src/udev/udev-builtin-input_id.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /*
   4  * expose input properties via udev
   5  *
   6  * Copyright (C) 2009 Martin Pitt <martin.pitt@ubuntu.com>
   7  * Portions Copyright (C) 2004 David Zeuthen, <david@fubar.dk>
   8  * Copyright (C) 2011 Kay Sievers <kay@vrfy.org>
   9  * Copyright (C) 2014 Carlos Garnacho <carlosg@gnome.org>
  10  * Copyright (C) 2014 David Herrmann <dh.herrmann@gmail.com>
  11  *
  12  * This program is free software: you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation, either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  24  */
  25
  26 #include <errno.h>
  27 #include <stdarg.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32 #include <linux/limits.h>
  33 #include <linux/input.h>
  34
  35 #include "fd-util.h"
  36 #include "string-util.h"
  37 #include "udev.h"
  38 #include "util.h"
  39
  40 /* we must use this kernel-compatible implementation */
  41 #define BITS_PER_LONG (sizeof(unsigned long) * 8)
  42 #define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
  43 #define OFF(x)  ((x)%BITS_PER_LONG)
  44 #define BIT(x)  (1UL<<OFF(x))
  45 #define LONG(x) ((x)/BITS_PER_LONG)
  46 #define test_bit(bit, array)    ((array[LONG(bit)] >> OFF(bit)) & 1)
  47
  48 static inline int abs_size_mm(const struct input_absinfo *absinfo) {
  49         /* Resolution is defined to be in units/mm for ABS_X/Y */
  50         return (absinfo->maximum - absinfo->minimum) / absinfo->resolution;
  51 }
  52
  53 static void extract_info(struct udev_device *dev, const char *devpath, bool test) {
  54         char width[DECIMAL_STR_MAX(int)], height[DECIMAL_STR_MAX(int)];
  55         struct input_absinfo xabsinfo = {}, yabsinfo = {};
  56         _cleanup_close_ int fd = -1;
  57
  58         fd = open(devpath, O_RDONLY|O_CLOEXEC);
  59         if (fd < 0)
  60                 return;
  61
  62         if (ioctl(fd, EVIOCGABS(ABS_X), &xabsinfo) < 0 ||
  63             ioctl(fd, EVIOCGABS(ABS_Y), &yabsinfo) < 0)
  64                 return;
  65
  66         if (xabsinfo.resolution <= 0 || yabsinfo.resolution <= 0)
  67                 return;
  68
  69         snprintf(width, sizeof(width), "%d", abs_size_mm(&xabsinfo));
  70         snprintf(height, sizeof(height), "%d", abs_size_mm(&yabsinfo));
  71
  72         udev_builtin_add_property(dev, test, "ID_INPUT_WIDTH_MM", width);
  73         udev_builtin_add_property(dev, test, "ID_INPUT_HEIGHT_MM", height);
  74 }
  75
  76 /*
  77  * Read a capability attribute and return bitmask.
