src/udev/udev-builtin-input_id.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /*
   4  * expose input properties via udev
   5  *
   6  * Copyright (C) 2009 Martin Pitt <martin.pitt@ubuntu.com>
   7  * Portions Copyright (C) 2004 David Zeuthen, <david@fubar.dk>
   8  * Copyright (C) 2011 Kay Sievers <kay@vrfy.org>
   9  * Copyright (C) 2014 Carlos Garnacho <carlosg@gnome.org>
  10  * Copyright (C) 2014 David Herrmann <dh.herrmann@gmail.com>
  11  *
  12  * This program is free software: you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation, either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  24  */
  25
  26 #include <errno.h>
  27 #include <stdarg.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32 #include <linux/limits.h>
  33 #include <linux/input.h>
  34
  35 #include "fd-util.h"
  36 #include "stdio-util.h"
  37 #include "string-util.h"
  38 #include "udev.h"
  39 #include "util.h"
  40
  41 /* we must use this kernel-compatible implementation */
  42 #define BITS_PER_LONG (sizeof(unsigned long) * 8)
  43 #define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
  44 #define OFF(x)  ((x)%BITS_PER_LONG)
  45 #define BIT(x)  (1UL<<OFF(x))
  46 #define LONG(x) ((x)/BITS_PER_LONG)
  47 #define test_bit(bit, array)    ((array[LONG(bit)] >> OFF(bit)) & 1)
  48
  49 static inline int abs_size_mm(const struct input_absinfo *absinfo) {
  50         /* Resolution is defined to be in units/mm for ABS_X/Y */
  51         return (absinfo->maximum - absinfo->minimum) / absinfo->resolution;
  52 }
  53
  54 static void extract_info(struct udev_device *dev, const char *devpath, bool test) {
  55         char width[DECIMAL_STR_MAX(int)], height[DECIMAL_STR_MAX(int)];
  56         struct input_absinfo xabsinfo = {}, yabsinfo = {};
  57         _cleanup_close_ int fd = -1;
  58
  59         fd = open(devpath, O_RDONLY|O_CLOEXEC);
  60         if (fd < 0)
  61                 return;
  62
  63         if (ioctl(fd, EVIOCGABS(ABS_X), &xabsinfo) < 0 ||
  64             ioctl(fd, EVIOCGABS(ABS_Y), &yabsinfo) < 0)
  65                 return;
  66
  67         if (xabsinfo.resolution <= 0 || yabsinfo.resolution <= 0)
  68                 return;
  69
  70         xsprintf(width, "%d", abs_size_mm(&xabsinfo));
  71         xsprintf(height, "%d", abs_size_mm(&yabsinfo));
  72
  73         udev_builtin_add_property(dev, test, "ID_INPUT_WIDTH_MM", width);
  74         udev_builtin_add_property(dev, test, "ID_INPUT_HEIGHT_MM", height);
  75 }
  76
  77 /*
  78  * Read a capability attribute and return bitmask.
