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

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/*
 * 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 <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

#include "formats-util.h"
#include "fs-util.h"
#include "selinux-util.h"
#include "smack-util.h"
#include "string-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", 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'", 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'", slink, target);
                do {
                        err = mkdir_parents_label(slink, 0755);
                        if (err != 0 && err != -ENOENT)
                                break;
                        mac_selinux_create_file_prepare(slink, S_IFLNK);
                        err = symlink(target, slink);
                        if (err != 0)
                                err = -errno;
                        mac_selinux_create_file_clear();
                } while (err == -ENOENT);
                if (err == 0)
                        goto exit;
        }

        log_debug("atomically replace '%s'", 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;
                mac_selinux_create_file_prepare(slink_tmp, S_IFLNK);
                err = symlink(target, slink_tmp);
                if (err != 0)
                        err = -errno;
                mac_selinux_create_file_clear();
        } while (err == -ENOENT);
        if (err != 0) {
                log_error_errno(errno, "symlink '%s' '%s' failed: %m", target, slink_tmp);
                goto exit;
        }
        err = rename(slink_tmp, slink);
        if (err != 0) {
                log_error_errno(errno, "rename '%s' '%s' failed: %m", 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'", 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'",
                                                  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) {
        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'", slink);
                if (unlink(slink) == 0)
                        rmdir_parents(slink, "/");
        } else {
                log_debug("creating link '%s' to '%s'", 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'",
                     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 = log_debug_errno(errno, "can not stat() node '%s' (%m)", 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",
                          udev_device_get_devnode(dev), udev_device_get_id_filename(dev));
                goto out;
        }

        if (apply) {
                bool selinux = false;
                bool smack = false;

                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", devnode, mode, uid, gid);
                        err = chmod(devnode, mode);
                        if (err < 0)
                                log_warning_errno(errno, "setting mode of %s to %#o failed: %m", devnode, mode);
                        err = chown(devnode, uid, gid);
                        if (err < 0)
                                log_warning_errno(errno, "setting owner of %s to uid=%u, gid=%u failed: %m", devnode, uid, gid);
                } else {
                        log_debug("preserve permissions %s, %#o, uid=%u, gid=%u", devnode, mode, uid, gid);
                }

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

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

                        if (streq(name, "selinux")) {
                                selinux = true;

                                r = mac_selinux_apply(devnode, label);
                                if (r < 0)
                                        log_error_errno(r, "SECLABEL: failed to set SELinux label '%s': %m", label);
                                else
                                        log_debug("SECLABEL: set SELinux label '%s'", label);

                        } else if (streq(name, "smack")) {
                                smack = true;

                                r = mac_smack_apply(devnode, SMACK_ATTR_ACCESS, label);
                                if (r < 0)
                                        log_error_errno(r, "SECLABEL: failed to set SMACK label '%s': %m", label);
                                else
                                        log_debug("SECLABEL: set SMACK label '%s'", label);

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

                /* set the defaults */
                if (!selinux)
                        mac_selinux_fix(devnode, true, false);
                if (!smack)
                        mac_smack_apply(devnode, SMACK_ATTR_ACCESS, NULL);
        }

