src/udev-builtin-input_id.c

   1 /*
   2  * compose persistent device path
   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.sievers@vrfy.org>
   7  *
   8  * This program is free software: you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation, either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <stdarg.h>
  25 #include <unistd.h>
  26 #include <string.h>
  27 #include <errno.h>
  28 #include <linux/limits.h>
  29 #include <linux/input.h>
  30
  31 #include "udev.h"
  32
  33 /* we must use this kernel-compatible implementation */
  34 #define BITS_PER_LONG (sizeof(unsigned long) * 8)
  35 #define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
  36 #define OFF(x)  ((x)%BITS_PER_LONG)
  37 #define BIT(x)  (1UL<<OFF(x))
  38 #define LONG(x) ((x)/BITS_PER_LONG)
  39 #define test_bit(bit, array)    ((array[LONG(bit)] >> OFF(bit)) & 1)
  40
  41 /*
  42  * Read a capability attribute and return bitmask.
  43  * @param dev udev_device
  44  * @param attr sysfs attribute name (e. g. "capabilities/key")
  45  * @param bitmask: Output array which has a sizeof of bitmask_size
  46  */
  47 static void get_cap_mask(struct udev_device *dev,
  48                          struct udev_device *pdev, const char* attr,
  49                          unsigned long *bitmask, size_t bitmask_size,
  50                          bool test)
  51 {
  52         struct udev *udev = udev_device_get_udev(dev);
  53         char text[4096];
  54         unsigned i;
  55         char* word;
  56         unsigned long val;
  57
  58         snprintf(text, sizeof(text), "%s", udev_device_get_sysattr_value(pdev, attr));
  59         info(udev, "%s raw kernel attribute: %s\n", attr, text);
  60
  61         memset (bitmask, 0, bitmask_size);
  62         i = 0;
  63         while ((word = strrchr(text, ' ')) != NULL) {
  64                 val = strtoul (word+1, NULL, 16);
  65                 if (i < bitmask_size/sizeof(unsigned long))
  66                         bitmask[i] = val;
  67                 else
  68                         info(udev, "ignoring %s block %lX which is larger than maximum size\n", attr, val);
  69                 *word = '\0';
  70                 ++i;
  71         }
  72         val = strtoul (text, NULL, 16);
  73         if (i < bitmask_size / sizeof(unsigned long))
  74                 bitmask[i] = val;
  75         else
  76                 info(udev, "ignoring %s block %lX which is larger than maximum size\n", attr, val);
  77
  78         if (test) {
  79                 /* printf pattern with the right unsigned long number of hex chars */
  80                 snprintf(text, sizeof(text), "  bit %%4u: %%0%zilX\n", 2 * sizeof(unsigned long));
  81                 info(udev, "%s decoded bit map:\n", attr);
  82                 val = bitmask_size / sizeof (unsigned long);
  83                 /* skip over leading zeros */
  84                 while (bitmask[val-1] == 0 && val > 0)
  85                         --val;
  86                 for (i = 0; i < val; ++i)
  87                         info(udev, text, i * BITS_PER_LONG, bitmask[i]);
  88         }
  89 }
  90
  91 /* pointer devices */
  92 static void test_pointers (struct udev_device *dev,
  93                            const unsigned long* bitmask_ev,
  94                            const unsigned long* bitmask_abs,
  95                            const unsigned long* bitmask_key,
  96                            const unsigned long* bitmask_rel,
  97                            bool test)
  98 {
  99         int is_mouse = 0;
 100         int is_touchpad = 0;
 101
 102         if (!test_bit (EV_KEY, bitmask_ev)) {
 103                 if (test_bit (EV_ABS, bitmask_ev) &&
 104                     test_bit (ABS_X, bitmask_abs) &&
 105                     test_bit (ABS_Y, bitmask_abs) &&
 106                     test_bit (ABS_Z, bitmask_abs))
 107                         udev_builtin_add_property(dev, test, "ID_INPUT_ACCELEROMETER", "1");
 108                 return;
 109         }
 110
 111         if (test_bit (EV_ABS, bitmask_ev) &&
 112             test_bit (ABS_X, bitmask_abs) && test_bit (ABS_Y, bitmask_abs)) {
 113                 if (test_bit (BTN_STYLUS, bitmask_key) || test_bit (BTN_TOOL_PEN, bitmask_key))
 114                         udev_builtin_add_property(dev, test, "ID_INPUT_TABLET", "1");
 115                 else if (test_bit (BTN_TOOL_FINGER, bitmask_key) && !test_bit (BTN_TOOL_PEN, bitmask_key))
 116                         is_touchpad = 1;
 117                 else if (test_bit (BTN_TRIGGER, bitmask_key) ||
 118                          test_bit (BTN_A, bitmask_key) ||
 119                          test_bit (BTN_1, bitmask_key))
