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171 lines
4.4 KiB
C
171 lines
4.4 KiB
C
/*
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* Copyright (C) 2004-2010 Kay Sievers <kay.sievers@vrfy.org>
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* Copyright (C) 2009 Canonical Ltd.
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* Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <sys/types.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <dirent.h>
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#include <stddef.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/inotify.h>
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#include "udev.h"
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static int inotify_fd = -1;
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/* inotify descriptor, will be shared with rules directory;
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* set to cloexec since we need our children to be able to add
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* watches for us
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*/
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int udev_watch_init(struct udev *udev)
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{
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inotify_fd = inotify_init1(IN_CLOEXEC);
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if (inotify_fd < 0)
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err(udev, "inotify_init failed: %m\n");
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return inotify_fd;
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}
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/* move any old watches directory out of the way, and then restore
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* the watches
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*/
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void udev_watch_restore(struct udev *udev)
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{
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char filename[UTIL_PATH_SIZE], oldname[UTIL_PATH_SIZE];
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if (inotify_fd < 0)
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return;
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util_strscpyl(oldname, sizeof(oldname), udev_get_run_path(udev), "/watch.old", NULL);
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util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/watch", NULL);
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if (rename(filename, oldname) == 0) {
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DIR *dir;
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struct dirent *ent;
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dir = opendir(oldname);
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if (dir == NULL) {
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err(udev, "unable to open old watches dir '%s', old watches will not be restored: %m", oldname);
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return;
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}
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for (ent = readdir(dir); ent != NULL; ent = readdir(dir)) {
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char device[UTIL_PATH_SIZE];
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char *s;
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size_t l;
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ssize_t len;
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struct udev_device *dev;
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if (ent->d_name[0] == '.')
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continue;
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s = device;
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l = util_strpcpy(&s, sizeof(device), udev_get_sys_path(udev));
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len = readlinkat(dirfd(dir), ent->d_name, s, l);
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if (len <= 0 || len == (ssize_t)l)
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goto unlink;
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s[len] = '\0';
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dev = udev_device_new_from_id_filename(udev, s);
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if (dev == NULL)
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goto unlink;
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info(udev, "restoring old watch on '%s'\n", udev_device_get_devnode(dev));
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udev_watch_begin(udev, dev);
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udev_device_unref(dev);
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unlink:
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unlinkat(dirfd(dir), ent->d_name, 0);
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}
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closedir(dir);
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rmdir(oldname);
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} else if (errno != ENOENT) {
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err(udev, "unable to move watches dir '%s', old watches will not be restored: %m", filename);
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}
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}
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void udev_watch_begin(struct udev *udev, struct udev_device *dev)
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{
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char filename[UTIL_PATH_SIZE];
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int wd;
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if (inotify_fd < 0)
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return;
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info(udev, "adding watch on '%s'\n", udev_device_get_devnode(dev));
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wd = inotify_add_watch(inotify_fd, udev_device_get_devnode(dev), IN_CLOSE_WRITE);
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if (wd < 0) {
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err(udev, "inotify_add_watch(%d, %s, %o) failed: %m\n",
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inotify_fd, udev_device_get_devnode(dev), IN_CLOSE_WRITE);
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return;
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}
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snprintf(filename, sizeof(filename), "%s/watch/%d", udev_get_run_path(udev), wd);
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util_create_path(udev, filename);
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unlink(filename);
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symlink(udev_device_get_id_filename(dev), filename);
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udev_device_set_watch_handle(dev, wd);
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}
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void udev_watch_end(struct udev *udev, struct udev_device *dev)
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{
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int wd;
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char filename[UTIL_PATH_SIZE];
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if (inotify_fd < 0)
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return;
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wd = udev_device_get_watch_handle(dev);
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if (wd < 0)
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return;
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info(udev, "removing watch on '%s'\n", udev_device_get_devnode(dev));
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inotify_rm_watch(inotify_fd, wd);
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snprintf(filename, sizeof(filename), "%s/watch/%d", udev_get_run_path(udev), wd);
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unlink(filename);
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udev_device_set_watch_handle(dev, -1);
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}
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struct udev_device *udev_watch_lookup(struct udev *udev, int wd)
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{
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char filename[UTIL_PATH_SIZE];
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char majmin[UTIL_PATH_SIZE];
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char *s;
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size_t l;
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ssize_t len;
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if (inotify_fd < 0 || wd < 0)
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return NULL;
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snprintf(filename, sizeof(filename), "%s/watch/%d", udev_get_run_path(udev), wd);
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s = majmin;
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l = util_strpcpy(&s, sizeof(majmin), udev_get_sys_path(udev));
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len = readlink(filename, s, l);
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if (len <= 0 || (size_t)len == l)
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return NULL;
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s[len] = '\0';
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return udev_device_new_from_id_filename(udev, s);
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}
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