/* * User level driver support for input subsystem * * Heavily based on evdev.c by Vojtech Pavlik * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org> * * Changes/Revisions: * 0.4 01/09/2014 (Benjamin Tissoires <benjamin.tissoires@redhat.com>) * - add UI_GET_SYSNAME ioctl * 0.3 09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>) * - updated ff support for the changes in kernel interface * - added MODULE_VERSION * 0.2 16/10/2004 (Micah Dowty <micah@navi.cx>) * - added force feedback support * - added UI_SET_PHYS * 0.1 20/06/2002 * - first public version */ #include <linux/poll.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/module.h> #include <linux/init.h> #include <linux/fs.h> #include <linux/miscdevice.h> #include <linux/uinput.h> #include <linux/input/mt.h> #include "../input-compat.h" static int uinput_dev_event(struct input_dev *dev, unsigned int type, unsigned int code, int value) { struct uinput_device *udev = input_get_drvdata(dev); udev->buff[udev->head].type = type; udev->buff[udev->head].code = code; udev->buff[udev->head].value = value; do_gettimeofday(&udev->buff[udev->head].time); udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE; wake_up_interruptible(&udev->waitq); return 0; } /* Atomically allocate an ID for the given request. Returns 0 on success. */ static bool uinput_request_alloc_id(struct uinput_device *udev, struct uinput_request *request) { unsigned int id; bool reserved = false; spin_lock(&udev->requests_lock); for (id = 0; id < UINPUT_NUM_REQUESTS; id++) { if (!udev->requests[id]) { request->id = id; udev->requests[id] = request; reserved = true; break; } } spin_unlock(&udev->requests_lock); return reserved; } static struct uinput_request *uinput_request_find(struct uinput_device *udev, unsigned int id) { /* Find an input request, by ID. Returns NULL if the ID isn't valid. */ if (id >= UINPUT_NUM_REQUESTS) return NULL; return udev->requests[id]; } static int uinput_request_reserve_slot(struct uinput_device *udev, struct uinput_request *request) { /* Allocate slot. If none are available right away, wait. */ return wait_event_interruptible(udev->requests_waitq, uinput_request_alloc_id(udev, request)); } static void uinput_request_done(struct uinput_device *udev, struct uinput_request *request) { /* Mark slot as available */ udev->requests[request->id] = NULL; wake_up(&udev->requests_waitq); complete(&request->done); } static int uinput_request_send(struct uinput_device *udev, struct uinput_request *request) { int retval; retval = mutex_lock_interruptible(&udev->mutex); if (retval) return retval; if (udev->state != UIST_CREATED) { retval = -ENODEV; goto out; } init_completion(&request->done); /* * Tell our userspace application about this new request * by queueing an input event. */ uinput_dev_event(udev->dev, EV_UINPUT, request->code, request->id); out: mutex_unlock(&udev->mutex); return retval; } static int uinput_request_submit(struct uinput_device *udev, struct uinput_request *request) { int error; error = uinput_request_reserve_slot(udev, request); if (error) return error; error = uinput_request_send(udev, request); if (error) { uinput_request_done(udev, request); return error; } wait_for_completion(&request->done); return request->retval; } /* * Fail all outstanding requests so handlers don't wait for the userspace * to finish processing them. */ static void uinput_flush_requests(struct uinput_device *udev) { struct uinput_request *request; int i; spin_lock(&udev->requests_lock); for (i = 0; i < UINPUT_NUM_REQUESTS; i++) { request = udev->requests[i]; if (request) { request->retval = -ENODEV; uinput_request_done(udev, request); } } spin_unlock(&udev->requests_lock); } static void uinput_dev_set_gain(struct input_dev *dev, u16 gain) { uinput_dev_event(dev, EV_FF, FF_GAIN, gain); } static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude) { uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude); } static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value) { return