src/udev/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@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         char text[4096];
  52         unsigned i;
  53         char* word;
  54         unsigned long val;
  55
  56         snprintf(text, sizeof(text), "%s", udev_device_get_sysattr_value(pdev, attr));
  57         log_debug("%s raw kernel attribute: %s", attr, text);
  58
  59         memzero(bitmask, bitmask_size);
  60         i = 0;
  61         while ((word = strrchr(text, ' ')) != NULL) {
  62                 val = strtoul (word+1, NULL, 16);
  63                 if (i < bitmask_size/sizeof(unsigned long))
  64                         bitmask[i] = val;
  65                 else
  66                         log_debug("ignoring %s block %lX which is larger than maximum size", attr, val);
  67                 *word = '\0';
  68                 ++i;
  69         }
  70         val = strtoul (text, NULL, 16);
  71         if (i < bitmask_size / sizeof(unsigned long))
  72                 bitmask[i] = val;
  73         else
  74                 log_debug("ignoring %s block %lX which is larger than maximum size", attr, val);
  75
  76         if (test) {
  77                 /* printf pattern with the right unsigned long number of hex chars */
  78                 snprintf(text, sizeof(text), "  bit %%4u: %%0%zilX\n", 2 * sizeof(unsigned long));
  79                 log_debug("%s decoded bit map:", attr);
  80                 val = bitmask_size / sizeof (unsigned long);
  81                 /* skip over leading zeros */
  82                 while (bitmask[val-1] == 0 && val > 0)
  83                         --val;
  84                 for (i = 0; i < val; ++i) {
  85                         DISABLE_WARNING_FORMAT_NONLITERAL;
  86                         log_debug(text, i * BITS_PER_LONG, bitmask[i]);
  87                         REENABLE_WARNING;
  88                 }
  89         }
  90 }
  91
  92 /* pointer devices */
  93 static void test_pointers (struct udev_device *dev,
  94                            const unsigned long* bitmask_ev,
  95                            const unsigned long* bitmask_abs,
  96                            const unsigned long* bitmask_key,
  97                            const unsigned long* bitmask_rel,
  98                            bool test) {
  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_MOUSE, bitmask_key))
 118                         /* This path is taken by VMware's USB mouse, which has
 119                          * absolute axes, but no touch/pressure button. */
 120                         is_mouse = 1;
 121                 else if (test_bit (BTN_TOUCH, bitmask_key))
 122                         udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHSCREEN", "1");
 123                 /* joysticks don't necessarily have to have buttons; e. g.
 124                  * rudders/pedals are joystick-like, but buttonless; they have
 125                  * other fancy axes */
 126                 else if (test_bit (BTN_TRIGGER, bitmask_key) ||
 127                          test_bit (BTN_A, bitmask_key) ||
 128                          test_bit (BTN_1, bitmask_key) ||
 129                          test_bit (ABS_RX, bitmask_abs) ||
 130                          test_bit (ABS_RY, bitmask_abs) ||
 131                          test_bit (ABS_RZ, bitmask_abs) ||
 132                          test_bit (ABS_THROTTLE, bitmask_abs) ||
 133                          test_bit (ABS_RUDDER, bitmask_abs) ||
 134                          test_bit (ABS_WHEEL, bitmask_abs) ||
 135                          test_bit (ABS_GAS, bitmask_abs) ||
 136                          test_bit (ABS_BRAKE, bitmask_abs))
 137                         udev_builtin_add_property(dev, test, "ID_INPUT_JOYSTICK", "1");
 138         }
 139
 140         if (test_bit (EV_REL, bitmask_ev) &&
 141             test_bit (REL_X, bitmask_rel) && test_bit (REL_Y, bitmask_rel) &&
 142             test_bit (BTN_MOUSE, bitmask_key))
