[thirdparty/systemd.git] / src / udev / udev-node.c

/*
 * Copyright (C) 2003-2013 Kay Sievers <kay@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 <string.h>
#include <stdio.h>
#include <stddef.h>
#include <stdbool.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <grp.h>
#include <dirent.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/types.h>
#ifdef HAVE_XATTR
#include <attr/xattr.h>
#endif

#include "smack-util.h"
#include "udev.h"

static int node_symlink(struct udev_device *dev, const char *node, const char *slink)
{
        struct stat stats;
        char target[UTIL_PATH_SIZE];
        char *s;
        size_t l;
        char slink_tmp[UTIL_PATH_SIZE + 32];
        int i = 0;
        int tail = 0;
        int err = 0;

        /* use relative link */
        target[0] = '\0';
        while (node[i] && (node[i] == slink[i])) {
                if (node[i] == '/')
                        tail = i+1;
                i++;
        }
        s = target;
        l = sizeof(target);
        while (slink[i] != '\0') {
                if (slink[i] == '/')
                        l = strpcpy(&s, l, "../");
                i++;
        }
        l = strscpy(s, l, &node[tail]);
        if (l == 0) {
                err = -EINVAL;
                goto exit;
        }

        /* preserve link with correct target, do not replace node of other device */
        if (lstat(slink, &stats) == 0) {
                if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
                        log_error("conflicting device node '%s' found, link to '%s' will not be created\n", slink, node);
                        goto exit;
                } else if (S_ISLNK(stats.st_mode)) {
                        char buf[UTIL_PATH_SIZE];
                        int len;

                        len = readlink(slink, buf, sizeof(buf));
                        if (len > 0 && len < (int)sizeof(buf)) {
                                buf[len] = '\0';
                                if (streq(target, buf)) {
                                        log_debug("preserve already existing symlink '%s' to '%s'\n", slink, target);
                                        label_fix(slink, true, false);
                                        utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW);
                                        goto exit;
                                }
                        }
                }
        } else {
                log_debug("creating symlink '%s' to '%s'\n", slink, target);
                do {
                        err = mkdir_parents_label(slink, 0755);
                        if (err != 0 && err != -ENOENT)
                                break;
                        label_context_set(slink, S_IFLNK);
                        err = symlink(target, slink);
                        if (err != 0)
                                err = -errno;
                        label_context_clear();
                } while (err == -ENOENT);
                if (err == 0)
                        goto exit;
        }

        log_debug("atomically replace '%s'\n", slink);
        strscpyl(slink_tmp, sizeof(slink_tmp), slink, ".tmp-", udev_device_get_id_filename(dev), NULL);
        unlink(slink_tmp);
        do {
                err = mkdir_parents_label(slink_tmp, 0755);
                if (err != 0 && err != -ENOENT)
                        break;
                label_context_set(slink_tmp, S_IFLNK);
                err = symlink(target, slink_tmp);
                if (err != 0)
                        err = -errno;
                label_context_clear();
        } while (err == -ENOENT);
        if (err != 0) {
                log_error("symlink '%s' '%s' failed: %m\n", target, slink_tmp);
                goto exit;
        }
        err = rename(slink_tmp, slink);
        if (err != 0) {
                log_error("rename '%s' '%s' failed: %m\n", slink_tmp, slink);
                unlink(slink_tmp);
        }
exit:
        return err;
}

/* find device node of device with highest priority */
static const char *link_find_prioritized(struct udev_device *dev, bool add, const char *stackdir, char *buf, size_t bufsize)
{
        struct udev *udev = udev_device_get_udev(dev);
        DIR *dir;
        int priority = 0;
        const char *target = NULL;

        if (add) {
                priority = udev_device_get_devlink_priority(dev);
                strscpy(buf, bufsize, udev_device_get_devnode(dev));
                target = buf;
        }

        dir = opendir(stackdir);
        if (dir == NULL)
                return target;
        for (;;) {
                struct udev_device *dev_db;
                struct dirent *dent;

                dent = readdir(dir);
                if (dent == NULL || dent->d_name[0] == '\0')
                        break;
                if (dent->d_name[0] == '.')
                        continue;

                log_debug("found '%s' claiming '%s'\n", dent->d_name, stackdir);

