[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>

#include "udev.h"
#include "smack-util.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 = -errno;
                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, 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, 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=%d, gid=%d",
                  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>
ea733a2f GKH	31
ea733a2f GKH	32	#include "udev.h"
9a4e038c	33	#include "smack-util.h"
9825617b	34
9ec6e95b	35	static int node_symlink(struct udev_device dev, const char node, const char *slink) {
912541b0 KS	36	struct stat stats;
	37	char target[UTIL_PATH_SIZE];
	38	char *s;
	39	size_t l;
38d70045	40	char slink_tmp[UTIL_PATH_SIZE + 32];
912541b0 KS	41	int i = 0;
	42	int tail = 0;
	43	int err = 0;
	44
	45	/* use relative link */
	46	target[0] = '\0';
	47	while (node[i] && (node[i] == slink[i])) {
	48	if (node[i] == '/')
	49	tail = i+1;
	50	i++;
	51	}
	52	s = target;
	53	l = sizeof(target);
	54	while (slink[i] != '\0') {
	55	if (slink[i] == '/')
d5a89d7d	56	l = strpcpy(&s, l, "../");
912541b0 KS	57	i++;
912541b0 KS	58	}
d5a89d7d	59	l = strscpy(s, l, &node[tail]);
912541b0 KS	60	if (l == 0) {
	61	err = -EINVAL;
	62	goto exit;
	63	}
	64
	65	/* preserve link with correct target, do not replace node of other device */
	66	if (lstat(slink, &stats) == 0) {
	67	if (S_ISBLK(stats.st_mode) \|\| S_ISCHR(stats.st_mode)) {
9f6445e3	68	log_error("conflicting device node '%s' found, link to '%s' will not be created", slink, node);
2be7287b	69	goto exit;
912541b0 KS	70	} else if (S_ISLNK(stats.st_mode)) {
	71	char buf[UTIL_PATH_SIZE];
	72	int len;
	73
912541b0 KS	74	len = readlink(slink, buf, sizeof(buf));
	75	if (len > 0 && len < (int)sizeof(buf)) {
	76	buf[len] = '\0';
090be865	77	if (streq(target, buf)) {
9f6445e3	78	log_debug("preserve already existing symlink '%s' to '%s'", slink, target);
c9bc0764	79	label_fix(slink, true, false);
912541b0 KS	80	utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW);
	81	goto exit;
	82	}
	83	}
	84	}
	85	} else {
9f6445e3	86	log_debug("creating symlink '%s' to '%s'", slink, target);
912541b0	87	do {
d2e54fae	88	err = mkdir_parents_label(slink, 0755);
912541b0 KS	89	if (err != 0 && err != -ENOENT)
912541b0 KS	90	break;
ecabcf8b	91	mac_selinux_create_file_prepare(slink, S_IFLNK);
912541b0 KS	92	err = symlink(target, slink);
	93	if (err != 0)
	94	err = -errno;
ecabcf8b	95	mac_selinux_create_file_clear();
912541b0 KS	96	} while (err == -ENOENT);
	97	if (err == 0)
	98	goto exit;
	99	}
	100
9f6445e3	101	log_debug("atomically replace '%s'", slink);
38d70045	102	strscpyl(slink_tmp, sizeof(slink_tmp), slink, ".tmp-", udev_device_get_id_filename(dev), NULL);
912541b0 KS	103	unlink(slink_tmp);
912541b0 KS	104	do {
d2e54fae	105	err = mkdir_parents_label(slink_tmp, 0755);
912541b0 KS	106	if (err != 0 && err != -ENOENT)
912541b0 KS	107	break;
ecabcf8b	108	mac_selinux_create_file_prepare(slink_tmp, S_IFLNK);
912541b0 KS	109	err = symlink(target, slink_tmp);
	110	if (err != 0)
	111	err = -errno;
ecabcf8b	112	mac_selinux_create_file_clear();
912541b0 KS	113	} while (err == -ENOENT);
912541b0 KS	114	if (err != 0) {
56f64d95	115	log_error_errno(errno, "symlink '%s' '%s' failed: %m", target, slink_tmp);
912541b0 KS	116	goto exit;
	117	}
	118	err = rename(slink_tmp, slink);
	119	if (err != 0) {
56f64d95	120	log_error_errno(errno, "rename '%s' '%s' failed: %m", slink_tmp, slink);
912541b0 KS	121	unlink(slink_tmp);
912541b0 KS	122	}
fa33d857	123	exit:
912541b0	124	return err;
fa33d857 KS	125	}
fa33d857 KS	126
6c29f2b9	127	/* find device node of device with highest priority */
9ec6e95b	128	static const char link_find_prioritized(struct udev_device dev, bool add, const char stackdir, char buf, size_t bufsize) {
912541b0 KS	129	struct udev *udev = udev_device_get_udev(dev);
	130	DIR *dir;
	131	int priority = 0;
	132	const char *target = NULL;
	133
	134	if (add) {
	135	priority = udev_device_get_devlink_priority(dev);
d5a89d7d	136	strscpy(buf, bufsize, udev_device_get_devnode(dev));
912541b0 KS	137	target = buf;
	138	}
	139
	140	dir = opendir(stackdir);
	141	if (dir == NULL)
	142	return target;
	143	for (;;) {
