src/udev/udev-builtin-input_id.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * expose input properties via udev
   4  *
   5  * Copyright (C) 2009 Martin Pitt <martin.pitt@ubuntu.com>
   6  * Portions Copyright (C) 2004 David Zeuthen, <david@fubar.dk>
   7  * Copyright (C) 2011 Kay Sievers <kay@vrfy.org>
   8  * Copyright (C) 2014 Carlos Garnacho <carlosg@gnome.org>
   9  * Copyright (C) 2014 David Herrmann <dh.herrmann@gmail.com>
  10  *
  11  * This program is free software: you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation, either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23  */
  24
  25 #include <errno.h>
  26 #include <stdarg.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <unistd.h>
  31 #include <linux/limits.h>
  32 #include <linux/input.h>
  33
  34 #include "fd-util.h"
  35 #include "missing.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 struct range {
  50         unsigned start;
  51         unsigned end;
  52 };
  53
  54 /* key code ranges above BTN_MISC (start is inclusive, stop is exclusive)*/
  55 static const struct range high_key_blocks[] = {
  56         { KEY_OK, BTN_DPAD_UP },
  57         { KEY_ALS_TOGGLE, BTN_TRIGGER_HAPPY }
  58 };
  59
  60 static inline int abs_size_mm(const struct input_absinfo *absinfo) {
  61         /* Resolution is defined to be in units/mm for ABS_X/Y */
  62         return (absinfo->maximum - absinfo->minimum) / absinfo->resolution;
  63 }
  64
  65 static void extract_info(struct udev_device *dev, const char *devpath, bool test) {
  66         char width[DECIMAL_STR_MAX(int)], height[DECIMAL_STR_MAX(int)];
  67         struct input_absinfo xabsinfo = {}, yabsinfo = {};
  68         _cleanup_close_ int fd = -1;
  69
  70         fd = open(devpath, O_RDONLY|O_CLOEXEC);
  71         if (fd < 0)
  72                 return;
  73
  74         if (ioctl(fd, EVIOCGABS(ABS_X), &xabsinfo) < 0 ||
  75             ioctl(fd, EVIOCGABS(ABS_Y), &yabsinfo) < 0)
  76                 return;
  77
  78         if (xabsinfo.resolution <= 0 || yabsinfo.resolution <= 0)
  79                 return;
  80
  81         xsprintf(width, "%d", abs_size_mm(&xabsinfo));
  82         xsprintf(height, "%d", abs_size_mm(&yabsinfo));
  83
  84         udev_builtin_add_property(dev, test, "ID_INPUT_WIDTH_MM", width);
  85         udev_builtin_add_property(dev, test, "ID_INPUT_HEIGHT_MM", height);
  86 }
  87
  88 /*
  89  * Read a capability attribute and return bitmask.
  90  * @param dev udev_device
  91  * @param attr sysfs attribute name (e. g. "capabilities/key")
  92  * @param bitmask: Output array which has a sizeof of bitmask_size
  93  */
  94 static void get_cap_mask(struct udev_device *dev,
  95                          struct udev_device *pdev, const char* attr,
  96                          unsigned long *bitmask, size_t bitmask_size,
  97                          bool test) {
  98         const char *v;
  99         char text[4096];
 100         unsigned i;
 101         char* word;
 102         unsigned long val;
 103
 104         v = udev_device_get_sysattr_value(pdev, attr);
 105         if (!v)
 106                 v = "";
 107
 108         xsprintf(text, "%s", v);
 109         log_debug("%s raw kernel attribute: %s", attr, text);
 110
 111         memzero(bitmask, bitmask_size);
 112         i = 0;
 113         while ((word = strrchr(text, ' ')) != NULL) {
 114                 val = strtoul (word+1, NULL, 16);
 115                 if (i < bitmask_size/sizeof(unsigned long))
 116                         bitmask[i] = val;
 117                 else
 118                         log_debug("ignoring %s block %lX which is larger than maximum size", attr, val);
 119                 *word = '\0';
 120                 ++i;
 121         }
 122         val = strtoul (text, NULL, 16);
 123         if (i < bitmask_size / sizeof(unsigned long))
 124                 bitmask[i] = val;
 125         else
 126                 log_debug("ignoring %s block %lX which is larger than maximum size", attr, val);
