udev_node.c - pub/scm/linux/hotplug/udev - Git at Google

 /*
  * udev-node.c - device node handling
  *
  * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
  * Copyright (C) 2004 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 <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
 #include <grp.h>
 #include <sys/stat.h>
 #include <sys/types.h>

 #include "udev.h"
 #include "udev_rules.h"
 #include "udev_selinux.h"


 int udev_node_mknod(struct udevice *udev, const char *file, dev_t devt, mode_t mode, uid_t uid, gid_t gid)
 {
 	struct stat stats;
 	int retval = 0;

 	if (major(devt) != 0 && strcmp(udev->dev->subsystem, "block") == 0)
 		mode |= S_IFBLK;
 	else
 		mode |= S_IFCHR;

 	if (stat(file, &stats) != 0)
 		goto create;

 	/* preserve node with already correct numbers, to prevent changing the inode number */
 	if ((stats.st_mode & S_IFMT) == (mode & S_IFMT) && (stats.st_rdev == devt)) {
 		info("preserve file '%s', because it has correct dev_t", file);
 		selinux_setfilecon(file, udev->dev->kernel_name, stats.st_mode);
 		goto perms;
 	}

 	if (unlink(file) != 0)
 		err("unlink(%s) failed: %s", file, strerror(errno));
 	else
 		dbg("already present file '%s' unlinked", file);

 create:
 	selinux_setfscreatecon(file, udev->dev->kernel_name, mode);
 	retval = mknod(file, mode, devt);
 	selinux_resetfscreatecon();
 	if (retval != 0) {
 		err("mknod(%s, %#o, %u, %u) failed: %s",
 		    file, mode, major(devt), minor(devt), strerror(errno));
 		goto exit;
 	}

 perms:
 	dbg("chmod(%s, %#o)", file, mode);
 	if (chmod(file, mode) != 0) {
 		err("chmod(%s, %#o) failed: %s", file, mode, strerror(errno));
 		goto exit;
 	}

 	if (uid != 0 || gid != 0) {
 		dbg("chown(%s, %u, %u)", file, uid, gid);
 		if (chown(file, uid, gid) != 0) {
 			err("chown(%s, %u, %u) failed: %s",
 			    file, uid, gid, strerror(errno));
 			goto exit;
 		}
 	}

 exit:
 	return retval;
 }

 int udev_node_add(struct udevice *udev, struct udevice *udev_old)
 {
 	char filename[PATH_SIZE];
 	struct name_entry *name_loop;
 	uid_t uid;
 	gid_t gid;
 	int tail;
 	int i;
 	int retval = 0;

 	selinux_init();

 	snprintf(filename, sizeof(filename), "%s/%s", udev_root, udev->name);
 	filename[sizeof(filename)-1] = '\0';

 	/* create parent directories if needed */
 	if (strchr(udev->name, '/'))
 		create_path(filename);

 	if (strcmp(udev->owner, "root") == 0)
 		uid = 0;
 	else {
 		char *endptr;
 		unsigned long id;

 		id = strtoul(udev->owner, &endptr, 10);
 		if (endptr[0] == '\0')
 			uid = (uid_t) id;
 		else
 			uid = lookup_user(udev->owner);
 	}

 	if (strcmp(udev->group, "root") == 0)
 		gid = 0;
 	else {
 		char *endptr;
 		unsigned long id;

 		id = strtoul(udev->group, &endptr, 10);
 		if (endptr[0] == '\0')
 			gid = (gid_t) id;
 		else
 			gid = lookup_group(udev->group);
 	}

 	info("creating device node '%s', major = '%d', minor = '%d', " "mode = '%#o', uid = '%d', gid = '%d'",
 	     filename, major(udev->devt), minor(udev->devt), udev->mode, uid, gid);

 	if (!udev->test_run)
 		if (udev_node_mknod(udev, filename, udev->devt, udev->mode, uid, gid) != 0) {
 			retval = -1;
 			goto exit;
 		}

 	setenv("DEVNAME", filename, 1);

 	/* create all_partitions if requested */
 	if (udev->partitions) {
 		char partitionname[PATH_SIZE];
 		char *attr;
 		int range;

 		/* take the maximum registered minor range */
 		attr = sysfs_attr_get_value(udev->dev->devpath, "range");
 		if (attr) {
 			range = atoi(attr);
 			if (range > 1)
 				udev->partitions = range-1;
 		}
 		info("creating device partition nodes '%s[1-%i]'", filename, udev->partitions);
 		if (!udev->test_run) {
 			for (i = 1; i <= udev->partitions; i++) {
 				dev_t part_devt;

 				snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i);
 				partitionname[sizeof(partitionname)-1] = '\0';
 				part_devt = makedev(major(udev->devt), minor(udev->devt) + i);
 				udev_node_mknod(udev, partitionname, part_devt, udev->mode, uid, gid);
 			}
 		}
 	}