  78  * @param dev udev_device
  79  * @param attr sysfs attribute name (e. g. "capabilities/key")
  80  * @param bitmask: Output array which has a sizeof of bitmask_size
  81  */
  82 static void get_cap_mask(struct udev_device *dev,
  83                          struct udev_device *pdev, const char* attr,
  84                          unsigned long *bitmask, size_t bitmask_size,
  85                          bool test) {
  86         const char *v;
  87         char text[4096];
  88         unsigned i;
  89         char* word;
  90         unsigned long val;
  91
  92         v = udev_device_get_sysattr_value(pdev, attr);
  93         if (!v)
  94                 v = "";
  95
  96         snprintf(text, sizeof(text), "%s", v);
  97         log_debug("%s raw kernel attribute: %s", attr, text);
  98
  99         memzero(bitmask, bitmask_size);
 100         i = 0;
 101         while ((word = strrchr(text, ' ')) != NULL) {
 102                 val = strtoul (word+1, NULL, 16);
 103                 if (i < bitmask_size/sizeof(unsigned long))
 104                         bitmask[i] = val;
 105                 else
 106                         log_debug("ignoring %s block %lX which is larger than maximum size", attr, val);
 107                 *word = '\0';
 108                 ++i;
 109         }
 110         val = strtoul (text, NULL, 16);
 111         if (i < bitmask_size / sizeof(unsigned long))
 112                 bitmask[i] = val;
 113         else
 114                 log_debug("ignoring %s block %lX which is larger than maximum size", attr, val);
 115
 116         if (test) {
 117                 /* printf pattern with the right unsigned long number of hex chars */
 118                 snprintf(text, sizeof(text), "  bit %%4u: %%0%zulX\n", 2 * sizeof(unsigned long));
 119                 log_debug("%s decoded bit map:", attr);
 120                 val = bitmask_size / sizeof (unsigned long);
 121                 /* skip over leading zeros */
 122                 while (bitmask[val-1] == 0 && val > 0)
 123                         --val;
 124                 for (i = 0; i < val; ++i) {
 125                         DISABLE_WARNING_FORMAT_NONLITERAL;
 126                         log_debug(text, i * BITS_PER_LONG, bitmask[i]);
 127                         REENABLE_WARNING;
 128                 }
 129         }
 130 }
 131
 132 /* pointer devices */
 133 static bool test_pointers(struct udev_device *dev,
 134                           const unsigned long* bitmask_ev,
 135                           const unsigned long* bitmask_abs,
 136                           const unsigned long* bitmask_key,
 137                           const unsigned long* bitmask_rel,
 138                           const unsigned long* bitmask_props,
 139                           bool test) {
 140         bool has_abs_coordinates = false;
 141         bool has_rel_coordinates = false;
 142         bool has_mt_coordinates = false;
 143         bool has_joystick_axes_or_buttons = false;
 144         bool is_direct = false;
 145         bool has_touch = false;
 146         bool has_3d_coordinates = false;
 147         bool has_keys = false;
 148         bool stylus_or_pen = false;
 149         bool finger_but_no_pen = false;
 150         bool has_mouse_button = false;
 151         bool is_mouse = false;
 152         bool is_touchpad = false;
 153         bool is_touchscreen = false;
 154         bool is_tablet = false;
 155         bool is_joystick = false;
 156         bool is_accelerometer = false;
 157         bool is_pointing_stick= false;
 158
 159         has_keys = test_bit(EV_KEY, bitmask_ev);
 160         has_abs_coordinates = test_bit(ABS_X, bitmask_abs) && test_bit(ABS_Y, bitmask_abs);
 161         has_3d_coordinates = has_abs_coordinates && test_bit(ABS_Z, bitmask_abs);
 162         is_accelerometer = test_bit(INPUT_PROP_ACCELEROMETER, bitmask_props);
 163
 164         if (!has_keys && has_3d_coordinates)
 165                 is_accelerometer = true;
 166
 167         if (is_accelerometer) {
 168                 udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
 169                 return true;
 170         }
 171
 172         is_pointing_stick = test_bit(INPUT_PROP_POINTING_STICK, bitmask_props);
 173         stylus_or_pen = test_bit(BTN_STYLUS, bitmask_key) || test_bit(BTN_TOOL_PEN, bitmask_key);
 174         finger_but_no_pen = test_bit(BTN_TOOL_FINGER, bitmask_key) && !test_bit(BTN_TOOL_PEN, bitmask_key);
 175         has_mouse_button = test_bit(BTN_LEFT, bitmask_key);
 176         has_rel_coordinates = test_bit(EV_REL, bitmask_ev) && test_bit(REL_X, bitmask_rel) && test_bit(REL_Y, bitmask_rel);
 177         has_mt_coordinates = test_bit(ABS_MT_POSITION_X, bitmask_abs) && test_bit(ABS_MT_POSITION_Y, bitmask_abs);
 178
 179         /* unset has_mt_coordinates if devices claims to have all abs axis */
 180         if(has_mt_coordinates && test_bit(ABS_MT_SLOT, bitmask_abs) && test_bit(ABS_MT_SLOT - 1, bitmask_abs))
 181                 has_mt_coordinates = false;
 182         is_direct = test_bit(INPUT_PROP_DIRECT, bitmask_props);
 183         has_touch = test_bit(BTN_TOUCH, bitmask_key);
 184         /* joysticks don't necessarily have buttons; e. g.
