src/udev/udev-builtin-input_id.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   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 <unistd.h>
  13 #include <linux/limits.h>
  14
  15 #include "device-util.h"
  16 #include "fd-util.h"
  17 #include "missing_input.h"
  18 #include "parse-util.h"
  19 #include "stdio-util.h"
  20 #include "string-util.h"
  21 #include "udev-builtin.h"
  22
  23 /* we must use this kernel-compatible implementation */
  24 #define BITS_PER_LONG (sizeof(unsigned long) * 8)
  25 #define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
  26 #define OFF(x)  ((x)%BITS_PER_LONG)
  27 #define BIT(x)  (1UL<<OFF(x))
  28 #define LONG(x) ((x)/BITS_PER_LONG)
  29 #define test_bit(bit, array)    ((array[LONG(bit)] >> OFF(bit)) & 1)
  30
  31 struct range {
  32         unsigned start;
  33         unsigned end;
  34 };
  35
  36 /* key code ranges above BTN_MISC (start is inclusive, stop is exclusive) */
  37 static const struct range high_key_blocks[] = {
  38         { KEY_OK, BTN_DPAD_UP },
  39         { KEY_ALS_TOGGLE, BTN_TRIGGER_HAPPY }
  40 };
  41
  42 static int abs_size_mm(const struct input_absinfo *absinfo) {
  43         /* Resolution is defined to be in units/mm for ABS_X/Y */
  44         return (absinfo->maximum - absinfo->minimum) / absinfo->resolution;
  45 }
  46
  47 static void extract_info(sd_device *dev, bool test) {
  48         char width[DECIMAL_STR_MAX(int)], height[DECIMAL_STR_MAX(int)];
  49         struct input_absinfo xabsinfo = {}, yabsinfo = {};
  50         _cleanup_close_ int fd = -EBADF;
  51
  52         fd = sd_device_open(dev, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
  53         if (fd < 0)
  54                 return;
  55
  56         if (ioctl(fd, EVIOCGABS(ABS_X), &xabsinfo) < 0 ||
  57             ioctl(fd, EVIOCGABS(ABS_Y), &yabsinfo) < 0)
  58                 return;
  59
  60         if (xabsinfo.resolution <= 0 || yabsinfo.resolution <= 0)
  61                 return;
  62
  63         xsprintf(width, "%d", abs_size_mm(&xabsinfo));
  64         xsprintf(height, "%d", abs_size_mm(&yabsinfo));
  65
  66         udev_builtin_add_property(dev, test, "ID_INPUT_WIDTH_MM", width);
  67         udev_builtin_add_property(dev, test, "ID_INPUT_HEIGHT_MM", height);
  68 }
  69
  70 /*
  71  * Read a capability attribute and return bitmask.
  72  * @param dev sd_device
  73  * @param attr sysfs attribute name (e. g. "capabilities/key")
  74  * @param bitmask: Output array which has a sizeof of bitmask_size
  75  */
  76 static void get_cap_mask(sd_device *pdev, const char* attr,
  77                          unsigned long *bitmask, size_t bitmask_size,
  78                          bool test) {
  79         const char *v;
  80         char text[4096];
  81         unsigned i;
  82         char* word;
  83         unsigned long val;
  84         int r;
  85
  86         if (sd_device_get_sysattr_value(pdev, attr, &v) < 0)
  87                 v = "";
  88
  89         xsprintf(text, "%s", v);
  90         log_device_debug(pdev, "%s raw kernel attribute: %s", attr, text);
  91
  92         memzero(bitmask, bitmask_size);
  93         i = 0;
  94         while ((word = strrchr(text, ' '))) {
  95                 r = safe_atolu_full(word+1, 16, &val);
  96                 if (r < 0)
  97                         log_device_debug_errno(pdev, r, "Ignoring %s block which failed to parse: %m", attr);
  98                 else 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         r = safe_atolu_full(text, 16, &val);
 106         if (r < 0)
 107                 log_device_debug_errno(pdev, r, "Ignoring %s block which failed to parse: %m", attr);
 108         else if (i < bitmask_size / sizeof(unsigned long))
 109                 bitmask[i] = val;
 110         else
 111                 log_device_debug(pdev, "Ignoring %s block %lX which is larger than maximum size", attr, val);
 112
 113         if (test && DEBUG_LOGGING) {