 120                         udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
 121                 else if (test_bit (BTN_MOUSE, bitmask_key))
 122                         /* This path is taken by VMware's USB mouse, which has
 123                          * absolute axes, but no touch/pressure button. */
 124                         is_mouse = 1;
 125                 else if (test_bit (BTN_TOUCH, bitmask_key))
 126                         udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
 127         }
 128
 129         if (test_bit (EV_REL, bitmask_ev) &&
 130             test_bit (REL_X, bitmask_rel) && test_bit (REL_Y, bitmask_rel) &&
 131             test_bit (BTN_MOUSE, bitmask_key))
 132                 is_mouse = 1;
 133
 134         if (is_mouse)
 135                 udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
 136         if (is_touchpad)
 137                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
 138 }
 139
 140 /* key like devices */
 141 static void test_key (struct udev_device *dev,
 142                       const unsigned long* bitmask_ev,
 143                       const unsigned long* bitmask_key,
 144                       bool test)
 145 {
 146         struct udev *udev = udev_device_get_udev(dev);
 147         unsigned i;
 148         unsigned long found;
 149         unsigned long mask;
 150
 151         /* do we have any KEY_* capability? */
 152         if (!test_bit (EV_KEY, bitmask_ev)) {
 153                 info(udev, "test_key: no EV_KEY capability\n");
 154                 return;
 155         }
 156
 157         /* only consider KEY_* here, not BTN_* */
 158         found = 0;
 159         for (i = 0; i < BTN_MISC/BITS_PER_LONG; ++i) {
 160                 found |= bitmask_key[i];
 161                 info(udev, "test_key: checking bit block %lu for any keys; found=%i\n", i*BITS_PER_LONG, found > 0);
 162         }
 163         /* If there are no keys in the lower block, check the higher block */
 164         if (!found) {
 165                 for (i = KEY_OK; i < BTN_TRIGGER_HAPPY; ++i) {
 166                         if (test_bit (i, bitmask_key)) {
 167                                 info(udev, "test_key: Found key %x in high block\n", i);
 168                                 found = 1;
 169                                 break;
 170                         }
 171                 }
 172         }
 173
 174         if (found > 0)
 175                 udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 176
 177         /* the first 32 bits are ESC, numbers, and Q to D; if we have all of
 178          * those, consider it a full keyboard; do not test KEY_RESERVED, though */
 179         mask = 0xFFFFFFFE;
 180         if ((bitmask_key[0] & mask) == mask)
 181                 udev_builtin_add_property(dev, test, "ID_INPUT_KEYBOARD", "1");
 182 }
 183
 184 static int builtin_input_id(struct udev_device *dev, int argc, char *argv[], bool test)
 185 {
 186         struct udev_device *pdev;
 187         unsigned long bitmask_ev[NBITS(EV_MAX)];
 188         unsigned long bitmask_abs[NBITS(ABS_MAX)];
 189         unsigned long bitmask_key[NBITS(KEY_MAX)];
 190         unsigned long bitmask_rel[NBITS(REL_MAX)];
 191
 192         /* walk up the parental chain until we find the real input device; the
 193          * argument is very likely a subdevice of this, like eventN */
 194         pdev = dev;
 195         while (pdev != NULL && udev_device_get_sysattr_value(pdev, "capabilities/ev") == NULL)
 196                 pdev = udev_device_get_parent_with_subsystem_devtype(pdev, "input", NULL);
 197
 198         /* not an "input" class device */
 199         if (pdev == NULL)
 200                 return EXIT_SUCCESS;
 201
 202         /* Use this as a flag that input devices were detected, so that this
 203          * program doesn't need to be called more than once per device */
 204         udev_builtin_add_property(dev, test, "ID_INPUT", "1");
 205         get_cap_mask(dev, pdev, "capabilities/ev", bitmask_ev, sizeof(bitmask_ev), test);
 206         get_cap_mask(dev, pdev, "capabilities/abs", bitmask_abs, sizeof(bitmask_abs), test);
 207         get_cap_mask(dev, pdev, "capabilities/rel", bitmask_rel, sizeof(bitmask_rel), test);
 208         get_cap_mask(dev, pdev, "capabilities/key", bitmask_key, sizeof(bitmask_key), test);
 209         test_pointers(dev, bitmask_ev, bitmask_abs, bitmask_key, bitmask_rel, test);
 210         test_key(dev, bitmask_ev, bitmask_key, test);
 211         return EXIT_SUCCESS;
 212 }
 213
 214 const struct udev_builtin udev_builtin_input_id = {
 215         .name = "input_id",
 216         .cmd = builtin_input_id,
 217         .help = "input device properties",
 218 };