                /* did we find ourself? */
                if (streq(dent->d_name, udev_device_get_id_filename(dev)))
                        continue;

                dev_db = udev_device_new_from_device_id(udev, dent->d_name);
                if (dev_db != NULL) {
                        const char *devnode;

                        devnode = udev_device_get_devnode(dev_db);
                        if (devnode != NULL) {
                                if (target == NULL || udev_device_get_devlink_priority(dev_db) > priority) {
                                        log_debug("'%s' claims priority %i for '%s'\n",
                                                  udev_device_get_syspath(dev_db), udev_device_get_devlink_priority(dev_db), stackdir);
                                        priority = udev_device_get_devlink_priority(dev_db);
                                        strscpy(buf, bufsize, devnode);
                                        target = buf;
                                }
                        }
                        udev_device_unref(dev_db);
                }
        }
        closedir(dir);
        return target;
}

/* manage "stack of names" with possibly specified device priorities */
static void link_update(struct udev_device *dev, const char *slink, bool add)
{
        struct udev *udev = udev_device_get_udev(dev);
        char name_enc[UTIL_PATH_SIZE];
        char filename[UTIL_PATH_SIZE * 2];
        char dirname[UTIL_PATH_SIZE];
        const char *target;
        char buf[UTIL_PATH_SIZE];

        util_path_encode(slink + strlen("/dev"), name_enc, sizeof(name_enc));
        strscpyl(dirname, sizeof(dirname), "/run/udev/links/", name_enc, NULL);
        strscpyl(filename, sizeof(filename), dirname, "/", udev_device_get_id_filename(dev), NULL);

        if (!add && unlink(filename) == 0)
                rmdir(dirname);

        target = link_find_prioritized(dev, add, dirname, buf, sizeof(buf));
        if (target == NULL) {
                log_debug("no reference left, remove '%s'\n", slink);
                if (unlink(slink) == 0)
                        util_delete_path(udev, slink);
        } else {
                log_debug("creating link '%s' to '%s'\n", slink, target);
                node_symlink(dev, target, slink);
        }

        if (add) {
                int err;

                do {
                        int fd;

                        err = mkdir_parents(filename, 0755);
                        if (err != 0 && err != -ENOENT)
                                break;
                        fd = open(filename, O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444);
                        if (fd >= 0)
                                close(fd);
                        else
                                err = -errno;
                } while (err == -ENOENT);
        }
}

void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev_old)
{
        struct udev_list_entry *list_entry;

        /* update possible left-over symlinks */
        udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev_old)) {
                const char *name = udev_list_entry_get_name(list_entry);
                struct udev_list_entry *list_entry_current;
                int found;

                /* check if old link name still belongs to this device */
                found = 0;
                udev_list_entry_foreach(list_entry_current, udev_device_get_devlinks_list_entry(dev)) {
                        const char *name_current = udev_list_entry_get_name(list_entry_current);

                        if (streq(name, name_current)) {
                                found = 1;
                                break;
                        }
                }
                if (found)
                        continue;

                log_debug("update old name, '%s' no longer belonging to '%s'\n",
                     name, udev_device_get_devpath(dev));
                link_update(dev, name, false);
        }
}

static int node_permissions_apply(struct udev_device *dev, bool apply,
                                  mode_t mode, uid_t uid, gid_t gid,
                                  struct udev_list *seclabel_list) {
        const char *devnode = udev_device_get_devnode(dev);
        dev_t devnum = udev_device_get_devnum(dev);
        struct stat stats;
        struct udev_list_entry *entry;
        int err = 0;

        if (streq(udev_device_get_subsystem(dev), "block"))
                mode |= S_IFBLK;
        else
                mode |= S_IFCHR;

        if (lstat(devnode, &stats) != 0) {
                err = -errno;
                log_debug("can not stat() node '%s' (%m)\n", devnode);
                goto out;
        }

        if (((stats.st_mode & S_IFMT) != (mode & S_IFMT)) || (stats.st_rdev != devnum)) {
                err = -EEXIST;
                log_debug("found node '%s' with non-matching devnum %s, skip handling\n",
                          udev_device_get_devnode(dev), udev_device_get_id_filename(dev));
                goto out;
        }

        if (apply) {
                bool selinux = false;
#ifdef HAVE_SMACK
                bool smack = false;
#endif

                if ((stats.st_mode & 0777) != (mode & 0777) || stats.st_uid != uid || stats.st_gid != gid) {
                        log_debug("set permissions %s, %#o, uid=%u, gid=%u\n", devnode, mode, uid, gid);
                        chmod(devnode, mode);
                        chown(devnode, uid, gid);
                } else {
                        log_debug("preserve permissions %s, %#o, uid=%u, gid=%u\n", devnode, mode, uid, gid);
                }

