Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 177 insertions, 0 deletions

diff --git a/src/udev/udev-watch.c b/src/udev/udev-watch.c
new file mode 100644
index 0000000..68b51d0
--- /dev/null
+++ b/src/udev/udev-watch.c
@@ -0,0 +1,177 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright © 2009 Canonical Ltd.
+ * Copyright © 2009 Scott James Remnant <scott@netsplit.com>
+ */
+
+#include <sys/inotify.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "device-private.h"
+#include "device-util.h"
+#include "dirent-util.h"
+#include "fs-util.h"
+#include "mkdir.h"
+#include "stdio-util.h"
+#include "udev-watch.h"
+
+static int inotify_fd = -1;
+
+/* inotify descriptor, will be shared with rules directory;
+ * set to cloexec since we need our children to be able to add
+ * watches for us. */
+int udev_watch_init(void) {
+        inotify_fd = inotify_init1(IN_CLOEXEC);
+        if (inotify_fd < 0)
+                return -errno;
+
+        return inotify_fd;
+}
+
+/* Move any old watches directory out of the way, and then restore the watches. */
+int udev_watch_restore(void) {
+        struct dirent *ent;
+        DIR *dir;
+        int r;
+
+        if (inotify_fd < 0)
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Invalid inotify descriptor.");
+
+        if (rename("/run/udev/watch", "/run/udev/watch.old") < 0) {
+                if (errno != ENOENT)
+                        return log_warning_errno(errno, "Failed to move watches directory /run/udev/watch. Old watches will not be restored: %m");
+
+                return 0;
+        }
+
+        dir = opendir("/run/udev/watch.old");
+        if (!dir)
+                return log_warning_errno(errno, "Failed to open old watches directory /run/udev/watch.old. Old watches will not be restored: %m");
+
+        FOREACH_DIRENT_ALL(ent, dir, break) {
+                _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
+                _cleanup_free_ char *device = NULL;
+
+                if (ent->d_name[0] == '.')
+                        continue;
+
+                r = readlinkat_malloc(dirfd(dir), ent->d_name, &device);
+                if (r < 0) {
+                        log_debug_errno(r, "Failed to read link '/run/udev/watch.old/%s', ignoring: %m", ent->d_name);
+                        goto unlink;
+                }
+
+                r = sd_device_new_from_device_id(&dev, device);
+                if (r < 0) {
+                        log_debug_errno(r, "Failed to create sd_device object for '%s', ignoring: %m", device);
+                        goto unlink;
+                }
+
+                log_device_debug(dev, "Restoring old watch");
+                (void) udev_watch_begin(dev);
+unlink:
+                (void) unlinkat(dirfd(dir), ent->d_name, 0);
+        }
+
+        (void) closedir(dir);
+        (void) rmdir("/run/udev/watch.old");
+
+        return 0;
+}
+
+int udev_watch_begin(sd_device *dev) {
+        char filename[STRLEN("/run/udev/watch/") + DECIMAL_STR_MAX(int)];
+        const char *devnode, *id_filename;
+        int wd, r;
+
+        if (inotify_fd < 0)
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Invalid inotify descriptor.");
+
+        r = sd_device_get_devname(dev, &devnode);
+        if (r < 0)
+                return log_device_error_errno(dev, r, "Failed to get device name: %m");
+
+        log_device_debug(dev, "Adding watch on '%s'", devnode);
+        wd = inotify_add_watch(inotify_fd, devnode, IN_CLOSE_WRITE);
+        if (wd < 0)
+                return log_device_full(dev,
+                                       errno == ENOENT ? LOG_DEBUG : LOG_ERR,
+                                       errno,
+                                       "Failed to add device '%s' to watch: %m", devnode);
+
+        device_set_watch_handle(dev, wd);
+
+        xsprintf(filename, "/run/udev/watch/%d", wd);
+        r = mkdir_parents(filename, 0755);
+        if (r < 0)
+                return log_device_error_errno(dev, r, "Failed to create parent directory of '%s': %m", filename);
+        (void) unlink(filename);
+
+        r = device_get_id_filename(dev, &id_filename);
+        if (r < 0)
+                return log_device_error_errno(dev, r, "Failed to get device id-filename: %m");
+
+        if (symlink(id_filename, filename) < 0)
+                return log_device_error_errno(dev, errno, "Failed to create symlink %s: %m", filename);
+
+        return 0;
+}
+
+int udev_watch_end(sd_device *dev) {
+        char filename[STRLEN("/run/udev/watch/") + DECIMAL_STR_MAX(int)];
+        int wd, r;
+
+        if (inotify_fd < 0)
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Invalid inotify descriptor.");
+
+        r = device_get_watch_handle(dev, &wd);
+        if (r == -ENOENT)
+                return 0;
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to get watch handle, ignoring: %m");
+
+        log_device_debug(dev, "Removing watch");
+        (void) inotify_rm_watch(inotify_fd, wd);
+
+        xsprintf(filename, "/run/udev/watch/%d", wd);
+        (void) unlink(filename);
+
+        device_set_watch_handle(dev, -1);
+
+        return 0;
+}
+
+int udev_watch_lookup(int wd, sd_device **ret) {
+        char filename[STRLEN("/run/udev/watch/") + DECIMAL_STR_MAX(int)];
+        _cleanup_free_ char *device = NULL;
+        int r;
+
+        assert(ret);
+
+        if (inotify_fd < 0)
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Invalid inotify descriptor.");
+
+        if (wd < 0)
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Invalid watch handle.");
+
+        xsprintf(filename, "/run/udev/watch/%d", wd);
+        r = readlink_malloc(filename, &device);
+        if (r == -ENOENT)
+                return 0;
+        if (r < 0)
+                return log_debug_errno(r, "Failed to read link '%s': %m", filename);
+
+        r = sd_device_new_from_device_id(ret, device);
+        if (r == -ENODEV)
+                return 0;
+        if (r < 0)
+                return log_debug_errno(r, "Failed to create sd_device object for '%s': %m", device);
+
+        return 1;
+}