eudev/udevinfo.c

/*
 * Copyright (C) 2004-2006 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.,
 *	51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 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 <getopt.h>
#include <sys/stat.h>
#include <sys/types.h>

#include "udev.h"

static void print_all_attributes(const char *devpath, const char *key)
{
	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)) {
			struct stat statbuf;
			char filename[PATH_SIZE];
			char *attr_value;
			char value[NAME_SIZE];
			size_t len;

			if (dent->d_name[0] == '.')
				continue;

			if (strcmp(dent->d_name, "uevent") == 0)
				continue;
			if (strcmp(dent->d_name, "dev") == 0)
				continue;

			strlcpy(filename, path, sizeof(filename));
			strlcat(filename, "/", sizeof(filename));
			strlcat(filename, dent->d_name, sizeof(filename));
			if (lstat(filename, &statbuf) != 0)
				continue;
			if (S_ISLNK(statbuf.st_mode))
				continue;

			attr_value = sysfs_attr_get_value(devpath, dent->d_name);
			if (attr_value == NULL)
				continue;
			len = strlcpy(value, attr_value, sizeof(value));
			if(len >= sizeof(value))
				len = sizeof(value) - 1;
			dbg("attr '%s'='%s'(%zi)\n", 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\n", dent->d_name);
				continue;
			}

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

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

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

	printf("\n"
	       "Udevinfo starts with the device specified by the devpath and then\n"
	       "walks up the chain of parent devices. It prints for every device\n"
	       "found, all possible attributes in the udev rules key format.\n"
	       "A rule to match, can be composed by the attributes of the device\n"
	       "and the attributes from one single parent device.\n"
	       "\n");

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

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

		print_all_attributes(dev->devpath, "ATTRS");
	}

	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);
	if (udev->link_priority != 0)
		printf("L: %i\n", udev->link_priority);
	if (udev->partitions != 0)
		printf("A:%u\n", udev->partitions);
	if (udev->ignore_remove)
		printf("R:%u\n", udev->ignore_remove);
	list_for_each_entry(name_loop, &udev->env_list, node)
		printf("E: %s\n", name_loop->name);
}

static void export_db(void) {
	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(NULL);
		if (udev_db == NULL)
			continue;
		if (udev_db_get_device(udev_db, name_loop->name) == 0)
			print_record(udev_db);
			printf("\n");
		udev_device_cleanup(udev_db);
	}
	name_list_cleanup(&name_list);
}

static int lookup_device_by_name(struct udevice *udev, const char *name)
{
	LIST_HEAD(name_list);
	int count;
	struct name_entry *device;
	int rc  = -1;

	count = udev_db_get_devices_by_name(name, &name_list);
	if (count <= 0)
		goto out;

	info("found %i devices for '%s'\n", count, name);

	/* select the device that seems to match */
	list_for_each_entry(device, &name_list, node) {
		char filename[PATH_SIZE];
		struct stat statbuf;

		udev_device_init(udev);
		if (udev_db_get_device(udev, device->name) != 0)
			continue;
		info("found db entry '%s'\n", device->name);

		/* make sure, we don't get a link of a differnt device */
		strlcpy(filename, udev_root, sizeof(filename));
		strlcat(filename, "/", sizeof(filename));
		strlcat(filename, name, sizeof(filename));
		if (stat(filename, &statbuf) != 0)
			continue;
		if (major(udev->devt) > 0 && udev->devt != statbuf.st_rdev) {
			info("skip '%s', dev_t doesn't match\n", udev->name);
			continue;
		}
		rc = 0;
		break;
	}
out:
	name_list_cleanup(&name_list);
	return rc;
}

static int stat_device(const char *name)
{
	struct stat statbuf;

	if (stat(name, &statbuf) != 0)
		return -1;

	printf("%d %d\n", major(statbuf.st_dev), minor(statbuf.st_dev));
	return 0;
}

int udevinfo(int argc, char *argv[], char *envp[])
{
	int option;
	struct udevice *udev;
	int root = 0;

	static const struct option options[] = {
		{ "name", 1, NULL, 'n' },
		{ "path", 1, NULL, 'p' },
		{ "query", 1, NULL, 'q' },
		{ "attribute-walk", 0, NULL, 'a' },
		{ "export-db", 0, NULL, 'e' },
		{ "root", 0, NULL, 'r' },
		{ "device-id-of-file", 1, NULL, 'd' },
		{ "version", 0, NULL, 1 }, /* -V outputs braindead format */
		{ "help", 0, NULL, 'h' },
		{}
	};

	enum action_type {
		ACTION_NONE,
		ACTION_QUERY,
		ACTION_ATTRIBUTE_WALK,
		ACTION_ROOT,
		ACTION_DEVICE_ID_FILE,
	} 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] = "";
	struct name_entry *name_loop;
	int rc = 0;

	logging_init("udevinfo");
	udev_config_init();
	sysfs_init();