                /* apply SECLABEL{$module}=$label */
                udev_list_entry_foreach(entry, udev_list_get_entry(seclabel_list)) {
                        const char *name, *label;

                        name = udev_list_entry_get_name(entry);
                        label = udev_list_entry_get_value(entry);

                        if (streq(name, "selinux")) {
                                selinux = true;
                                if (label_apply(devnode, label) < 0)
                                        log_error("SECLABEL: failed to set SELinux label '%s'", label);
                                else
                                        log_debug("SECLABEL: set SELinux label '%s'", label);

#ifdef HAVE_SMACK
                        } else if (streq(name, "smack") && use_smack()) {
                                smack = true;
                                if (lsetxattr(devnode, "security.SMACK64", label, strlen(label), 0) < 0)
                                        log_error("SECLABEL: failed to set SMACK label '%s'", label);
                                else
                                        log_debug("SECLABEL: set SMACK label '%s'", label);
#endif

                        } else
                                log_error("SECLABEL: unknown subsystem, ignoring '%s'='%s'", name, label);
                }

                /* set the defaults */
                if (!selinux)
                        label_fix(devnode, true, false);
#ifdef HAVE_SMACK
                if (!smack && use_smack())
                        lremovexattr(devnode, "security.SMACK64");
#endif
        }

        /* always update timestamp when we re-use the node, like on media change events */
        utimensat(AT_FDCWD, devnode, NULL, 0);
out:
        return err;
}

void udev_node_add(struct udev_device *dev, bool apply,
                   mode_t mode, uid_t uid, gid_t gid,
                   struct udev_list *seclabel_list) {
        char filename[UTIL_PATH_SIZE];
        struct udev_list_entry *list_entry;

        log_debug("handling device node '%s', devnum=%s, mode=%#o, uid=%d, gid=%d\n",
                  udev_device_get_devnode(dev), udev_device_get_id_filename(dev), mode, uid, gid);

        if (node_permissions_apply(dev, apply, mode, uid, gid, seclabel_list) < 0)
                return;

        /* always add /dev/{block,char}/$major:$minor */
        snprintf(filename, sizeof(filename), "/dev/%s/%u:%u",
                 streq(udev_device_get_subsystem(dev), "block") ? "block" : "char",
                 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
        node_symlink(dev, udev_device_get_devnode(dev), filename);

        /* create/update symlinks, add symlinks to name index */
        udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
                        link_update(dev, udev_list_entry_get_name(list_entry), true);
}

void udev_node_remove(struct udev_device *dev)
{
        struct udev_list_entry *list_entry;
        char filename[UTIL_PATH_SIZE];

        /* remove/update symlinks, remove symlinks from name index */
        udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
                link_update(dev, udev_list_entry_get_name(list_entry), false);

