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 #include "util.h"
  23
  24 /* we must use this kernel-compatible implementation */
  25 #define BITS_PER_LONG (sizeof(unsigned long) * 8)
  26 #define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
  27 #define OFF(x)  ((x)%BITS_PER_LONG)
  28 #define BIT(x)  (1UL<<OFF(x))
  29 #define LONG(x) ((x)/BITS_PER_LONG)
  30 #define test_bit(bit, array)    ((array[LONG(bit)] >> OFF(bit)) & 1)
  31
  32 struct range {
  33         unsigned start;
  34         unsigned end;
  35 };
  36
  37 /* key code ranges above BTN_MISC (start is inclusive, stop is exclusive) */
  38 static const struct range high_key_blocks[] = {
  39         { KEY_OK, BTN_DPAD_UP },
  40         { KEY_ALS_TOGGLE, BTN_TRIGGER_HAPPY }
  41 };
  42
  43 static int abs_size_mm(const struct input_absinfo *absinfo) {
  44         /* Resolution is defined to be in units/mm for ABS_X/Y */
  45         return (absinfo->maximum - absinfo->minimum) / absinfo->resolution;
  46 }
  47
  48 static void extract_info(sd_device *dev, bool test) {
  49         char width[DECIMAL_STR_MAX(int)], height[DECIMAL_STR_MAX(int)];
  50         struct input_absinfo xabsinfo = {}, yabsinfo = {};
  51         _cleanup_close_ int fd = -1;
  52
  53         fd = sd_device_open(dev, O_RDONLY|O_CLOEXEC|O_NONBLOCK);
  54         if (fd < 0)
  55                 return;
  56
  57         if (ioctl(fd, EVIOCGABS(ABS_X), &xabsinfo) < 0 ||
  58             ioctl(fd, EVIOCGABS(ABS_Y), &yabsinfo) < 0)
  59                 return;
  60
  61         if (xabsinfo.resolution <= 0 || yabsinfo.resolution <= 0)
  62                 return;
  63
  64         xsprintf(width, "%d", abs_size_mm(&xabsinfo));
  65         xsprintf(height, "%d", abs_size_mm(&yabsinfo));
  66
  67         udev_builtin_add_property(dev, test, "ID_INPUT_WIDTH_MM", width);
  68         udev_builtin_add_property(dev, test, "ID_INPUT_HEIGHT_MM", height);
  69 }
  70
  71 /*
  72  * Read a capability attribute and return bitmask.
  73  * @param dev sd_device
  74  * @param attr sysfs attribute name (e. g. "capabilities/key")
  75  * @param bitmask: Output array which has a sizeof of bitmask_size
  76  */
  77 static void get_cap_mask(sd_device *pdev, const char* attr,
  78                          unsigned long *bitmask, size_t bitmask_size,
  79                          bool test) {
  80         const char *v;
  81         char text[4096];
  82         unsigned i;
  83         char* word;
  84         unsigned long val;
  85         int r;
  86
  87         if (sd_device_get_sysattr_value(pdev, attr, &v) < 0)
  88                 v = "";
  89
  90         xsprintf(text, "%s", v);
  91         log_device_debug(pdev, "%s raw kernel attribute: %s", attr, text);
  92
  93         memzero(bitmask, bitmask_size);
  94         i = 0;
  95         while ((word = strrchr(text, ' '))) {
  96                 r = safe_atolu_full(word+1, 16, &val);
  97                 if (r < 0)
  98                         log_device_debug_errno(pdev, r, "Ignoring %s block which failed to parse: %m", attr);
  99                 else if (i < bitmask_size / sizeof(unsigned long))
 100                         bitmask[i] = val;
 101                 else
 102                         log_device_debug(pdev, "Ignoring %s block %lX which is larger than maximum size", attr, val);
 103                 *word = '\0';
 104                 i++;
 105         }
 106         r = safe_atolu_full(text, 16, &val);
 107         if (r < 0)
 108                 log_device_debug_errno(pdev, r, "Ignoring %s block which failed to parse: %m", attr);
 109         else if (i < bitmask_size / sizeof(unsigned long))
 110                 bitmask[i] = val;
 111         else
 112                 log_device_debug(pdev, "Ignoring %s block %lX which is larger than maximum size", attr, val);
 113
 114         if (test && DEBUG_LOGGING) {
 115                 log_device_debug(pdev, "%s decoded bit map:", attr);
 116