        /* 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="UID_FMT", gid="GID_FMT,
                  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
3f65d731 ZJS	1	/-- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil --/
3f65d731 ZJS	2
ea733a2f	3	/*
22582bb2	4	* Copyright (C) 2003-2013 Kay Sievers <kay@vrfy.org>
ea733a2f	5	*
55e9959b KS	6	* This program is free software: you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation, either version 2 of the License, or
	9	* (at your option) any later version.
ea733a2f	10	*
55e9959b KS	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
ea733a2f GKH	18	*/
ea733a2f GKH	19
24f0605c	20	#include <dirent.h>
07630cea LP	21	#include <errno.h>
	22	#include <fcntl.h>
	23	#include <stdbool.h>
	24	#include <stddef.h>
	25	#include <stdio.h>
	26	#include <string.h>
32ff5bca	27	#include <sys/stat.h>
07630cea	28	#include <unistd.h>
ea733a2f	29
6482f626	30	#include "formats-util.h"
f4f15635	31	#include "fs-util.h"
07630cea LP	32	#include "selinux-util.h"
	33	#include "smack-util.h"
	34	#include "string-util.h"
	35	#include "udev.h"
9825617b	36
9ec6e95b	37	static int node_symlink(struct udev_device dev, const char node, const char *slink) {
912541b0 KS	38	struct stat stats;
	39	char target[UTIL_PATH_SIZE];
	40	char *s;
	41	size_t l;
38d70045	42	char slink_tmp[UTIL_PATH_SIZE + 32];
912541b0 KS	43	int i = 0;
	44	int tail = 0;
	45	int err = 0;
	46
	47	/* use relative link */
	48	target[0] = '\0';
	49	while (node[i] && (node[i] == slink[i])) {
	50	if (node[i] == '/')
	51	tail = i+1;
	52	i++;
	53	}
	54	s = target;
	55	l = sizeof(target);
	56	while (slink[i] != '\0') {
	57	if (slink[i] == '/')
d5a89d7d	58	l = strpcpy(&s, l, "../");
912541b0 KS	59	i++;
912541b0 KS	60	}
d5a89d7d	61	l = strscpy(s, l, &node[tail]);
912541b0 KS	62	if (l == 0) {
	63	err = -EINVAL;
	64	goto exit;
	65	}
	66
	67	/* preserve link with correct target, do not replace node of other device */
	68	if (lstat(slink, &stats) == 0) {
	69	if (S_ISBLK(stats.st_mode) \|\| S_ISCHR(stats.st_mode)) {
9f6445e3	70	log_error("conflicting device node '%s' found, link to '%s' will not be created", slink, node);
2be7287b	71	goto exit;
912541b0 KS	72	} else if (S_ISLNK(stats.st_mode)) {
	73	char buf[UTIL_PATH_SIZE];
	74	int len;
	75
912541b0 KS	76	len = readlink(slink, buf, sizeof(buf));
	77	if (len > 0 && len < (int)sizeof(buf)) {
	78	buf[len] = '\0';
090be865	79	if (streq(target, buf)) {
9f6445e3	80	log_debug("preserve already existing symlink '%s' to '%s'", slink, target);
c9bc0764	81	label_fix(slink, true, false);
912541b0 KS	82	utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW);
	83	goto exit;
	84	}
	85	}
	86	}
	87	} else {
9f6445e3	88	log_debug("creating symlink '%s' to '%s'", slink, target);
912541b0	89	do {
d2e54fae	90	err = mkdir_parents_label(slink, 0755);
912541b0 KS	91	if (err != 0 && err != -ENOENT)
912541b0 KS	92	break;
ecabcf8b	93	mac_selinux_create_file_prepare(slink, S_IFLNK);
912541b0 KS	94	err = symlink(target, slink);
	95	if (err != 0)
	96	err = -errno;
ecabcf8b	97	mac_selinux_create_file_clear();
912541b0 KS	98	} while (err == -ENOENT);
	99	if (err == 0)
	100	goto exit;
	101	}
	102
9f6445e3	103	log_debug("atomically replace '%s'", slink);
38d70045	104	strscpyl(slink_tmp, sizeof(slink_tmp), slink, ".tmp-", udev_device_get_id_filename(dev), NULL);
912541b0 KS	105	unlink(slink_tmp);
912541b0 KS	106	do {
d2e54fae	107	err = mkdir_parents_label(slink_tmp, 0755);
912541b0 KS	108	if (err != 0 && err != -ENOENT)
