text: /*
   * Copyright © 2015 Red Hat, Inc.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   * and/or sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice (including the next
   * paragraph) shall be included in all copies or substantial portions of the
   * Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
   * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   * DEALINGS IN THE SOFTWARE.
   */
  
  #include "config.h"
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <libudev.h>
  
  #include "libinput-util.h"
  
  #if HAVE_LIBWACOM
  #include <libwacom/libwacom.h>
  
  static void
  wacom_handle_paired(struct udev_device *device,
  		    int *vendor_id,
  		    int *product_id)
  {
  	WacomDeviceDatabase *db = NULL;
  	WacomDevice *tablet = NULL;
  	const WacomMatch *paired;
  
  	db = libwacom_database_new();
  	if (!db)
  		goto out;
  
  	tablet = libwacom_new_from_usbid(db, *vendor_id, *product_id, NULL);
  	if (!tablet)
  		goto out;
  	paired = libwacom_get_paired_device(tablet);
  	if (!paired)
  		goto out;
  
  	*vendor_id = libwacom_match_get_vendor_id(paired);
  	*product_id = libwacom_match_get_product_id(paired);
  
  out:
  	if (tablet)
  		libwacom_destroy(tablet);
  	if (db)
  		libwacom_database_destroy(db);
  }
  #endif
  
  static int
  find_tree_distance(struct udev_device *a, struct udev_device *b)
  {
  	struct udev_device *ancestor_a = a;
  	int dist_a = 0;
  
  	while (ancestor_a != NULL) {
  		const char *path_a = udev_device_get_syspath(ancestor_a);
  		struct udev_device *ancestor_b = b;
  		int dist_b = 0;
  
  		while (ancestor_b != NULL) {
  			const char *path_b = udev_device_get_syspath(ancestor_b);
  
  			if (streq(path_a, path_b))
  				return dist_a + dist_b;
  
  			dist_b++;
  			ancestor_b = udev_device_get_parent(ancestor_b);
  		}
  
  		dist_a++;
  		ancestor_a = udev_device_get_parent(ancestor_a);
  	}
  	return -1;
  }
  
  static void
  wacom_handle_ekr(struct udev_device *device,
  		 int *vendor_id,
  		 int *product_id,
  		 char **phys_attr)
  {
  	struct udev *udev;
  	struct udev_enumerate *e;
  	struct udev_list_entry *entry = NULL;
  	int best_dist = -1;
  
  	udev = udev_device_get_udev(device);
  	e = udev_enumerate_new(udev);
  	udev_enumerate_add_match_subsystem(e, "input");
  	udev_enumerate_add_match_sysname(e, "input*");
  	udev_enumerate_scan_devices(e);
  
  	udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(e)) {
  		struct udev_device *d;
  		const char *path, *phys;
  		const char *pidstr, *vidstr;
  		int pid, vid, dist;
  
  		/* Find and use the closest Wacom device on the system,
  		 * relying on wacom_handle_paired() to fix our ID later
  		 * if needed.
  		 */
  		path = udev_list_entry_get_name(entry);
  		d = udev_device_new_from_syspath(udev, path);
  		if (!d)
  			continue;
  
  		vidstr = udev_device_get_property_value(d, "ID_VENDOR_ID");
  		pidstr = udev_device_get_property_value(d, "ID_MODEL_ID");
  		phys = udev_device_get_sysattr_value(d, "phys");
  
  		if (vidstr && pidstr && phys &&
  		    safe_atoi_base(vidstr, &vid, 16) &&
  		    safe_atoi_base(pidstr, &pid, 16) &&
  		    vid == VENDOR_ID_WACOM &&
  		    pid != PRODUCT_ID_WACOM_EKR) {
  			dist = find_tree_distance(device, d);
  			if (dist > 0 && (dist < best_dist || best_dist < 0)) {
  				*vendor_id = vid;
  				*product_id = pid;
  				best_dist = dist;
  
  				free(*phys_attr);
  				*phys_attr = safe_strdup(phys);
  			}
  		}
  
  		udev_device_unref(d);
  	}
  
  	udev_enumerate_unref(e);
  }
  
  int main(int argc, char **argv)
  {
  	int rc = 1;
  	struct udev *udev = NULL;
  	struct udev_device *device = NULL;
  	const char *syspath,
  	           *phys = NULL;
  	const char *product;
  	int bustype, vendor_id, product_id, version;
  	char group[1024];
  	char *str;
  
  	if (argc != 2)
  		return 1;
  
  	syspath = argv[1];
  
  	udev = udev_new();
  	if (!udev)
  		goto out;
  
  	device = udev_device_new_from_syspath(udev, syspath);
  	if (!device)
  		goto out;
  
  	/* Find the first parent with ATTRS{phys} set. For tablets that
  	 * value looks like usb-0000:00:14.0-1/input1. Drop the /input1
  	 * bit and use the remainder as device group identifier */
  	while (device != NULL) {
  		struct udev_device *parent;
  
  		phys = udev_device_get_sysattr_value(device, "phys");
  		if (phys)
  			break;
  
  		parent = udev_device_get_parent(device);
  		udev_device_ref(parent);
  		udev_device_unref(device);
  		device = parent;
  	}
  
  	if (!phys)
  		goto out;
  
  	/* udev sets PRODUCT on the same device we find PHYS on, let's rely
  	   on that*/
  	product = udev_device_get_property_value(device, "PRODUCT");
  	if (!product)
  		product = "00/00/00/00";
  
  	if (sscanf(product,
  		   "%x/%x/%x/%x",
  		   &bustype,
  		   &vendor_id,
  		   &product_id,
  		   &version) != 4) {
  		snprintf(group, sizeof(group), "%s:%s", product, phys);
  	} else {
  	    char *physmatch = NULL;
  
  #if HAVE_LIBWACOM
  	    if (vendor_id == VENDOR_ID_WACOM) {
  		    if (product_id == PRODUCT_ID_WACOM_EKR)
  			    wacom_handle_ekr(device,
  					     &vendor_id,
  					     &product_id,
  					     &physmatch);
  		    /* This is called for the EKR as well */
  		    wacom_handle_paired(device,
  					&vendor_id,
  					&product_id);
  	    }
  #endif
  	    snprintf(group,
  		     sizeof(group),
  		     "%x/%x/%x:%s",
  		     bustype,
  		     vendor_id,
  		     product_id,
  		     physmatch ? physmatch : phys);
  
  	    free(physmatch);
  	}
  
  	str = strstr(group, "/input");
  	if (str)
  		*str = '\0';
  
  	/* Cintiq 22HD Touch has
  	   usb-0000:00:14.0-6.3.1/input0 for the touch
  	   usb-0000:00:14.0-6.3.0/input0 for the pen
  	   Check if there's a . after the last -, if so, cut off the string
  	   there.
  	  */
  	str = strrchr(group, '.');
  	if (str && str > strrchr(group, '-'))
  		*str = '\0';
  
  	printf("LIBINPUT_DEVICE_GROUP=%s\n", group);
  
  	rc = 0;
  out:
  	if (device)
  		udev_device_unref(device);
  	if (udev)
  		udev_unref(udev);
  
  	return rc;
  }
  