src/udev/udev-builtin-input_id.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * expose input properties via udev
   4  *
   5  * Portions Copyright © 2004 David Zeuthen, <david@fubar.dk>
   6  * Copyright © 2014 Carlos Garnacho <carlosg@gnome.org>
   7  */
   8
   9 #include <errno.h>
  10 #include <fcntl.h>
  11 #include <stdarg.h>
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <unistd.h>
  15 #include <linux/limits.h>
  16 #include <linux/input.h>
  17
  18 #include "device-util.h"
  19 #include "fd-util.h"
  20 #include "missing_input.h"
  21 #include "stdio-util.h"
  22 #include "string-util.h"
  23 #include "udev-builtin.h"
  24 #include "util.h"
  25
  26 /* we must use this kernel-compatible implementation */
  27 #define BITS_PER_LONG (sizeof(unsigned long) * 8)
  28 #define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
  29 #define OFF(x)  ((x)%BITS_PER_LONG)
  30 #define BIT(x)  (1UL<<OFF(x))
  31 #define LONG(x) ((x)/BITS_PER_LONG)
  32 #define test_bit(bit, array)    ((array[LONG(bit)] >> OFF(bit)) & 1)
  33
  34 struct range {
  35         unsigned start;
  36         unsigned end;
  37 };
  38
  39 /* key code ranges above BTN_MISC (start is inclusive, stop is exclusive)*/
  40 static const struct range high_key_blocks[] = {
  41         { KEY_OK, BTN_DPAD_UP },
  42         { KEY_ALS_TOGGLE, BTN_TRIGGER_HAPPY }
  43 };
  44
  45 static int abs_size_mm(const struct input_absinfo *absinfo) {
  46         /* Resolution is defined to be in units/mm for ABS_X/Y */
  47         return (absinfo->maximum - absinfo->minimum) / absinfo->resolution;
  48 }
  49
  50 static void extract_info(sd_device *dev, const char *devpath, bool test) {
  51         char width[DECIMAL_STR_MAX(int)], height[DECIMAL_STR_MAX(int)];
  52         struct input_absinfo xabsinfo = {}, yabsinfo = {};
  53         _cleanup_close_ int fd = -1;
  54
  55         fd = open(devpath, O_RDONLY|O_CLOEXEC);
  56         if (fd < 0)
  57                 return;
  58
  59         if (ioctl(fd, EVIOCGABS(ABS_X), &xabsinfo) < 0 ||
  60             ioctl(fd, EVIOCGABS(ABS_Y), &yabsinfo) < 0)
  61                 return;
  62
  63         if (xabsinfo.resolution <= 0 || yabsinfo.resolution <= 0)
  64                 return;
  65
  66         xsprintf(width, "%d", abs_size_mm(&xabsinfo));
  67         xsprintf(height, "%d", abs_size_mm(&yabsinfo));
  68
  69         udev_builtin_add_property(dev, test, "ID_INPUT_WIDTH_MM", width);
  70         udev_builtin_add_property(dev, test, "ID_INPUT_HEIGHT_MM", height);
  71 }
  72
  73 /*
  74  * Read a capability attribute and return bitmask.
