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

/*
 * Copyright (C) 2003-2010 Kay Sievers <kay.sievers@vrfy.org>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, 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"

#define TMP_FILE_EXT                ".udev-tmp"

static int node_symlink(struct udev *udev, 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 + sizeof(TMP_FILE_EXT)];
        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 = util_strpcpy(&s, l, "../");
                i++;
        }
        l = util_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)) {
                        struct stat stats2;

                        log_debug("found existing node instead of symlink '%s'\n", slink);
                        if (lstat(node, &stats2) == 0) {
                                if ((stats.st_mode & S_IFMT) == (stats2.st_mode & S_IFMT) &&
                                    stats.st_rdev == stats2.st_rdev && stats.st_ino != stats2.st_ino) {
                                        log_debug("replace device node '%s' with symlink to our node '%s'\n",
                                             slink, node);
                                } else {
                                        log_error("device node '%s' already exists, "
                                            "link to '%s' will not overwrite it\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 (strcmp(target, buf) == 0) {
                                        log_debug("preserve already existing symlink '%s' to '%s'\n", slink, target);
                                        udev_selinux_lsetfilecon(udev, slink, S_IFLNK);
                                        utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW);
                                        goto exit;
                                }
                        }
                }
        } else {
                log_debug("creating symlink '%s' to '%s'\n", slink, target);
                do {
                        err = util_create_path_selinux(udev, slink);
                        if (err != 0 && err != -ENOENT)
                                break;
                        udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
                        err = symlink(target, slink);
                        if (err != 0)
                                err = -errno;
                        udev_selinux_resetfscreatecon(udev);
                } while (err == -ENOENT);
                if (err == 0)
                        goto exit;
        }

        log_debug("atomically replace '%s'\n", slink);
        util_strscpyl(slink_tmp, sizeof(slink_tmp), slink, TMP_FILE_EXT, NULL);
        unlink(slink_tmp);
        do {
                err = util_create_path_selinux(udev, slink_tmp);
                if (err != 0 && err != -ENOENT)
                        break;
                udev_selinux_setfscreatecon(udev, slink_tmp, S_IFLNK);
                err = symlink(target, slink_tmp);
                if (err != 0)
                        err = -errno;
                udev_selinux_resetfscreatecon(udev);
        } 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);
                util_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 (strcmp(dent->d_name, udev_device_get_id_filename(dev)) == 0)
                        continue;

                dev_db = udev_device_new_from_id_filename(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);
                                        util_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(udev_get_dev_path(udev))+1], name_enc, sizeof(name_enc));
        util_strscpyl(dirname, sizeof(dirname), udev_get_run_path(udev), "/links/", name_enc, NULL);
        util_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(udev, target, slink);
        }

        if (add) {
                int err;

                do {
                        int fd;

                        err = util_create_path(udev, filename);
                        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 *udev = udev_device_get_udev(dev);
        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 (strcmp(name, name_current) == 0) {
                                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, 0);
        }
}

static int node_fixup(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
{
        struct udev *udev = udev_device_get_udev(dev);
        const char *devnode = udev_device_get_devnode(dev);
        dev_t devnum = udev_device_get_devnum(dev);
        struct stat stats;
        int err = 0;

        if (strcmp(udev_device_get_subsystem(dev), "block") == 0)
                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 ((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);
        }

        /*
         * Set initial selinux file context only on add events.
         * We set the proper context on bootup (triger) or for newly
         * added devices, but we don't change it later, in case
         * something else has set a custom context in the meantime.
         */
        if (strcmp(udev_device_get_action(dev), "add") == 0)
                udev_selinux_lsetfilecon(udev, devnode, mode);

        /* 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, mode_t mode, uid_t uid, gid_t gid)
{
        struct udev *udev = udev_device_get_udev(dev);
        char filename[UTIL_PATH_SIZE];
        struct udev_list_entry *list_entry;
        int err = 0;

        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_fixup(dev, mode, uid, gid) < 0)
                return;

