systemd/udev/udevadm-trigger.c

/*
 * Copyright (C) 2008-2009 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, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <getopt.h>
#include <errno.h>
#include <dirent.h>
#include <fcntl.h>
#include <syslog.h>
#include <fnmatch.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>

#include "udev.h"

static int verbose;
static int dry_run;

static void exec_list(struct udev_enumerate *udev_enumerate, const char *action)
{
	struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
	struct udev_list_entry *entry;

	udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(udev_enumerate)) {
		char filename[UTIL_PATH_SIZE];
		int fd;

		if (verbose)
			printf("%s\n", udev_list_entry_get_name(entry));
		if (dry_run)
			continue;
		util_strscpyl(filename, sizeof(filename), udev_list_entry_get_name(entry), "/uevent", NULL);
		fd = open(filename, O_WRONLY);
		if (fd < 0) {
			dbg(udev, "error on opening %s: %m\n", filename);
			continue;
		}
		if (write(fd, action, strlen(action)) < 0)
			info(udev, "error writing '%s' to '%s': %m\n", action, filename);
		close(fd);
	}
}

static const char *keyval(const char *str, const char **val, char *buf, size_t size)
{
	char *pos;

	util_strscpy(buf, size,str);
	pos = strchr(buf, '=');
	if (pos != NULL) {
		pos[0] = 0;
		pos++;
	}
	*val = pos;
	return buf;
}

static int adm_trigger(struct udev *udev, int argc, char *argv[])
{
	static const struct option options[] = {
		{ "verbose", no_argument, NULL, 'v' },
		{ "dry-run", no_argument, NULL, 'n' },
		{ "type", required_argument, NULL, 't' },
		{ "action", required_argument, NULL, 'c' },
		{ "subsystem-match", required_argument, NULL, 's' },
		{ "subsystem-nomatch", required_argument, NULL, 'S' },
		{ "attr-match", required_argument, NULL, 'a' },
		{ "attr-nomatch", required_argument, NULL, 'A' },
		{ "property-match", required_argument, NULL, 'p' },
		{ "tag-match", required_argument, NULL, 'g' },
		{ "sysname-match", required_argument, NULL, 'y' },
		{ "parent-match", required_argument, NULL, 'b' },
		{ "help", no_argument, NULL, 'h' },
		{}
	};
	enum {
		TYPE_DEVICES,
		TYPE_SUBSYSTEMS,
	} device_type = TYPE_DEVICES;
	const char *action = "change";
	struct udev_enumerate *udev_enumerate;
	int rc = 0;

	dbg(udev, "version %s\n", VERSION);
	udev_enumerate = udev_enumerate_new(udev);
	if (udev_enumerate == NULL) {
		rc = 1;
		goto exit;
	}

	for (;;) {
		int option;
		const char *key;
		const char *val;
		char buf[UTIL_PATH_SIZE];

		option = getopt_long(argc, argv, "vng:o:t:hc:p:s:S:a:A:y:b:", options, NULL);
		if (option == -1)
			break;

		switch (option) {
		case 'v':
			verbose = 1;
			break;
		case 'n':
			dry_run = 1;
			break;
		case 't':
			if (strcmp(optarg, "devices") == 0) {
				device_type = TYPE_DEVICES;
			} else if (strcmp(optarg, "subsystems") == 0) {
				device_type = TYPE_SUBSYSTEMS;
			} else {
				err(udev, "unknown type --type=%s\n", optarg);
				rc = 2;
				goto exit;
			}
			break;
		case 'c':
			action = optarg;
			break;
		case 's':
			udev_enumerate_add_match_subsystem(udev_enumerate, optarg);
			break;
		case 'S':
			udev_enumerate_add_nomatch_subsystem(udev_enumerate, optarg);
			break;
		case 'a':
			key = keyval(optarg, &val, buf, sizeof(buf));
			udev_enumerate_add_match_sysattr(udev_enumerate, key, val);
			break;
		case 'A':
			key = keyval(optarg, &val, buf, sizeof(buf));
			udev_enumerate_add_nomatch_sysattr(udev_enumerate, key, val);
			break;
		case 'p':
			key = keyval(optarg, &val, buf, sizeof(buf));
			udev_enumerate_add_match_property(udev_enumerate, key, val);
			break;
		case 'g':
			udev_enumerate_add_match_tag(udev_enumerate, optarg);
			break;
		case 'y':
			udev_enumerate_add_match_sysname(udev_enumerate, optarg);
			break;
		case 'b': {
			char path[UTIL_PATH_SIZE];
			struct udev_device *dev;

			/* add sys dir if needed */
			if (strncmp(optarg, udev_get_sys_path(udev), strlen(udev_get_sys_path(udev))) != 0)
				util_strscpyl(path, sizeof(path), udev_get_sys_path(udev), optarg, NULL);
			else
				util_strscpy(path, sizeof(path), optarg);
			util_remove_trailing_chars(path, '/');
			dev = udev_device_new_from_syspath(udev, path);
			if (dev == NULL) {
				err(udev, "unable to open the device '%s'\n", optarg);
				rc = 2;
				goto exit;
			}
			udev_enumerate_add_match_parent(udev_enumerate, dev);
			/* drop reference immediately, enumerate pins the device as long as needed */
			udev_device_unref(dev);
			break;
		}
		case 'h':
			printf("Usage: udevadm trigger OPTIONS\n"
			       "  --verbose                       print the list of devices while running\n"
			       "  --dry-run                       do not actually trigger the events\n"
			       "  --type=                         type of events to trigger\n"
			       "      devices                       sys devices (default)\n"
			       "      subsystems                    sys subsystems and drivers\n"
			       "  --action=<action>               event action value, default is \"change\"\n"
			       "  --subsystem-match=<subsystem>   trigger devices from a matching subsystem\n"
			       "  --subsystem-nomatch=<subsystem> exclude devices from a matching subsystem\n"
			       "  --attr-match=<file[=<value>]>   trigger devices with a matching attribute\n"
			       "  --attr-nomatch=<file[=<value>]> exclude devices with a matching attribute\n"
			       "  --property-match=<key>=<value>  trigger devices with a matching property\n"
			       "  --tag-match=<key>=<value>       trigger devices with a matching property\n"
			       "  --sysname-match=<name>          trigger devices with a matching name\n"
			       "  --parent-match=<name>           trigger devices with that parent device\n"
			       "  --help\n\n");
			goto exit;
		default:
			rc = 1;
			goto exit;
		}
	}

	switch (device_type) {
	case TYPE_SUBSYSTEMS:
		udev_enumerate_scan_subsystems(udev_enumerate);
		exec_list(udev_enumerate, action);
		goto exit;
	case TYPE_DEVICES:
		udev_enumerate_scan_devices(udev_enumerate);
		exec_list(udev_enumerate, action);
		goto exit;
	default:
		goto exit;
	}
exit:
	udev_enumerate_unref(udev_enumerate);
	return rc;
}

const struct udevadm_cmd udevadm_trigger = {
	.name = "trigger",
	.cmd = adm_trigger,
	.help = "request events from the kernel",
};