 	/* create symlink(s) if requested */
 	if (!list_empty(&udev->symlink_list)) {
 		char symlinks[512] = "";

 		list_for_each_entry(name_loop, &udev->symlink_list, node) {
 			char linktarget[PATH_SIZE];

 			snprintf(filename, sizeof(filename), "%s/%s", udev_root, name_loop->name);
 			filename[sizeof(filename)-1] = '\0';

 			dbg("symlink '%s' to node '%s' requested", filename, udev->name);
 			if (!udev->test_run)
 				if (strchr(filename, '/'))
 					create_path(filename);

 			/* optimize relative link */
 			linktarget[0] = '\0';
 			i = 0;
 			tail = 0;
 			while (udev->name[i] && (udev->name[i] == name_loop->name[i])) {
 				if (udev->name[i] == '/')
 					tail = i+1;
 				i++;
 			}
 			while (name_loop->name[i] != '\0') {
 				if (name_loop->name[i] == '/')
 					strlcat(linktarget, "../", sizeof(linktarget));
 				i++;
 			}

 			strlcat(linktarget, &udev->name[tail], sizeof(linktarget));

 			info("creating symlink '%s' to '%s'", filename, linktarget);
 			if (!udev->test_run) {
 				unlink(filename);
 				selinux_setfscreatecon(filename, NULL, S_IFLNK);
 				if (symlink(linktarget, filename) != 0)
 					err("symlink(%s, %s) failed: %s", linktarget, filename, strerror(errno));
 				selinux_resetfscreatecon();
 			}

 			strlcat(symlinks, filename, sizeof(symlinks));
 			strlcat(symlinks, " ", sizeof(symlinks));
 		}

 		remove_trailing_chars(symlinks, ' ');
 		setenv("DEVLINKS", symlinks, 1);
 	}

 exit:
 	selinux_exit();
 	return retval;
 }

 void udev_node_remove_symlinks(struct udevice *udev)
 {
 	char filename[PATH_SIZE];
 	struct name_entry *name_loop;
 	struct stat stats;

 	if (!list_empty(&udev->symlink_list)) {
 		char symlinks[512] = "";

 		list_for_each_entry(name_loop, &udev->symlink_list, node) {
 			snprintf(filename, sizeof(filename), "%s/%s", udev_root, name_loop->name);
 			filename[sizeof(filename)-1] = '\0';

 			if (stat(filename, &stats) != 0) {
 				dbg("symlink '%s' not found", filename);
 				continue;
 			}
 			if (udev->devt && stats.st_rdev != udev->devt) {
 				info("symlink '%s' points to a different device, skip removal", filename);
 				continue;
 			}

 			info("removing symlink '%s'", filename);
 			if (!udev->test_run) {
 				unlink(filename);

 				if (strchr(filename, '/'))
 					delete_path(filename);
 			}

 			strlcat(symlinks, filename, sizeof(symlinks));
 			strlcat(symlinks, " ", sizeof(symlinks));
 		}

 		remove_trailing_chars(symlinks, ' ');
 		if (symlinks[0] != '\0')
 			setenv("DEVLINKS", symlinks, 1);
 	}
 }

 int udev_node_remove(struct udevice *udev)
 {
 	char filename[PATH_SIZE];
 	char partitionname[PATH_SIZE];
 	struct stat stats;
 	int retval;
 	int num;

 	udev_node_remove_symlinks(udev);

 	snprintf(filename, sizeof(filename), "%s/%s", udev_root, udev->name);
 	filename[sizeof(filename)-1] = '\0';

 	if (stat(filename, &stats) != 0) {
 		dbg("device node '%s' not found", filename);
 		return -1;
 	}
 	if (udev->devt && stats.st_rdev != udev->devt) {
 		info("device node '%s' points to a different device, skip removal", filename);
 		return -1;
 	}

 	info("removing device node '%s'", filename);
 	retval = unlink_secure(filename);
 	if (retval)
 		return retval;

 	setenv("DEVNAME", filename, 1);

 	num = udev->partitions;
 	if (num > 0) {
 		int i;

 		info("removing all_partitions '%s[1-%i]'", filename, num);
 		if (num > 255) {
 			info("garbage from udev database, skip all_partitions removal");
 			return -1;
 		}
 		for (i = 1; i <= num; i++) {
 			snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i);
 			partitionname[sizeof(partitionname)-1] = '\0';
 			unlink_secure(partitionname);
 		}
 	}

 	if (strchr(udev->name, '/'))
 		delete_path(filename);

 	return retval;
 }
	/*
	* udev-node.c - device node handling
	*
	* Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
	* Copyright (C) 2004 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 <fcntl.h>
	#include <unistd.h>
	#include <errno.h>
	#include <grp.h>
	#include <sys/stat.h>
	#include <sys/types.h>

