diff options
| -rw-r--r-- | drivers/input/evdev.c | 234 | ||||
| -rw-r--r-- | include/uapi/linux/input.h | 60 |
2 files changed, 292 insertions, 2 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index 08d496411f75..6b10f5b29218 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -58,10 +58,55 @@ struct evdev_client { struct list_head node; int clk_type; bool revoked; + unsigned long *evmasks[EV_CNT]; unsigned int bufsize; struct input_event buffer[]; }; +static size_t evdev_get_mask_cnt(unsigned int type) +{ + static const size_t counts[EV_CNT] = { + /* EV_SYN==0 is EV_CNT, _not_ SYN_CNT, see EVIOCGBIT */ + [EV_SYN] = EV_CNT, + [EV_KEY] = KEY_CNT, + [EV_REL] = REL_CNT, + [EV_ABS] = ABS_CNT, + [EV_MSC] = MSC_CNT, + [EV_SW] = SW_CNT, + [EV_LED] = LED_CNT, + [EV_SND] = SND_CNT, + [EV_FF] = FF_CNT, + }; + + return (type < EV_CNT) ? counts[type] : 0; +} + +/* requires the buffer lock to be held */ +static bool __evdev_is_filtered(struct evdev_client *client, + unsigned int type, + unsigned int code) +{ + unsigned long *mask; + size_t cnt; + + /* EV_SYN and unknown codes are never filtered */ + if (type == EV_SYN || type >= EV_CNT) + return false; + + /* first test whether the type is filtered */ + mask = client->evmasks[0]; + if (mask && !test_bit(type, mask)) + return true; + + /* unknown values are never filtered */ + cnt = evdev_get_mask_cnt(type); + if (!cnt || code >= cnt) + return false; + + mask = client->evmasks[type]; + return mask && !test_bit(code, mask); +} + /* flush queued events of type @type, caller must hold client->buffer_lock */ static void __evdev_flush_queue(struct evdev_client *client, unsigned int type) { @@ -226,12 +271,21 @@ static void evdev_pass_values(struct evdev_client *client, spin_lock(&client->buffer_lock); for (v = vals; v != vals + count; v++) { + if (__evdev_is_filtered(client, v->type, v->code)) + continue; + + if (v->type == EV_SYN && v->code == SYN_REPORT) { + /* drop empty SYN_REPORT */ + if (client->packet_head == client->head) + continue; + + wakeup = true; + } + event.type = v->type; event.code = v->code; event.value = v->value; __pass_event(client, &event); - if (v->type == EV_SYN && v->code == SYN_REPORT) - wakeup = true; } spin_unlock(&client->buffer_lock); @@ -410,6 +464,7 @@ static int evdev_release(struct inode *inode, struct file *file) { struct evdev_client *client = file->private_data; struct evdev *evdev = client->evdev; + unsigned int i; mutex_lock(&evdev->mutex); evdev_ungrab(evdev, client); @@ -417,6 +472,9 @@ static int evdev_release(struct inode *inode, struct file *file) evdev_detach_client(evdev, client); + for (i = 0; i < EV_CNT; ++i) + kfree(client->evmasks[i]); + kvfree(client); evdev_close_device(evdev); @@ -627,7 +685,46 @@ static int bits_to_user(unsigned long *bits, unsigned int maxbit, return len; } + +static int bits_from_user(unsigned long *bits, unsigned int maxbit, + unsigned int maxlen, const void __user *p, int compat) +{ + int len, i; + + if (compat) { + if (maxlen % sizeof(compat_long_t)) + return -EINVAL; + + len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t); + if (len > maxlen) + len = maxlen; + + for (i = 0; i < len / sizeof(compat_long_t); i++) + if (copy_from_user((compat_long_t *) bits + + i + 1 - ((i % 2) << 1), + (compat_long_t __user *) p + i, + sizeof(compat_long_t))) + return -EFAULT; + if (i % 2) + *((compat_long_t *) bits + i - 1) = 0; + + } else { + if (maxlen % sizeof(long)) + return -EINVAL; + + len = BITS_TO_LONGS(maxbit) * sizeof(long); + if (len > maxlen) + len = maxlen; + + if (copy_from_user(bits, p, len)) + return -EFAULT; + } + + return len; +} + #else + static int bits_to_user(unsigned long *bits, unsigned int maxbit, unsigned int maxlen, void __user *p, int compat) { @@ -640,6 +737,24 @@ static int bits_to_user(unsigned long *bits, unsigned int maxbit, return copy_to_user(p, bits, len) ? -EFAULT : len; } + +static int bits_from_user(unsigned long *bits, unsigned int maxbit, + unsigned int maxlen, const void __user *p, int compat) +{ + size_t chunk_size = compat ? sizeof(compat_long_t) : sizeof(long); + int len; + + if (maxlen % chunk_size) + return -EINVAL; + + len = compat ? BITS_TO_LONGS_COMPAT(maxbit) : BITS_TO_LONGS(maxbit); + len *= chunk_size; + if (len > maxlen) + len = maxlen; + + return copy_from_user(bits, p, len) ? -EFAULT : len; +} + #endif /* __BIG_ENDIAN */ #else @@ -655,6 +770,21 @@ static int bits_to_user(unsigned long *bits, unsigned int maxbit, return copy_to_user(p, bits, len) ? -EFAULT : len; } +static int bits_from_user(unsigned long *bits, unsigned int maxbit, + unsigned int maxlen, const void __user *p, int compat) +{ + int len; + + if (maxlen % sizeof(long)) + return -EINVAL; + + len = BITS_TO_LONGS(maxbit) * sizeof(long); + if (len > maxlen) + len = maxlen; + + return copy_from_user(bits, p, len) ? -EFAULT : len; +} + #endif /* CONFIG_COMPAT */ static int str_to_user(const char *str, unsigned int maxlen, void __user *p) @@ -849,6 +979,81 @@ static int evdev_revoke(struct evdev *evdev, struct evdev_client *client, return 0; } +/* must be called with evdev-mutex held */ +static int evdev_set_mask(struct evdev_client *client, + unsigned int type, + const void __user *codes, + u32 codes_size, + int compat) +{ + unsigned long flags, *mask, *oldmask; + size_t cnt; + int error; + + /* we allow unknown types and 'codes_size > size' for forward-compat */ + cnt = evdev_get_mask_cnt(type); + if (!cnt) + return 0; + + mask = kcalloc(sizeof(unsigned long), BITS_TO_LONGS(cnt), GFP_KERNEL); + if (!mask) + return -ENOMEM; + + error = bits_from_user(mask, cnt - 1, codes_size, codes, compat); + if (error < 0) { + kfree(mask); + return error; + } + + spin_lock_irqsave(&client->buffer_lock, flags); + oldmask = client->evmasks[type]; + client->evmasks[type] = mask; + spin_unlock_irqrestore(&client->buffer_lock, flags); + + kfree(oldmask); + + return 0; +} + +/* must be called with evdev-mutex held */ +static int evdev_get_mask(struct evdev_client *client, + unsigned int type, + void __user *codes, + u32 codes_size, + int compat) +{ + unsigned long *mask; + size_t cnt, size, xfer_size; + int i; + int error; + + /* we allow unknown types and 'codes_size > size' for forward-compat */ + cnt = evdev_get_mask_cnt(type); + size = sizeof(unsigned long) * BITS_TO_LONGS(cnt); + xfer_size = min_t(size_t, codes_size, size); + + if (cnt > 0) { + mask = client->evmasks[type]; + if (mask) { + error = bits_to_user(mask, cnt - 1, + xfer_size, codes, compat); + if (error < 0) + return error; + } else { + /* fake mask with all bits set */ + for (i = 0; i < xfer_size; i++) + if (put_user(0xffU, (u8 __user *)codes + i)) + return -EFAULT; + } + } + + if (xfer_size < codes_size) + if (clear_user(codes + xfer_size, codes_size - xfer_size)) + return -EFAULT; + + return 0; +} + static long evdev_do_ioctl(struct file *file, unsigned int cmd, void __user *p, int compat_mode) { @@ -856,6 +1061,7 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd, struct evdev *evdev = client->evdev; struct input_dev *dev = evdev->handle.dev; struct input_absinfo abs; + struct input_mask mask; struct ff_effect effect; int __user *ip = (int __user *)p; unsigned int i, t, u, v; @@ -917,6 +1123,30 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd, else return evdev_revoke(evdev, client, file); + case EVIOCGMASK: { + void __user *codes_ptr; + + if (copy_from_user(&mask, p, sizeof(mask))) + return -EFAULT; + + codes_ptr = (void __user *)(unsigned long)mask.codes_ptr; + return