912541b0 KS	109	break;
ecabcf8b	110	mac_selinux_create_file_prepare(slink_tmp, S_IFLNK);
912541b0 KS	111	err = symlink(target, slink_tmp);
	112	if (err != 0)
	113	err = -errno;
ecabcf8b	114	mac_selinux_create_file_clear();
912541b0 KS	115	} while (err == -ENOENT);
912541b0 KS	116	if (err != 0) {
56f64d95	117	log_error_errno(errno, "symlink '%s' '%s' failed: %m", target, slink_tmp);
912541b0 KS	118	goto exit;
	119	}
	120	err = rename(slink_tmp, slink);
	121	if (err != 0) {
56f64d95	122	log_error_errno(errno, "rename '%s' '%s' failed: %m", slink_tmp, slink);
912541b0 KS	123	unlink(slink_tmp);
912541b0 KS	124	}
fa33d857	125	exit:
912541b0	126	return err;
fa33d857 KS	127	}
fa33d857 KS	128
6c29f2b9	129	/* find device node of device with highest priority */
9ec6e95b	130	static const char link_find_prioritized(struct udev_device dev, bool add, const char stackdir, char buf, size_t bufsize) {
912541b0 KS	131	struct udev *udev = udev_device_get_udev(dev);
	132	DIR *dir;
	133	int priority = 0;
	134	const char *target = NULL;
	135
	136	if (add) {
	137	priority = udev_device_get_devlink_priority(dev);
d5a89d7d	138	strscpy(buf, bufsize, udev_device_get_devnode(dev));
912541b0 KS	139	target = buf;
	140	}
	141
	142	dir = opendir(stackdir);
	143	if (dir == NULL)
	144	return target;
	145	for (;;) {
	146	struct udev_device *dev_db;
	147	struct dirent *dent;
	148
	149	dent = readdir(dir);
	150	if (dent == NULL \|\| dent->d_name[0] == '\0')
	151	break;
	152	if (dent->d_name[0] == '.')
	153	continue;
	154
9f6445e3	155	log_debug("found '%s' claiming '%s'", dent->d_name, stackdir);
912541b0 KS	156
912541b0 KS	157	/* did we find ourself? */
090be865	158	if (streq(dent->d_name, udev_device_get_id_filename(dev)))
912541b0 KS	159	continue;
912541b0 KS	160
dbf61afb	161	dev_db = udev_device_new_from_device_id(udev, dent->d_name);
912541b0 KS	162	if (dev_db != NULL) {
	163	const char *devnode;
	164
	165	devnode = udev_device_get_devnode(dev_db);
	166	if (devnode != NULL) {
912541b0	167	if (target == NULL \|\| udev_device_get_devlink_priority(dev_db) > priority) {
9f6445e3	168	log_debug("'%s' claims priority %i for '%s'",
baa30fbc	169	udev_device_get_syspath(dev_db), udev_device_get_devlink_priority(dev_db), stackdir);
912541b0	170	priority = udev_device_get_devlink_priority(dev_db);
d5a89d7d	171	strscpy(buf, bufsize, devnode);
912541b0 KS	172	target = buf;
	173	}
	174	}
	175	udev_device_unref(dev_db);
	176	}
	177	}
	178	closedir(dir);
	179	return target;
aa8734ff KS	180	}
aa8734ff KS	181
6c29f2b9	182	/* manage "stack of names" with possibly specified device priorities */
9ec6e95b	183	static void link_update(struct udev_device dev, const char slink, bool add) {
912541b0 KS	184	char name_enc[UTIL_PATH_SIZE];
	185	char filename[UTIL_PATH_SIZE * 2];
	186	char dirname[UTIL_PATH_SIZE];
	187	const char *target;
	188	char buf[UTIL_PATH_SIZE];
	189
4cb72937	190	util_path_encode(slink + strlen("/dev"), name_enc, sizeof(name_enc));
d5a89d7d KS	191	strscpyl(dirname, sizeof(dirname), "/run/udev/links/", name_enc, NULL);
d5a89d7d KS	192	strscpyl(filename, sizeof(filename), dirname, "/", udev_device_get_id_filename(dev), NULL);
912541b0	193
baa30fbc KS	194	if (!add && unlink(filename) == 0)
baa30fbc KS	195	rmdir(dirname);
912541b0 KS	196
	197	target = link_find_prioritized(dev, add, dirname, buf, sizeof(buf));
	198	if (target == NULL) {
9f6445e3	199	log_debug("no reference left, remove '%s'", slink);
912541b0	200	if (unlink(slink) == 0)