  79  * @param dev udev_device
  80  * @param attr sysfs attribute name (e. g. "capabilities/key")
  81  * @param bitmask: Output array which has a sizeof of bitmask_size
  82  */
  83 static void get_cap_mask(struct udev_device *dev,
  84                          struct udev_device *pdev, const char* attr,
  85                          unsigned long *bitmask, size_t bitmask_size,
  86                          bool test) {
  87         const char *v;
  88         char text[4096];
  89         unsigned i;
  90         char* word;
  91         unsigned long val;
  92
  93         v = udev_device_get_sysattr_value(pdev, attr);
  94         if (!v)
  95                 v = "";
  96
  97         xsprintf(text, "%s", v);
  98         log_debug("%s raw kernel attribute: %s", attr, text);
  99
 100         memzero(bitmask, bitmask_size);
 101         i = 0;
 102         while ((word = strrchr(text, ' ')) != NULL) {
 103                 val = strtoul (word+1, NULL, 16);
 104                 if (i < bitmask_size/sizeof(unsigned long))
 105                         bitmask[i] = val;
 106                 else
 107                         log_debug("ignoring %s block %lX which is larger than maximum size", attr, val);
 108                 *word = '\0';
 109                 ++i;
 110         }
 111         val = strtoul (text, NULL, 16);
 112         if (i < bitmask_size / sizeof(unsigned long))
 113                 bitmask[i] = val;
 114         else
 115                 log_debug("ignoring %s block %lX which is larger than maximum size", attr, val);
 116
 117         if (test) {
 118                 /* printf pattern with the right unsigned long number of hex chars */
 119                 xsprintf(text, "  bit %%4u: %%0%zulX\n",
 120                          2 * sizeof(unsigned long));
 121                 log_debug("%s decoded bit map:", attr);
 122                 val = bitmask_size / sizeof (unsigned long);
 123                 /* skip over leading zeros */
 124                 while (bitmask[val-1] == 0 && val > 0)
 125                         --val;
 126                 for (i = 0; i < val; ++i) {
 127                         DISABLE_WARNING_FORMAT_NONLITERAL;
 128                         log_debug(text, i * BITS_PER_LONG, bitmask[i]);
 129                         REENABLE_WARNING;
 130                 }
 131         }
 132 }
 133
 134 /* pointer devices */
 135 static bool test_pointers(struct udev_device *dev,
 136                           const unsigned long* bitmask_ev,
 137                           const unsigned long* bitmask_abs,
 138                           const unsigned long* bitmask_key,
 139                           const unsigned long* bitmask_rel,
 140                           const unsigned long* bitmask_props,
 141                           bool test) {
 142         bool has_abs_coordinates = false;
 143         bool has_rel_coordinates = false;
 144         bool has_mt_coordinates = false;
 145         bool has_joystick_axes_or_buttons = false;
 146         bool is_direct = false;
 147         bool has_touch = false;
 148         bool has_3d_coordinates = false;
 149         bool has_keys = false;
 150         bool stylus_or_pen = false;
 151         bool finger_but_no_pen = false;
 152         bool has_mouse_button = false;
 153         bool is_mouse = false;
 154         bool is_touchpad = false;
 155         bool is_touchscreen = false;
 156         bool is_tablet = false;
 157         bool is_joystick = false;
 158         bool is_accelerometer = false;
 159         bool is_pointing_stick= false;
 160
 161         has_keys = test_bit(EV_KEY, bitmask_ev);
 162         has_abs_coordinates = test_bit(ABS_X, bitmask_abs) && test_bit(ABS_Y, bitmask_abs);
 163         has_3d_coordinates = has_abs_coordinates && test_bit(ABS_Z, bitmask_abs);
 164         is_accelerometer = test_bit(INPUT_PROP_ACCELEROMETER, bitmask_props);
 165
 166         if (!has_keys && has_3d_coordinates)
 167                 is_accelerometer = true;
 168
 169         if (is_accelerometer) {
 170                 udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
 171                 return true;
 172         }
 173
 174         is_pointing_stick = test_bit(INPUT_PROP_POINTING_STICK, bitmask_props);
 175         stylus_or_pen = test_bit(BTN_STYLUS, bitmask_key) || test_bit(BTN_TOOL_PEN, bitmask_key);
 176         finger_but_no_pen = test_bit(BTN_TOOL_FINGER, bitmask_key) && !test_bit(BTN_TOOL_PEN, bitmask_key);
 177         has_mouse_button = test_bit(BTN_LEFT, bitmask_key);
 178         has_rel_coordinates = test_bit(EV_REL, bitmask_ev) && test_bit(REL_X, bitmask_rel) && test_bit(REL_Y, bitmask_rel);
 179         has_mt_coordinates = test_bit(ABS_MT_POSITION_X, bitmask_abs) && test_bit(ABS_MT_POSITION_Y, bitmask_abs);
 180
 181         /* unset has_mt_coordinates if devices claims to have all abs axis */
 182         if(has_mt_coordinates && test_bit(ABS_MT_SLOT, bitmask_abs) && test_bit(ABS_MT_SLOT - 1, bitmask_abs))
 183                 has_mt_coordinates = false;
 184         is_direct = test_bit(INPUT_PROP_DIRECT, bitmask_props);
 185         has_touch = test_bit(BTN_TOUCH, bitmask_key);
 186         /* joysticks don't necessarily have buttons; e. g.