 127
 128         if (test) {
 129                 /* printf pattern with the right unsigned long number of hex chars */
 130                 xsprintf(text, "  bit %%4u: %%0%zulX\n",
 131                          2 * sizeof(unsigned long));
 132                 log_debug("%s decoded bit map:", attr);
 133                 val = bitmask_size / sizeof (unsigned long);
 134                 /* skip over leading zeros */
 135                 while (bitmask[val-1] == 0 && val > 0)
 136                         --val;
 137                 for (i = 0; i < val; ++i) {
 138                         DISABLE_WARNING_FORMAT_NONLITERAL;
 139                         log_debug(text, i * BITS_PER_LONG, bitmask[i]);
 140                         REENABLE_WARNING;
 141                 }
 142         }
 143 }
 144
 145 /* pointer devices */
 146 static bool test_pointers(struct udev_device *dev,
 147                           const unsigned long* bitmask_ev,
 148                           const unsigned long* bitmask_abs,
 149                           const unsigned long* bitmask_key,
 150                           const unsigned long* bitmask_rel,
 151                           const unsigned long* bitmask_props,
 152                           bool test) {
 153         int button, axis;
 154         bool has_abs_coordinates = false;
 155         bool has_rel_coordinates = false;
 156         bool has_mt_coordinates = false;
 157         bool has_joystick_axes_or_buttons = false;
 158         bool is_direct = false;
 159         bool has_touch = false;
 160         bool has_3d_coordinates = false;
 161         bool has_keys = false;
 162         bool stylus_or_pen = false;
 163         bool finger_but_no_pen = false;
 164         bool has_mouse_button = false;
 165         bool is_mouse = false;
 166         bool is_touchpad = false;
 167         bool is_touchscreen = false;
 168         bool is_tablet = false;
 169         bool is_joystick = false;
 170         bool is_accelerometer = false;
 171         bool is_pointing_stick= false;
 172
 173         has_keys = test_bit(EV_KEY, bitmask_ev);
 174         has_abs_coordinates = test_bit(ABS_X, bitmask_abs) && test_bit(ABS_Y, bitmask_abs);
 175         has_3d_coordinates = has_abs_coordinates && test_bit(ABS_Z, bitmask_abs);
 176         is_accelerometer = test_bit(INPUT_PROP_ACCELEROMETER, bitmask_props);
 177
 178         if (!has_keys && has_3d_coordinates)
 179                 is_accelerometer = true;
 180
 181         if (is_accelerometer) {
 182                 udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
 183                 return true;
 184         }
 185
 186         is_pointing_stick = test_bit(INPUT_PROP_POINTING_STICK, bitmask_props);
 187         stylus_or_pen = test_bit(BTN_STYLUS, bitmask_key) || test_bit(BTN_TOOL_PEN, bitmask_key);
 188         finger_but_no_pen = test_bit(BTN_TOOL_FINGER, bitmask_key) && !test_bit(BTN_TOOL_PEN, bitmask_key);
 189         for (button = BTN_MOUSE; button < BTN_JOYSTICK && !has_mouse_button; button++)
 190                 has_mouse_button = test_bit(button, bitmask_key);
 191         has_rel_coordinates = test_bit(EV_REL, bitmask_ev) && test_bit(REL_X, bitmask_rel) && test_bit(REL_Y, bitmask_rel);
 192         has_mt_coordinates = test_bit(ABS_MT_POSITION_X, bitmask_abs) && test_bit(ABS_MT_POSITION_Y, bitmask_abs);
 193
 194         /* unset has_mt_coordinates if devices claims to have all abs axis */
 195         if (has_mt_coordinates && test_bit(ABS_MT_SLOT, bitmask_abs) && test_bit(ABS_MT_SLOT - 1, bitmask_abs))
 196                 has_mt_coordinates = false;
 197         is_direct = test_bit(INPUT_PROP_DIRECT, bitmask_props);
 198         has_touch = test_bit(BTN_TOUCH, bitmask_key);
 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         for (button = BTN_JOYSTICK; button < BTN_DIGI && !has_joystick_axes_or_buttons; button++)
 203                 has_joystick_axes_or_buttons = test_bit(button, bitmask_key);