	144	struct udev_device *dev_db;
	145	struct dirent *dent;
	146
	147	dent = readdir(dir);
	148	if (dent == NULL \|\| dent->d_name[0] == '\0')
	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) {
	266	err = -errno;
56f64d95	267	log_debug_errno(errno, "can not stat() node '%s' (%m)", devnode);
912541b0 KS	268	goto out;
	269	}
	270
	271	if (((stats.st_mode & S_IFMT) != (mode & S_IFMT)) \|\| (stats.st_rdev != devnum)) {
	272	err = -EEXIST;
9f6445e3	273	log_debug("found node '%s' with non-matching devnum %s, skip handling",
baa30fbc	274	udev_device_get_devnode(dev), udev_device_get_id_filename(dev));
912541b0 KS	275	goto out;
	276	}
	277
22582bb2	278	if (apply) {
b7e2b764	279	bool selinux = false;
b7e2b764	280	bool smack = false;
b7e2b764	281
48a849ee	282	if ((stats.st_mode & 0777) != (mode & 0777) \|\| stats.st_uid != uid \|\| stats.st_gid != gid) {
9f6445e3	283	log_debug("set permissions %s, %#o, uid=%u, gid=%u", devnode, mode, uid, gid);
543afdc6 TG	284	err = chmod(devnode, mode);
543afdc6 TG	285	if (err < 0)
56f64d95	286	log_warning_errno(errno, "setting mode of %s to %#o failed: %m", devnode, mode);
543afdc6 TG	287	err = chown(devnode, uid, gid);
543afdc6 TG	288	if (err < 0)
56f64d95	289	log_warning_errno(errno, "setting owner of %s to uid=%u, gid=%u failed: %m", devnode, uid, gid);
48a849ee	290	} else {
9f6445e3	291	log_debug("preserve permissions %s, %#o, uid=%u, gid=%u", devnode, mode, uid, gid);
48a849ee	292	}
c26547d6	293
c26547d6 KS	294	/* apply SECLABEL{$module}=$label */
	295	udev_list_entry_foreach(entry, udev_list_get_entry(seclabel_list)) {
	296	const char name, label;
d53e386d	297	int r;
c26547d6 KS	298
	299	name = udev_list_entry_get_name(entry);
	300	label = udev_list_entry_get_value(entry);
	301
	302	if (streq(name, "selinux")) {
b7e2b764	303	selinux = true;
d53e386d	304
ecabcf8b LP	305	r = mac_selinux_apply(devnode, label);
ecabcf8b LP	306	if (r < 0)
da927ba9	307	log_error_errno(r, "SECLABEL: failed to set SELinux label '%s': %m", label);
463b5dbb KS	308	else
463b5dbb KS	309	log_debug("SECLABEL: set SELinux label '%s'", label);
c26547d6	310
9a4e038c	311	} else if (streq(name, "smack")) {
b7e2b764	312	smack = true;
d53e386d LP	313
	314	r = mac_smack_apply(devnode, label);
	315	if (r < 0)
da927ba9	316	log_error_errno(r, "SECLABEL: failed to set SMACK label '%s': %m", label);
c26547d6 KS	317	else
c26547d6 KS	318	log_debug("SECLABEL: set SMACK label '%s'", label);
c26547d6 KS	319
	320	} else
	321	log_error("SECLABEL: unknown subsystem, ignoring '%s'='%s'", name, label);
	322	}
b7e2b764 KS	323
	324	/* set the defaults */
	325	if (!selinux)
2ec62d8e	326	mac_selinux_fix(devnode, true, false);
9a4e038c	327	if (!smack)
c80d766c	328	mac_smack_apply(devnode, NULL);
48a849ee	329	}
912541b0 KS	330
	331	/* always update timestamp when we re-use the node, like on media change events */
	332	utimensat(AT_FDCWD, devnode, NULL, 0);
220893b3	333	out:
912541b0	334	return err;
220893b3 KS	335	}
220893b3 KS	336
c26547d6 KS	337	void udev_node_add(struct udev_device *dev, bool apply,
	338	mode_t mode, uid_t uid, gid_t gid,
	339	struct udev_list *seclabel_list) {
912541b0 KS	340	char filename[UTIL_PATH_SIZE];
912541b0 KS	341	struct udev_list_entry *list_entry;
912541b0	342
9f6445e3	343	log_debug("handling device node '%s', devnum=%s, mode=%#o, uid=%d, gid=%d",
baa30fbc	344	udev_device_get_devnode(dev), udev_device_get_id_filename(dev), mode, uid, gid);
912541b0	345
c26547d6	346	if (node_permissions_apply(dev, apply, mode, uid, gid, seclabel_list) < 0)
e7f32890	347	return;
912541b0 KS	348
912541b0 KS	349	/* always add /dev/{block,char}/$major:$minor */
4cb72937	350	snprintf(filename, sizeof(filename), "/dev/%s/%u:%u",
090be865	351	streq(udev_device_get_subsystem(dev), "block") ? "block" : "char",
912541b0	352	major(udev_device_get_devnum(dev)), 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;
912541b0	362	char filename[UTIL_PATH_SIZE];
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 */
4cb72937	369	snprintf(filename, sizeof(filename), "/dev/%s/%u:%u",
090be865	370	streq(udev_device_get_subsystem(dev), "block") ? "block" : "char",
912541b0 KS	371	major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
912541b0 KS	372	unlink(filename);
ea733a2f	373	}