evdev_get_mask(client, + mask.type, codes_ptr, mask.codes_size, + compat_mode); + } + + case EVIOCSMASK: { + const void __user *codes_ptr; + + if (copy_from_user(&mask, p, sizeof(mask))) + return -EFAULT; + + codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr; + return evdev_set_mask(client, + mask.type, codes_ptr, mask.codes_size, + compat_mode); + } + case EVIOCSCLOCKID: if (copy_from_user(&i, p, sizeof(unsigned int))) return -EFAULT; diff --git a/include/uapi/linux/input.h b/include/uapi/linux/input.h index 4f9f2a0f5573..2758687300b4 100644 --- a/include/uapi/linux/input.h +++ b/include/uapi/linux/input.h @@ -98,6 +98,12 @@ struct input_keymap_entry { __u8 scancode[32]; }; +struct input_mask { + __u32 type; + __u32 codes_size; + __u64 codes_ptr; +}; + #define EVIOCGVERSION _IOR('E', 0x01, int) /* get driver version */ #define EVIOCGID _IOR('E', 0x02, struct input_id) /* get device ID */ #define EVIOCGREP _IOR('E', 0x03, unsigned int[2]) /* get repeat settings */ @@ -155,6 +161,60 @@ struct input_keymap_entry { #define EVIOCGRAB _IOW('E', 0x90, int) /* Grab/Release device */ #define EVIOCREVOKE _IOW('E', 0x91, int) /* Revoke device access */ +/** + * EVIOCGMASK - Retrieve current event mask + * + * This ioctl allows user to retrieve the current event mask for specific + * event type. The argument must be of type "struct input_mask" and + * specifies the event type to query, the address of the receive buffer and + * the size of the receive buffer. + * + * The event mask is a per-client mask that specifies which events are + * forwarded to the client. Each event code is represented by a single bit + * in the event mask. If the bit is set, the event is passed to the client + * normally. Otherwise, the event is filtered and will never be queued on + * the client's receive buffer. + * + * Event masks do not affect global state of the input device. They only + * affect the file descriptor they are applied to. + * + * The default event mask for a client has all bits set, i.e. all events + * are forwarded to the client. If the kernel is queried for an unknown + * event type or if the receive buffer is larger than the number of + * event codes known to the kernel, the kernel returns all zeroes for those + * codes. + * + * At maximum, codes_size bytes are copied. + * + * This ioctl may fail with ENODEV in case the file is revoked, EFAULT + * if the receive-buffer points to invalid memory, or EINVAL if the kernel + * does not implement the ioctl. + */ +#define EVIOCGMASK _IOR('E', 0x92, struct input_mask) /* Get event-masks */ + +/** + * EVIOCSMASK - Set event mask + * + * This ioctl is the counterpart to EVIOCGMASK. Instead of receiving the + * current event mask, this changes the client's event mask for a specific + * type. See EVIOCGMASK for a description of event-masks and the + * argument-type. + * + * This ioctl provides full forward compatibility. If the passed event type + * is unknown to the kernel, or if the number of event codes specified in + * the mask is bigger than what is known to the kernel, the ioctl is still + * accepted and applied. However, any unknown codes are left untouched and + * stay cleared. That means, the kernel always filters unknown codes + * regardless of what the client requests. If the new mask doesn't cover + * all known event-codes, all remaining codes are automatically cleared and + * thus filtered. + * + * This ioctl may fail with ENODEV in case the file is revoked. EFAULT is + * returned if the receive-buffer points to invalid memory. EINVAL is returned + * if the kernel does not implement the ioctl. + */ +#define EVIOCSMASK _IOW('E', 0x93, struct input_mask) /* Set event-masks */ + #define EVIOCSCLOCKID _IOW('E', 0xa0, int) /* Set clockid to be used for timestamps */ /* |