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

	while (1) {
		option = getopt_long(argc, argv, "aed:n:p:q:rVh", options, NULL);
		if (option == -1)
			break;

		dbg("option '%c'\n", option);
		switch (option) {
		case 'n':
			/* remove /dev if given */
			if (strncmp(optarg, udev_root, strlen(udev_root)) == 0)
				strlcpy(name, &optarg[strlen(udev_root)+1], sizeof(name));
			else
				strlcpy(name, optarg, sizeof(name));
			remove_trailing_chars(name, '/');
			dbg("name: %s\n", name);
			break;
		case 'p':
			/* remove /sys if given */
			if (strncmp(optarg, sysfs_path, strlen(sysfs_path)) == 0)
				strlcpy(path, &optarg[strlen(sysfs_path)], sizeof(path));
			else
				strlcpy(path, optarg, sizeof(path));
			remove_trailing_chars(path, '/');

			/* possibly resolve to real devpath */
			if (sysfs_resolve_link(path, sizeof(path)) != 0) {
				char temp[PATH_SIZE];
				char *pos;

				/* also check if the parent is a link */
				strlcpy(temp, path, sizeof(temp));
				pos = strrchr(temp, '/');
				if (pos != 0) {
					char tail[PATH_SIZE];

					strlcpy(tail, pos, sizeof(tail));
					pos[0] = '\0';
					if (sysfs_resolve_link(temp, sizeof(temp)) == 0) {
						strlcpy(path, temp, sizeof(path));
						strlcat(path, tail, sizeof(path));
					}
				}
			}
			dbg("path: %s\n", path);
			break;
		case 'q':
			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 'd':
			action = ACTION_DEVICE_ID_FILE;
			strlcpy(name, optarg, sizeof(name));
			break;
		case 'a':
			action = ACTION_ATTRIBUTE_WALK;
			break;
		case 'e':
			export_db();
			goto exit;
		case 1:
			printf("%s\n", UDEV_VERSION);
			goto exit;
		case 'V':
			printf("udevinfo, version %s\n", UDEV_VERSION);
			goto exit;
		case 'h':
			printf("Usage: udevadm info OPTIONS\n"
			       "  --query=<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"
			       "  --path=<devpath>           sysfs device path used for query or chain\n"
			       "  --name=<name>              node or symlink name used for query\n"
			       "  --root                     prepend to query result or print udev_root\n"
			       "  --attribute-walk           print all key matches while walking along chain\n"
			       "                             of parent devices\n"
			       "  --device-id-of-file=<file> print major/minor of underlying device\n"
			       "  --export-db                export the content of the udev database\n"
			       "  --help                     print this text\n"
			       "\n");
			goto exit;
		default:
			goto exit;
		}
	}

	/* run action */
	switch (action) {
	case ACTION_QUERY:
		/* needs devpath or node/symlink name for query */
		if (path[0] != '\0') {
			if (udev_db_get_device(udev, path) != 0) {
				fprintf(stderr, "no record for '%s' in database\n", path);
				rc = 3;
				goto exit;
			}
		} else if (name[0] != '\0') {
			if (lookup_device_by_name(udev, name) != 0) {
				fprintf(stderr, "node name not found\n");
				rc = 4;
				goto exit;
			}
		} else {
			fprintf(stderr, "query needs --path or node --name 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:
			list_for_each_entry(name_loop, &udev->symlink_list, node) {
				char c = name_loop->node.next != &udev->symlink_list ? ' ' : '\n';

				if (root)
					printf("%s/%s%c", udev_root, name_loop->name, c);
				else
					printf("%s%c", name_loop->name, c);
			}
			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:
			fprintf(stderr, "unknown query type\n");
			break;
		}
		break;
	case ACTION_ATTRIBUTE_WALK:
		if (path[0] != '\0') {
			if (print_device_chain(path) != 0) {
				fprintf(stderr, "no valid sysfs device found\n");
				rc = 4;
				goto exit;
			}
		} else if (name[0] != '\0') {
			if (lookup_device_by_name(udev, name) != 0) {
				fprintf(stderr, "node name not found\n");
				rc = 4;
				goto exit;
			}
			if (print_device_chain(udev->dev->devpath) != 0) {
				fprintf(stderr, "no valid sysfs device found\n");
				rc = 4;
				goto exit;
			}
		} else {
			fprintf(stderr, "attribute walk needs --path or node --name specified\n");
			rc = 5;
			goto exit;
		}
		break;
	case ACTION_DEVICE_ID_FILE:
		if (stat_device(name) != 0)
			rc = 6;
		break;
	case ACTION_ROOT:
		printf("%s\n", udev_root);
		break;
	default:
		fprintf(stderr, "missing option\n");
		rc = 1;
		break;
	}

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