	#include "udev.h"
	#include "udev_rules.h"
	#include "udev_selinux.h"


	int udev_node_mknod(struct udevice udev, const char file, dev_t devt, mode_t mode, uid_t uid, gid_t gid)
	{
	struct stat stats;
	int retval = 0;

	if (major(devt) != 0 && strcmp(udev->dev->subsystem, "block") == 0)
	mode \|= S_IFBLK;
	else
	mode \|= S_IFCHR;

	if (stat(file, &stats) != 0)
	goto create;

	/* preserve node with already correct numbers, to prevent changing the inode number */
	if ((stats.st_mode & S_IFMT) == (mode & S_IFMT) && (stats.st_rdev == devt)) {
	info("preserve file '%s', because it has correct dev_t", file);
	selinux_setfilecon(file, udev->dev->kernel_name, stats.st_mode);
	goto perms;
	}

	if (unlink(file) != 0)
	err("unlink(%s) failed: %s", file, strerror(errno));
	else
	dbg("already present file '%s' unlinked", file);

	create:
	selinux_setfscreatecon(file, udev->dev->kernel_name, mode);
	retval = mknod(file, mode, devt);
	selinux_resetfscreatecon();
	if (retval != 0) {
	err("mknod(%s, %#o, %u, %u) failed: %s",
	file, mode, major(devt), minor(devt), strerror(errno));
	goto exit;
	}

	perms:
	dbg("chmod(%s, %#o)", file, mode);
	if (chmod(file, mode) != 0) {
	err("chmod(%s, %#o) failed: %s", file, mode, strerror(errno));
	goto exit;
	}

	if (uid != 0 \|\| gid != 0) {
	dbg("chown(%s, %u, %u)", file, uid, gid);
	if (chown(file, uid, gid) != 0) {
	err("chown(%s, %u, %u) failed: %s",
	file, uid, gid, strerror(errno));
	goto exit;
	}
	}

	exit:
	return retval;
	}

	int udev_node_add(struct udevice udev, struct udevice udev_old)
	{
	char filename[PATH_SIZE];
	struct name_entry *name_loop;
	uid_t uid;
	gid_t gid;
	int tail;
	int i;
	int retval = 0;

	selinux_init();

	snprintf(filename, sizeof(filename), "%s/%s", udev_root, udev->name);
	filename[sizeof(filename)-1] = '\0';

	/* create parent directories if needed */
	if (strchr(udev->name, '/'))
	create_path(filename);

	if (strcmp(udev->owner, "root") == 0)
	uid = 0;
	else {
	char *endptr;
	unsigned long id;

	id = strtoul(udev->owner, &endptr, 10);
	if (endptr[0] == '\0')
	uid = (uid_t) id;
	else
	uid = lookup_user(udev->owner);
	}

	if (strcmp(udev->group, "root") == 0)
	gid = 0;
	else {
	char *endptr;
	unsigned long id;

	id = strtoul(udev->group, &endptr, 10);
	if (endptr[0] == '\0')
	gid = (gid_t) id;
	else
	gid = lookup_group(udev->group);
	}

	info("creating device node '%s', major = '%d', minor = '%d', " "mode = '%#o', uid = '%d', gid = '%d'",
	filename, major(udev->devt), minor(udev->devt), udev->mode, uid, gid);

	if (!udev->test_run)
	if (udev_node_mknod(udev, filename, udev->devt, udev->mode, uid, gid) != 0) {
	retval = -1;
	goto exit;
	}

	setenv("DEVNAME", filename, 1);

	/* create all_partitions if requested */
	if (udev->partitions) {
	char partitionname[PATH_SIZE];
	char *attr;
	int range;

	/* take the maximum registered minor range */
	attr = sysfs_attr_get_value(udev->dev->devpath, "range");
	if (attr) {
	range = atoi(attr);
	if (range > 1)
	udev->partitions = range-1;
	}
	info("creating device partition nodes '%s[1-%i]'", filename, udev->partitions);
	if (!udev->test_run) {
	for (i = 1; i <= udev->partitions; i++) {
	dev_t part_devt;

	snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i);
	partitionname[sizeof(partitionname)-1] = '\0';
	part_devt = makedev(major(udev->devt), minor(udev->devt) + i);
	udev_node_mknod(udev, partitionname, part_devt, udev->mode, uid, gid);
	}
	}
	}