 187          * rudders/pedals are joystick-like, but buttonless; they have
 188          * other fancy axes */
 189         has_joystick_axes_or_buttons = test_bit(BTN_TRIGGER, bitmask_key) ||
 190                                        test_bit(BTN_A, bitmask_key) ||
 191                                        test_bit(BTN_1, bitmask_key) ||
 192                                        test_bit(ABS_RX, bitmask_abs) ||
 193                                        test_bit(ABS_RY, bitmask_abs) ||
 194                                        test_bit(ABS_RZ, bitmask_abs) ||
 195                                        test_bit(ABS_THROTTLE, bitmask_abs) ||
 196                                        test_bit(ABS_RUDDER, bitmask_abs) ||
 197                                        test_bit(ABS_WHEEL, bitmask_abs) ||
 198                                        test_bit(ABS_GAS, bitmask_abs) ||
 199                                        test_bit(ABS_BRAKE, bitmask_abs);
 200
 201         if (has_abs_coordinates) {
 202                 if (stylus_or_pen)
 203                         is_tablet = true;
 204                 else if (finger_but_no_pen && !is_direct)
 205                         is_touchpad = true;
 206                 else if (has_mouse_button)
 207                         /* This path is taken by VMware's USB mouse, which has
 208                          * absolute axes, but no touch/pressure button. */
 209                         is_mouse = true;
 210                 else if (has_touch || is_direct)
 211                         is_touchscreen = true;
 212                 else if (has_joystick_axes_or_buttons)
 213                         is_joystick = true;
 214         }
 215         if (has_mt_coordinates && (is_direct || has_touch))
 216                 is_touchscreen = true;
 217
 218         if (has_rel_coordinates && has_mouse_button)
 219                 is_mouse = true;
 220
 221         if (is_pointing_stick)
 222                 udev_builtin_add_property(dev, test, "ID_INPUT_POINTINGSTICK", "1");
 223         if (is_mouse)
 224                 udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
 225         if (is_touchpad)
 226                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
 227         if (is_touchscreen)
 228                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
 229         if (is_joystick)
 230                 udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
 231         if (is_tablet)
 232                 udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
 233
 234         return is_tablet || is_mouse || is_touchpad || is_touchscreen || is_joystick || is_pointing_stick;
 235 }
 236
 237 /* key like devices */
 238 static bool test_key(struct udev_device *dev,
 239                      const unsigned long* bitmask_ev,
 240                      const unsigned long* bitmask_key,
 241                      bool test) {
 242         unsigned i;
 243         unsigned long found;
 244         unsigned long mask;
 245         bool ret = false;
 246
 247         /* do we have any KEY_* capability? */
 248         if (!test_bit(EV_KEY, bitmask_ev)) {
 249                 log_debug("test_key: no EV_KEY capability");
 250                 return false;
 251         }
 252
 253         /* only consider KEY_* here, not BTN_* */
 254         found = 0;
 255         for (i = 0; i < BTN_MISC/BITS_PER_LONG; ++i) {
 256                 found |= bitmask_key[i];
 257                 log_debug("test_key: checking bit block %lu for any keys; found=%i", (unsigned long)i*BITS_PER_LONG, found > 0);
 258         }
 259         /* If there are no keys in the lower block, check the higher block */
 260         if (!found) {
 261                 for (i = KEY_OK; i < BTN_TRIGGER_HAPPY; ++i) {
