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%zilX\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 void 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                            bool test) {
 135         int is_mouse = 0;
 136         int is_touchpad = 0;
 137
 138         if (!test_bit (EV_KEY, bitmask_ev)) {
 139                 if (test_bit (EV_ABS, bitmask_ev) &&
 140                     test_bit (ABS_X, bitmask_abs) &&
 141                     test_bit (ABS_Y, bitmask_abs) &&
 142                     test_bit (ABS_Z, bitmask_abs))
 143                         udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
 144                 return;
 145         }
 146
 147         if (test_bit (EV_ABS, bitmask_ev) &&
 148             test_bit (ABS_X, bitmask_abs) && test_bit (ABS_Y, bitmask_abs)) {
 149                 if (test_bit (BTN_STYLUS, bitmask_key) || test_bit (BTN_TOOL_PEN, bitmask_key))
 150                         udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
 151                 else if (test_bit (BTN_TOOL_FINGER, bitmask_key) && !test_bit (BTN_TOOL_PEN, bitmask_key))
 152                         is_touchpad = 1;
 153                 else if (test_bit (BTN_MOUSE, bitmask_key))
 154                         /* This path is taken by VMware's USB mouse, which has
 155                          * absolute axes, but no touch/pressure button. */
 156                         is_mouse = 1;
 157                 else if (test_bit (BTN_TOUCH, bitmask_key))
 158                         udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
 159                 /* joysticks don't necessarily have to have buttons; e. g.
 160                  * rudders/pedals are joystick-like, but buttonless; they have
 161                  * other fancy axes */
 162                 else if (test_bit (BTN_TRIGGER, bitmask_key) ||
 163                          test_bit (BTN_A, bitmask_key) ||
 164                          test_bit (BTN_1, bitmask_key) ||
 165                          test_bit (ABS_RX, bitmask_abs) ||
 166                          test_bit (ABS_RY, bitmask_abs) ||
 167                          test_bit (ABS_RZ, bitmask_abs) ||
 168                          test_bit (ABS_THROTTLE, bitmask_abs) ||
 169                          test_bit (ABS_RUDDER, bitmask_abs) ||
 170                          test_bit (ABS_WHEEL, bitmask_abs) ||
 171                          test_bit (ABS_GAS, bitmask_abs) ||
 172                          test_bit (ABS_BRAKE, bitmask_abs))
 173                         udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
 174         }
 175
 176         if (test_bit (EV_REL, bitmask_ev) &&
 177             test_bit (REL_X, bitmask_rel) && test_bit (REL_Y, bitmask_rel) &&
 178             test_bit (BTN_MOUSE, bitmask_key))
 179                 is_mouse = 1;
 180
 181         if (is_mouse)
 182                 udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
 183         if (is_touchpad)
 184                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
 185 }
 186
 187 /* key like devices */
 188 static void test_key (struct udev_device *dev,
 189                       const unsigned long* bitmask_ev,
 190                       const unsigned long* bitmask_key,
 191                       bool test) {
 192         unsigned i;
 193         unsigned long found;
 194         unsigned long mask;
 195
 196         /* do we have any KEY_* capability? */
 197         if (!test_bit (EV_KEY, bitmask_ev)) {
 198                 log_debug("test_key: no EV_KEY capability");
 199                 return;
 200         }
 201
 202         /* only consider KEY_* here, not BTN_* */
 203         found = 0;
 204         for (i = 0; i < BTN_MISC/BITS_PER_LONG; ++i) {
 205                 found |= bitmask_key[i];
 206                 log_debug("test_key: checking bit block %lu for any keys; found=%i", (unsigned long)i*BITS_PER_LONG, found > 0);
 207         }
 208         /* If there are no keys in the lower block, check the higher block */
 209         if (!found) {
 210                 for (i = KEY_OK; i < BTN_TRIGGER_HAPPY; ++i) {
 211                         if (test_bit (i, bitmask_key)) {
 212                                 log_debug("test_key: Found key %x in high block", i);
 213                                 found = 1;
 214                                 break;
 215                         }
 216                 }
 217         }
 218
 219         if (found > 0)
 220                 udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 221
 222         /* the first 32 bits are ESC, numbers, and Q to D; if we have all of
 223          * those, consider it a full keyboard; do not test KEY_RESERVED, though */
 224         mask = 0xFFFFFFFE;
 225         if ((bitmask_key[0] & mask) == mask)
 226                 udev_builtin_add_property(dev, test, "ID_INPUT_KEYBOARD", "1");
 227 }
 228
 229 static int builtin_input_id(struct udev_device *dev, int argc, char *argv[], bool test) {
 230         struct udev_device *pdev;
 231         unsigned long bitmask_ev[NBITS(EV_MAX)];
 232         unsigned long bitmask_abs[NBITS(ABS_MAX)];
 233         unsigned long bitmask_key[NBITS(KEY_MAX)];
 234         unsigned long bitmask_rel[NBITS(REL_MAX)];
 235         const char *sysname, *devnode;
 236
 237         /* walk up the parental chain until we find the real input device; the
 238          * argument is very likely a subdevice of this, like eventN */
 239         pdev = dev;
 240         while (pdev != NULL && udev_device_get_sysattr_value(pdev, "capabilities/ev") == NULL)
 241                 pdev = udev_device_get_parent_with_subsystem_devtype(pdev, "input", NULL);
 242
 243         if (pdev) {
 244                 /* Use this as a flag that input devices were detected, so that this
 245                  * program doesn't need to be called more than once per device */
 246                 udev_builtin_add_property(dev, test, "ID_INPUT", "1");
 247                 get_cap_mask(dev, pdev, "capabilities/ev", bitmask_ev, sizeof(bitmask_ev), test);
 248                 get_cap_mask(dev, pdev, "capabilities/abs", bitmask_abs, sizeof(bitmask_abs), test);
 249                 get_cap_mask(dev, pdev, "capabilities/rel", bitmask_rel, sizeof(bitmask_rel), test);
 250                 get_cap_mask(dev, pdev, "capabilities/key", bitmask_key, sizeof(bitmask_key), test);
 251                 test_pointers(dev, bitmask_ev, bitmask_abs, bitmask_key, bitmask_rel, test);
 252                 test_key(dev, bitmask_ev, bitmask_key, test);
 253         }
 254
 255         devnode = udev_device_get_devnode(dev);
 256         sysname = udev_device_get_sysname(dev);
 257         if (devnode && sysname && startswith(sysname, "event"))
 258                 extract_info(dev, devnode, test);
 259
 260         return EXIT_SUCCESS;
 261 }
 262
 263 const struct udev_builtin udev_builtin_input_id = {
 264         .name = "input_id",
 265         .cmd = builtin_input_id,
 266         .help = "Input device properties",
 267 };