 114                 log_device_debug(pdev, "%s decoded bit map:", attr);
 115
 116                 val = bitmask_size / sizeof (unsigned long);
 117                 /* skip trailing zeros */
 118                 while (bitmask[val-1] == 0 && val > 0)
 119                         --val;
 120
 121                 /* IN_SET() cannot be used in assert_cc(). */
 122                 assert_cc(sizeof(unsigned long) == 4 || sizeof(unsigned long) == 8);
 123                 for (unsigned long j = 0; j < val; j++)
 124                         log_device_debug(pdev,
 125                                          sizeof(unsigned long) == 4 ? "  bit %4lu: %08lX\n" : "  bit %4lu: %016lX\n",
 126                                          j * BITS_PER_LONG, bitmask[j]);
 127         }
 128 }
 129
 130 static struct input_id get_input_id(sd_device *dev) {
 131         const char *v;
 132         struct input_id id = {};
 133
 134         if (sd_device_get_sysattr_value(dev, "id/bustype", &v) >= 0)
 135                 (void) safe_atoux16(v, &id.bustype);
 136         if (sd_device_get_sysattr_value(dev, "id/vendor", &v) >= 0)
 137                 (void) safe_atoux16(v, &id.vendor);
 138         if (sd_device_get_sysattr_value(dev, "id/product", &v) >= 0)
 139                 (void) safe_atoux16(v, &id.product);
 140         if (sd_device_get_sysattr_value(dev, "id/version", &v) >= 0)
 141                 (void) safe_atoux16(v, &id.version);
 142
 143         return id;
 144 }
 145
 146 /* pointer devices */
 147 static bool test_pointers(sd_device *dev,
 148                           const struct input_id *id,
 149                           const unsigned long* bitmask_ev,
 150                           const unsigned long* bitmask_abs,
 151                           const unsigned long* bitmask_key,
 152                           const unsigned long* bitmask_rel,
 153                           const unsigned long* bitmask_props,
 154                           bool test) {
 155         bool has_abs_coordinates = false;
 156         bool has_rel_coordinates = false;
 157         bool has_mt_coordinates = false;
 158         size_t num_joystick_axes = 0;
 159         size_t num_joystick_buttons = 0;
 160         bool has_pad_buttons = false;
 161         bool is_direct = false;
 162         bool has_touch = false;
 163         bool has_3d_coordinates = false;
 164         bool has_keys = false;
 165         bool has_stylus = false;
 166         bool has_pen = false;
 167         bool finger_but_no_pen = false;
 168         bool has_mouse_button = false;
 169         bool is_mouse = false;
 170         bool is_abs_mouse = false;
 171         bool is_touchpad = false;
 172         bool is_touchscreen = false;
 173         bool is_tablet = false;
 174         bool is_tablet_pad = false;
 175         bool is_joystick = false;
 176         bool is_accelerometer = false;
 177         bool is_pointing_stick = false;
 178
 179         has_keys = test_bit(EV_KEY, bitmask_ev);
 180         has_abs_coordinates = test_bit(ABS_X, bitmask_abs) && test_bit(ABS_Y, bitmask_abs);
 181         has_3d_coordinates = has_abs_coordinates && test_bit(ABS_Z, bitmask_abs);
 182         is_accelerometer = test_bit(INPUT_PROP_ACCELEROMETER, bitmask_props);
 183
 184         if (!has_keys && has_3d_coordinates)
 185                 is_accelerometer = true;
 186
 187         if (is_accelerometer) {
 188                 udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
 189                 return true;
 190         }
 191
 192         is_pointing_stick = test_bit(INPUT_PROP_POINTING_STICK, bitmask_props);
 193         has_stylus = test_bit(BTN_STYLUS, bitmask_key);
 194         has_pen = test_bit(BTN_TOOL_PEN, bitmask_key);
 195         finger_but_no_pen = test_bit(BTN_TOOL_FINGER, bitmask_key) && !test_bit(BTN_TOOL_PEN, bitmask_key);
 196         for (int button = BTN_MOUSE; button < BTN_JOYSTICK && !has_mouse_button; button++)
 197                 has_mouse_button = test_bit(button, bitmask_key);
