[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 <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 "dirent-util.h"
#include "format-util.h"
#include "fs-util.h"
#include "selinux-util.h"
#include "smack-util.h"
#include "stdio-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;
        struct dirent *dent;
        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;
        FOREACH_DIRENT_ALL(dent, dir, break) {
                struct udev_device *dev_db;

                if (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[sizeof("/dev/block/:") + 2*DECIMAL_STR_MAX(unsigned)];
        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 */
        xsprintf(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[sizeof("/dev/block/:") + 2*DECIMAL_STR_MAX(unsigned)];

        /* 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 */
        xsprintf(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	*/
ea733a2f GKH	17
07630cea LP	18	#include <errno.h>
	19	#include <fcntl.h>
	20	#include <stdbool.h>
	21	#include <stddef.h>
	22	#include <stdio.h>
	23	#include <string.h>
32ff5bca	24	#include <sys/stat.h>
07630cea	25	#include <unistd.h>
ea733a2f	26
8fb3f009	27	#include "dirent-util.h"
f97b34a6	28	#include "format-util.h"
f4f15635	29	#include "fs-util.h"
07630cea LP	30	#include "selinux-util.h"
07630cea LP	31	#include "smack-util.h"
d054f0a4	32	#include "stdio-util.h"
07630cea LP	33	#include "string-util.h"
07630cea LP	34	#include "udev.h"
9825617b	35
9ec6e95b	36	static int node_symlink(struct udev_device dev, const char node, const char *slink) {
912541b0 KS	37	struct stat stats;
	38	char target[UTIL_PATH_SIZE];
	39	char *s;
	40	size_t l;
38d70045	41	char slink_tmp[UTIL_PATH_SIZE + 32];
912541b0 KS	42	int i = 0;
	43	int tail = 0;
	44	int err = 0;
	45
	46	/* use relative link */
	47	target[0] = '\0';
	48	while (node[i] && (node[i] == slink[i])) {
	49	if (node[i] == '/')
	50	tail = i+1;
	51	i++;
	52	}
	53	s = target;
	54	l = sizeof(target);
	55	while (slink[i] != '\0') {
	56	if (slink[i] == '/')
d5a89d7d	57	l = strpcpy(&s, l, "../");
912541b0 KS	58	i++;
912541b0 KS	59	}
d5a89d7d	60	l = strscpy(s, l, &node[tail]);
912541b0 KS	61	if (l == 0) {
	62	err = -EINVAL;
	63	goto exit;
	64	}
	65
	66	/* preserve link with correct target, do not replace node of other device */
	67	if (lstat(slink, &stats) == 0) {
	68	if (S_ISBLK(stats.st_mode) \|\| S_ISCHR(stats.st_mode)) {
9f6445e3	69	log_error("conflicting device node '%s' found, link to '%s' will not be created", slink, node);
2be7287b	70	goto exit;
912541b0 KS	71	} else if (S_ISLNK(stats.st_mode)) {
	72	char buf[UTIL_PATH_SIZE];
	73	int len;
	74
912541b0 KS	75	len = readlink(slink, buf, sizeof(buf));
	76	if (len > 0 && len < (int)sizeof(buf)) {
	77	buf[len] = '\0';
090be865	78	if (streq(target, buf)) {
9f6445e3	79	log_debug("preserve already existing symlink '%s' to '%s'", slink, target);
c9bc0764	80	label_fix(slink, true, false);
912541b0 KS	81	utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW);
	82	goto exit;
	83	}
	84	}
	85	}
	86	} else {
9f6445e3	87	log_debug("creating symlink '%s' to '%s'", slink, target);
912541b0	88	do {
d2e54fae	89	err = mkdir_parents_label(slink, 0755);
912541b0 KS	90	if (err != 0 && err != -ENOENT)
912541b0 KS	91	break;
ecabcf8b	92	mac_selinux_create_file_prepare(slink, S_IFLNK);
912541b0 KS	93	err = symlink(target, slink);
	94	if (err != 0)
	95	err = -errno;
ecabcf8b	96	mac_selinux_create_file_clear();
912541b0 KS	97	} while (err == -ENOENT);
	98	if (err == 0)
	99	goto exit;
	100	}
