./tools/notsd-move

1 files changed, 375 insertions, 0 deletions

diff --git a/src/grp-udev/libudev-core/udev-node.c b/src/grp-udev/libudev-core/udev-node.c
new file mode 100644
index 0000000000..3a2daa89ad
--- /dev/null
+++ b/src/grp-udev/libudev-core/udev-node.c
@@ -0,0 +1,375 @@
+/*
+ * 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 "basic/formats-util.h"
+#include "basic/fs-util.h"
+#include "basic/selinux-util.h"
+#include "basic/smack-util.h"
+#include "basic/stdio-util.h"
+#include "basic/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 */
+        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[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 */
+        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);
+}