        /* always add /dev/{block,char}/$major:$minor */
        snprintf(filename, sizeof(filename), "%s/%s/%u:%u",
                 udev_get_dev_path(udev),
                 strcmp(udev_device_get_subsystem(dev), "block") == 0 ? "block" : "char",
                 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
        node_symlink(udev, 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)) {
                if (udev_list_entry_get_num(list_entry))
                        /* simple unmanaged link name */
                        node_symlink(udev, udev_device_get_devnode(dev), udev_list_entry_get_name(list_entry));
                else
                        link_update(dev, udev_list_entry_get_name(list_entry), 1);
        }
}

void udev_node_remove(struct udev_device *dev)
{
        struct udev *udev = udev_device_get_udev(dev);
        struct udev_list_entry *list_entry;
        const char *devnode;
        struct stat stats;
        struct udev_device *dev_check;
        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), 0);

        /* remove /dev/{block,char}/$major:$minor */
        snprintf(filename, sizeof(filename), "%s/%s/%u:%u",
                 udev_get_dev_path(udev),
                 strcmp(udev_device_get_subsystem(dev), "block") == 0 ? "block" : "char",
                 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
        unlink(filename);
}
Commit	Line	Data
ea733a2f	1	/*
0ec5b5e1	2	* Copyright (C) 2003-2010 Kay Sievers <kay.sievers@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"
9825617b	33
912541b0	34	#define TMP_FILE_EXT ".udev-tmp"
ea733a2f	35
aa8734ff	36	static int node_symlink(struct udev udev, const char node, const char *slink)
fa33d857	37	{
912541b0 KS	38	struct stat stats;
	39	char target[UTIL_PATH_SIZE];
	40	char *s;
	41	size_t l;
	42	char slink_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
	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] == '/')
	58	l = util_strpcpy(&s, l, "../");
	59	i++;
	60	}
	61	l = util_strscpy(s, l, &node[tail]);
	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)) {
	70	struct stat stats2;
	71
baa30fbc	72	log_debug("found existing node instead of symlink '%s'\n", slink);
912541b0 KS	73	if (lstat(node, &stats2) == 0) {
	74	if ((stats.st_mode & S_IFMT) == (stats2.st_mode & S_IFMT) &&
	75	stats.st_rdev == stats2.st_rdev && stats.st_ino != stats2.st_ino) {
baa30fbc	76	log_debug("replace device node '%s' with symlink to our node '%s'\n",
912541b0 KS	77	slink, node);
912541b0 KS	78	} else {
baa30fbc	79	log_error("device node '%s' already exists, "
912541b0 KS	80	"link to '%s' will not overwrite it\n",
	81	slink, node);
	82	goto exit;
	83	}
	84	}
	85	} else if (S_ISLNK(stats.st_mode)) {
	86	char buf[UTIL_PATH_SIZE];
	87	int len;
	88
912541b0 KS	89	len = readlink(slink, buf, sizeof(buf));
	90	if (len > 0 && len < (int)sizeof(buf)) {
	91	buf[len] = '\0';
	92	if (strcmp(target, buf) == 0) {
baa30fbc	93	log_debug("preserve already existing symlink '%s' to '%s'\n", slink, target);
912541b0 KS	94	udev_selinux_lsetfilecon(udev, slink, S_IFLNK);
	95	utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW);
	96	goto exit;
	97	}
	98	}
	99	}
	100	} else {
baa30fbc	101	log_debug("creating symlink '%s' to '%s'\n", slink, target);
