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 <stdlib.h>
  13 #include <unistd.h>
  14 #include <linux/limits.h>
  15
  16 #include "device-util.h"
  17 #include "fd-util.h"
  18 #include "missing_input.h"
  19 #include "parse-util.h"
  20 #include "stdio-util.h"
  21 #include "string-util.h"
  22 #include "udev-builtin.h"
  23 #include "util.h"
  24
  25 /* we must use this kernel-compatible implementation */
  26 #define BITS_PER_LONG (sizeof(unsigned long) * 8)
  27 #define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
  28 #define OFF(x)  ((x)%BITS_PER_LONG)
  29 #define BIT(x)  (1UL<<OFF(x))
  30 #define LONG(x) ((x)/BITS_PER_LONG)
  31 #define test_bit(bit, array)    ((array[LONG(bit)] >> OFF(bit)) & 1)
  32
  33 struct range {
  34         unsigned start;
  35         unsigned end;
  36 };
  37
  38 /* key code ranges above BTN_MISC (start is inclusive, stop is exclusive)*/
  39 static const struct range high_key_blocks[] = {
  40         { KEY_OK, BTN_DPAD_UP },
  41         { KEY_ALS_TOGGLE, BTN_TRIGGER_HAPPY }
  42 };
  43
  44 static int abs_size_mm(const struct input_absinfo *absinfo) {
  45         /* Resolution is defined to be in units/mm for ABS_X/Y */
  46         return (absinfo->maximum - absinfo->minimum) / absinfo->resolution;
  47 }
  48
  49 static void extract_info(sd_device *dev, const char *devpath, bool test) {
  50         char width[DECIMAL_STR_MAX(int)], height[DECIMAL_STR_MAX(int)];
  51         struct input_absinfo xabsinfo = {}, yabsinfo = {};
  52         _cleanup_close_ int fd = -1;
  53
  54         fd = open(devpath, O_RDONLY|O_CLOEXEC);
  55         if (fd < 0)
  56                 return;
  57
  58         if (ioctl(fd, EVIOCGABS(ABS_X), &xabsinfo) < 0 ||
  59             ioctl(fd, EVIOCGABS(ABS_Y), &yabsinfo) < 0)
  60                 return;
  61
  62         if (xabsinfo.resolution <= 0 || yabsinfo.resolution <= 0)
  63                 return;
  64
  65         xsprintf(width, "%d", abs_size_mm(&xabsinfo));
  66         xsprintf(height, "%d", abs_size_mm(&yabsinfo));
  67
  68         udev_builtin_add_property(dev, test, "ID_INPUT_WIDTH_MM", width);
  69         udev_builtin_add_property(dev, test, "ID_INPUT_HEIGHT_MM", height);
  70 }
  71
  72 /*
  73  * Read a capability attribute and return bitmask.
  74  * @param dev sd_device
  75  * @param attr sysfs attribute name (e. g. "capabilities/key")
  76  * @param bitmask: Output array which has a sizeof of bitmask_size
  77  */
  78 static void get_cap_mask(sd_device *pdev, const char* attr,
  79                          unsigned long *bitmask, size_t bitmask_size,
  80                          bool test) {
  81         const char *v;
  82         char text[4096];
  83         unsigned i;
  84         char* word;
  85         unsigned long val;
  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, ' ')) != NULL) {
  96                 val = strtoul(word+1, NULL, 16);
  97                 if (i < bitmask_size / sizeof(unsigned long))
  98                         bitmask[i] = val;
  99                 else
 100                         log_device_debug(pdev, "Ignoring %s block %lX which is larger than maximum size", attr, val);
 101                 *word = '\0';
 102                 ++i;
 103         }
 104         val = strtoul (text, NULL, 16);
 105         if (i < bitmask_size / sizeof(unsigned long))
 106                 bitmask[i] = val;
 107         else
 108                 log_device_debug(pdev, "Ignoring %s block %lX which is larger than maximum size", attr, val);
 109
 110         if (test) {
 111                 /* printf pattern with the right unsigned long number of hex chars */
 112                 xsprintf(text, "  bit %%4u: %%0%zulX\n",
 113                          2 * sizeof(unsigned long));
 114                 log_device_debug(pdev, "%s decoded bit map:", attr);
 115                 val = bitmask_size / sizeof (unsigned long);
 116                 /* skip over leading zeros */
 117                 while (bitmask[val-1] == 0 && val > 0)
 118                         --val;