37d52274	201	rmdir_parents(slink, "/");
912541b0	202	} else {
9f6445e3	203	log_debug("creating link '%s' to '%s'", slink, target);
38d70045	204	node_symlink(dev, target, slink);
912541b0 KS	205	}
	206
	207	if (add) {
	208	int err;
	209
912541b0 KS	210	do {
	211	int fd;
	212
3cbd5f6b	213	err = mkdir_parents(filename, 0755);
912541b0 KS	214	if (err != 0 && err != -ENOENT)
	215	break;
	216	fd = open(filename, O_WRONLY\|O_CREAT\|O_CLOEXEC\|O_TRUNC\|O_NOFOLLOW, 0444);
	217	if (fd >= 0)
	218	close(fd);
	219	else
	220	err = -errno;
	221	} while (err == -ENOENT);
	222	}
24f0605c KS	223	}
24f0605c KS	224
9ec6e95b	225	void udev_node_update_old_links(struct udev_device dev, struct udev_device dev_old) {
912541b0 KS	226	struct udev_list_entry *list_entry;
	227
	228	/* update possible left-over symlinks */
	229	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev_old)) {
	230	const char *name = udev_list_entry_get_name(list_entry);
	231	struct udev_list_entry *list_entry_current;
	232	int found;
	233
	234	/* check if old link name still belongs to this device */
	235	found = 0;
	236	udev_list_entry_foreach(list_entry_current, udev_device_get_devlinks_list_entry(dev)) {
	237	const char *name_current = udev_list_entry_get_name(list_entry_current);
	238
090be865	239	if (streq(name, name_current)) {
912541b0 KS	240	found = 1;
	241	break;
	242	}
	243	}
	244	if (found)
	245	continue;
	246
9f6445e3	247	log_debug("update old name, '%s' no longer belonging to '%s'",
912541b0	248	name, udev_device_get_devpath(dev));
8a173387	249	link_update(dev, name, false);
912541b0	250	}
24f0605c KS	251	}
24f0605c KS	252
c26547d6 KS	253	static int node_permissions_apply(struct udev_device *dev, bool apply,
	254	mode_t mode, uid_t uid, gid_t gid,
	255	struct udev_list *seclabel_list) {
912541b0 KS	256	const char *devnode = udev_device_get_devnode(dev);
	257	dev_t devnum = udev_device_get_devnum(dev);
	258	struct stat stats;
c26547d6	259	struct udev_list_entry *entry;
912541b0 KS	260	int err = 0;
912541b0 KS	261
090be865	262	if (streq(udev_device_get_subsystem(dev), "block"))
912541b0 KS	263	mode \|= S_IFBLK;
	264	else
	265	mode \|= S_IFCHR;
	266
	267	if (lstat(devnode, &stats) != 0) {
e1427b13	268	err = log_debug_errno(errno, "can not stat() node '%s' (%m)", devnode);
912541b0 KS	269	goto out;
	270	}
	271
	272	if (((stats.st_mode & S_IFMT) != (mode & S_IFMT)) \|\| (stats.st_rdev != devnum)) {
	273	err = -EEXIST;
9f6445e3	274	log_debug("found node '%s' with non-matching devnum %s, skip handling",
baa30fbc	275	udev_device_get_devnode(dev), udev_device_get_id_filename(dev));
912541b0 KS	276	goto out;
	277	}
	278
22582bb2	279	if (apply) {
b7e2b764	280	bool selinux = false;
b7e2b764	281	bool smack = false;
b7e2b764	282
48a849ee	283	if ((stats.st_mode & 0777) != (mode & 0777) \|\| stats.st_uid != uid \|\| stats.st_gid != gid) {
9f6445e3	284	log_debug("set permissions %s, %#o, uid=%u, gid=%u", devnode, mode, uid, gid);
543afdc6 TG	285	err = chmod(devnode, mode);
543afdc6 TG	286	if (err < 0)
56f64d95	287	log_warning_errno(errno, "setting mode of %s to %#o failed: %m", devnode, mode);
543afdc6 TG	288	err = chown(devnode, uid, gid);
543afdc6 TG	289	if (err < 0)
56f64d95	290	log_warning_errno(errno, "setting owner of %s to uid=%u, gid=%u failed: %m", devnode, uid, gid);
48a849ee	291	} else {
9f6445e3	292	log_debug("preserve permissions %s, %#o, uid=%u, gid=%u", devnode, mode, uid, gid);
48a849ee	293	}
c26547d6	294
c26547d6 KS	295	/* apply SECLABEL{$module}=$label */
