xref/systemd/udevinfo.c

	udevinfo.c revision 1aa1e24848903d11780db1ade355be73ad61a937
/*
 * udevinfo.c - fetches stored device information or sysfs attributes
 *
 * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
 *
 *	This program is free software; you can redistribute it and/or modify it
 *	under the terms of the GNU General Public License as published by the
 *	Free Software Foundation version 2 of the License.
 *
 *	This program is distributed in the hope that it will be useful, but
 *	WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *	General Public License for more details.
 *
 *	You should have received a copy of the GNU General Public License along
 *	with this program; if not, write to the Free Software Foundation, Inc.,
 *	675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stddef.h>
#include <ctype.h>
#include <stdarg.h>
#include <unistd.h>
#include <dirent.h>
#include <errno.h>

#include "udev.h"


#ifdef USE_LOG
void log_message (int priority, const char *format, ...)
{
	va_list	args;

	if (priority > udev_log_priority)
		return;

	va_start(args, format);
	vsyslog(priority, format, args);
	va_end(args);
}
#endif

static void print_all_attributes(const char *devpath)
{
	char path[PATH_SIZE];
	DIR *dir;
	struct dirent *dent;

	strlcpy(path, sysfs_path, sizeof(path));
	strlcat(path, devpath, sizeof(path));

	dir = opendir(path);
	if (dir != NULL) {
		for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
			char *attr_value;
			char value[NAME_SIZE];
			size_t len;

			attr_value = sysfs_attr_get_value(devpath, dent->d_name);
			if (attr_value == NULL)
				continue;
			len = strlcpy(value, attr_value, sizeof(value));
			dbg("attr '%s'='%s'(%zi)", dent->d_name, value, len);

			/* remove trailing newlines */
			while (len && value[len-1] == '\n')
				value[--len] = '\0';

			/* skip nonprintable attributes */
			while (len && isprint(value[len-1]))
				len--;
			if (len) {
				dbg("attribute value of '%s' non-printable, skip", dent->d_name);
				continue;
			}

			replace_untrusted_chars(value);
			printf("    SYSFS{%s}==\"%s\"\n", dent->d_name, value);
		}
	}
	printf("\n");
}

static int print_device_chain(const char *devpath)
{
	struct sysfs_device *dev;

	printf("\n"
	       "udevinfo starts with the device the node belongs to and then walks up the\n"
	       "device chain, to print for every device found, all possibly useful attributes\n"
	       "in the udev key format.\n"
	       "Only attributes within one device section may be used together in one rule,\n"
	       "to match the device for which the node will be created.\n"
	       "\n");

	dev = sysfs_device_get(devpath);
	if (dev == NULL)
		return -1;

	printf("  looking at device '%s':\n", dev->devpath);
	printf("    KERNEL==\"%s\"\n", dev->kernel_name);
	printf("    SUBSYSTEM==\"%s\"\n", dev->subsystem);
	print_all_attributes(dev->devpath);

	/* walk up the chain of devices */
	while (1) {
		dev = sysfs_device_get_parent(dev);
		if (dev == NULL)
			break;
		printf("  looking at device '%s':\n", dev->devpath);
		printf("    ID==\"%s\"\n", dev->kernel_name);
		printf("    BUS==\"%s\"\n", dev->subsystem);
		printf("    DRIVER==\"%s\"\n", dev->driver);

		print_all_attributes(dev->devpath);
	}

	return 0;
}

static void print_record(struct udevice *udev)
{
	struct name_entry *name_loop;

	printf("P: %s\n", udev->dev->devpath);
	printf("N: %s\n", udev->name);
	list_for_each_entry(name_loop, &udev->symlink_list, node)
		printf("S: %s\n", name_loop->name);
	list_for_each_entry(name_loop, &udev->env_list, node)
		printf("E: %s\n", name_loop->name);
}

static void export_name_devpath(struct udevice *udev) {
	printf("%s=%s/%s\n", udev->dev->devpath, udev_root, udev->name);
}

static void export_record(struct udevice *udev) {
	print_record(udev);
	printf("\n");
}

static void export_db(void fnct(struct udevice *udev)) {
	LIST_HEAD(name_list);
	struct name_entry *name_loop;

	udev_db_get_all_entries(&name_list);
	list_for_each_entry(name_loop, &name_list, node) {
		struct udevice *udev_db;

		udev_db = udev_device_init();
		if (udev_db == NULL)
			continue;
		if (udev_db_get_device(udev_db, name_loop->name) == 0)
			fnct(udev_db);
		udev_device_cleanup(udev_db);
	}
	name_list_cleanup(&name_list);
}

static void print_help(void)
{
	fprintf(stderr, "Usage: udevinfo [-anpqrVh]\n"
	       "  -q TYPE  query database for the specified value:\n"
	       "             'name'    name of device node\n"
	       "             'symlink' pointing to node\n"
	       "             'path'    sysfs device path\n"
	       "             'env'     the device related imported environment\n"
	       "             'all'     all values\n"
	       "\n"
	       "  -p PATH  sysfs device path used for query or chain\n"
	       "  -n NAME  node/symlink name used for query\n"
	       "\n"
	       "  -r       prepend to query result or print udev_root\n"
	       "  -a       print all SYSFS_attributes along the device chain\n"
	       "  -e       export the content of the udev database\n"
	       "  -V       print udev version\n"
	       "  -h       print this help text\n"
	       "\n");
}

int main(int argc, char *argv[], char *envp[])
{
	static const char short_options[] = "aden:p:q:rVh";
	int option;
	struct udevice *udev;
	int root = 0;