 119                 for (i = 0; i < val; ++i) {
 120                         DISABLE_WARNING_FORMAT_NONLITERAL;
 121                         log_device_debug(pdev, text, i * BITS_PER_LONG, bitmask[i]);
 122                         REENABLE_WARNING;
 123                 }
 124         }
 125 }
 126
 127 static struct input_id get_input_id(sd_device *dev) {
 128         const char *v;
 129         struct input_id id = {};
 130
 131         if (sd_device_get_sysattr_value(dev, "id/bustype", &v) >= 0)
 132                 (void) safe_atoux16(v, &id.bustype);
 133         if (sd_device_get_sysattr_value(dev, "id/vendor", &v) >= 0)
 134                 (void) safe_atoux16(v, &id.vendor);
 135         if (sd_device_get_sysattr_value(dev, "id/product", &v) >= 0)
 136                 (void) safe_atoux16(v, &id.product);
 137         if (sd_device_get_sysattr_value(dev, "id/version", &v) >= 0)
 138                 (void) safe_atoux16(v, &id.version);
 139
 140         return id;
 141 }
 142
 143 /* pointer devices */
 144 static bool test_pointers(sd_device *dev,
 145                           const struct input_id *id,
 146                           const unsigned long* bitmask_ev,
 147                           const unsigned long* bitmask_abs,
 148                           const unsigned long* bitmask_key,
 149                           const unsigned long* bitmask_rel,
 150                           const unsigned long* bitmask_props,
 151                           bool test) {
 152         int button, axis;
 153         bool has_abs_coordinates = false;
 154         bool has_rel_coordinates = false;
 155         bool has_mt_coordinates = false;
 156         bool has_joystick_axes_or_buttons = false;
 157         bool is_direct = false;
 158         bool has_touch = false;
 159         bool has_3d_coordinates = false;
 160         bool has_keys = false;
 161         bool stylus_or_pen = false;
 162         bool finger_but_no_pen = false;
 163         bool has_mouse_button = false;
 164         bool is_mouse = false;
 165         bool is_touchpad = false;
 166         bool is_touchscreen = false;
 167         bool is_tablet = false;
 168         bool is_joystick = false;
 169         bool is_accelerometer = false;
 170         bool is_pointing_stick = false;
 171
 172         has_keys = test_bit(EV_KEY, bitmask_ev);
 173         has_abs_coordinates = test_bit(ABS_X, bitmask_abs) && test_bit(ABS_Y, bitmask_abs);
 174         has_3d_coordinates = has_abs_coordinates && test_bit(ABS_Z, bitmask_abs);
 175         is_accelerometer = test_bit(INPUT_PROP_ACCELEROMETER, bitmask_props);
 176
 177         if (!has_keys && has_3d_coordinates)
 178                 is_accelerometer = true;
 179
 180         if (is_accelerometer) {
 181                 udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
 182                 return true;
 183         }
 184
 185         is_pointing_stick = test_bit(INPUT_PROP_POINTING_STICK, bitmask_props);
 186         stylus_or_pen = test_bit(BTN_STYLUS, bitmask_key) || test_bit(BTN_TOOL_PEN, bitmask_key);
 187         finger_but_no_pen = test_bit(BTN_TOOL_FINGER, bitmask_key) && !test_bit(BTN_TOOL_PEN, bitmask_key);
 188         for (button = BTN_MOUSE; button < BTN_JOYSTICK && !has_mouse_button; button++)
 189                 has_mouse_button = test_bit(button, bitmask_key);
 190         has_rel_coordinates = test_bit(EV_REL, bitmask_ev) && test_bit(REL_X, bitmask_rel) && test_bit(REL_Y, bitmask_rel);
 191         has_mt_coordinates = test_bit(ABS_MT_POSITION_X, bitmask_abs) && test_bit(ABS_MT_POSITION_Y, bitmask_abs);
 192
 193         /* unset has_mt_coordinates if devices claims to have all abs axis */
 194         if (has_mt_coordinates && test_bit(ABS_MT_SLOT, bitmask_abs) && test_bit(ABS_MT_SLOT - 1, bitmask_abs))
 195                 has_mt_coordinates = false;
 196         is_direct = test_bit(INPUT_PROP_DIRECT, bitmask_props);
 197         has_touch = test_bit(BTN_TOUCH, bitmask_key);
 198
 199         /* joysticks don't necessarily have buttons; e. g.
