// SPDX-License-Identifier: GPL-2.0-or-later/* * User level driver support for input subsystem * * Heavily based on evdev.c by Vojtech Pavlik * * 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 <uapi/linux/uinput.h>#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/overflow.h>#include <linux/input/mt.h>#include "../input-compat.h" #define UINPUT_NAME "uinput"#define UINPUT_BUFFER_SIZE 16#define UINPUT_NUM_REQUESTS 16#define UINPUT_TIMESTAMP_ALLOWED_OFFSET_SECS 10 enum uinput_state { UIST_NEW_DEVICE, UIST_SETUP_COMPLETE, UIST_CREATED }; struct uinput_request { unsigned int id; unsigned int code; /* UI_FF_UPLOAD, UI_FF_ERASE */ int retval; struct completion done; union { unsigned int effect_id; struct { struct ff_effect *effect; struct ff_effect *old; } upload; } u;}; struct uinput_device { struct input_dev *dev; struct mutex mutex; enum uinput_state state; wait_queue_head_t waitq; unsigned char ready; unsigned char head; unsigned char tail; struct input_event buff[UINPUT_BUFFER_SIZE]; unsigned int ff_effects_max; struct uinput_request *requests[UINPUT_NUM_REQUESTS]; wait_queue_head_t requests_waitq; spinlock_t requests_lock;}; 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); struct timespec64 ts; ktime_get_ts64(&ts); udev->buff[udev->head] = (struct input_event) { .input_event_sec = ts.tv_sec, .input_event_usec = ts.tv_nsec / NSEC_PER_USEC, .type = type, .code = code, .value = value, }; 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_release_slot(struct uinput_device *udev, unsigned int id){ /* Mark slot as available */ spin_lock(&udev->requests_lock); udev->requests[id] = NULL; spin_unlock(&udev->requests_lock); wake_up(&udev->requests_waitq);} 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 retval; retval = uinput_request_reserve_slot(udev, request); if (retval) return retval; retval = uinput_request_send(udev, request); if (retval) goto out; if (!wait_for_completion_timeout(&request->done, 30 * HZ)) { retval = -ETIMEDOUT; goto out; } retval = request->retval; out: uinput_request_release_slot(udev, request->id); return 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; complete(&request->done); } } 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 int uinput_dev_flush(struct input_dev *dev, struct file *file){ /* * If we are called with file == NULL that means we are tearing * down the device, and therefore we can not handle FF erase * requests: either we are handling UI_DEV_DESTROY (and holding * the udev->mutex), or the file descriptor is closed and there is * nobody on the other side anymore. */ return file ? input_ff_flush(dev, file) : 0;} 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; /* * The standard input_ff_flush() implementation does * not quite work for uinput as we can't reasonably * handle FF requests during device teardown. */ dev->flush = uinput_dev_flush; } dev->event = uinput_dev_event; input_set_drvdata(udev->dev, udev); 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; stream_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, range; 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 (!check_sub_overflow(max, min, &range) && abs->flat > range) { 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_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);Lines 1–500 of 1136. 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// SPDX-License-Identifier: GPL-2.0-or-later /* * User level driver support for input subsystem * * Heavily based on evdev.c by Vojtech Pavlik * * 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 <uapi/linux/uinput.h> #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/overflow.h> #include <linux/input/mt.h> #include "../input-compat.h" #define UINPUT_NAME "uinput" #define UINPUT_BUFFER_SIZE 16 #define UINPUT_NUM_REQUESTS 16 #define UINPUT_TIMESTAMP_ALLOWED_OFFSET_SECS 10 enum uinput_state { UIST_NEW_DEVICE, UIST_SETUP_COMPLETE, UIST_CREATED }; struct uinput_request { unsigned int id; unsigned int code; /* UI_FF_UPLOAD, UI_FF_ERASE */ int retval; struct completion done; union { unsigned int effect_id; struct { struct ff_effect *effect; struct ff_effect *old; } upload; } u; }; struct uinput_device { struct input_dev *dev; struct mutex mutex; enum uinput_state state; wait_queue_head_t waitq; unsigned char ready; unsigned char head; unsigned char tail; struct input_event buff[UINPUT_BUFFER_SIZE]; unsigned int ff_effects_max; struct uinput_request *requests[UINPUT_NUM_REQUESTS]; wait_queue_head_t requests_waitq; spinlock_t requests_lock; }; 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); struct timespec64 ts; ktime_get_ts64(&ts); udev->buff[udev->head] = (struct input_event) { .input_event_sec = ts.tv_sec, .input_event_usec = ts.tv_nsec / NSEC_PER_USEC, .type = type, .code = code, .value = value, }; 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_release_slot(struct uinput_device *udev, unsigned int id) { /* Mark slot as available */ spin_lock(&udev->requests_lock); udev->requests[id] = NULL; spin_unlock(&udev->requests_lock); wake_up(&udev->requests_waitq); } 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 retval; retval = uinput_request_reserve_slot(udev, request); if (retval) return retval; retval = uinput_request_send(udev, request); if (retval) goto out; if (!wait_for_completion_timeout(&request->done, 30 * HZ)) { retval = -ETIMEDOUT; goto out; } retval = request->retval; out: uinput_request_release_slot(udev, request->id); return 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; complete(&request->done); } } 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 int uinput_dev_flush(struct input_dev *dev, struct file *file) { /* * If we are called with file == NULL that means we are tearing * down the device, and therefore we can not handle FF erase * requests: either we are handling UI_DEV_DESTROY (and holding * the udev->mutex), or the file descriptor is closed and there is * nobody on the other side anymore. */ return file ? input_ff_flush(dev, file) : 0; } 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; /* * The standard input_ff_flush() implementation does * not quite work for uinput as we can't reasonably * handle FF requests during device teardown. */ dev->flush = uinput_dev_flush; } dev->event = uinput_dev_event; input_set_drvdata(udev->dev, udev); 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; stream_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, range; 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 (!check_sub_overflow(max, min, &range) && abs->flat > range) { 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_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);