912541b0 KS	102	do {
	103	err = util_create_path_selinux(udev, slink);
	104	if (err != 0 && err != -ENOENT)
	105	break;
	106	udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
	107	err = symlink(target, slink);
	108	if (err != 0)
	109	err = -errno;
	110	udev_selinux_resetfscreatecon(udev);
	111	} while (err == -ENOENT);
	112	if (err == 0)
	113	goto exit;
	114	}
	115
baa30fbc	116	log_debug("atomically replace '%s'\n", slink);
912541b0 KS	117	util_strscpyl(slink_tmp, sizeof(slink_tmp), slink, TMP_FILE_EXT, NULL);
	118	unlink(slink_tmp);
	119	do {
	120	err = util_create_path_selinux(udev, slink_tmp);
	121	if (err != 0 && err != -ENOENT)
	122	break;
	123	udev_selinux_setfscreatecon(udev, slink_tmp, S_IFLNK);
	124	err = symlink(target, slink_tmp);
	125	if (err != 0)
	126	err = -errno;
	127	udev_selinux_resetfscreatecon(udev);
	128	} while (err == -ENOENT);
	129	if (err != 0) {
baa30fbc	130	log_error("symlink '%s' '%s' failed: %m\n", target, slink_tmp);
912541b0 KS	131	goto exit;
	132	}
	133	err = rename(slink_tmp, slink);
	134	if (err != 0) {
baa30fbc	135	log_error("rename '%s' '%s' failed: %m\n", slink_tmp, slink);
912541b0 KS	136	unlink(slink_tmp);
912541b0 KS	137	}
fa33d857	138	exit:
912541b0	139	return err;
fa33d857 KS	140	}
fa33d857 KS	141
6c29f2b9 KS	142	/* find device node of device with highest priority */
6c29f2b9 KS	143	static const char link_find_prioritized(struct udev_device dev, bool add, const char stackdir, char buf, size_t bufsize)
24f0605c	144	{
912541b0 KS	145	struct udev *udev = udev_device_get_udev(dev);
	146	DIR *dir;
	147	int priority = 0;
	148	const char *target = NULL;
	149
	150	if (add) {
	151	priority = udev_device_get_devlink_priority(dev);
	152	util_strscpy(buf, bufsize, udev_device_get_devnode(dev));
	153	target = buf;
	154	}
	155
	156	dir = opendir(stackdir);
	157	if (dir == NULL)
	158	return target;
	159	for (;;) {
	160	struct udev_device *dev_db;
	161	struct dirent *dent;
	162
	163	dent = readdir(dir);
	164	if (dent == NULL \|\| dent->d_name[0] == '\0')
	165	break;
	166	if (dent->d_name[0] == '.')
	167	continue;
	168
baa30fbc	169	log_debug("found '%s' claiming '%s'\n", dent->d_name, stackdir);
912541b0 KS	170
	171	/* did we find ourself? */
	172	if (strcmp(dent->d_name, udev_device_get_id_filename(dev)) == 0)
	173	continue;
	174
	175	dev_db = udev_device_new_from_id_filename(udev, dent->d_name);
	176	if (dev_db != NULL) {
	177	const char *devnode;
	178
	179	devnode = udev_device_get_devnode(dev_db);
	180	if (devnode != NULL) {
912541b0	181	if (target == NULL \|\| udev_device_get_devlink_priority(dev_db) > priority) {
baa30fbc KS	182	log_debug("'%s' claims priority %i for '%s'\n",
baa30fbc KS	183	udev_device_get_syspath(dev_db), udev_device_get_devlink_priority(dev_db), stackdir);
912541b0 KS	184	priority = udev_device_get_devlink_priority(dev_db);
	185	util_strscpy(buf, bufsize, devnode);
	186	target = buf;
	187	}
	188	}
	189	udev_device_unref(dev_db);
	190	}
	191	}
	192	closedir(dir);
	193	return target;
aa8734ff KS	194	}
aa8734ff KS	195
6c29f2b9 KS	196	/* manage "stack of names" with possibly specified device priorities */
6c29f2b9 KS	197	static void link_update(struct udev_device dev, const char slink, bool add)
aa8734ff	198	{
