src/udev/udev-builtin-input_id.c

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