        /* remove /dev/{block,char}/$major:$minor */
        snprintf(filename, sizeof(filename), "/dev/%s/%u:%u",
                 streq(udev_device_get_subsystem(dev), "block") ? "block" : "char",
                 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
        unlink(filename);
}
Commit	Line	Data
ea733a2f	1	/*
22582bb2	2	* Copyright (C) 2003-2013 Kay Sievers <kay@vrfy.org>
ea733a2f	3	*
55e9959b KS	4	* This program is free software: you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation, either version 2 of the License, or
	7	* (at your option) any later version.
ea733a2f	8	*
55e9959b KS	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program. If not, see <http://www.gnu.org/licenses/>.
ea733a2f GKH	16	*/
	17
	18	#include <stdlib.h>
	19	#include <string.h>
	20	#include <stdio.h>
1aa1e248	21	#include <stddef.h>
6c29f2b9	22	#include <stdbool.h>
ea733a2f GKH	23	#include <fcntl.h>
	24	#include <unistd.h>
	25	#include <errno.h>
67f69ae1	26	#include <grp.h>
24f0605c	27	#include <dirent.h>
56073914	28	#include <sys/time.h>
32ff5bca	29	#include <sys/stat.h>
10950dfe	30	#include <sys/types.h>
c26547d6 KS	31	#ifdef HAVE_XATTR
	32	#include <attr/xattr.h>
	33	#endif
ea733a2f	34
d682b3a7	35	#include "smack-util.h"
ea733a2f	36	#include "udev.h"
9825617b	37
38d70045	38	static int node_symlink(struct udev_device dev, const char node, const char *slink)
fa33d857	39	{
912541b0 KS	40	struct stat stats;
	41	char target[UTIL_PATH_SIZE];
	42	char *s;
	43	size_t l;
38d70045	44	char slink_tmp[UTIL_PATH_SIZE + 32];
912541b0 KS	45	int i = 0;
	46	int tail = 0;
	47	int err = 0;
	48
	49	/* use relative link */
	50	target[0] = '\0';
	51	while (node[i] && (node[i] == slink[i])) {
	52	if (node[i] == '/')
	53	tail = i+1;
	54	i++;
	55	}
	56	s = target;
	57	l = sizeof(target);
	58	while (slink[i] != '\0') {
	59	if (slink[i] == '/')
d5a89d7d	60	l = strpcpy(&s, l, "../");
912541b0 KS	61	i++;
912541b0 KS	62	}
d5a89d7d	63	l = strscpy(s, l, &node[tail]);
912541b0 KS	64	if (l == 0) {
	65	err = -EINVAL;
	66	goto exit;
	67	}
	68
	69	/* preserve link with correct target, do not replace node of other device */
	70	if (lstat(slink, &stats) == 0) {
	71	if (S_ISBLK(stats.st_mode) \|\| S_ISCHR(stats.st_mode)) {
2be7287b KS	72	log_error("conflicting device node '%s' found, link to '%s' will not be created\n", slink, node);
2be7287b KS	73	goto exit;
912541b0 KS	74	} else if (S_ISLNK(stats.st_mode)) {
	75	char buf[UTIL_PATH_SIZE];
	76	int len;
	77
912541b0 KS	78	len = readlink(slink, buf, sizeof(buf));
	79	if (len > 0 && len < (int)sizeof(buf)) {
	80	buf[len] = '\0';
090be865	81	if (streq(target, buf)) {
baa30fbc	82	log_debug("preserve already existing symlink '%s' to '%s'\n", slink, target);
c9bc0764	83	label_fix(slink, true, false);
912541b0 KS	84	utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW);
	85	goto exit;
	86	}
	87	}
	88	}
	89	} else {
baa30fbc	90	log_debug("creating symlink '%s' to '%s'\n", slink, target);
912541b0	91	do {
d2e54fae	92	err = mkdir_parents_label(slink, 0755);
912541b0 KS	93	if (err != 0 && err != -ENOENT)
912541b0 KS	94	break;
e9a5ef7c	95	label_context_set(slink, S_IFLNK);
912541b0 KS	96	err = symlink(target, slink);
	97	if (err != 0)
	98	err = -errno;
e9a5ef7c	99	label_context_clear();
912541b0 KS	100	} while (err == -ENOENT);
	101	if (err == 0)
	102	goto exit;
	103	}
	104
baa30fbc	105	log_debug("atomically replace '%s'\n", slink);
