diff options
Diffstat (limited to 'drivers/hid/hidraw.c')
| -rw-r--r-- | drivers/hid/hidraw.c | 656 |
1 files changed, 656 insertions, 0 deletions
diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c new file mode 100644 index 000000000..b617aada5 --- /dev/null +++ b/drivers/hid/hidraw.c @@ -0,0 +1,656 @@ +// 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 DECLARE_RWSEM(minors_rwsem); + +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_rwsem); + + 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; + down_read(&minors_rwsem); + ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT); + up_read(&minors_rwsem); + 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 device 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_rwsem); + + 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; + } + + /* + * Technically not writing to the hidraw_table but a write lock is + * required to protect the device refcount. This is symmetrical to + * hidraw_release(). + */ + down_write(&minors_rwsem); + 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: + up_write(&minors_rwsem); +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; + + down_write(&minors_rwsem); + + spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags); + for (int 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); + + up_write(&minors_rwsem); + 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; + + down_read(&minors_rwsem); + 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; + } + + if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSINPUT(0))) { + int len = _IOC_SIZE(cmd); + ret = hidraw_send_report(file, user_arg, len, HID_INPUT_REPORT); + break; + } + if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGINPUT(0))) { + int len = _IOC_SIZE(cmd); + ret = hidraw_get_report(file, user_arg, len, HID_INPUT_REPORT); + break; + } + + if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSOUTPUT(0))) { + int len = _IOC_SIZE(cmd); + ret = hidraw_send_report(file, user_arg, len, HID_OUTPUT_REPORT); + break; + } + if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGOUTPUT(0))) { + int len = _IOC_SIZE(cmd); + ret = hidraw_get_report(file, user_arg, len, HID_OUTPUT_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: + up_read(&minors_rwsem); + 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; + + down_write(&minors_rwsem); + + for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) { + if (hidraw_table[minor]) + continue; + hidraw_table[minor] = dev; + result = 0; + break; + } + + if (result) { + up_write(&minors_rwsem); + 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; + up_write(&minors_rwsem); + 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; + + up_write(&minors_rwsem); +out: + return result; + +} +EXPORT_SYMBOL_GPL(hidraw_connect); + +void hidraw_disconnect(struct hid_device *hid) +{ + struct hidraw *hidraw = hid->hidraw; + + down_write(&minors_rwsem); + + drop_ref(hidraw, 1); + + up_write(&minors_rwsem); +} +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); + +} |