	101
9f6445e3	102	log_debug("atomically replace '%s'", slink);
38d70045	103	strscpyl(slink_tmp, sizeof(slink_tmp), slink, ".tmp-", udev_device_get_id_filename(dev), NULL);
912541b0 KS	104	unlink(slink_tmp);
912541b0 KS	105	do {
d2e54fae	106	err = mkdir_parents_label(slink_tmp, 0755);
912541b0 KS	107	if (err != 0 && err != -ENOENT)
912541b0 KS	108	break;
ecabcf8b	109	mac_selinux_create_file_prepare(slink_tmp, S_IFLNK);
912541b0 KS	110	err = symlink(target, slink_tmp);
	111	if (err != 0)
	112	err = -errno;
ecabcf8b	113	mac_selinux_create_file_clear();
912541b0 KS	114	} while (err == -ENOENT);
912541b0 KS	115	if (err != 0) {
56f64d95	116	log_error_errno(errno, "symlink '%s' '%s' failed: %m", target, slink_tmp);
912541b0 KS	117	goto exit;
	118	}
	119	err = rename(slink_tmp, slink);
	120	if (err != 0) {
56f64d95	121	log_error_errno(errno, "rename '%s' '%s' failed: %m", slink_tmp, slink);
912541b0 KS	122	unlink(slink_tmp);
912541b0 KS	123	}
fa33d857	124	exit:
912541b0	125	return err;
fa33d857 KS	126	}
fa33d857 KS	127
6c29f2b9	128	/* find device node of device with highest priority */
9ec6e95b	129	static const char link_find_prioritized(struct udev_device dev, bool add, const char stackdir, char buf, size_t bufsize) {
912541b0 KS	130	struct udev *udev = udev_device_get_udev(dev);
912541b0 KS	131	DIR *dir;
8fb3f009	132	struct dirent *dent;
912541b0 KS	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;
8fb3f009	145	FOREACH_DIRENT_ALL(dent, dir, break) {
912541b0	146	struct udev_device *dev_db;
912541b0	147
8fb3f009	148	if (dent->d_name[0] == '\0')
912541b0 KS	149	break;
	150	if (dent->d_name[0] == '.')
	151	continue;
	152
9f6445e3	153	log_debug("found '%s' claiming '%s'", dent->d_name, stackdir);
912541b0 KS	154
912541b0 KS	155	/* did we find ourself? */
090be865	156	if (streq(dent->d_name, udev_device_get_id_filename(dev)))
912541b0 KS	157	continue;
912541b0 KS	158
dbf61afb	159	dev_db = udev_device_new_from_device_id(udev, dent->d_name);
912541b0 KS	160	if (dev_db != NULL) {
	161	const char *devnode;
	162
	163	devnode = udev_device_get_devnode(dev_db);
	164	if (devnode != NULL) {
912541b0	165	if (target == NULL \|\| udev_device_get_devlink_priority(dev_db) > priority) {
9f6445e3	166	log_debug("'%s' claims priority %i for '%s'",
baa30fbc	167	udev_device_get_syspath(dev_db), udev_device_get_devlink_priority(dev_db), stackdir);
912541b0	168	priority = udev_device_get_devlink_priority(dev_db);
d5a89d7d	169	strscpy(buf, bufsize, devnode);
912541b0 KS	170	target = buf;
	171	}
	172	}
	173	udev_device_unref(dev_db);
	174	}
	175	}
	176	closedir(dir);
	177	return target;
aa8734ff KS	178	}
aa8734ff KS	179
6c29f2b9	180	/* manage "stack of names" with possibly specified device priorities */
9ec6e95b	181	static void link_update(struct udev_device dev, const char slink, bool add) {
912541b0 KS	182	char name_enc[UTIL_PATH_SIZE];
	183	char filename[UTIL_PATH_SIZE * 2];
	184	char dirname[UTIL_PATH_SIZE];
	185	const char *target;
	186	char buf[UTIL_PATH_SIZE];
	187
4cb72937	188	util_path_encode(slink + strlen("/dev"), name_enc, sizeof(name_enc));
d5a89d7d KS	189	strscpyl(dirname, sizeof(dirname), "/run/udev/links/", name_enc, NULL);
d5a89d7d KS	190	strscpyl(filename, sizeof(filename), dirname, "/", udev_device_get_id_filename(dev), NULL);
912541b0	191
baa30fbc KS	192	if (!add && unlink(filename) == 0)
baa30fbc KS	193	rmdir(dirname);
912541b0 KS	194
	195	target = link_find_prioritized(dev, add, dirname, buf, sizeof(buf));
	196	if (target == NULL) {
9f6445e3	197	log_debug("no reference left, remove '%s'", slink);