 185          * rudders/pedals are joystick-like, but buttonless; they have
 186          * other fancy axes */
 187         has_joystick_axes_or_buttons = test_bit(BTN_TRIGGER, bitmask_key) ||
 188                                        test_bit(BTN_A, bitmask_key) ||
 189                                        test_bit(BTN_1, bitmask_key) ||
 190                                        test_bit(ABS_RX, bitmask_abs) ||
 191                                        test_bit(ABS_RY, bitmask_abs) ||
 192                                        test_bit(ABS_RZ, bitmask_abs) ||
 193                                        test_bit(ABS_THROTTLE, bitmask_abs) ||
 194                                        test_bit(ABS_RUDDER, bitmask_abs) ||
 195                                        test_bit(ABS_WHEEL, bitmask_abs) ||
 196                                        test_bit(ABS_GAS, bitmask_abs) ||
 197                                        test_bit(ABS_BRAKE, bitmask_abs);
 198
 199         if (has_abs_coordinates) {
 200                 if (stylus_or_pen)
 201                         is_tablet = true;
 202                 else if (finger_but_no_pen && !is_direct)
 203                         is_touchpad = true;
 204                 else if (has_mouse_button)
 205                         /* This path is taken by VMware's USB mouse, which has
 206                          * absolute axes, but no touch/pressure button. */
 207                         is_mouse = true;
 208                 else if (has_touch || is_direct)
 209                         is_touchscreen = true;
 210                 else if (has_joystick_axes_or_buttons)
 211                         is_joystick = true;
 212         }
 213         if (has_mt_coordinates && (is_direct || has_touch))
 214                 is_touchscreen = true;
 215
 216         if (has_rel_coordinates && has_mouse_button)
 217                 is_mouse = true;
 218
 219         if (is_pointing_stick)
 220                 udev_builtin_add_property(dev, test, "ID_INPUT_POINTINGSTICK", "1");
 221         if (is_mouse)
 222                 udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
 223         if (is_touchpad)
 224                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
 225         if (is_touchscreen)
 226                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
 227         if (is_joystick)
 228                 udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
 229         if (is_tablet)
 230                 udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
 231
 232         return is_tablet || is_mouse || is_touchpad || is_touchscreen || is_joystick || is_pointing_stick;
 233 }
 234
 235 /* key like devices */
 236 static bool test_key(struct udev_device *dev,
 237                      const unsigned long* bitmask_ev,
 238                      const unsigned long* bitmask_key,
 239                      bool test) {
 240         unsigned i;
 241         unsigned long found;
 242         unsigned long mask;
 243         bool ret = false;
 244
 245         /* do we have any KEY_* capability? */
 246         if (!test_bit(EV_KEY, bitmask_ev)) {
 247                 log_debug("test_key: no EV_KEY capability");
 248                 return false;
 249         }
 250
 251         /* only consider KEY_* here, not BTN_* */
 252         found = 0;
 253         for (i = 0; i < BTN_MISC/BITS_PER_LONG; ++i) {
 254                 found |= bitmask_key[i];
 255                 log_debug("test_key: checking bit block %lu for any keys; found=%i", (unsigned long)i*BITS_PER_LONG, found > 0);
 256         }
 257         /* If there are no keys in the lower block, check the higher block */
 258         if (!found) {
 259                 for (i = KEY_OK; i < BTN_TRIGGER_HAPPY; ++i) {