  75  * @param dev sd_device
  76  * @param attr sysfs attribute name (e. g. "capabilities/key")
  77  * @param bitmask: Output array which has a sizeof of bitmask_size
  78  */
  79 static void get_cap_mask(sd_device *pdev, const char* attr,
  80                          unsigned long *bitmask, size_t bitmask_size,
  81                          bool test) {
  82         const char *v;
  83         char text[4096];
  84         unsigned i;
  85         char* word;
  86         unsigned long val;
  87
  88         if (sd_device_get_sysattr_value(pdev, attr, &v) < 0)
  89                 v = "";
  90
  91         xsprintf(text, "%s", v);
  92         log_device_debug(pdev, "%s raw kernel attribute: %s", attr, text);
  93
  94         memzero(bitmask, bitmask_size);
  95         i = 0;
  96         while ((word = strrchr(text, ' ')) != NULL) {
  97                 val = strtoul(word+1, NULL, 16);
  98                 if (i < bitmask_size / sizeof(unsigned long))
  99                         bitmask[i] = val;
 100                 else
 101                         log_device_debug(pdev, "Ignoring %s block %lX which is larger than maximum size", attr, val);
 102                 *word = '\0';
 103                 ++i;
 104         }
 105         val = strtoul (text, NULL, 16);
 106         if (i < bitmask_size / sizeof(unsigned long))
 107                 bitmask[i] = val;
 108         else
 109                 log_device_debug(pdev, "Ignoring %s block %lX which is larger than maximum size", attr, val);
 110
 111         if (test) {
 112                 /* printf pattern with the right unsigned long number of hex chars */
 113                 xsprintf(text, "  bit %%4u: %%0%zulX\n",
 114                          2 * sizeof(unsigned long));
 115                 log_device_debug(pdev, "%s decoded bit map:", attr);
 116                 val = bitmask_size / sizeof (unsigned long);
 117                 /* skip over leading zeros */
 118                 while (bitmask[val-1] == 0 && val > 0)
 119                         --val;
 120                 for (i = 0; i < val; ++i) {
 121                         DISABLE_WARNING_FORMAT_NONLITERAL;
 122                         log_device_debug(pdev, text, i * BITS_PER_LONG, bitmask[i]);
 123                         REENABLE_WARNING;
 124                 }
 125         }
 126 }
 127
 128 /* pointer devices */
 129 static bool test_pointers(sd_device *dev,
 130                           const unsigned long* bitmask_ev,
 131                           const unsigned long* bitmask_abs,
 132                           const unsigned long* bitmask_key,
 133                           const unsigned long* bitmask_rel,
 134                           const unsigned long* bitmask_props,
 135                           bool test) {
 136         int button, axis;
 137         bool has_abs_coordinates = false;
 138         bool has_rel_coordinates = false;
 139         bool has_mt_coordinates = false;
 140         bool has_joystick_axes_or_buttons = false;
 141         bool is_direct = false;
 142         bool has_touch = false;
 143         bool has_3d_coordinates = false;
 144         bool has_keys = false;
 145         bool stylus_or_pen = false;
 146         bool finger_but_no_pen = false;
 147         bool has_mouse_button = false;
 148         bool is_mouse = false;
 149         bool is_touchpad = false;
 150         bool is_touchscreen = false;
 151         bool is_tablet = false;
 152         bool is_joystick = false;
 153         bool is_accelerometer = false;
 154         bool is_pointing_stick= false;
 155
 156         has_keys = test_bit(EV_KEY, bitmask_ev);
 157         has_abs_coordinates = test_bit(ABS_X, bitmask_abs) && test_bit(ABS_Y, bitmask_abs);
 158         has_3d_coordinates = has_abs_coordinates && test_bit(ABS_Z, bitmask_abs);
 159         is_accelerometer = test_bit(INPUT_PROP_ACCELEROMETER, bitmask_props);
 160
 161         if (!has_keys && has_3d_coordinates)
 162                 is_accelerometer = true;
 163
 164         if (is_accelerometer) {
 165                 udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
 166                 return true;
 167         }
 168
 169         is_pointing_stick = test_bit(INPUT_PROP_POINTING_STICK, bitmask_props);
 170         stylus_or_pen = test_bit(BTN_STYLUS, bitmask_key) || test_bit(BTN_TOOL_PEN, bitmask_key);
 171         finger_but_no_pen = test_bit(BTN_TOOL_FINGER, bitmask_key) && !test_bit(BTN_TOOL_PEN, bitmask_key);
 172         for (button = BTN_MOUSE; button < BTN_JOYSTICK && !has_mouse_button; button++)
 173                 has_mouse_button = test_bit(button, bitmask_key);
 174         has_rel_coordinates = test_bit(EV_REL, bitmask_ev) && test_bit(REL_X, bitmask_rel) && test_bit(REL_Y, bitmask_rel);
 175         has_mt_coordinates = test_bit(ABS_MT_POSITION_X, bitmask_abs) && test_bit(ABS_MT_POSITION_Y, bitmask_abs);
 176
 177         /* unset has_mt_coordinates if devices claims to have all abs axis */
 178         if (has_mt_coordinates && test_bit(ABS_MT_SLOT, bitmask_abs) && test_bit(ABS_MT_SLOT - 1, bitmask_abs))
 179                 has_mt_coordinates = false;
 180         is_direct = test_bit(INPUT_PROP_DIRECT, bitmask_props);
 181         has_touch = test_bit(BTN_TOUCH, bitmask_key);
 182
 183         /* joysticks don't necessarily have buttons; e. g.