912541b0	198	if (unlink(slink) == 0)
37d52274	199	rmdir_parents(slink, "/");
912541b0	200	} else {
9f6445e3	201	log_debug("creating link '%s' to '%s'", slink, target);
38d70045	202	node_symlink(dev, target, slink);
912541b0 KS	203	}
	204
	205	if (add) {
	206	int err;
	207
912541b0 KS	208	do {
	209	int fd;
	210
3cbd5f6b	211	err = mkdir_parents(filename, 0755);
912541b0 KS	212	if (err != 0 && err != -ENOENT)
	213	break;
	214	fd = open(filename, O_WRONLY\|O_CREAT\|O_CLOEXEC\|O_TRUNC\|O_NOFOLLOW, 0444);
	215	if (fd >= 0)
	216	close(fd);
	217	else
	218	err = -errno;
	219	} while (err == -ENOENT);
	220	}
24f0605c KS	221	}
24f0605c KS	222
9ec6e95b	223	void udev_node_update_old_links(struct udev_device dev, struct udev_device dev_old) {
912541b0 KS	224	struct udev_list_entry *list_entry;
	225
	226	/* update possible left-over symlinks */
	227	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev_old)) {
	228	const char *name = udev_list_entry_get_name(list_entry);
	229	struct udev_list_entry *list_entry_current;
	230	int found;
	231
	232	/* check if old link name still belongs to this device */
	233	found = 0;
	234	udev_list_entry_foreach(list_entry_current, udev_device_get_devlinks_list_entry(dev)) {
	235	const char *name_current = udev_list_entry_get_name(list_entry_current);
	236
090be865	237	if (streq(name, name_current)) {
912541b0 KS	238	found = 1;
	239	break;
	240	}
	241	}
	242	if (found)
	243	continue;
	244
9f6445e3	245	log_debug("update old name, '%s' no longer belonging to '%s'",
912541b0	246	name, udev_device_get_devpath(dev));
8a173387	247	link_update(dev, name, false);
912541b0	248	}
24f0605c KS	249	}
24f0605c KS	250
c26547d6 KS	251	static int node_permissions_apply(struct udev_device *dev, bool apply,
	252	mode_t mode, uid_t uid, gid_t gid,
	253	struct udev_list *seclabel_list) {
912541b0 KS	254	const char *devnode = udev_device_get_devnode(dev);
	255	dev_t devnum = udev_device_get_devnum(dev);
	256	struct stat stats;
c26547d6	257	struct udev_list_entry *entry;
912541b0 KS	258	int err = 0;
912541b0 KS	259
090be865	260	if (streq(udev_device_get_subsystem(dev), "block"))
912541b0 KS	261	mode \|= S_IFBLK;
	262	else
	263	mode \|= S_IFCHR;
	264
	265	if (lstat(devnode, &stats) != 0) {
e1427b13	266	err = log_debug_errno(errno, "can not stat() node '%s' (%m)", devnode);
912541b0 KS	267	goto out;
	268	}
	269
	270	if (((stats.st_mode & S_IFMT) != (mode & S_IFMT)) \|\| (stats.st_rdev != devnum)) {
	271	err = -EEXIST;
9f6445e3	272	log_debug("found node '%s' with non-matching devnum %s, skip handling",
baa30fbc	273	udev_device_get_devnode(dev), udev_device_get_id_filename(dev));
912541b0 KS	274	goto out;
	275	}
	276
22582bb2	277	if (apply) {
b7e2b764	278	bool selinux = false;
b7e2b764	279	bool smack = false;
b7e2b764	280
48a849ee	281	if ((stats.st_mode & 0777) != (mode & 0777) \|\| stats.st_uid != uid \|\| stats.st_gid != gid) {
9f6445e3	282	log_debug("set permissions %s, %#o, uid=%u, gid=%u", devnode, mode, uid, gid);
543afdc6 TG	283	err = chmod(devnode, mode);
543afdc6 TG	284	if (err < 0)
56f64d95	285	log_warning_errno(errno, "setting mode of %s to %#o failed: %m", devnode, mode);
543afdc6 TG	286	err = chown(devnode, uid, gid);
543afdc6 TG	287	if (err < 0)
56f64d95	288	log_warning_errno(errno, "setting owner of %s to uid=%u, gid=%u failed: %m", devnode, uid, gid);
48a849ee	289	} else {
9f6445e3	290	log_debug("preserve permissions %s, %#o, uid=%u, gid=%u", devnode, mode, uid, gid);
48a849ee	291	}
c26547d6	292
c26547d6 KS	293	/* apply SECLABEL{$module}=$label */
