Systemd/udev/udev-util.c

/*
 * Copyright (C) 2004-2008 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 <stdio.h>
#include <stddef.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <dirent.h>
#include <syslog.h>
#include <pwd.h>
#include <grp.h>
#include <sys/types.h>
#include <sys/utsname.h>

#include "udev.h"

struct name_entry *name_list_add(struct udev *udev, struct list_head *name_list, const char *name, int sort)
{
	struct name_entry *name_loop;
	struct name_entry *name_new;

	/* avoid duplicate entries */
	list_for_each_entry(name_loop, name_list, node) {
		if (strcmp(name_loop->name, name) == 0) {
			dbg(udev, "'%s' is already in the list\n", name);
			return name_loop;
		}
	}

	if (sort)
		list_for_each_entry(name_loop, name_list, node) {
			if (strcmp(name_loop->name, name) > 0)
				break;
		}

	name_new = malloc(sizeof(struct name_entry));
	if (name_new == NULL)
		return NULL;
	memset(name_new, 0x00, sizeof(struct name_entry));
	util_strlcpy(name_new->name, name, sizeof(name_new->name));
	dbg(udev, "adding '%s'\n", name_new->name);
	list_add_tail(&name_new->node, &name_loop->node);

	return name_new;
}

struct name_entry *name_list_key_add(struct udev *udev, struct list_head *name_list, const char *key, const char *value)
{
	struct name_entry *name_loop;
	struct name_entry *name_new;
	size_t keylen = strlen(key);

	list_for_each_entry(name_loop, name_list, node) {
		if (strncmp(name_loop->name, key, keylen) != 0)
			continue;
		if (name_loop->name[keylen] != '=')
			continue;
		dbg(udev, "key already present '%s', replace it\n", name_loop->name);
		snprintf(name_loop->name, sizeof(name_loop->name), "%s=%s", key, value);
		name_loop->name[sizeof(name_loop->name)-1] = '\0';
		return name_loop;
	}

	name_new = malloc(sizeof(struct name_entry));
	if (name_new == NULL)
		return NULL;
	memset(name_new, 0x00, sizeof(struct name_entry));
	snprintf(name_new->name, sizeof(name_new->name), "%s=%s", key, value);
	name_new->name[sizeof(name_new->name)-1] = '\0';
	dbg(udev, "adding '%s'\n", name_new->name);
	list_add_tail(&name_new->node, &name_loop->node);

	return name_new;
}

int name_list_key_remove(struct udev *udev, struct list_head *name_list, const char *key)
{
	struct name_entry *name_loop;
	struct name_entry *name_tmp;
	size_t keylen = strlen(key);
	int retval = 0;

	list_for_each_entry_safe(name_loop, name_tmp, name_list, node) {
		if (strncmp(name_loop->name, key, keylen) != 0)
			continue;
		if (name_loop->name[keylen] != '=')
			continue;
		list_del(&name_loop->node);
		free(name_loop);
		retval = 1;
		break;
	}
	return retval;
}

void name_list_cleanup(struct udev *udev, struct list_head *name_list)
{
	struct name_entry *name_loop;
	struct name_entry *name_tmp;

	list_for_each_entry_safe(name_loop, name_tmp, name_list, node) {
		list_del(&name_loop->node);
		free(name_loop);
	}
}

uid_t lookup_user(struct udev *udev, const char *user)
{
	struct passwd *pw;
	uid_t uid = 0;

	errno = 0;
	pw = getpwnam(user);
	if (pw == NULL) {
		if (errno == 0 || errno == ENOENT || errno == ESRCH)
			err(udev, "specified user '%s' unknown\n", user);
		else
			err(udev, "error resolving user '%s': %m\n", user);
	} else
		uid = pw->pw_uid;

	return uid;
}

extern gid_t lookup_group(struct udev *udev, const char *group)
{
	struct group *gr;
	gid_t gid = 0;

	errno = 0;
	gr = getgrnam(group);
	if (gr == NULL) {
		if (errno == 0 || errno == ENOENT || errno == ESRCH)
			err(udev, "specified group '%s' unknown\n", group);
		else
			err(udev, "error resolving group '%s': %m\n", group);
	} else
		gid = gr->gr_gid;

	return gid;
}