 200          * rudders/pedals are joystick-like, but buttonless; they have
 201          * other fancy axes. Others have buttons only but no axes.
 202          *
 203          * The BTN_JOYSTICK range starts after the mouse range, so a mouse
 204          * with more than 16 buttons runs into the joystick range (e.g. Mad
 205          * Catz Mad Catz M.M.O.TE). Skip those.
 206          */
 207         if (!test_bit(BTN_JOYSTICK - 1, bitmask_key)) {
 208                 for (button = BTN_JOYSTICK; button < BTN_DIGI && !has_joystick_axes_or_buttons; button++)
 209                         has_joystick_axes_or_buttons = test_bit(button, bitmask_key);
 210                 for (button = BTN_TRIGGER_HAPPY1; button <= BTN_TRIGGER_HAPPY40 && !has_joystick_axes_or_buttons; button++)
 211                         has_joystick_axes_or_buttons = test_bit(button, bitmask_key);
 212                 for (button = BTN_DPAD_UP; button <= BTN_DPAD_RIGHT && !has_joystick_axes_or_buttons; button++)
 213                         has_joystick_axes_or_buttons = test_bit(button, bitmask_key);
 214         }
 215         for (axis = ABS_RX; axis < ABS_PRESSURE && !has_joystick_axes_or_buttons; axis++)
 216                 has_joystick_axes_or_buttons = test_bit(axis, bitmask_abs);
 217
 218         if (has_abs_coordinates) {
 219                 if (stylus_or_pen)
 220                         is_tablet = true;
 221                 else if (finger_but_no_pen && !is_direct)
 222                         is_touchpad = true;
 223                 else if (has_mouse_button)
 224                         /* This path is taken by VMware's USB mouse, which has
 225                          * absolute axes, but no touch/pressure button. */
 226                         is_mouse = true;
 227                 else if (has_touch || is_direct)
 228                         is_touchscreen = true;
 229                 else if (has_joystick_axes_or_buttons)
 230                         is_joystick = true;
 231         } else if (has_joystick_axes_or_buttons)
 232                 is_joystick = true;
 233
 234         if (has_mt_coordinates) {
 235                 if (stylus_or_pen)
 236                         is_tablet = true;
 237                 else if (finger_but_no_pen && !is_direct)
 238                         is_touchpad = true;
 239                 else if (has_touch || is_direct)
 240                         is_touchscreen = true;
 241         }
 242
 243         if (!is_tablet && !is_touchpad && !is_joystick &&
 244             has_mouse_button &&
 245             (has_rel_coordinates ||
 246             !has_abs_coordinates)) /* mouse buttons and no axis */
 247                 is_mouse = true;
 248
 249         /* There is no such thing as an i2c mouse */
 250         if (is_mouse && id->bustype == BUS_I2C)
 251                 is_pointing_stick = true;
 252
 253         if (is_pointing_stick)
 254                 udev_builtin_add_property(dev, test, "ID_INPUT_POINTINGSTICK", "1");
 255         if (is_mouse)
 256                 udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
 257         if (is_touchpad)
 258                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
 259         if (is_touchscreen)
 260                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
 261         if (is_joystick)
 262                 udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
 263         if (is_tablet)
 264                 udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
 265
 266         return is_tablet || is_mouse || is_touchpad || is_touchscreen || is_joystick || is_pointing_stick;
 267 }
 268
 269 /* key like devices */
 270 static bool test_key(sd_device *dev,
 271                      const unsigned long* bitmask_ev,
 272                      const unsigned long* bitmask_key,
 273                      bool test) {
 274         unsigned i;
 275         unsigned long found;
 276         unsigned long mask;
 277         bool ret = false;
 278
 279         /* do we have any KEY_* capability? */
 280         if (!test_bit(EV_KEY, bitmask_ev)) {
 281                 log_device_debug(dev, "test_key: no EV_KEY capability");
 282                 return false;
 283         }
 284
 285         /* only consider KEY_* here, not BTN_* */
 286         found = 0;
 287         for (i = 0; i < BTN_MISC/BITS_PER_LONG; ++i) {
 288                 found |= bitmask_key[i];
 289                 log_device_debug(dev, "test_key: checking bit block %lu for any keys; found=%i", (unsigned long)i*BITS_PER_LONG, found > 0);