uinput_dev_event(dev, EV_FF, effect_id, value); } static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *effect, struct ff_effect *old) { struct uinput_device *udev = input_get_drvdata(dev); struct uinput_request request; /* * uinput driver does not currently support periodic effects with * custom waveform since it does not have a way to pass buffer of * samples (custom_data) to userspace. If ever there is a device * supporting custom waveforms we would need to define an additional * ioctl (UI_UPLOAD_SAMPLES) but for now we just bail out. */ if (effect->type == FF_PERIODIC && effect->u.periodic.waveform == FF_CUSTOM) return -EINVAL; request.code = UI_FF_UPLOAD; request.u.upload.effect = effect; request.u.upload.old = old; return uinput_request_submit(udev, &request); } static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id) { struct uinput_device *udev = input_get_drvdata(dev); struct uinput_request request; if (!test_bit(EV_FF, dev->evbit)) return -ENOSYS; request.code = UI_FF_ERASE; request.u.effect_id = effect_id; return uinput_request_submit(udev, &request); } static void uinput_destroy_device(struct uinput_device *udev) { const char *name, *phys; struct input_dev *dev = udev->dev; enum uinput_state old_state = udev->state; udev->state = UIST_NEW_DEVICE; if (dev) { name = dev->name; phys = dev->phys; if (old_state == UIST_CREATED) { uinput_flush_requests(udev); input_unregister_device(dev); } else { input_free_device(dev); } kfree(name); kfree(phys); udev->dev = NULL; } } static int uinput_create_device(struct uinput_device *udev) { struct input_dev *dev = udev->dev; int error, nslot; if (udev->state != UIST_SETUP_COMPLETE) { printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME); return -EINVAL; } if (test_bit(EV_ABS, dev->evbit)) { input_alloc_absinfo(dev); if (!dev->absinfo) { error = -EINVAL; goto fail1; } if (test_bit(ABS_MT_SLOT, dev->absbit)) { nslot = input_abs_get_max(dev, ABS_MT_SLOT) + 1; error = input_mt_init_slots(dev, nslot, 0); if (error) goto fail1; } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) { input_set_events_per_packet(dev, 60); } } if (test_bit(EV_FF, dev->evbit) && !udev->ff_effects_max) { printk(KERN_DEBUG "%s: ff_effects_max should be non-zero when FF_BIT is set\n", UINPUT_NAME); error = -EINVAL; goto fail1; } if (udev->ff_effects_max) { error = input_ff_create(dev, udev->ff_effects_max); if (error) goto fail1; dev->ff->upload = uinput_dev_upload_effect; dev->ff->erase = uinput_dev_erase_effect; dev->ff->playback = uinput_dev_playback; dev->ff->set_gain = uinput_dev_set_gain; dev->ff->set_autocenter = uinput_dev_set_autocenter; } error = input_register_device(udev->dev); if (error) goto fail2; udev->state = UIST_CREATED; return 0; fail2: input_ff_destroy(dev); fail1: uinput_destroy_device(udev); return error; } static int uinput_open(struct inode *inode, struct file *file) { struct uinput_device *newdev; newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL); if (!newdev) return -ENOMEM; mutex_init(&newdev->mutex); spin_lock_init(&newdev->requests_lock); init_waitqueue_head(&newdev->requests_waitq); init_waitqueue_head(&newdev->waitq); newdev->state = UIST_NEW_DEVICE; file->private_data = newdev; nonseekable_open(inode, file); return 0; } static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code, const struct input_absinfo *abs) { int min, max; min = abs->minimum; max = abs->maximum; if ((min != 0 || max != 0) && max <= min) { printk(KERN_DEBUG "%s: invalid abs[%02x] min:%d max:%d\n", UINPUT_NAME, code, min, max); return -EINVAL; } if (abs->flat > max - min) { printk(KERN_DEBUG "%s: abs_flat #%02x out of range: %d (min:%d/max:%d)\n", UINPUT_NAME, code, abs->flat, min, max); return -EINVAL; } return 0; } static int uinput_validate_absbits(struct input_dev *dev) { unsigned int cnt; int error; if (!test_bit(EV_ABS, dev->evbit)) return 0; /* * Check if absmin/absmax/absfuzz/absflat are sane. */ for_each_set_bit(cnt, dev->absbit, ABS_CNT) { if (!dev->absinfo) return -EINVAL; error = uinput_validate_absinfo(dev, cnt, &dev->absinfo[cnt]); if (error) return error; } return 0; } static int uinput_allocate_device(struct uinput_device *udev) { udev->dev = input_allocate_device(); if (!udev->dev) return -ENOMEM; udev->dev->event = uinput_dev_event; input_set_drvdata(udev->dev, udev); return 0; } static int uinput_dev_setup(struct uinput_device *udev, struct uinput_setup __user *arg) { struct uinput_setup setup; struct input_dev *dev; if (udev->state == UIST_CREATED) return -EINVAL; if (copy_from_user(&setup, arg, sizeof(setup))) return -EFAULT; if (!setup.name[0]) return -EINVAL; dev = udev->dev; dev->id = setup.id; udev->ff_effects_max = setup.ff_effects_max; kfree(dev->name); dev->name = kstrndup(setup.name, UINPUT_MAX_NAME_SIZE, GFP_KERNEL); if (!dev->name) return -ENOMEM; udev->state = UIST_SETUP_COMPLETE; return 0; } static int uinput_abs_setup(struct uinput_device *udev, struct uinput_setup __user *arg, size_t size) { struct uinput_abs_setup setup = {}; struct input_dev *dev; int error; if (size > sizeof(setup)) return -E2BIG; if (udev->state == UIST_CREATED) return -EINVAL; if (copy_from_user(&setup, arg, size)) return -EFAULT; if (setup.code > ABS_MAX) return -ERANGE; dev = udev->dev; error = uinput_validate_absinfo(dev, setup.code, &setup.absinfo); if (error) return error; input_alloc_absinfo(dev); if (!dev->absinfo) return -ENOMEM; set_bit(setup.code, dev->absbit); dev->absinfo[setup.code] = setup.absinfo; return 0; } /* legacy setup via write() */ static int uinput_setup_device_legacy(struct uinput_device *udev, const char __user *buffer, size_t count) { struct uinput_user_dev *user_dev; struct input_dev *dev; int i; int retval; if (count != sizeof(struct uinput_user_dev)) return -EINVAL; if (!udev->dev) { retval = uinput_allocate_device(udev); if (retval) return retval; } dev = udev->dev; user_dev = memdup_user(buffer, sizeof(struct uinput_user_dev)); if (IS_ERR(user_dev)) return PTR_ERR(user_dev); udev->ff_effects_max = user_dev->ff_effects_max; /* Ensure name is filled in */ if (!user_dev->name[0]) { retval = -EINVAL; goto exit; } kfree(dev->name); dev->name = kstrndup(user_dev->name, UINPUT_MAX_NAME_SIZE, GFP_KERNEL); if (!dev->name) { retval = -ENOMEM; goto exit; } dev->id.bustype = user_dev->id.bustype; dev->id.vendor = user_dev->id.vendor; dev->id.product = user_dev->id.product; dev->id.version = user_dev->id.version; for (i = 0; i < ABS_CNT; i++) { input_abs_set_max(dev, i, user_dev->absmax[i]); input_abs_set_min(dev, i, user_dev->absmin[i]); input_abs_set_fuzz(dev, i, user_dev->absfuzz[i]); input_abs_set_flat(dev, i, user_dev->absflat[i]); } retval = uinput_validate_absbits(dev); if (retval < 0) goto exit; udev->state = UIST_SETUP_COMPLETE; retval = count; exit: kfree(user_dev); return retval; } 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 ssize_t uinput_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) { struct uinput_device *udev = file->private_data; int retval; if (count == 0) return 0; retval = mutex_lock_interruptible(&udev->mutex); if (retval) return retval; retval = udev->state == UIST_CREATED ? uinput_inject_events(udev, buffer, count) : uinput_setup_device_legacy(udev, buffer, count); mutex_unlock(&udev->mutex); return retval; } static bool uinput_fetch_next_event(struct uinput_device *udev, struct input_event *event) { bool have_event; spin_lock_irq(&udev->dev->event_lock); have_event = udev->head != udev->tail; if (have_event) { *event = udev->buff[udev->tail]; udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE; } spin_unlock_irq(&udev->dev->event_lock); return have_event; } 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; 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 unsigned int