	enum action_type {
		ACTION_NONE,
		ACTION_QUERY,
		ACTION_ATTRIBUTE_WALK,
		ACTION_ROOT,
	} action = ACTION_NONE;

	enum query_type {
		QUERY_NONE,
		QUERY_NAME,
		QUERY_PATH,
		QUERY_SYMLINK,
		QUERY_ENV,
		QUERY_ALL,
	} query = QUERY_NONE;

	char path[PATH_SIZE] = "";
	char name[PATH_SIZE] = "";
	char temp[PATH_SIZE];
	struct name_entry *name_loop;
	char *pos;
	int rc = 0;

	logging_init("udevinfo");

	udev_config_init();
	sysfs_init();

	udev = udev_device_init();
	if (udev == NULL) {
		rc = 1;
		goto exit;
	}

	/* get command line options */
	while (1) {
		option = getopt(argc, argv, short_options);
		if (option == -1)
			break;

		dbg("option '%c'", option);
		switch (option) {
		case 'n':
			dbg("udev name: %s\n", optarg);
			strlcpy(name, optarg, sizeof(name));
			break;
		case 'p':
			dbg("udev path: %s\n", optarg);
			/* remove sysfs mountpoint if not given */
			if (strncmp(optarg, sysfs_path, strlen(sysfs_path)) == 0)
				strlcpy(path, &optarg[strlen(sysfs_path)], sizeof(path));
			else
				strlcpy(path, optarg, sizeof(path));
			break;
		case 'q':
			dbg("udev query: %s\n", optarg);
			action = ACTION_QUERY;
			if (strcmp(optarg, "name") == 0) {
				query = QUERY_NAME;
				break;
			}
			if (strcmp(optarg, "symlink") == 0) {
				query = QUERY_SYMLINK;
				break;
			}
			if (strcmp(optarg, "path") == 0) {
				query = QUERY_PATH;
				break;
			}
			if (strcmp(optarg, "env") == 0) {
				query = QUERY_ENV;
				break;
			}
			if (strcmp(optarg, "all") == 0) {
				query = QUERY_ALL;
				break;
			}
			fprintf(stderr, "unknown query type\n");
			rc = 2;
			goto exit;
		case 'r':
			if (action == ACTION_NONE)
				action = ACTION_ROOT;
			root = 1;
			break;
		case 'a':
			action = ACTION_ATTRIBUTE_WALK;
			break;
		case 'd':
			export_db(export_name_devpath);
			goto exit;
		case 'e':
			export_db(export_record);
			goto exit;
		case 'V':
			printf("udevinfo, version %s\n", UDEV_VERSION);
			goto exit;
		case 'h':
		case '?':
		default:
			print_help();
			goto exit;
		}
	}

	/* run action */
	switch (action) {
	case ACTION_QUERY:
		/* need devpath or node/symlink name for query */
		if (path[0] != '\0') {
			/* remove sysfs_path if given */
			if (strncmp(path, sysfs_path, strlen(sysfs_path)) == 0) {
				pos = path + strlen(sysfs_path);
			} else {
				if (path[0] != '/') {
					/* prepend '/' if missing */
					strcpy(temp, "/");
					strlcpy(temp, path, sizeof(temp));
					pos = temp;
				} else {
					pos = path;
				}
			}
			if (udev_db_get_device(udev, pos) != 0) {
				fprintf(stderr, "no record for '%s' in database\n", pos);
				rc = 3;
				goto exit;
			}
		} else if (name[0] != '\0') {
			char devpath[PATH_SIZE];
			int len;

			/* remove udev_root if given */
			len = strlen(udev_root);
			if (strncmp(name, udev_root, len) == 0) {
				pos = &name[len+1];
			} else
				pos = name;

			if (udev_db_lookup_name(pos, devpath, sizeof(devpath)) != 0) {
				fprintf(stderr, "no record for '%s' in database\n", pos);
				rc = 3;
				goto exit;
			}
			udev_db_get_device(udev, devpath);
		} else {
			fprintf(stderr, "query needs device path(-p) or node name(-n) specified\n");
			rc = 4;
			goto exit;
		}

		switch(query) {
		case QUERY_NAME:
			if (root)
				printf("%s/%s\n", udev_root, udev->name);
			else
				printf("%s\n", udev->name);
			break;
		case QUERY_SYMLINK:
			if (list_empty(&udev->symlink_list))
				goto exit;
			if (root)
				list_for_each_entry(name_loop, &udev->symlink_list, node)
					printf("%s/%s ", udev_root, name_loop->name);
			else
				list_for_each_entry(name_loop, &udev->symlink_list, node)
					printf("%s ", name_loop->name);
			printf("\n");
			break;
		case QUERY_PATH:
			printf("%s\n", udev->dev->devpath);
			goto exit;
		case QUERY_ENV:
			list_for_each_entry(name_loop, &udev->env_list, node)
				printf("%s\n", name_loop->name);
			break;
		case QUERY_ALL:
			print_record(udev);
			break;
		default:
			print_help();
			break;
		}
		break;
	case ACTION_ATTRIBUTE_WALK:
		if (path[0] == '\0') {
			fprintf(stderr, "attribute walk on device chain needs path(-p) specified\n");
			rc = 4;
			goto exit;
		} else
			print_device_chain(path);
		break;
	case ACTION_ROOT:
		printf("%s\n", udev_root);
		break;
	default:
		print_help();
		rc = 1;
		break;
	}

exit:
	udev_device_cleanup(udev);
	sysfs_cleanup();
	logging_close();
	return rc;
}