 198         has_rel_coordinates = test_bit(EV_REL, bitmask_ev) && test_bit(REL_X, bitmask_rel) && test_bit(REL_Y, bitmask_rel);
 199         has_mt_coordinates = test_bit(ABS_MT_POSITION_X, bitmask_abs) && test_bit(ABS_MT_POSITION_Y, bitmask_abs);
 200
 201         /* unset has_mt_coordinates if devices claims to have all abs axis */
 202         if (has_mt_coordinates && test_bit(ABS_MT_SLOT, bitmask_abs) && test_bit(ABS_MT_SLOT - 1, bitmask_abs))
 203                 has_mt_coordinates = false;
 204         is_direct = test_bit(INPUT_PROP_DIRECT, bitmask_props);
 205         has_touch = test_bit(BTN_TOUCH, bitmask_key);
 206         has_pad_buttons = test_bit(BTN_0, bitmask_key) && has_stylus && !has_pen;
 207
 208         /* joysticks don't necessarily have buttons; e. g.
 209          * rudders/pedals are joystick-like, but buttonless; they have
 210          * other fancy axes. Others have buttons only but no axes.
 211          *
 212          * The BTN_JOYSTICK range starts after the mouse range, so a mouse
 213          * with more than 16 buttons runs into the joystick range (e.g. Mad
 214          * Catz Mad Catz M.M.O.TE). Skip those.
 215          */
 216         if (!test_bit(BTN_JOYSTICK - 1, bitmask_key)) {
 217                 for (int button = BTN_JOYSTICK; button < BTN_DIGI; button++)
 218                         if (test_bit(button, bitmask_key))
 219                                 num_joystick_buttons++;
 220                 for (int button = BTN_TRIGGER_HAPPY1; button <= BTN_TRIGGER_HAPPY40; button++)
 221                         if (test_bit(button, bitmask_key))
 222                                 num_joystick_buttons++;
 223                 for (int button = BTN_DPAD_UP; button <= BTN_DPAD_RIGHT; button++)
 224                         if (test_bit(button, bitmask_key))
 225                                 num_joystick_buttons++;
 226         }
 227         for (int axis = ABS_RX; axis < ABS_PRESSURE; axis++)
 228                 if (test_bit(axis, bitmask_abs))
 229                         num_joystick_axes++;
 230
 231         if (has_abs_coordinates) {
 232                 if (has_stylus || has_pen)
 233                         is_tablet = true;
 234                 else if (finger_but_no_pen && !is_direct)
 235                         is_touchpad = true;
 236                 else if (has_mouse_button)
 237                         /* This path is taken by VMware's USB mouse, which has
 238                          * absolute axes, but no touch/pressure button. */
 239                         is_abs_mouse = true;
 240                 else if (has_touch || is_direct)
 241                         is_touchscreen = true;
 242                 else if (num_joystick_buttons > 0 || num_joystick_axes > 0)
 243                         is_joystick = true;
 244         } else if (num_joystick_buttons > 0 || num_joystick_axes > 0)
 245                 is_joystick = true;
 246
 247         if (has_mt_coordinates) {
 248                 if (has_stylus || has_pen)
 249                         is_tablet = true;
 250                 else if (finger_but_no_pen && !is_direct)
 251                         is_touchpad = true;
 252                 else if (has_touch || is_direct)
 253                         is_touchscreen = true;
 254         }
 255
 256         if (is_tablet && has_pad_buttons)
 257                 is_tablet_pad = true;
 258
 259         if (!is_tablet && !is_touchpad && !is_joystick &&
 260             has_mouse_button &&
 261             (has_rel_coordinates ||
 262             !has_abs_coordinates)) /* mouse buttons and no axis */
 263                 is_mouse = true;
 264
 265         /* There is no such thing as an i2c mouse */
 266         if (is_mouse && id->bustype == BUS_I2C)
 267                 is_pointing_stick = true;
 268
 269         /* Joystick un-detection. Some keyboards have random joystick buttons
 270          * set. Avoid those being labeled as ID_INPUT_JOYSTICK with some heuristics.