 117                 val = bitmask_size / sizeof (unsigned long);
 118                 /* skip trailing zeros */
 119                 while (bitmask[val-1] == 0 && val > 0)
 120                         --val;
 121
 122                 /* IN_SET() cannot be used in assert_cc(). */
 123                 assert_cc(sizeof(unsigned long) == 4 || sizeof(unsigned long) == 8);
 124                 for (unsigned long j = 0; j < val; j++)
 125                         log_device_debug(pdev,
 126                                          sizeof(unsigned long) == 4 ? "  bit %4lu: %08lX\n" : "  bit %4lu: %016lX\n",
 127                                          j * BITS_PER_LONG, bitmask[j]);
 128         }
 129 }
 130
 131 static struct input_id get_input_id(sd_device *dev) {
 132         const char *v;
 133         struct input_id id = {};
 134
 135         if (sd_device_get_sysattr_value(dev, "id/bustype", &v) >= 0)
 136                 (void) safe_atoux16(v, &id.bustype);
 137         if (sd_device_get_sysattr_value(dev, "id/vendor", &v) >= 0)
 138                 (void) safe_atoux16(v, &id.vendor);
 139         if (sd_device_get_sysattr_value(dev, "id/product", &v) >= 0)
 140                 (void) safe_atoux16(v, &id.product);
 141         if (sd_device_get_sysattr_value(dev, "id/version", &v) >= 0)
 142                 (void) safe_atoux16(v, &id.version);
 143
 144         return id;
 145 }
 146
 147 /* pointer devices */
 148 static bool test_pointers(sd_device *dev,
 149                           const struct input_id *id,
 150                           const unsigned long* bitmask_ev,
 151                           const unsigned long* bitmask_abs,
 152                           const unsigned long* bitmask_key,
 153                           const unsigned long* bitmask_rel,
 154                           const unsigned long* bitmask_props,
 155                           bool test) {
 156         bool has_abs_coordinates = false;
 157         bool has_rel_coordinates = false;
 158         bool has_mt_coordinates = false;
 159         size_t num_joystick_axes = 0;
 160         size_t num_joystick_buttons = 0;
 161         bool has_pad_buttons = false;
 162         bool is_direct = false;
 163         bool has_touch = false;
 164         bool has_3d_coordinates = false;
 165         bool has_keys = false;
 166         bool has_stylus = false;
 167         bool has_pen = false;
 168         bool finger_but_no_pen = false;
 169         bool has_mouse_button = false;
 170         bool is_mouse = false;
 171         bool is_abs_mouse = false;
 172         bool is_touchpad = false;
 173         bool is_touchscreen = false;
 174         bool is_tablet = false;
 175         bool is_tablet_pad = false;
 176         bool is_joystick = false;
 177         bool is_accelerometer = false;
 178         bool is_pointing_stick = false;
 179
 180         has_keys = test_bit(EV_KEY, bitmask_ev);
 181         has_abs_coordinates = test_bit(ABS_X, bitmask_abs) && test_bit(ABS_Y, bitmask_abs);
 182         has_3d_coordinates = has_abs_coordinates && test_bit(ABS_Z, bitmask_abs);
 183         is_accelerometer = test_bit(INPUT_PROP_ACCELEROMETER, bitmask_props);
 184
 185         if (!has_keys && has_3d_coordinates)
 186                 is_accelerometer = true;
 187
 188         if (is_accelerometer) {
 189                 udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
 190                 return true;
 191         }
 192
 193         is_pointing_stick = test_bit(INPUT_PROP_POINTING_STICK, bitmask_props);
 194         has_stylus = test_bit(BTN_STYLUS, bitmask_key);
 195         has_pen = test_bit(BTN_TOOL_PEN, bitmask_key);
 196         finger_but_no_pen = test_bit(BTN_TOOL_FINGER, bitmask_key) && !test_bit(BTN_TOOL_PEN, bitmask_key);
 197         for (int button = BTN_MOUSE; button < BTN_JOYSTICK && !has_mouse_button; button++)
 198                 has_mouse_button = test_bit(button, bitmask_key);