	/* create symlink(s) if requested */
	if (!list_empty(&udev->symlink_list)) {
	char symlinks[512] = "";

	list_for_each_entry(name_loop, &udev->symlink_list, node) {
	char linktarget[PATH_SIZE];

	snprintf(filename, sizeof(filename), "%s/%s", udev_root, name_loop->name);
	filename[sizeof(filename)-1] = '\0';

	dbg("symlink '%s' to node '%s' requested", filename, udev->name);
	if (!udev->test_run)
	if (strchr(filename, '/'))
	create_path(filename);

	/* optimize relative link */
	linktarget[0] = '\0';
	i = 0;
	tail = 0;
	while (udev->name[i] && (udev->name[i] == name_loop->name[i])) {
	if (udev->name[i] == '/')
	tail = i+1;
	i++;
	}
	while (name_loop->name[i] != '\0') {
	if (name_loop->name[i] == '/')
	strlcat(linktarget, "../", sizeof(linktarget));
	i++;
	}

	strlcat(linktarget, &udev->name[tail], sizeof(linktarget));

	info("creating symlink '%s' to '%s'", filename, linktarget);
	if (!udev->test_run) {
	unlink(filename);
	selinux_setfscreatecon(filename, NULL, S_IFLNK);
	if (symlink(linktarget, filename) != 0)
	err("symlink(%s, %s) failed: %s", linktarget, filename, strerror(errno));
	selinux_resetfscreatecon();
	}

	strlcat(symlinks, filename, sizeof(symlinks));
	strlcat(symlinks, " ", sizeof(symlinks));
	}

	remove_trailing_chars(symlinks, ' ');
	setenv("DEVLINKS", symlinks, 1);
	}

	exit:
	selinux_exit();
	return retval;
	}

	void udev_node_remove_symlinks(struct udevice *udev)
	{
	char filename[PATH_SIZE];
	struct name_entry *name_loop;
	struct stat stats;

	if (!list_empty(&udev->symlink_list)) {
	char symlinks[512] = "";

	list_for_each_entry(name_loop, &udev->symlink_list, node) {
	snprintf(filename, sizeof(filename), "%s/%s", udev_root, name_loop->name);
	filename[sizeof(filename)-1] = '\0';

	if (stat(filename, &stats) != 0) {
	dbg("symlink '%s' not found", filename);
	continue;
	}
	if (udev->devt && stats.st_rdev != udev->devt) {
	info("symlink '%s' points to a different device, skip removal", filename);
	continue;
	}

	info("removing symlink '%s'", filename);
	if (!udev->test_run) {
	unlink(filename);

	if (strchr(filename, '/'))
	delete_path(filename);
	}

	strlcat(symlinks, filename, sizeof(symlinks));
	strlcat(symlinks, " ", sizeof(symlinks));
	}

	remove_trailing_chars(symlinks, ' ');
	if (symlinks[0] != '\0')
	setenv("DEVLINKS", symlinks, 1);
	}
	}

	int udev_node_remove(struct udevice *udev)
	{
	char filename[PATH_SIZE];
	char partitionname[PATH_SIZE];
	struct stat stats;
	int retval;
	int num;

	udev_node_remove_symlinks(udev);

	snprintf(filename, sizeof(filename), "%s/%s", udev_root, udev->name);
	filename[sizeof(filename)-1] = '\0';

	if (stat(filename, &stats) != 0) {
	dbg("device node '%s' not found", filename);
	return -1;
	}
	if (udev->devt && stats.st_rdev != udev->devt) {
	info("device node '%s' points to a different device, skip removal", filename);
	return -1;
	}

	info("removing device node '%s'", filename);
	retval = unlink_secure(filename);
	if (retval)
	return retval;

	setenv("DEVNAME", filename, 1);

	num = udev->partitions;
	if (num > 0) {
	int i;

	info("removing all_partitions '%s[1-%i]'", filename, num);
	if (num > 255) {
	info("garbage from udev database, skip all_partitions removal");
	return -1;
	}
	for (i = 1; i <= num; i++) {
	snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i);
	partitionname[sizeof(partitionname)-1] = '\0';
	unlink_secure(partitionname);
	}
	}

	if (strchr(udev->name, '/'))
	delete_path(filename);

	return retval;
	}