 204         for (button = BTN_TRIGGER_HAPPY1; button <= BTN_TRIGGER_HAPPY40 && !has_joystick_axes_or_buttons; button++)
 205                 has_joystick_axes_or_buttons = test_bit(button, bitmask_key);
 206         for (button = BTN_DPAD_UP; button <= BTN_DPAD_RIGHT && !has_joystick_axes_or_buttons; button++)
 207                 has_joystick_axes_or_buttons = test_bit(button, bitmask_key);
 208         for (axis = ABS_RX; axis < ABS_PRESSURE && !has_joystick_axes_or_buttons; axis++)
 209                 has_joystick_axes_or_buttons = test_bit(axis, bitmask_abs);
 210
 211         if (has_abs_coordinates) {
 212                 if (stylus_or_pen)
 213                         is_tablet = true;
 214                 else if (finger_but_no_pen && !is_direct)
 215                         is_touchpad = true;
 216                 else if (has_mouse_button)
 217                         /* This path is taken by VMware's USB mouse, which has
 218                          * absolute axes, but no touch/pressure button. */
 219                         is_mouse = true;
 220                 else if (has_touch || is_direct)
 221                         is_touchscreen = true;
 222                 else if (has_joystick_axes_or_buttons)
 223                         is_joystick = true;
 224         } else if (has_joystick_axes_or_buttons) {
 225                 is_joystick = true;
 226         }
 227
 228         if (has_mt_coordinates) {
 229                 if (stylus_or_pen)
 230                         is_tablet = true;
 231                 else if (finger_but_no_pen && !is_direct)
 232                         is_touchpad = true;
 233                 else if (has_touch || is_direct)
 234                         is_touchscreen = true;
 235         }
 236
 237         if (has_mouse_button &&
 238             (has_rel_coordinates ||
 239             !has_abs_coordinates)) /* mouse buttons and no axis */
 240                 is_mouse = true;
 241
 242         if (is_pointing_stick)
 243                 udev_builtin_add_property(dev, test, "ID_INPUT_POINTINGSTICK", "1");
 244         if (is_mouse)
 245                 udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
 246         if (is_touchpad)
 247                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
 248         if (is_touchscreen)
 249                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
 250         if (is_joystick)
 251                 udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
 252         if (is_tablet)
 253                 udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
 254
 255         return is_tablet || is_mouse || is_touchpad || is_touchscreen || is_joystick || is_pointing_stick;
 256 }
 257
 258 /* key like devices */
 259 static bool test_key(struct udev_device *dev,
 260                      const unsigned long* bitmask_ev,
 261                      const unsigned long* bitmask_key,
 262                      bool test) {
 263         unsigned i;
 264         unsigned long found;
 265         unsigned long mask;
 266         bool ret = false;
 267
 268         /* do we have any KEY_* capability? */
 269         if (!test_bit(EV_KEY, bitmask_ev)) {
 270                 log_debug("test_key: no EV_KEY capability");
 271                 return false;
 272         }
 273
 274         /* only consider KEY_* here, not BTN_* */
 275         found = 0;
 276         for (i = 0; i < BTN_MISC/BITS_PER_LONG; ++i) {
 277                 found |= bitmask_key[i];
 278                 log_debug("test_key: checking bit block %lu for any keys; found=%i", (unsigned long)i*BITS_PER_LONG, found > 0);
 279         }
 280         /* If there are no keys in the lower block, check the higher blocks */
 281         if (!found) {
 282                 unsigned block;
 283                 for (block = 0; block < (sizeof(high_key_blocks) / sizeof(struct range)); ++block) {
 284                         for (i = high_key_blocks[block].start; i < high_key_blocks[block].end; ++i) {