 199         has_rel_coordinates = test_bit(EV_REL, bitmask_ev) && test_bit(REL_X, bitmask_rel) && test_bit(REL_Y, bitmask_rel);
 200         has_mt_coordinates = test_bit(ABS_MT_POSITION_X, bitmask_abs) && test_bit(ABS_MT_POSITION_Y, bitmask_abs);
 201
 202         /* unset has_mt_coordinates if devices claims to have all abs axis */
 203         if (has_mt_coordinates && test_bit(ABS_MT_SLOT, bitmask_abs) && test_bit(ABS_MT_SLOT - 1, bitmask_abs))
 204                 has_mt_coordinates = false;
 205         is_direct = test_bit(INPUT_PROP_DIRECT, bitmask_props);
 206         has_touch = test_bit(BTN_TOUCH, bitmask_key);
 207         has_pad_buttons = test_bit(BTN_0, bitmask_key) && has_stylus && !has_pen;
 208
 209         /* joysticks don't necessarily have buttons; e. g.
 210          * rudders/pedals are joystick-like, but buttonless; they have
 211          * other fancy axes. Others have buttons only but no axes.
 212          *
 213          * The BTN_JOYSTICK range starts after the mouse range, so a mouse
 214          * with more than 16 buttons runs into the joystick range (e.g. Mad
 215          * Catz Mad Catz M.M.O.TE). Skip those.
 216          */
 217         if (!test_bit(BTN_JOYSTICK - 1, bitmask_key)) {
 218                 for (int button = BTN_JOYSTICK; button < BTN_DIGI; button++)
 219                         if (test_bit(button, bitmask_key))
 220                                 num_joystick_buttons++;
 221                 for (int button = BTN_TRIGGER_HAPPY1; button <= BTN_TRIGGER_HAPPY40; button++)
 222                         if (test_bit(button, bitmask_key))
 223                                 num_joystick_buttons++;
 224                 for (int button = BTN_DPAD_UP; button <= BTN_DPAD_RIGHT; button++)
 225                         if (test_bit(button, bitmask_key))
 226                                 num_joystick_buttons++;
 227         }
 228         for (int axis = ABS_RX; axis < ABS_PRESSURE; axis++)
 229                 if (test_bit(axis, bitmask_abs))
 230                         num_joystick_axes++;
 231
 232         if (has_abs_coordinates) {
 233                 if (has_stylus || has_pen)
 234                         is_tablet = true;
 235                 else if (finger_but_no_pen && !is_direct)
 236                         is_touchpad = true;
 237                 else if (has_mouse_button)
 238                         /* This path is taken by VMware's USB mouse, which has
 239                          * absolute axes, but no touch/pressure button. */
 240                         is_abs_mouse = true;
 241                 else if (has_touch || is_direct)
 242                         is_touchscreen = true;
 243                 else if (num_joystick_buttons > 0 || num_joystick_axes > 0)
 244                         is_joystick = true;
 245         } else if (num_joystick_buttons > 0 || num_joystick_axes > 0)
 246                 is_joystick = true;
 247
 248         if (has_mt_coordinates) {
 249                 if (has_stylus || has_pen)
 250                         is_tablet = true;
 251                 else if (finger_but_no_pen && !is_direct)
 252                         is_touchpad = true;
 253                 else if (has_touch || is_direct)
 254                         is_touchscreen = true;
 255         }
 256
 257         if (is_tablet && has_pad_buttons)
 258                 is_tablet_pad = true;
 259
 260         if (!is_tablet && !is_touchpad && !is_joystick &&
 261             has_mouse_button &&
 262             (has_rel_coordinates ||
 263             !has_abs_coordinates)) /* mouse buttons and no axis */
 264                 is_mouse = true;
 265
 266         /* There is no such thing as an i2c mouse */
 267         if (is_mouse && id->bustype == BUS_I2C)
 268                 is_pointing_stick = true;
 269
 270         /* Joystick un-detection. Some keyboards have random joystick buttons
 271          * set. Avoid those being labeled as ID_INPUT_JOYSTICK with some heuristics.