	296	udev_list_entry_foreach(entry, udev_list_get_entry(seclabel_list)) {
	297	const char name, label;
d53e386d	298	int r;
c26547d6 KS	299
	300	name = udev_list_entry_get_name(entry);
	301	label = udev_list_entry_get_value(entry);
	302
	303	if (streq(name, "selinux")) {
b7e2b764	304	selinux = true;
d53e386d	305
ecabcf8b LP	306	r = mac_selinux_apply(devnode, label);
ecabcf8b LP	307	if (r < 0)
da927ba9	308	log_error_errno(r, "SECLABEL: failed to set SELinux label '%s': %m", label);
463b5dbb KS	309	else
463b5dbb KS	310	log_debug("SECLABEL: set SELinux label '%s'", label);
c26547d6	311
9a4e038c	312	} else if (streq(name, "smack")) {
b7e2b764	313	smack = true;
d53e386d	314
5ab58c20	315	r = mac_smack_apply(devnode, SMACK_ATTR_ACCESS, label);
d53e386d	316	if (r < 0)
da927ba9	317	log_error_errno(r, "SECLABEL: failed to set SMACK label '%s': %m", label);
c26547d6 KS	318	else
c26547d6 KS	319	log_debug("SECLABEL: set SMACK label '%s'", label);
c26547d6 KS	320
	321	} else
	322	log_error("SECLABEL: unknown subsystem, ignoring '%s'='%s'", name, label);
	323	}
b7e2b764 KS	324
	325	/* set the defaults */
	326	if (!selinux)
2ec62d8e	327	mac_selinux_fix(devnode, true, false);
9a4e038c	328	if (!smack)
5ab58c20	329	mac_smack_apply(devnode, SMACK_ATTR_ACCESS, NULL);
48a849ee	330	}
912541b0 KS	331
	332	/* always update timestamp when we re-use the node, like on media change events */
	333	utimensat(AT_FDCWD, devnode, NULL, 0);
220893b3	334	out:
912541b0	335	return err;
220893b3 KS	336	}
220893b3 KS	337
c26547d6 KS	338	void udev_node_add(struct udev_device *dev, bool apply,
	339	mode_t mode, uid_t uid, gid_t gid,
	340	struct udev_list *seclabel_list) {
912541b0 KS	341	char filename[UTIL_PATH_SIZE];
912541b0 KS	342	struct udev_list_entry *list_entry;
912541b0	343
1fa2f38f	344	log_debug("handling device node '%s', devnum=%s, mode=%#o, uid="UID_FMT", gid="GID_FMT,
baa30fbc	345	udev_device_get_devnode(dev), udev_device_get_id_filename(dev), mode, uid, gid);
912541b0	346
c26547d6	347	if (node_permissions_apply(dev, apply, mode, uid, gid, seclabel_list) < 0)
e7f32890	348	return;
912541b0 KS	349
912541b0 KS	350	/* always add /dev/{block,char}/$major:$minor */
4cb72937	351	snprintf(filename, sizeof(filename), "/dev/%s/%u:%u",
090be865	352	streq(udev_device_get_subsystem(dev), "block") ? "block" : "char",
912541b0	353	major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
38d70045	354	node_symlink(dev, udev_device_get_devnode(dev), filename);
912541b0 KS	355
912541b0 KS	356	/* create/update symlinks, add symlinks to name index */
8a173387 KS	357	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
8a173387 KS	358	link_update(dev, udev_list_entry_get_name(list_entry), true);
ea733a2f GKH	359	}
ea733a2f GKH	360
9ec6e95b	361	void udev_node_remove(struct udev_device *dev) {
912541b0	362	struct udev_list_entry *list_entry;
912541b0	363	char filename[UTIL_PATH_SIZE];
912541b0 KS	364
	365	/* remove/update symlinks, remove symlinks from name index */
	366	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
8a173387	367	link_update(dev, udev_list_entry_get_name(list_entry), false);
912541b0 KS	368
912541b0 KS	369	/* remove /dev/{block,char}/$major:$minor */
4cb72937	370	snprintf(filename, sizeof(filename), "/dev/%s/%u:%u",
090be865	371	streq(udev_device_get_subsystem(dev), "block") ? "block" : "char",
912541b0 KS	372	major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
912541b0 KS	373	unlink(filename);
ea733a2f	374	}