	294	udev_list_entry_foreach(entry, udev_list_get_entry(seclabel_list)) {
	295	const char name, label;
d53e386d	296	int r;
c26547d6 KS	297
	298	name = udev_list_entry_get_name(entry);
	299	label = udev_list_entry_get_value(entry);
	300
	301	if (streq(name, "selinux")) {
b7e2b764	302	selinux = true;
d53e386d	303
ecabcf8b LP	304	r = mac_selinux_apply(devnode, label);
ecabcf8b LP	305	if (r < 0)
da927ba9	306	log_error_errno(r, "SECLABEL: failed to set SELinux label '%s': %m", label);
463b5dbb KS	307	else
463b5dbb KS	308	log_debug("SECLABEL: set SELinux label '%s'", label);
c26547d6	309
9a4e038c	310	} else if (streq(name, "smack")) {
b7e2b764	311	smack = true;
d53e386d	312
5ab58c20	313	r = mac_smack_apply(devnode, SMACK_ATTR_ACCESS, label);
d53e386d	314	if (r < 0)
da927ba9	315	log_error_errno(r, "SECLABEL: failed to set SMACK label '%s': %m", label);
c26547d6 KS	316	else
c26547d6 KS	317	log_debug("SECLABEL: set SMACK label '%s'", label);
c26547d6 KS	318
	319	} else
	320	log_error("SECLABEL: unknown subsystem, ignoring '%s'='%s'", name, label);
	321	}
b7e2b764 KS	322
	323	/* set the defaults */
	324	if (!selinux)
2ec62d8e	325	mac_selinux_fix(devnode, true, false);
9a4e038c	326	if (!smack)
5ab58c20	327	mac_smack_apply(devnode, SMACK_ATTR_ACCESS, NULL);
48a849ee	328	}
912541b0 KS	329
	330	/* always update timestamp when we re-use the node, like on media change events */
	331	utimensat(AT_FDCWD, devnode, NULL, 0);
220893b3	332	out:
912541b0	333	return err;
220893b3 KS	334	}
220893b3 KS	335
c26547d6 KS	336	void udev_node_add(struct udev_device *dev, bool apply,
	337	mode_t mode, uid_t uid, gid_t gid,
	338	struct udev_list *seclabel_list) {
e02c6135	339	char filename[sizeof("/dev/block/:") + 2*DECIMAL_STR_MAX(unsigned)];
912541b0	340	struct udev_list_entry *list_entry;
912541b0	341
1fa2f38f	342	log_debug("handling device node '%s', devnum=%s, mode=%#o, uid="UID_FMT", gid="GID_FMT,
baa30fbc	343	udev_device_get_devnode(dev), udev_device_get_id_filename(dev), mode, uid, gid);
912541b0	344
c26547d6	345	if (node_permissions_apply(dev, apply, mode, uid, gid, seclabel_list) < 0)
e7f32890	346	return;
912541b0 KS	347
912541b0 KS	348	/* always add /dev/{block,char}/$major:$minor */
d054f0a4	349	xsprintf(filename, "/dev/%s/%u:%u",
090be865	350	streq(udev_device_get_subsystem(dev), "block") ? "block" : "char",
d054f0a4 DM	351	major(udev_device_get_devnum(dev)),
d054f0a4 DM	352	minor(udev_device_get_devnum(dev)));
38d70045	353	node_symlink(dev, udev_device_get_devnode(dev), filename);
912541b0 KS	354
912541b0 KS	355	/* create/update symlinks, add symlinks to name index */
8a173387 KS	356	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
8a173387 KS	357	link_update(dev, udev_list_entry_get_name(list_entry), true);
ea733a2f GKH	358	}
ea733a2f GKH	359
9ec6e95b	360	void udev_node_remove(struct udev_device *dev) {
912541b0	361	struct udev_list_entry *list_entry;
e02c6135	362	char filename[sizeof("/dev/block/:") + 2*DECIMAL_STR_MAX(unsigned)];
912541b0 KS	363
	364	/* remove/update symlinks, remove symlinks from name index */
	365	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
8a173387	366	link_update(dev, udev_list_entry_get_name(list_entry), false);
912541b0 KS	367
912541b0 KS	368	/* remove /dev/{block,char}/$major:$minor */
d054f0a4	369	xsprintf(filename, "/dev/%s/%u:%u",
090be865	370	streq(udev_device_get_subsystem(dev), "block") ? "block" : "char",
d054f0a4 DM	371	major(udev_device_get_devnum(dev)),
d054f0a4 DM	372	minor(udev_device_get_devnum(dev)));
912541b0	373	unlink(filename);
ea733a2f	374	}