38d70045	106	strscpyl(slink_tmp, sizeof(slink_tmp), slink, ".tmp-", udev_device_get_id_filename(dev), NULL);
912541b0 KS	107	unlink(slink_tmp);
912541b0 KS	108	do {
d2e54fae	109	err = mkdir_parents_label(slink_tmp, 0755);
912541b0 KS	110	if (err != 0 && err != -ENOENT)
912541b0 KS	111	break;
e9a5ef7c	112	label_context_set(slink_tmp, S_IFLNK);
912541b0 KS	113	err = symlink(target, slink_tmp);
	114	if (err != 0)
	115	err = -errno;
e9a5ef7c	116	label_context_clear();
912541b0 KS	117	} while (err == -ENOENT);
912541b0 KS	118	if (err != 0) {
baa30fbc	119	log_error("symlink '%s' '%s' failed: %m\n", target, slink_tmp);
912541b0 KS	120	goto exit;
	121	}
	122	err = rename(slink_tmp, slink);
	123	if (err != 0) {
baa30fbc	124	log_error("rename '%s' '%s' failed: %m\n", slink_tmp, slink);
912541b0 KS	125	unlink(slink_tmp);
912541b0 KS	126	}
fa33d857	127	exit:
912541b0	128	return err;
fa33d857 KS	129	}
fa33d857 KS	130
6c29f2b9 KS	131	/* find device node of device with highest priority */
6c29f2b9 KS	132	static const char link_find_prioritized(struct udev_device dev, bool add, const char stackdir, char buf, size_t bufsize)
24f0605c	133	{
912541b0 KS	134	struct udev *udev = udev_device_get_udev(dev);
	135	DIR *dir;
	136	int priority = 0;
	137	const char *target = NULL;
	138
	139	if (add) {
	140	priority = udev_device_get_devlink_priority(dev);
d5a89d7d	141	strscpy(buf, bufsize, udev_device_get_devnode(dev));
912541b0 KS	142	target = buf;
	143	}
	144
	145	dir = opendir(stackdir);
	146	if (dir == NULL)
	147	return target;
	148	for (;;) {
	149	struct udev_device *dev_db;
	150	struct dirent *dent;
	151
	152	dent = readdir(dir);
	153	if (dent == NULL \|\| dent->d_name[0] == '\0')
	154	break;
	155	if (dent->d_name[0] == '.')
	156	continue;
	157
baa30fbc	158	log_debug("found '%s' claiming '%s'\n", dent->d_name, stackdir);
912541b0 KS	159
912541b0 KS	160	/* did we find ourself? */
090be865	161	if (streq(dent->d_name, udev_device_get_id_filename(dev)))
912541b0 KS	162	continue;
912541b0 KS	163
dbf61afb	164	dev_db = udev_device_new_from_device_id(udev, dent->d_name);
912541b0 KS	165	if (dev_db != NULL) {
	166	const char *devnode;
	167
	168	devnode = udev_device_get_devnode(dev_db);
	169	if (devnode != NULL) {
912541b0	170	if (target == NULL \|\| udev_device_get_devlink_priority(dev_db) > priority) {
baa30fbc KS	171	log_debug("'%s' claims priority %i for '%s'\n",
baa30fbc KS	172	udev_device_get_syspath(dev_db), udev_device_get_devlink_priority(dev_db), stackdir);
912541b0	173	priority = udev_device_get_devlink_priority(dev_db);
d5a89d7d	174	strscpy(buf, bufsize, devnode);
912541b0 KS	175	target = buf;
	176	}
	177	}
	178	udev_device_unref(dev_db);
	179	}
	180	}
	181	closedir(dir);
	182	return target;
aa8734ff KS	183	}
aa8734ff KS	184
6c29f2b9 KS	185	/* manage "stack of names" with possibly specified device priorities */
6c29f2b9 KS	186	static void link_update(struct udev_device dev, const char slink, bool add)
aa8734ff	187	{
912541b0 KS	188	struct udev *udev = udev_device_get_udev(dev);
	189	char name_enc[UTIL_PATH_SIZE];
	190	char filename[UTIL_PATH_SIZE * 2];
	191	char dirname[UTIL_PATH_SIZE];
	192	const char *target;
	193	char buf[UTIL_PATH_SIZE];
	194
4cb72937	195	util_path_encode(slink + strlen("/dev"), name_enc, sizeof(name_enc));
d5a89d7d KS	196	strscpyl(dirname, sizeof(dirname), "/run/udev/links/", name_enc, NULL);
d5a89d7d KS	197	strscpyl(filename, sizeof(filename), dirname, "/", udev_device_get_id_filename(dev), NULL);
912541b0	198