 260                         if (test_bit(i, bitmask_key)) {
 261                                 log_debug("test_key: Found key %x in high block", i);
 262                                 found = 1;
 263                                 break;
 264                         }
 265                 }
 266         }
 267
 268         if (found > 0) {
 269                 udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 270                 ret = true;
 271         }
 272
 273         /* the first 32 bits are ESC, numbers, and Q to D; if we have all of
 274          * those, consider it a full keyboard; do not test KEY_RESERVED, though */
 275         mask = 0xFFFFFFFE;
 276         if ((bitmask_key[0] & mask) == mask) {
 277                 udev_builtin_add_property(dev, test, "ID_INPUT_KEYBOARD", "1");
 278                 ret = true;
 279         }
 280
 281         return ret;
 282 }
 283
 284 static int builtin_input_id(struct udev_device *dev, int argc, char *argv[], bool test) {
 285         struct udev_device *pdev;
 286         unsigned long bitmask_ev[NBITS(EV_MAX)];
 287         unsigned long bitmask_abs[NBITS(ABS_MAX)];
 288         unsigned long bitmask_key[NBITS(KEY_MAX)];
 289         unsigned long bitmask_rel[NBITS(REL_MAX)];
 290         unsigned long bitmask_props[NBITS(INPUT_PROP_MAX)];
 291         const char *sysname, *devnode;
 292         bool is_pointer;
 293         bool is_key;
 294
 295         assert(dev);
 296
 297         /* walk up the parental chain until we find the real input device; the
 298          * argument is very likely a subdevice of this, like eventN */
 299         pdev = dev;
 300         while (pdev != NULL && udev_device_get_sysattr_value(pdev, "capabilities/ev") == NULL)
 301                 pdev = udev_device_get_parent_with_subsystem_devtype(pdev, "input", NULL);
 302
 303         if (pdev) {
 304                 /* Use this as a flag that input devices were detected, so that this
 305                  * program doesn't need to be called more than once per device */
 306                 udev_builtin_add_property(dev, test, "ID_INPUT", "1");
 307                 get_cap_mask(dev, pdev, "capabilities/ev", bitmask_ev, sizeof(bitmask_ev), test);
 308                 get_cap_mask(dev, pdev, "capabilities/abs", bitmask_abs, sizeof(bitmask_abs), test);
 309                 get_cap_mask(dev, pdev, "capabilities/rel", bitmask_rel, sizeof(bitmask_rel), test);
 310                 get_cap_mask(dev, pdev, "capabilities/key", bitmask_key, sizeof(bitmask_key), test);
 311                 get_cap_mask(dev, pdev, "properties", bitmask_props, sizeof(bitmask_props), test);
 312                 is_pointer = test_pointers(dev, bitmask_ev, bitmask_abs,
 313                                            bitmask_key, bitmask_rel,
 314                                            bitmask_props, test);
 315                 is_key = test_key(dev, bitmask_ev, bitmask_key, test);
 316                 /* Some evdev nodes have only a scrollwheel */
 317                 if (!is_pointer && !is_key && test_bit(EV_REL, bitmask_ev) &&
 318                     (test_bit(REL_WHEEL, bitmask_rel) || test_bit(REL_HWHEEL, bitmask_rel)))
 319                         udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 320         }
 321
 322         devnode = udev_device_get_devnode(dev);
 323         sysname = udev_device_get_sysname(dev);
 324         if (devnode && sysname && startswith(sysname, "event"))
 325                 extract_info(dev, devnode, test);
 326
 327         return EXIT_SUCCESS;
 328 }
 329
 330 const struct udev_builtin udev_builtin_input_id = {
 331         .name = "input_id",
 332         .cmd = builtin_input_id,
 333         .help = "Input device properties",
 334 };