+		mutex_unlock(&minors_lock);
+		result = PTR_ERR(dev->dev);
+		kfree(dev);
+		goto out;
+	}
+
+	init_waitqueue_head(&dev->wait);
+	spin_lock_init(&dev->list_lock);
+	INIT_LIST_HEAD(&dev->list);
+
+	dev->hid = hid;
+	dev->minor = minor;
+
+	dev->exist = 1;
+	hid->hidraw = dev;
+
+	mutex_unlock(&minors_lock);
+out:
+	return result;
+
+}
+EXPORT_SYMBOL_GPL(hidraw_connect);
+
+void hidraw_disconnect(struct hid_device *hid)
+{
+	struct hidraw *hidraw = hid->hidraw;
+
+	mutex_lock(&minors_lock);
+
+	drop_ref(hidraw, 1);
+
+	mutex_unlock(&minors_lock);
+}
+EXPORT_SYMBOL_GPL(hidraw_disconnect);
+
+int __init hidraw_init(void)
+{
+	int result;
+	dev_t dev_id;
+
+	result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
+			HIDRAW_MAX_DEVICES, "hidraw");
+	if (result < 0) {
+		pr_warn("can't get major number\n");
+		goto out;
+	}
+
+	hidraw_major = MAJOR(dev_id);
+
+	hidraw_class = class_create(THIS_MODULE, "hidraw");
+	if (IS_ERR(hidraw_class)) {
+		result = PTR_ERR(hidraw_class);
+		goto error_cdev;
+	}
+
+        cdev_init(&hidraw_cdev, &hidraw_ops);
+	result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
+	if (result < 0)
+		goto error_class;
+
+	pr_info("raw HID events driver (C) Jiri Kosina\n");
+out:
+	return result;
+
+error_class:
+	class_destroy(hidraw_class);
+error_cdev:
+	unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
+	goto out;
+}
+
+void hidraw_exit(void)
+{
+	dev_t dev_id = MKDEV(hidraw_major, 0);
+
+	cdev_del(&hidraw_cdev);
+	class_destroy(hidraw_class);
+	unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
+
+}