 184          * rudders/pedals are joystick-like, but buttonless; they have
 185          * other fancy axes. Others have buttons only but no axes.
 186          *
 187          * The BTN_JOYSTICK range starts after the mouse range, so a mouse
 188          * with more than 16 buttons runs into the joystick range (e.g. Mad
 189          * Catz Mad Catz M.M.O.TE). Skip those.
 190          */
 191         if (!test_bit(BTN_JOYSTICK - 1, bitmask_key)) {
 192                 for (button = BTN_JOYSTICK; button < BTN_DIGI && !has_joystick_axes_or_buttons; button++)
 193                         has_joystick_axes_or_buttons = test_bit(button, bitmask_key);
 194                 for (button = BTN_TRIGGER_HAPPY1; button <= BTN_TRIGGER_HAPPY40 && !has_joystick_axes_or_buttons; button++)
 195                         has_joystick_axes_or_buttons = test_bit(button, bitmask_key);
 196                 for (button = BTN_DPAD_UP; button <= BTN_DPAD_RIGHT && !has_joystick_axes_or_buttons; button++)
 197                         has_joystick_axes_or_buttons = test_bit(button, bitmask_key);
 198         }
 199         for (axis = ABS_RX; axis < ABS_PRESSURE && !has_joystick_axes_or_buttons; axis++)
 200                 has_joystick_axes_or_buttons = test_bit(axis, bitmask_abs);
 201
 202         if (has_abs_coordinates) {
 203                 if (stylus_or_pen)
 204                         is_tablet = true;
 205                 else if (finger_but_no_pen && !is_direct)
 206                         is_touchpad = true;
 207                 else if (has_mouse_button)
 208                         /* This path is taken by VMware's USB mouse, which has
 209                          * absolute axes, but no touch/pressure button. */
 210                         is_mouse = true;
 211                 else if (has_touch || is_direct)
 212                         is_touchscreen = true;
 213                 else if (has_joystick_axes_or_buttons)
 214                         is_joystick = true;
 215         } else if (has_joystick_axes_or_buttons) {
 216                 is_joystick = true;
 217         }
 218
 219         if (has_mt_coordinates) {
 220                 if (stylus_or_pen)
 221                         is_tablet = true;
 222                 else if (finger_but_no_pen && !is_direct)
 223                         is_touchpad = true;
 224                 else if (has_touch || is_direct)
 225                         is_touchscreen = true;
 226         }
 227
 228         if (!is_tablet && !is_touchpad && !is_joystick &&
 229             has_mouse_button &&
 230             (has_rel_coordinates ||
 231             !has_abs_coordinates)) /* mouse buttons and no axis */
 232                 is_mouse = true;
 233
 234         if (is_pointing_stick)
 235                 udev_builtin_add_property(dev, test, "ID_INPUT_POINTINGSTICK", "1");
 236         if (is_mouse)
 237                 udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
 238         if (is_touchpad)
 239                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
 240         if (is_touchscreen)
 241                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
 242         if (is_joystick)
 243                 udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
 244         if (is_tablet)
 245                 udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
 246
 247         return is_tablet || is_mouse || is_touchpad || is_touchscreen || is_joystick || is_pointing_stick;
 248 }
 249
 250 /* key like devices */
 251 static bool test_key(sd_device *dev,
 252                      const unsigned long* bitmask_ev,
 253                      const unsigned long* bitmask_key,
 254                      bool test) {
 255         unsigned i;
 256         unsigned long found;
 257         unsigned long mask;
 258         bool ret = false;
 259
 260         /* do we have any KEY_* capability? */
 261         if (!test_bit(EV_KEY, bitmask_ev)) {
 262                 log_device_debug(dev, "test_key: no EV_KEY capability");
 263                 return false;
 264         }
 265
 266         /* only consider KEY_* here, not BTN_* */
 267         found = 0;
 268         for (i = 0; i < BTN_MISC/BITS_PER_LONG; ++i) {
 269                 found |= bitmask_key[i];
 270                 log_device_debug(dev, "test_key: checking bit block %lu for any keys; found=%i", (unsigned long)i*BITS_PER_LONG, found > 0);
 271         }
