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