 272          * The well-known keys represent a (randomly picked) set of key groups.
 273          * A joystick may have one of those but probably not several. And a joystick with less than 2 buttons
 274          * or axes is not a joystick either.
 275          * libinput uses similar heuristics, any changes here should be added to libinput too.
 276          */
 277         if (is_joystick) {
 278                 static const unsigned int well_known_keyboard_keys[] = {
 279                         KEY_LEFTCTRL, KEY_CAPSLOCK, KEY_NUMLOCK, KEY_INSERT,
 280                         KEY_MUTE, KEY_CALC, KEY_FILE, KEY_MAIL, KEY_PLAYPAUSE,
 281                         KEY_BRIGHTNESSDOWN,
 282                 };
 283                 size_t num_well_known_keys = 0;
 284
 285                 if (has_keys)
 286                         for (size_t i = 0; i < ELEMENTSOF(well_known_keyboard_keys); i++)
 287                                 if (test_bit(well_known_keyboard_keys[i], bitmask_key))
 288                                         num_well_known_keys++;
 289
 290                 if (num_well_known_keys >= 4 || num_joystick_buttons + num_joystick_axes < 2) {
 291                         log_device_debug(dev, "Input device has %zd joystick buttons and %zd axes but also %zd keyboard key sets, "
 292                                          "assuming this is a keyboard, not a joystick.",
 293                                          num_joystick_buttons, num_joystick_axes, num_well_known_keys);
 294                         is_joystick = false;
 295                 }
 296         }
 297
 298         if (is_pointing_stick)
 299                 udev_builtin_add_property(dev, test, "ID_INPUT_POINTINGSTICK", "1");
 300         if (is_mouse || is_abs_mouse)
 301                 udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
 302         if (is_touchpad)
 303                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
 304         if (is_touchscreen)
 305                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
 306         if (is_joystick)
 307                 udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
 308         if (is_tablet)
 309                 udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
 310         if (is_tablet_pad)
 311                 udev_builtin_add_property(dev, test, "ID_INPUT_TABLET_PAD", "1");
 312
 313         return is_tablet || is_mouse || is_abs_mouse || is_touchpad || is_touchscreen || is_joystick || is_pointing_stick;
 314 }
 315
 316 /* key like devices */
 317 static bool test_key(sd_device *dev,
 318                      const unsigned long* bitmask_ev,
 319                      const unsigned long* bitmask_key,
 320                      bool test) {
 321
 322         bool found = false;
 323
 324         /* do we have any KEY_* capability? */
 325         if (!test_bit(EV_KEY, bitmask_ev)) {
 326                 log_device_debug(dev, "test_key: no EV_KEY capability");
 327                 return false;
 328         }
 329
 330         /* only consider KEY_* here, not BTN_* */
 331         for (size_t i = 0; i < BTN_MISC/BITS_PER_LONG && !found; i++) {
 332                 if (bitmask_key[i])
 333                         found = true;
 334
 335                 log_device_debug(dev, "test_key: checking bit block %zu for any keys; found=%s",
 336                                  i * BITS_PER_LONG, yes_no(found));
 337         }
 338         /* If there are no keys in the lower block, check the higher blocks */
 339         for (size_t block = 0; block < sizeof(high_key_blocks) / sizeof(struct range) && !found; block++)
 340                 for (unsigned i = high_key_blocks[block].start; i < high_key_blocks[block].end && !found; i++)
 341                         if (test_bit(i, bitmask_key)) {