baa30fbc KS	199	if (!add && unlink(filename) == 0)
baa30fbc KS	200	rmdir(dirname);
912541b0 KS	201
	202	target = link_find_prioritized(dev, add, dirname, buf, sizeof(buf));
	203	if (target == NULL) {
baa30fbc	204	log_debug("no reference left, remove '%s'\n", slink);
912541b0 KS	205	if (unlink(slink) == 0)
	206	util_delete_path(udev, slink);
	207	} else {
baa30fbc	208	log_debug("creating link '%s' to '%s'\n", slink, target);
38d70045	209	node_symlink(dev, target, slink);
912541b0 KS	210	}
	211
	212	if (add) {
	213	int err;
	214
912541b0 KS	215	do {
	216	int fd;
	217
3cbd5f6b	218	err = mkdir_parents(filename, 0755);
912541b0 KS	219	if (err != 0 && err != -ENOENT)
	220	break;
	221	fd = open(filename, O_WRONLY\|O_CREAT\|O_CLOEXEC\|O_TRUNC\|O_NOFOLLOW, 0444);
	222	if (fd >= 0)
	223	close(fd);
	224	else
	225	err = -errno;
	226	} while (err == -ENOENT);
	227	}
24f0605c KS	228	}
24f0605c KS	229
ec2dd02e	230	void udev_node_update_old_links(struct udev_device dev, struct udev_device dev_old)
24f0605c	231	{
912541b0 KS	232	struct udev_list_entry *list_entry;
	233
	234	/* update possible left-over symlinks */
	235	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev_old)) {
	236	const char *name = udev_list_entry_get_name(list_entry);
	237	struct udev_list_entry *list_entry_current;
	238	int found;
	239
	240	/* check if old link name still belongs to this device */
	241	found = 0;
	242	udev_list_entry_foreach(list_entry_current, udev_device_get_devlinks_list_entry(dev)) {
	243	const char *name_current = udev_list_entry_get_name(list_entry_current);
	244
090be865	245	if (streq(name, name_current)) {
912541b0 KS	246	found = 1;
	247	break;
	248	}
	249	}
	250	if (found)
	251	continue;
	252
baa30fbc	253	log_debug("update old name, '%s' no longer belonging to '%s'\n",
912541b0	254	name, udev_device_get_devpath(dev));
8a173387	255	link_update(dev, name, false);
912541b0	256	}
24f0605c KS	257	}
24f0605c KS	258
c26547d6 KS	259	static int node_permissions_apply(struct udev_device *dev, bool apply,
	260	mode_t mode, uid_t uid, gid_t gid,
	261	struct udev_list *seclabel_list) {
912541b0 KS	262	const char *devnode = udev_device_get_devnode(dev);
	263	dev_t devnum = udev_device_get_devnum(dev);
	264	struct stat stats;
c26547d6	265	struct udev_list_entry *entry;
912541b0 KS	266	int err = 0;
912541b0 KS	267
090be865	268	if (streq(udev_device_get_subsystem(dev), "block"))
912541b0 KS	269	mode \|= S_IFBLK;
	270	else
	271	mode \|= S_IFCHR;
	272
	273	if (lstat(devnode, &stats) != 0) {
	274	err = -errno;
baa30fbc	275	log_debug("can not stat() node '%s' (%m)\n", devnode);
912541b0 KS	276	goto out;
	277	}
	278
	279	if (((stats.st_mode & S_IFMT) != (mode & S_IFMT)) \|\| (stats.st_rdev != devnum)) {
	280	err = -EEXIST;
baa30fbc KS	281	log_debug("found node '%s' with non-matching devnum %s, skip handling\n",
baa30fbc KS	282	udev_device_get_devnode(dev), udev_device_get_id_filename(dev));
912541b0 KS	283	goto out;
	284	}
	285
22582bb2	286	if (apply) {
b7e2b764 KS	287	bool selinux = false;
	288	#ifdef HAVE_SMACK
	289	bool smack = false;
	290	#endif
	291
48a849ee KS	292	if ((stats.st_mode & 0777) != (mode & 0777) \|\| stats.st_uid != uid \|\| stats.st_gid != gid) {
	293	log_debug("set permissions %s, %#o, uid=%u, gid=%u\n", devnode, mode, uid, gid);
	294	chmod(devnode, mode);
	295	chown(devnode, uid, gid);
	296	} else {
	297	log_debug("preserve permissions %s, %#o, uid=%u, gid=%u\n", devnode, mode, uid, gid);
	298	}
