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