 342                                 log_device_debug(dev, "test_key: Found key %x in high block", i);
 343                                 found = true;
 344                         }
 345
 346         if (found)
 347                 udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 348
 349         /* the first 32 bits are ESC, numbers, and Q to D; if we have all of
 350          * those, consider it a full keyboard; do not test KEY_RESERVED, though */
 351         if (FLAGS_SET(bitmask_key[0], 0xFFFFFFFE)) {
 352                 udev_builtin_add_property(dev, test, "ID_INPUT_KEYBOARD", "1");
 353                 return true;
 354         }
 355
 356         return found;
 357 }
 358
 359 static int builtin_input_id(sd_device *dev, sd_netlink **rtnl, int argc, char *argv[], bool test) {
 360         sd_device *pdev;
 361         unsigned long bitmask_ev[NBITS(EV_MAX)];
 362         unsigned long bitmask_abs[NBITS(ABS_MAX)];
 363         unsigned long bitmask_key[NBITS(KEY_MAX)];
 364         unsigned long bitmask_rel[NBITS(REL_MAX)];
 365         unsigned long bitmask_props[NBITS(INPUT_PROP_MAX)];
 366         const char *sysname;
 367         bool is_pointer;
 368         bool is_key;
 369
 370         assert(dev);
 371
 372         /* walk up the parental chain until we find the real input device; the
 373          * argument is very likely a subdevice of this, like eventN */
 374         for (pdev = dev; pdev; ) {
 375                 const char *s;
 376
 377                 if (sd_device_get_sysattr_value(pdev, "capabilities/ev", &s) >= 0)
 378                         break;
 379
 380                 if (sd_device_get_parent_with_subsystem_devtype(pdev, "input", NULL, &pdev) >= 0)
 381                         continue;
 382
 383                 pdev = NULL;
 384                 break;
 385         }
 386
 387         if (pdev) {
 388                 struct input_id id = get_input_id(pdev);
 389
 390                 /* Use this as a flag that input devices were detected, so that this
 391                  * program doesn't need to be called more than once per device */
 392                 udev_builtin_add_property(dev, test, "ID_INPUT", "1");
 393                 get_cap_mask(pdev, "capabilities/ev", bitmask_ev, sizeof(bitmask_ev), test);
 394                 get_cap_mask(pdev, "capabilities/abs", bitmask_abs, sizeof(bitmask_abs), test);
 395                 get_cap_mask(pdev, "capabilities/rel", bitmask_rel, sizeof(bitmask_rel), test);
 396                 get_cap_mask(pdev, "capabilities/key", bitmask_key, sizeof(bitmask_key), test);
 397                 get_cap_mask(pdev, "properties", bitmask_props, sizeof(bitmask_props), test);
 398                 is_pointer = test_pointers(dev, &id, bitmask_ev, bitmask_abs,
 399                                            bitmask_key, bitmask_rel,
 400                                            bitmask_props, test);
 401                 is_key = test_key(dev, bitmask_ev, bitmask_key, test);
 402                 /* Some evdev nodes have only a scrollwheel */
 403                 if (!is_pointer && !is_key && test_bit(EV_REL, bitmask_ev) &&
 404                     (test_bit(REL_WHEEL, bitmask_rel) || test_bit(REL_HWHEEL, bitmask_rel)))
 405                         udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 406                 if (test_bit(EV_SW, bitmask_ev))
 407                         udev_builtin_add_property(dev, test, "ID_INPUT_SWITCH", "1");
 408
 409         }
 410
 411         if (sd_device_get_sysname(dev, &sysname) >= 0 &&
 412             startswith(sysname, "event"))
 413                 extract_info(dev, test);
 414
 415         return 0;
 416 }
 417
 418 const UdevBuiltin udev_builtin_input_id = {
 419         .name = "input_id",
 420         .cmd = builtin_input_id,
 421         .help = "Input device properties",
 422 };