912541b0 KS	199	struct udev *udev = udev_device_get_udev(dev);
	200	char name_enc[UTIL_PATH_SIZE];
	201	char filename[UTIL_PATH_SIZE * 2];
	202	char dirname[UTIL_PATH_SIZE];
	203	const char *target;
	204	char buf[UTIL_PATH_SIZE];
	205
912541b0 KS	206	util_path_encode(&slink[strlen(udev_get_dev_path(udev))+1], name_enc, sizeof(name_enc));
	207	util_strscpyl(dirname, sizeof(dirname), udev_get_run_path(udev), "/links/", name_enc, NULL);
	208	util_strscpyl(filename, sizeof(filename), dirname, "/", udev_device_get_id_filename(dev), NULL);
	209
baa30fbc KS	210	if (!add && unlink(filename) == 0)
baa30fbc KS	211	rmdir(dirname);
912541b0 KS	212
	213	target = link_find_prioritized(dev, add, dirname, buf, sizeof(buf));
	214	if (target == NULL) {
baa30fbc	215	log_debug("no reference left, remove '%s'\n", slink);
912541b0 KS	216	if (unlink(slink) == 0)
	217	util_delete_path(udev, slink);
	218	} else {
baa30fbc	219	log_debug("creating link '%s' to '%s'\n", slink, target);
912541b0 KS	220	node_symlink(udev, target, slink);
	221	}
	222
	223	if (add) {
	224	int err;
	225
912541b0 KS	226	do {
	227	int fd;
	228
	229	err = util_create_path(udev, filename);
	230	if (err != 0 && err != -ENOENT)
	231	break;
	232	fd = open(filename, O_WRONLY\|O_CREAT\|O_CLOEXEC\|O_TRUNC\|O_NOFOLLOW, 0444);
	233	if (fd >= 0)
	234	close(fd);
	235	else
	236	err = -errno;
	237	} while (err == -ENOENT);
	238	}
24f0605c KS	239	}
24f0605c KS	240
ec2dd02e	241	void udev_node_update_old_links(struct udev_device dev, struct udev_device dev_old)
24f0605c	242	{
912541b0 KS	243	struct udev *udev = udev_device_get_udev(dev);
	244	struct udev_list_entry *list_entry;
	245
	246	/* update possible left-over symlinks */
	247	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev_old)) {
	248	const char *name = udev_list_entry_get_name(list_entry);
	249	struct udev_list_entry *list_entry_current;
	250	int found;
	251
	252	/* check if old link name still belongs to this device */
	253	found = 0;
	254	udev_list_entry_foreach(list_entry_current, udev_device_get_devlinks_list_entry(dev)) {
	255	const char *name_current = udev_list_entry_get_name(list_entry_current);
	256
	257	if (strcmp(name, name_current) == 0) {
	258	found = 1;
	259	break;
	260	}
	261	}
	262	if (found)
	263	continue;
	264
baa30fbc	265	log_debug("update old name, '%s' no longer belonging to '%s'\n",
912541b0 KS	266	name, udev_device_get_devpath(dev));
	267	link_update(dev, name, 0);
	268	}
24f0605c KS	269	}
24f0605c KS	270
220893b3 KS	271	static int node_fixup(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
220893b3 KS	272	{
912541b0 KS	273	struct udev *udev = udev_device_get_udev(dev);
	274	const char *devnode = udev_device_get_devnode(dev);
	275	dev_t devnum = udev_device_get_devnum(dev);
	276	struct stat stats;
	277	int err = 0;
	278
	279	if (strcmp(udev_device_get_subsystem(dev), "block") == 0)
	280	mode \|= S_IFBLK;
	281	else
	282	mode \|= S_IFCHR;
	283
	284	if (lstat(devnode, &stats) != 0) {
	285	err = -errno;
baa30fbc	286	log_debug("can not stat() node '%s' (%m)\n", devnode);
912541b0 KS	287	goto out;
	288	}
	289
	290	if (((stats.st_mode & S_IFMT) != (mode & S_IFMT)) \|\| (stats.st_rdev != devnum)) {
	291	err = -EEXIST;
baa30fbc KS	292	log_debug("found node '%s' with non-matching devnum %s, skip handling\n",