 143                 is_mouse = 1;
 144
 145         if (is_mouse)
 146                 udev_builtin_add_property(dev, test, "ID_INPUT_MOUSE", "1");
 147         if (is_touchpad)
 148                 udev_builtin_add_property(dev, test, "ID_INPUT_TOUCHPAD", "1");
 149 }
 150
 151 /* key like devices */
 152 static void test_key (struct udev_device *dev,
 153                       const unsigned long* bitmask_ev,
 154                       const unsigned long* bitmask_key,
 155                       bool test) {
 156         unsigned i;
 157         unsigned long found;
 158         unsigned long mask;
 159
 160         /* do we have any KEY_* capability? */
 161         if (!test_bit (EV_KEY, bitmask_ev)) {
 162                 log_debug("test_key: no EV_KEY capability");
 163                 return;
 164         }
 165
 166         /* only consider KEY_* here, not BTN_* */
 167         found = 0;
 168         for (i = 0; i < BTN_MISC/BITS_PER_LONG; ++i) {
 169                 found |= bitmask_key[i];
 170                 log_debug("test_key: checking bit block %lu for any keys; found=%i", (unsigned long)i*BITS_PER_LONG, found > 0);
 171         }
 172         /* If there are no keys in the lower block, check the higher block */
 173         if (!found) {
 174                 for (i = KEY_OK; i < BTN_TRIGGER_HAPPY; ++i) {
 175                         if (test_bit (i, bitmask_key)) {
 176                                 log_debug("test_key: Found key %x in high block", i);
 177                                 found = 1;
 178                                 break;
 179                         }
 180                 }
 181         }
 182
 183         if (found > 0)
 184                 udev_builtin_add_property(dev, test, "ID_INPUT_KEY", "1");
 185
 186         /* the first 32 bits are ESC, numbers, and Q to D; if we have all of
 187          * those, consider it a full keyboard; do not test KEY_RESERVED, though */
 188         mask = 0xFFFFFFFE;
 189         if ((bitmask_key[0] & mask) == mask)
 190                 udev_builtin_add_property(dev, test, "ID_INPUT_KEYBOARD", "1");
 191 }
 192
 193 static int builtin_input_id(struct udev_device *dev, int argc, char *argv[], bool test) {
 194         struct udev_device *pdev;
 195         unsigned long bitmask_ev[NBITS(EV_MAX)];
 196         unsigned long bitmask_abs[NBITS(ABS_MAX)];
 197         unsigned long bitmask_key[NBITS(KEY_MAX)];
 198         unsigned long bitmask_rel[NBITS(REL_MAX)];
 199
 200         /* walk up the parental chain until we find the real input device; the
 201          * argument is very likely a subdevice of this, like eventN */
 202         pdev = dev;
 203         while (pdev != NULL && udev_device_get_sysattr_value(pdev, "capabilities/ev") == NULL)
 204                 pdev = udev_device_get_parent_with_subsystem_devtype(pdev, "input", NULL);
 205
 206         /* not an "input" class device */
 207         if (pdev == NULL)
 208                 return EXIT_SUCCESS;
 209
 210         /* Use this as a flag that input devices were detected, so that this
 211          * program doesn't need to be called more than once per device */
 212         udev_builtin_add_property(dev, test, "ID_INPUT", "1");
 213         get_cap_mask(dev, pdev, "capabilities/ev", bitmask_ev, sizeof(bitmask_ev), test);
 214         get_cap_mask(dev, pdev, "capabilities/abs", bitmask_abs, sizeof(bitmask_abs), test);
 215         get_cap_mask(dev, pdev, "capabilities/rel", bitmask_rel, sizeof(bitmask_rel), test);
 216         get_cap_mask(dev, pdev, "capabilities/key", bitmask_key, sizeof(bitmask_key), test);
 217         test_pointers(dev, bitmask_ev, bitmask_abs, bitmask_key, bitmask_rel, test);
 218         test_key(dev, bitmask_ev, bitmask_key, test);
 219         return EXIT_SUCCESS;
 220 }
 221
 222 const struct udev_builtin udev_builtin_input_id = {
 223         .name = "input_id",
 224         .cmd = builtin_input_id,
 225         .help = "input device properties",
 226 };