 271          * The well-known keys represent a (randomly picked) set of key groups.
 272          * A joystick may have one of those but probably not several. And a joystick with less than 2 buttons
 273          * or axes is not a joystick either.
 274          * libinput uses similar heuristics, any changes here should be added to libinput too.
 275          */
 276         if (is_joystick) {
 277                 static const unsigned int well_known_keyboard_keys[] = {
 278                         KEY_LEFTCTRL, KEY_CAPSLOCK, KEY_NUMLOCK, KEY_INSERT,
 279                         KEY_MUTE, KEY_CALC, KEY_FILE, KEY_MAIL, KEY_PLAYPAUSE,
 280                         KEY_BRIGHTNESSDOWN,
 281                 };
 282                 size_t num_well_known_keys = 0;
 283
 284                 if (has_keys)
 285                         for (size_t i = 0; i < ELEMENTSOF(well_known_keyboard_keys); i++)
 286                                 if (test_bit(well_known_keyboard_keys[i], bitmask_key))
 287                                         num_well_known_keys++;
 288
 289                 if (num_well_known_keys >= 4 || num_joystick_buttons + num_joystick_axes < 2) {
 290                         log_device_debug(dev, "Input device has %zu joystick buttons and %zu axes but also %zu keyboard key sets, "
 291                                          "assuming this is a keyboard, not a joystick.",
 292                                          num_joystick_buttons, num_joystick_axes, num_well_known_keys);
 293                         is_joystick = false;
 294                 }
 295         }
 296
 297         if (is_pointing_stick)
 298                 udev_builtin_add_property(dev, test, "ID_INPUT_POINTINGSTICK", "1");
 299         if (is_mouse || is_abs_mouse)
 300                 udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
 301         if (is_touchpad)
 302                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
 303         if (is_touchscreen)
 304                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
 305         if (is_joystick)
 306                 udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
 307         if (is_tablet)
 308                 udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
 309         if (is_tablet_pad)
 310                 udev_builtin_add_property(dev, test, "ID_INPUT_TABLET_PAD", "1");
 311
 312         return is_tablet || is_mouse || is_abs_mouse || is_touchpad || is_touchscreen || is_joystick || is_pointing_stick;
 313 }
 314
 315 /* key like devices */
 316 static bool test_key(sd_device *dev,
 317                      const unsigned long* bitmask_ev,
 318                      const unsigned long* bitmask_key,
 319                      bool test) {
 320
 321         bool found = false;
 322
 323         /* do we have any KEY_* capability? */
 324         if (!test_bit(EV_KEY, bitmask_ev)) {
 325                 log_device_debug(dev, "test_key: no EV_KEY capability");
 326                 return false;
 327         }
 328
 329         /* only consider KEY_* here, not BTN_* */
 330         for (size_t i = 0; i < BTN_MISC/BITS_PER_LONG && !found; i++) {
 331                 if (bitmask_key[i])
 332                         found = true;
 333
 334                 log_device_debug(dev, "test_key: checking bit block %zu for any keys; found=%s",
 335                                  i * BITS_PER_LONG, yes_no(found));
 336         }
 337         /* If there are no keys in the lower block, check the higher blocks */
 338         for (size_t block = 0; block < sizeof(high_key_blocks) / sizeof(struct range) && !found; block++)
 339                 for (unsigned i = high_key_blocks[block].start; i < high_key_blocks[block].end && !found; i++)
 340                         if (test_bit(i, bitmask_key)) {