baa30fbc KS	293	udev_device_get_devnode(dev), udev_device_get_id_filename(dev));
912541b0 KS	294	goto out;
	295	}
	296
	297	if ((stats.st_mode & 0777) != (mode & 0777) \|\| stats.st_uid != uid \|\| stats.st_gid != gid) {
baa30fbc	298	log_debug("set permissions %s, %#o, uid=%u, gid=%u\n", devnode, mode, uid, gid);
912541b0 KS	299	chmod(devnode, mode);
	300	chown(devnode, uid, gid);
	301	} else {
baa30fbc	302	log_debug("preserve permissions %s, %#o, uid=%u, gid=%u\n", devnode, mode, uid, gid);
912541b0 KS	303	}
	304
	305	/*
	306	* Set initial selinux file context only on add events.
	307	* We set the proper context on bootup (triger) or for newly
	308	* added devices, but we don't change it later, in case
	309	* something else has set a custom context in the meantime.
	310	*/
	311	if (strcmp(udev_device_get_action(dev), "add") == 0)
	312	udev_selinux_lsetfilecon(udev, devnode, mode);
	313
	314	/* always update timestamp when we re-use the node, like on media change events */
	315	utimensat(AT_FDCWD, devnode, NULL, 0);
220893b3	316	out:
912541b0	317	return err;
220893b3 KS	318	}
220893b3 KS	319
e7f32890	320	void udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
97853b4f	321	{
912541b0 KS	322	struct udev *udev = udev_device_get_udev(dev);
	323	char filename[UTIL_PATH_SIZE];
	324	struct udev_list_entry *list_entry;
	325	int err = 0;
	326
baa30fbc KS	327	log_debug("handling device node '%s', devnum=%s, mode=%#o, uid=%d, gid=%d\n",
baa30fbc KS	328	udev_device_get_devnode(dev), udev_device_get_id_filename(dev), mode, uid, gid);
912541b0	329
e7f32890 KS	330	if (node_fixup(dev, mode, uid, gid) < 0)
e7f32890 KS	331	return;
912541b0 KS	332
	333	/* always add /dev/{block,char}/$major:$minor */
	334	snprintf(filename, sizeof(filename), "%s/%s/%u:%u",
	335	udev_get_dev_path(udev),
	336	strcmp(udev_device_get_subsystem(dev), "block") == 0 ? "block" : "char",
	337	major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
	338	node_symlink(udev, udev_device_get_devnode(dev), filename);
	339
	340	/* create/update symlinks, add symlinks to name index */
	341	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) {
	342	if (udev_list_entry_get_num(list_entry))
	343	/* simple unmanaged link name */
	344	node_symlink(udev, udev_device_get_devnode(dev), udev_list_entry_get_name(list_entry));
	345	else
	346	link_update(dev, udev_list_entry_get_name(list_entry), 1);
	347	}
ea733a2f GKH	348	}
ea733a2f GKH	349
e7f32890	350	void udev_node_remove(struct udev_device *dev)
ff9a488d	351	{
912541b0 KS	352	struct udev *udev = udev_device_get_udev(dev);
	353	struct udev_list_entry *list_entry;
	354	const char *devnode;
	355	struct stat stats;
	356	struct udev_device *dev_check;
	357	char filename[UTIL_PATH_SIZE];
912541b0 KS	358
	359	/* remove/update symlinks, remove symlinks from name index */
	360	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
	361	link_update(dev, udev_list_entry_get_name(list_entry), 0);
	362
	363	/* remove /dev/{block,char}/$major:$minor */
	364	snprintf(filename, sizeof(filename), "%s/%s/%u:%u",
	365	udev_get_dev_path(udev),
	366	strcmp(udev_device_get_subsystem(dev), "block") == 0 ? "block" : "char",
	367	major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
	368	unlink(filename);
ea733a2f	369	}