uinput_poll(struct file *file, poll_table *wait) { struct uinput_device *udev = file->private_data; poll_wait(file, &udev->waitq, wait); if (udev->head != udev->tail) return POLLIN | POLLRDNORM; return 0; } static int uinput_release(struct inode *inode, struct file *file) { struct uinput_device *udev = file->private_data; uinput_destroy_device(udev); kfree(udev); return 0; } #ifdef CONFIG_COMPAT struct uinput_ff_upload_compat { __u32 request_id; __s32 retval; struct ff_effect_compat effect; struct ff_effect_compat old; }; static int uinput_ff_upload_to_user(char __user *buffer, const struct uinput_ff_upload *ff_up) { if (in_compat_syscall()) { struct uinput_ff_upload_compat ff_up_compat; ff_up_compat.request_id = ff_up->request_id; ff_up_compat.retval = ff_up->retval; /* * It so happens that the pointer that gives us the trouble * is the last field in the structure. Since we don't support * custom waveforms in uinput anyway we can just copy the whole * thing (to the compat size) and ignore the pointer. */ memcpy(&ff_up_compat.effect, &ff_up->effect, sizeof(struct ff_effect_compat)); memcpy(&ff_up_compat.old, &ff_up->old, sizeof(struct ff_effect_compat)); if (copy_to_user(buffer, &ff_up_compat, sizeof(struct uinput_ff_upload_compat))) return -EFAULT; } else { if (copy_to_user(buffer, ff_up, sizeof(struct uinput_ff_upload))) return -EFAULT; } return 0; } static int uinput_ff_upload_from_user(const char __user *buffer, struct uinput_ff_upload *ff_up) { if (in_compat_syscall()) { struct uinput_ff_upload_compat ff_up_compat; if (copy_from_user(&ff_up_compat, buffer, sizeof(struct uinput_ff_upload_compat))) return -EFAULT; ff_up->request_id = ff_up_compat.request_id; ff_up->retval = ff_up_compat.retval; memcpy(&ff_up->effect, &ff_up_compat.effect, sizeof(struct ff_effect_compat)); memcpy(&ff_up->old, &ff_up_compat.old, sizeof(struct ff_effect_compat)); } else { if (copy_from_user(ff_up, buffer, sizeof(struct uinput_ff_upload))) return -EFAULT; } return 0; } #else static int uinput_ff_upload_to_user(char __user *buffer, const struct uinput_ff_upload *ff_up) { if (copy_to_user(buffer, ff_up, sizeof(struct uinput_ff_upload))) return -EFAULT; return 0; } static int uinput_ff_upload_from_user(const char __user *buffer, struct uinput_ff_upload *ff_up) { if (copy_from_user(ff_up, buffer, sizeof(struct uinput_ff_upload))) return -EFAULT; return 0; } #endif #define uinput_set_bit(_arg, _bit, _max) \ ({ \ int __ret = 0; \ if (udev->state == UIST_CREATED) \ __ret = -EINVAL; \ else if ((_arg) > (_max)) \ __ret = -EINVAL; \ else set_bit((_arg), udev->dev->_bit); \ __ret; \ }) static int uinput_str_to_user(void __user *dest, const char *str, unsigned int maxlen) { char __user *p = dest; int len, ret; if (!str) return -ENOENT; if (maxlen == 0) return -EINVAL; len = strlen(str) + 1; if (len > maxlen) len = maxlen; ret = copy_to_user(p, str, len); if (ret) return -EFAULT; /* force terminating '\0' */ ret = put_user(0, p + len - 1); return ret ? -EFAULT : len; } static long uinput_ioctl_handler(struct file *file, unsigned int cmd, unsigned long arg, void __user *p) { int retval; struct uinput_device *udev = file->private_data; struct uinput_ff_upload ff_up; struct uinput_ff_erase ff_erase; struct uinput_request *req; char *phys; const char *name; unsigned int size; retval = mutex_lock_interruptible(&udev->mutex); if (retval) return retval; if (!udev->dev) { retval = uinput_allocate_device(udev); if (retval) goto out; } switch (cmd) { case UI_GET_VERSION: if (put_user(UINPUT_VERSION, (unsigned int __user *)p)) retval = -EFAULT; goto out; case UI_DEV_CREATE: retval = uinput_create_device(udev); goto out; case UI_DEV_DESTROY: uinput_destroy_device(udev); goto out; case UI_DEV_SETUP: retval = uinput_dev_setup(udev, p); goto out; /* UI_ABS_SETUP is handled in the variable size ioctls */ case UI_SET_EVBIT: retval = uinput_set_bit(arg, evbit, EV_MAX); goto out; case UI_SET_KEYBIT: retval = uinput_set_bit(arg, keybit, KEY_MAX); goto out; case UI_SET_RELBIT: retval = uinput_set_bit(arg, relbit, REL_MAX); goto out; case UI_SET_ABSBIT: retval = uinput_set_bit(arg, absbit, ABS_MAX); goto out; case UI_SET_MSCBIT: retval = uinput_set_bit(arg, mscbit, MSC_MAX); goto out; case UI_SET_LEDBIT: retval = uinput_set_bit(arg, ledbit, LED_MAX); goto out; case UI_SET_SNDBIT: retval = uinput_set_bit(arg, sndbit, SND_MAX); goto out; case UI_SET_FFBIT: retval = uinput_set_bit(arg, ffbit, FF_MAX); goto out; case UI_SET_SWBIT: retval = uinput_set_bit(arg, swbit, SW_MAX); goto out; case UI_SET_PROPBIT: retval = uinput_set_bit(arg, propbit, INPUT_PROP_MAX); goto out; case UI_SET_PHYS: if (udev->state == UIST_CREATED) { retval = -EINVAL; goto out; } phys = strndup_user(p, 1024); if (IS_ERR(phys)) { retval = PTR_ERR(phys); goto out; } kfree(udev->dev->phys); udev->dev->phys = phys; goto out; case UI_BEGIN_FF_UPLOAD: retval = uinput_ff_upload_from_user(p, &ff_up); if (retval) goto out; req = uinput_request_find(udev, ff_up.request_id); if (!req || req->code != UI_FF_UPLOAD || !req->u.upload.effect) { retval = -EINVAL; goto out; } ff_up.retval = 0; ff_up.effect = *req->u.upload.effect; if (req->u.upload.old) ff_up.old = *req->u.upload.old; else memset(&ff_up.old, 0, sizeof(struct ff_effect)); retval = uinput_ff_upload_to_user(p, &ff_up); goto out; case UI_BEGIN_FF_ERASE: if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) { retval = -EFAULT; goto out; } req = uinput_request_find(udev, ff_erase.request_id); if (!req || req->code != UI_FF_ERASE) { retval = -EINVAL; goto out; } ff_erase.retval = 0; ff_erase.effect_id = req->u.effect_id; if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) { retval = -EFAULT; goto out; } goto out; case UI_END_FF_UPLOAD: retval = uinput_ff_upload_from_user(p, &ff_up); if (retval) goto out; req = uinput_request_find(udev, ff_up.request_id); if (!req || req->code != UI_FF_UPLOAD || !req->u.upload.effect) { retval = -EINVAL; goto out; } req->retval = ff_up.retval; uinput_request_done(udev, req); goto out; case UI_END_FF_ERASE: if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) { retval = -EFAULT; goto out; } req = uinput_request_find(udev, ff_erase.request_id); if (!req || req->code != UI_FF_ERASE) { retval = -EINVAL; goto out; } req->retval = ff_erase.retval; uinput_request_done(udev, req); goto out; } size = _IOC_SIZE(cmd); /* Now check variable-length commands */ switch (cmd & ~IOCSIZE_MASK) { case UI_GET_SYSNAME(0): if (udev->state != UIST_CREATED) { retval = -ENOENT; goto out; } name = dev_name(&udev->dev->dev); retval = uinput_str_to_user(p, name, size); goto out; case UI_ABS_SETUP & ~IOCSIZE_MASK: retval = uinput_abs_setup(udev, p, size); goto out; } retval = -EINVAL; out: mutex_unlock(&udev->mutex); return retval; } static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { return uinput_ioctl_handler(file, cmd, arg, (void __user *)arg); } #ifdef CONFIG_COMPAT #define UI_SET_PHYS_COMPAT _IOW(UINPUT_IOCTL_BASE, 108, compat_uptr_t) static long uinput_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { if (cmd == UI_SET_PHYS_COMPAT) cmd = UI_SET_PHYS; return uinput_ioctl_handler(file, cmd, arg, compat_ptr(arg)); } #endif static const struct file_operations uinput_fops = { .owner = THIS_MODULE, .open = uinput_open, .release = uinput_release, .read = uinput_read, .write = uinput_write, .poll = uinput_poll, .unlocked_ioctl = uinput_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = uinput_compat_ioctl, #endif .llseek = no_llseek, }; static struct miscdevice uinput_misc = { .fops = &uinput_fops, .minor = UINPUT_MINOR, .name = UINPUT_NAME, }; module_misc_device(uinput_misc); MODULE_ALIAS_MISCDEV(UINPUT_MINOR); MODULE_ALIAS("devname:" UINPUT_NAME); MODULE_AUTHOR("Aristeu Sergio Rozanski Filho"); MODULE_DESCRIPTION("User level driver support for input subsystem"); MODULE_LICENSE("GPL"); MODULE_VERSION("0.3");