 262                         if (test_bit(i, bitmask_key)) {
 263                                 log_debug("test_key: Found key %x in high block", i);
 264                                 found = 1;
 265                                 break;
 266                         }
 267                 }
 268         }
 269
 270         if (found > 0) {
 271                 udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 272                 ret = true;
 273         }
 274
 275         /* the first 32 bits are ESC, numbers, and Q to D; if we have all of
 276          * those, consider it a full keyboard; do not test KEY_RESERVED, though */
 277         mask = 0xFFFFFFFE;
 278         if ((bitmask_key[0] & mask) == mask) {
 279                 udev_builtin_add_property(dev, test, "ID_INPUT_KEYBOARD", "1");
 280                 ret = true;
 281         }
 282
 283         return ret;
 284 }
 285
 286 static int builtin_input_id(struct udev_device *dev, int argc, char *argv[], bool test) {
 287         struct udev_device *pdev;
 288         unsigned long bitmask_ev[NBITS(EV_MAX)];
 289         unsigned long bitmask_abs[NBITS(ABS_MAX)];
 290         unsigned long bitmask_key[NBITS(KEY_MAX)];
 291         unsigned long bitmask_rel[NBITS(REL_MAX)];
 292         unsigned long bitmask_props[NBITS(INPUT_PROP_MAX)];
 293         const char *sysname, *devnode;
 294         bool is_pointer;
 295         bool is_key;
 296
 297         assert(dev);
 298
 299         /* walk up the parental chain until we find the real input device; the
 300          * argument is very likely a subdevice of this, like eventN */
 301         pdev = dev;
 302         while (pdev != NULL && udev_device_get_sysattr_value(pdev, "capabilities/ev") == NULL)
 303                 pdev = udev_device_get_parent_with_subsystem_devtype(pdev, "input", NULL);
 304
 305         if (pdev) {
 306                 /* Use this as a flag that input devices were detected, so that this
 307                  * program doesn't need to be called more than once per device */
 308                 udev_builtin_add_property(dev, test, "ID_INPUT", "1");
 309                 get_cap_mask(dev, pdev, "capabilities/ev", bitmask_ev, sizeof(bitmask_ev), test);
 310                 get_cap_mask(dev, pdev, "capabilities/abs", bitmask_abs, sizeof(bitmask_abs), test);
 311                 get_cap_mask(dev, pdev, "capabilities/rel", bitmask_rel, sizeof(bitmask_rel), test);
 312                 get_cap_mask(dev, pdev, "capabilities/key", bitmask_key, sizeof(bitmask_key), test);
 313                 get_cap_mask(dev, pdev, "properties", bitmask_props, sizeof(bitmask_props), test);
 314                 is_pointer = test_pointers(dev, bitmask_ev, bitmask_abs,
 315                                            bitmask_key, bitmask_rel,
 316                                            bitmask_props, test);
 317                 is_key = test_key(dev, bitmask_ev, bitmask_key, test);
 318                 /* Some evdev nodes have only a scrollwheel */
 319                 if (!is_pointer && !is_key && test_bit(EV_REL, bitmask_ev) &&
 320                     (test_bit(REL_WHEEL, bitmask_rel) || test_bit(REL_HWHEEL, bitmask_rel)))
 321                         udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 322         }
 323
 324         devnode = udev_device_get_devnode(dev);
 325         sysname = udev_device_get_sysname(dev);
 326         if (devnode && sysname && startswith(sysname, "event"))
 327                 extract_info(dev, devnode, test);
 328
 329         return EXIT_SUCCESS;
 330 }
 331
 332 const struct udev_builtin udev_builtin_input_id = {
 333         .name = "input_id",
 334         .cmd = builtin_input_id,
 335         .help = "Input device properties",
 336 };