 341                                 log_device_debug(dev, "test_key: Found key %x in high block", i);
 342                                 found = true;
 343                         }
 344
 345         if (found)
 346                 udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 347
 348         /* the first 32 bits are ESC, numbers, and Q to D; if we have all of
 349          * those, consider it a full keyboard; do not test KEY_RESERVED, though */
 350         if (FLAGS_SET(bitmask_key[0], 0xFFFFFFFE)) {
 351                 udev_builtin_add_property(dev, test, "ID_INPUT_KEYBOARD", "1");
 352                 return true;
 353         }
 354
 355         return found;
 356 }
 357
 358 static int builtin_input_id(sd_device *dev, sd_netlink **rtnl, int argc, char *argv[], bool test) {
 359         sd_device *pdev;
 360         unsigned long bitmask_ev[NBITS(EV_MAX)];
 361         unsigned long bitmask_abs[NBITS(ABS_MAX)];
 362         unsigned long bitmask_key[NBITS(KEY_MAX)];
 363         unsigned long bitmask_rel[NBITS(REL_MAX)];
 364         unsigned long bitmask_props[NBITS(INPUT_PROP_MAX)];
 365         const char *sysname;
 366         bool is_pointer;
 367         bool is_key;
 368
 369         assert(dev);
 370
 371         /* walk up the parental chain until we find the real input device; the
 372          * argument is very likely a subdevice of this, like eventN */
 373         for (pdev = dev; pdev; ) {
 374                 const char *s;
 375
 376                 if (sd_device_get_sysattr_value(pdev, "capabilities/ev", &s) >= 0)
 377                         break;
 378
 379                 if (sd_device_get_parent_with_subsystem_devtype(pdev, "input", NULL, &pdev) >= 0)
 380                         continue;
 381
 382                 pdev = NULL;
 383                 break;
 384         }
 385
 386         if (pdev) {
 387                 struct input_id id = get_input_id(pdev);
 388
 389                 /* Use this as a flag that input devices were detected, so that this
 390                  * program doesn't need to be called more than once per device */
 391                 udev_builtin_add_property(dev, test, "ID_INPUT", "1");
 392                 get_cap_mask(pdev, "capabilities/ev", bitmask_ev, sizeof(bitmask_ev), test);
 393                 get_cap_mask(pdev, "capabilities/abs", bitmask_abs, sizeof(bitmask_abs), test);
 394                 get_cap_mask(pdev, "capabilities/rel", bitmask_rel, sizeof(bitmask_rel), test);
 395                 get_cap_mask(pdev, "capabilities/key", bitmask_key, sizeof(bitmask_key), test);
 396                 get_cap_mask(pdev, "properties", bitmask_props, sizeof(bitmask_props), test);
 397                 is_pointer = test_pointers(dev, &id, bitmask_ev, bitmask_abs,
 398                                            bitmask_key, bitmask_rel,
 399                                            bitmask_props, test);
 400                 is_key = test_key(dev, bitmask_ev, bitmask_key, test);
 401                 /* Some evdev nodes have only a scrollwheel */
 402                 if (!is_pointer && !is_key && test_bit(EV_REL, bitmask_ev) &&
 403                     (test_bit(REL_WHEEL, bitmask_rel) || test_bit(REL_HWHEEL, bitmask_rel)))
 404                         udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 405                 if (test_bit(EV_SW, bitmask_ev))
 406                         udev_builtin_add_property(dev, test, "ID_INPUT_SWITCH", "1");
 407
 408         }
 409
 410         if (sd_device_get_sysname(dev, &sysname) >= 0 &&
 411             startswith(sysname, "event"))
 412                 extract_info(dev, test);
 413
 414         return 0;
 415 }
 416
 417 const UdevBuiltin udev_builtin_input_id = {
 418         .name = "input_id",
 419         .cmd = builtin_input_id,
 420         .help = "Input device properties",
 421 };