move imported udev into place

1 files changed, 379 insertions, 0 deletions

diff --git a/src/udev/udev-node.c b/src/udev/udev-node.c
new file mode 100644
index 0000000000..7a01a479ee
--- /dev/null
+++ b/src/udev/udev-node.c
@@ -0,0 +1,379 @@
+/*
+ * 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;
+
+                        info(udev, "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) {
+                                        info(udev, "replace device node '%s' with symlink to our node '%s'\n",
+                                             slink, node);
+                                } else {
+                                        err(udev, "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;
+
+                        dbg(udev, "found existing symlink '%s'\n", slink);
+                        len = readlink(slink, buf, sizeof(buf));
+                        if (len > 0 && len < (int)sizeof(buf)) {
+                                buf[len] = '\0';
+                                if (strcmp(target, buf) == 0) {
+                                        info(udev, "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 {
+                info(udev, "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;
+        }
+
+        info(udev, "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) {
+                err(udev, "symlink '%s' '%s' failed: %m\n", target, slink_tmp);
+                goto exit;
+        }
+        err = rename(slink_tmp, slink);
+        if (err != 0) {
+                err(udev, "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;
+
+                info(udev, "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) {
+                                dbg(udev, "compare priority of '%s'(%i) > '%s'(%i)\n", target, priority,
+                                    udev_device_get_devnode(dev_db), udev_device_get_devlink_priority(dev_db));
+                                if (target == NULL || udev_device_get_devlink_priority(dev_db) > priority) {
+                                        info(udev, "'%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];
+
+        dbg(udev, "update symlink '%s' of '%s'\n", slink, udev_device_get_syspath(dev));
+
+        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) {
+                dbg(udev, "removing index: '%s'\n", filename);
+                if (unlink(filename) == 0)
+                        rmdir(dirname);
+        }
+
+        target = link_find_prioritized(dev, add, dirname, buf, sizeof(buf));
+        if (target == NULL) {
+                info(udev, "no reference left, remove '%s'\n", slink);
+                if (unlink(slink) == 0)
+                        util_delete_path(udev, slink);
+        } else {
+                info(udev, "creating link '%s' to '%s'\n", slink, target);
+                node_symlink(udev, target, slink);
+        }
+
+        if (add) {
+                int err;
+
+                dbg(udev, "creating index: '%s'\n", filename);
+                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;
+
+                info(udev, "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;
+                info(udev, "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;
+                info(udev, "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) {
+                info(udev, "set permissions %s, %#o, uid=%u, gid=%u\n", devnode, mode, uid, gid);
+                chmod(devnode, mode);
+                chown(devnode, uid, gid);
+        } else {
+                info(udev, "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;
+
+        info(udev, "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);
+}