c26547d6	299
c26547d6 KS	300	/* apply SECLABEL{$module}=$label */
	301	udev_list_entry_foreach(entry, udev_list_get_entry(seclabel_list)) {
	302	const char name, label;
	303
	304	name = udev_list_entry_get_name(entry);
	305	label = udev_list_entry_get_value(entry);
	306
	307	if (streq(name, "selinux")) {
b7e2b764	308	selinux = true;
463b5dbb KS	309	if (label_apply(devnode, label) < 0)
	310	log_error("SECLABEL: failed to set SELinux label '%s'", label);
	311	else
	312	log_debug("SECLABEL: set SELinux label '%s'", label);
c26547d6	313
b7e2b764	314	#ifdef HAVE_SMACK
d682b3a7	315	} else if (streq(name, "smack") && use_smack()) {
b7e2b764	316	smack = true;
c26547d6 KS	317	if (lsetxattr(devnode, "security.SMACK64", label, strlen(label), 0) < 0)
	318	log_error("SECLABEL: failed to set SMACK label '%s'", label);
	319	else
	320	log_debug("SECLABEL: set SMACK label '%s'", label);
	321	#endif
	322
	323	} else
	324	log_error("SECLABEL: unknown subsystem, ignoring '%s'='%s'", name, label);
	325	}
b7e2b764 KS	326
	327	/* set the defaults */
	328	if (!selinux)
	329	label_fix(devnode, true, false);
	330	#ifdef HAVE_SMACK
d682b3a7	331	if (!smack && use_smack())
b7e2b764 KS	332	lremovexattr(devnode, "security.SMACK64");
b7e2b764 KS	333	#endif
48a849ee	334	}
912541b0 KS	335
	336	/* always update timestamp when we re-use the node, like on media change events */
	337	utimensat(AT_FDCWD, devnode, NULL, 0);
220893b3	338	out:
912541b0	339	return err;
220893b3 KS	340	}
220893b3 KS	341
c26547d6 KS	342	void udev_node_add(struct udev_device *dev, bool apply,
	343	mode_t mode, uid_t uid, gid_t gid,
	344	struct udev_list *seclabel_list) {
912541b0 KS	345	char filename[UTIL_PATH_SIZE];
912541b0 KS	346	struct udev_list_entry *list_entry;
912541b0	347
baa30fbc KS	348	log_debug("handling device node '%s', devnum=%s, mode=%#o, uid=%d, gid=%d\n",
baa30fbc KS	349	udev_device_get_devnode(dev), udev_device_get_id_filename(dev), mode, uid, gid);
912541b0	350
c26547d6	351	if (node_permissions_apply(dev, apply, mode, uid, gid, seclabel_list) < 0)
e7f32890	352	return;
912541b0 KS	353
912541b0 KS	354	/* always add /dev/{block,char}/$major:$minor */
4cb72937	355	snprintf(filename, sizeof(filename), "/dev/%s/%u:%u",
090be865	356	streq(udev_device_get_subsystem(dev), "block") ? "block" : "char",
912541b0	357	major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
38d70045	358	node_symlink(dev, udev_device_get_devnode(dev), filename);
912541b0 KS	359
912541b0 KS	360	/* create/update symlinks, add symlinks to name index */
8a173387 KS	361	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
8a173387 KS	362	link_update(dev, udev_list_entry_get_name(list_entry), true);
ea733a2f GKH	363	}
ea733a2f GKH	364
e7f32890	365	void udev_node_remove(struct udev_device *dev)
ff9a488d	366	{
912541b0	367	struct udev_list_entry *list_entry;
912541b0	368	char filename[UTIL_PATH_SIZE];
912541b0 KS	369
	370	/* remove/update symlinks, remove symlinks from name index */
	371	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
8a173387	372	link_update(dev, udev_list_entry_get_name(list_entry), false);
912541b0 KS	373
912541b0 KS	374	/* remove /dev/{block,char}/$major:$minor */
4cb72937	375	snprintf(filename, sizeof(filename), "/dev/%s/%u:%u",
090be865	376	streq(udev_device_get_subsystem(dev), "block") ? "block" : "char",
912541b0 KS	377	major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
912541b0 KS	378	unlink(filename);
ea733a2f	379	}