 285                                 if (test_bit(i, bitmask_key)) {
 286                                         log_debug("test_key: Found key %x in high block", i);
 287                                         found = 1;
 288                                         break;
 289                                 }
 290                         }
 291                 }
 292         }
 293
 294         if (found > 0) {
 295                 udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 296                 ret = true;
 297         }
 298
 299         /* the first 32 bits are ESC, numbers, and Q to D; if we have all of
 300          * those, consider it a full keyboard; do not test KEY_RESERVED, though */
 301         mask = 0xFFFFFFFE;
 302         if ((bitmask_key[0] & mask) == mask) {
 303                 udev_builtin_add_property(dev, test, "ID_INPUT_KEYBOARD", "1");
 304                 ret = true;
 305         }
 306
 307         return ret;
 308 }
 309
 310 static int builtin_input_id(struct udev_device *dev, int argc, char *argv[], bool test) {
 311         struct udev_device *pdev;
 312         unsigned long bitmask_ev[NBITS(EV_MAX)];
 313         unsigned long bitmask_abs[NBITS(ABS_MAX)];
 314         unsigned long bitmask_key[NBITS(KEY_MAX)];
 315         unsigned long bitmask_rel[NBITS(REL_MAX)];
 316         unsigned long bitmask_props[NBITS(INPUT_PROP_MAX)];
 317         const char *sysname, *devnode;
 318         bool is_pointer;
 319         bool is_key;
 320
 321         assert(dev);
 322
 323         /* walk up the parental chain until we find the real input device; the
 324          * argument is very likely a subdevice of this, like eventN */
 325         pdev = dev;
 326         while (pdev != NULL && udev_device_get_sysattr_value(pdev, "capabilities/ev") == NULL)
 327                 pdev = udev_device_get_parent_with_subsystem_devtype(pdev, "input", NULL);
 328
 329         if (pdev) {
 330                 /* Use this as a flag that input devices were detected, so that this
 331                  * program doesn't need to be called more than once per device */
 332                 udev_builtin_add_property(dev, test, "ID_INPUT", "1");
 333                 get_cap_mask(dev, pdev, "capabilities/ev", bitmask_ev, sizeof(bitmask_ev), test);
 334                 get_cap_mask(dev, pdev, "capabilities/abs", bitmask_abs, sizeof(bitmask_abs), test);
 335                 get_cap_mask(dev, pdev, "capabilities/rel", bitmask_rel, sizeof(bitmask_rel), test);
 336                 get_cap_mask(dev, pdev, "capabilities/key", bitmask_key, sizeof(bitmask_key), test);
 337                 get_cap_mask(dev, pdev, "properties", bitmask_props, sizeof(bitmask_props), test);
 338                 is_pointer = test_pointers(dev, bitmask_ev, bitmask_abs,
 339                                            bitmask_key, bitmask_rel,
 340                                            bitmask_props, test);
 341                 is_key = test_key(dev, bitmask_ev, bitmask_key, test);
 342                 /* Some evdev nodes have only a scrollwheel */
 343                 if (!is_pointer && !is_key && test_bit(EV_REL, bitmask_ev) &&
 344                     (test_bit(REL_WHEEL, bitmask_rel) || test_bit(REL_HWHEEL, bitmask_rel)))
 345                         udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 346                 if (test_bit(EV_SW, bitmask_ev))
 347                         udev_builtin_add_property(dev, test, "ID_INPUT_SWITCH", "1");
 348
 349         }
 350
 351         devnode = udev_device_get_devnode(dev);
 352         sysname = udev_device_get_sysname(dev);
 353         if (devnode && sysname && startswith(sysname, "event"))
 354                 extract_info(dev, devnode, test);
 355
 356         return EXIT_SUCCESS;
 357 }
 358
 359 const struct udev_builtin udev_builtin_input_id = {
 360         .name = "input_id",
 361         .cmd = builtin_input_id,
 362         .help = "Input device properties",
 363 };