 272         /* If there are no keys in the lower block, check the higher blocks */
 273         if (!found) {
 274                 unsigned block;
 275                 for (block = 0; block < (sizeof(high_key_blocks) / sizeof(struct range)); ++block) {
 276                         for (i = high_key_blocks[block].start; i < high_key_blocks[block].end; ++i) {
 277                                 if (test_bit(i, bitmask_key)) {
 278                                         log_device_debug(dev, "test_key: Found key %x in high block", i);
 279                                         found = 1;
 280                                         break;
 281                                 }
 282                         }
 283                 }
 284         }
 285
 286         if (found > 0) {
 287                 udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 288                 ret = true;
 289         }
 290
 291         /* the first 32 bits are ESC, numbers, and Q to D; if we have all of
 292          * those, consider it a full keyboard; do not test KEY_RESERVED, though */
 293         mask = 0xFFFFFFFE;
 294         if (FLAGS_SET(bitmask_key[0], mask)) {
 295                 udev_builtin_add_property(dev, test, "ID_INPUT_KEYBOARD", "1");
 296                 ret = true;
 297         }
 298
 299         return ret;
 300 }
 301
 302 static int builtin_input_id(sd_device *dev, int argc, char *argv[], bool test) {
 303         sd_device *pdev;
 304         unsigned long bitmask_ev[NBITS(EV_MAX)];
 305         unsigned long bitmask_abs[NBITS(ABS_MAX)];
 306         unsigned long bitmask_key[NBITS(KEY_MAX)];
 307         unsigned long bitmask_rel[NBITS(REL_MAX)];
 308         unsigned long bitmask_props[NBITS(INPUT_PROP_MAX)];
 309         const char *sysname, *devnode;
 310         bool is_pointer;
 311         bool is_key;
 312
 313         assert(dev);
 314
 315         /* walk up the parental chain until we find the real input device; the
 316          * argument is very likely a subdevice of this, like eventN */
 317         for (pdev = dev; pdev; ) {
 318                 const char *s;
 319
 320                 if (sd_device_get_sysattr_value(pdev, "capabilities/ev", &s) >= 0)
 321                         break;
 322
 323                 if (sd_device_get_parent_with_subsystem_devtype(pdev, "input", NULL, &pdev) >= 0)
 324                         continue;
 325
 326                 pdev = NULL;
 327                 break;
 328         }
 329
 330         if (pdev) {
 331                 /* Use this as a flag that input devices were detected, so that this
 332                  * program doesn't need to be called more than once per device */
 333                 udev_builtin_add_property(dev, test, "ID_INPUT", "1");
 334                 get_cap_mask(pdev, "capabilities/ev", bitmask_ev, sizeof(bitmask_ev), test);
 335                 get_cap_mask(pdev, "capabilities/abs", bitmask_abs, sizeof(bitmask_abs), test);
 336                 get_cap_mask(pdev, "capabilities/rel", bitmask_rel, sizeof(bitmask_rel), test);
 337                 get_cap_mask(pdev, "capabilities/key", bitmask_key, sizeof(bitmask_key), test);
 338                 get_cap_mask(pdev, "properties", bitmask_props, sizeof(bitmask_props), test);
 339                 is_pointer = test_pointers(dev, bitmask_ev, bitmask_abs,
 340                                            bitmask_key, bitmask_rel,
 341                                            bitmask_props, test);
 342                 is_key = test_key(dev, bitmask_ev, bitmask_key, test);
 343                 /* Some evdev nodes have only a scrollwheel */
 344                 if (!is_pointer && !is_key && test_bit(EV_REL, bitmask_ev) &&
 345                     (test_bit(REL_WHEEL, bitmask_rel) || test_bit(REL_HWHEEL, bitmask_rel)))
 346                         udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 347                 if (test_bit(EV_SW, bitmask_ev))
 348                         udev_builtin_add_property(dev, test, "ID_INPUT_SWITCH", "1");
 349
 350         }
 351
 352         if (sd_device_get_devname(dev, &devnode) >= 0 &&
 353             sd_device_get_sysname(dev, &sysname) >= 0 &&
 354             startswith(sysname, "event"))
 355                 extract_info(dev, devnode, test);
 356
 357         return 0;
 358 }
 359
 360 const UdevBuiltin udev_builtin_input_id = {
 361         .name = "input_id",
 362         .cmd = builtin_input_id,
 363         .help = "Input device properties",
 364 };