 290         }
 291         /* If there are no keys in the lower block, check the higher blocks */
 292         if (!found) {
 293                 unsigned block;
 294                 for (block = 0; block < (sizeof(high_key_blocks) / sizeof(struct range)); ++block) {
 295                         for (i = high_key_blocks[block].start; i < high_key_blocks[block].end; ++i) {
 296                                 if (test_bit(i, bitmask_key)) {
 297                                         log_device_debug(dev, "test_key: Found key %x in high block", i);
 298                                         found = 1;
 299                                         break;
 300                                 }
 301                         }
 302                 }
 303         }
 304
 305         if (found > 0) {
 306                 udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 307                 ret = true;
 308         }
 309
 310         /* the first 32 bits are ESC, numbers, and Q to D; if we have all of
 311          * those, consider it a full keyboard; do not test KEY_RESERVED, though */
 312         mask = 0xFFFFFFFE;
 313         if (FLAGS_SET(bitmask_key[0], mask)) {
 314                 udev_builtin_add_property(dev, test, "ID_INPUT_KEYBOARD", "1");
 315                 ret = true;
 316         }
 317
 318         return ret;
 319 }
 320
 321 static int builtin_input_id(sd_device *dev, int argc, char *argv[], bool test) {
 322         sd_device *pdev;
 323         unsigned long bitmask_ev[NBITS(EV_MAX)];
 324         unsigned long bitmask_abs[NBITS(ABS_MAX)];
 325         unsigned long bitmask_key[NBITS(KEY_MAX)];
 326         unsigned long bitmask_rel[NBITS(REL_MAX)];
 327         unsigned long bitmask_props[NBITS(INPUT_PROP_MAX)];
 328         const char *sysname, *devnode;
 329         bool is_pointer;
 330         bool is_key;
 331
 332         assert(dev);
 333
 334         /* walk up the parental chain until we find the real input device; the
 335          * argument is very likely a subdevice of this, like eventN */
 336         for (pdev = dev; pdev; ) {
 337                 const char *s;
 338
 339                 if (sd_device_get_sysattr_value(pdev, "capabilities/ev", &s) >= 0)
 340                         break;
 341
 342                 if (sd_device_get_parent_with_subsystem_devtype(pdev, "input", NULL, &pdev) >= 0)
 343                         continue;
 344
 345                 pdev = NULL;
 346                 break;
 347         }
 348
 349         if (pdev) {
 350                 struct input_id id = get_input_id(pdev);
 351
 352                 /* Use this as a flag that input devices were detected, so that this
 353                  * program doesn't need to be called more than once per device */
 354                 udev_builtin_add_property(dev, test, "ID_INPUT", "1");
 355                 get_cap_mask(pdev, "capabilities/ev", bitmask_ev, sizeof(bitmask_ev), test);
 356                 get_cap_mask(pdev, "capabilities/abs", bitmask_abs, sizeof(bitmask_abs), test);
 357                 get_cap_mask(pdev, "capabilities/rel", bitmask_rel, sizeof(bitmask_rel), test);
 358                 get_cap_mask(pdev, "capabilities/key", bitmask_key, sizeof(bitmask_key), test);
 359                 get_cap_mask(pdev, "properties", bitmask_props, sizeof(bitmask_props), test);
 360                 is_pointer = test_pointers(dev, &id, bitmask_ev, bitmask_abs,
 361                                            bitmask_key, bitmask_rel,
 362                                            bitmask_props, test);
 363                 is_key = test_key(dev, bitmask_ev, bitmask_key, test);
 364                 /* Some evdev nodes have only a scrollwheel */
 365                 if (!is_pointer && !is_key && test_bit(EV_REL, bitmask_ev) &&
 366                     (test_bit(REL_WHEEL, bitmask_rel) || test_bit(REL_HWHEEL, bitmask_rel)))
 367                         udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 368                 if (test_bit(EV_SW, bitmask_ev))
 369                         udev_builtin_add_property(dev, test, "ID_INPUT_SWITCH", "1");
 370
 371         }
 372
 373         if (sd_device_get_devname(dev, &devnode) >= 0 &&
 374             sd_device_get_sysname(dev, &sysname) >= 0 &&
 375             startswith(sysname, "event"))
 376                 extract_info(dev, devnode, test);
 377
 378         return 0;
 379 }
 380
 381 const UdevBuiltin udev_builtin_input_id = {
 382         .name = "input_id",
 383         .cmd = builtin_input_id,
 384         .help = "Input device properties",
 385 };