udev-watch: replace udev_device by sd_device and modernize code a bit

1 files changed, 123 insertions, 80 deletions

diff --git a/src/udev/udev-watch.c b/src/udev/udev-watch.c
index 439117181a..d3e4391ee9 100644
--- a/src/udev/udev-watch.c
+++ b/src/udev/udev-watch.c
@@ -4,136 +4,179 @@
  * Copyright © 2009 Scott James Remnant <scott@netsplit.com>
  */
 
-#include <errno.h>
-#include <stddef.h>
-#include <stdio.h>
 #include <sys/inotify.h>
 #include <unistd.h>
 
+#include "device-private.h"
 #include "dirent-util.h"
+#include "mkdir.h"
 #include "stdio-util.h"
-#include "udev.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
- */
+ * watches for us. */
 int udev_watch_init(void) {
         inotify_fd = inotify_init1(IN_CLOEXEC);
         if (inotify_fd < 0)
-                log_error_errno(errno, "inotify_init failed: %m");
+                return log_error_errno(errno, "Failed to create inotify descriptor: %m");
+
         return inotify_fd;
 }
 
-/* move any old watches directory out of the way, and then restore
- * the watches
- */
-void udev_watch_restore(void) {
-        if (inotify_fd < 0)
-                return;
+/* 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 (rename("/run/udev/watch", "/run/udev/watch.old") == 0) {
-                DIR *dir;
-                struct dirent *ent;
+        if (inotify_fd < 0)
+                return log_error_errno(EINVAL, "Invalid inotify descriptor.");
 
-                dir = opendir("/run/udev/watch.old");
-                if (dir == NULL) {
-                        log_error_errno(errno, "unable to open old watches dir /run/udev/watch.old; old watches will not be restored: %m");
-                        return;
-                }
+        if (rename("/run/udev/watch", "/run/udev/watch.old") < 0) {
+                if (errno != ENOENT)
+                        return log_error_errno(errno, "Failed to move watches directory /run/udev/watch. Old watches will not be restored: %m");
 
-                FOREACH_DIRENT_ALL(ent, dir, break) {
-                        char device[UTIL_PATH_SIZE];
-                        ssize_t len;
-                        struct udev_device *dev;
+                return 0;
+        }
 
-                        if (ent->d_name[0] == '.')
-                                continue;
+        dir = opendir("/run/udev/watch.old");
+        if (!dir)
+                return log_error_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;
+                char device[PATH_MAX];
+                ssize_t len;
+
+                if (ent->d_name[0] == '.')
+                        continue;
+
+                len = readlinkat(dirfd(dir), ent->d_name, device, sizeof(device));
+                if (len <= 0) {
+                        log_error_errno(errno, "Failed to read link '/run/udev/watch.old/%s', ignoring: %m", ent->d_name);
+                        goto unlink;
+                } else if (len >= (ssize_t) sizeof(device)) {
+                        log_error("Path specified by link '/run/udev/watch.old/%s' is truncated, ignoring.", ent->d_name);
+                        goto unlink;
+                }
+                device[len] = '\0';
 
-                        len = readlinkat(dirfd(dir), ent->d_name, device, sizeof(device));
-                        if (len <= 0 || len == (ssize_t)sizeof(device))
-                                goto unlink;
-                        device[len] = '\0';
+                r = sd_device_new_from_device_id(&dev, device);
+                if (r < 0) {
+                        log_error_errno(r, "Failed to create sd_device object for '%s', ignoring: %m", device);
+                        goto unlink;
+                }
 
-                        dev = udev_device_new_from_device_id(NULL, device);
-                        if (dev == NULL)
-                                goto unlink;
+                if (DEBUG_LOGGING) {
+                        const char *devnode = NULL;
 
-                        log_debug("restoring old watch on '%s'", udev_device_get_devnode(dev));
-                        udev_watch_begin(dev);
-                        udev_device_unref(dev);
-unlink:
-                        (void) unlinkat(dirfd(dir), ent->d_name, 0);
+                        (void) sd_device_get_devname(dev, &devnode);
+                        log_debug("Restoring old watch on '%s'", strnull(devnode));
                 }
+                (void) udev_watch_begin(dev);
+unlink:
+                (void) unlinkat(dirfd(dir), ent->d_name, 0);
+        }
 
-                closedir(dir);
-                rmdir("/run/udev/watch.old");
+        (void) closedir(dir);
+        (void) rmdir("/run/udev/watch.old");
 
-        } else if (errno != ENOENT)
-                log_error_errno(errno, "unable to move watches dir /run/udev/watch; old watches will not be restored: %m");
+        return 0;
 }
 
-void udev_watch_begin(struct udev_device *dev) {
-        char filename[sizeof("/run/udev/watch/") + DECIMAL_STR_MAX(int)];
-        int wd;
-        int r;
+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("adding watch on '%s'", udev_device_get_devnode(dev));
-        wd = inotify_add_watch(inotify_fd, udev_device_get_devnode(dev), IN_CLOSE_WRITE);
-        if (wd < 0) {
-                log_error_errno(errno, "inotify_add_watch(%d, %s, %o) failed: %m",
-                                inotify_fd, udev_device_get_devnode(dev), IN_CLOSE_WRITE);
-                return;
-        }
+                return log_error_errno(EINVAL, "Invalid inotify descriptor.");
+
+        r = sd_device_get_devname(dev, &devnode);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get device name: %m");
+
+        log_debug("Adding watch on '%s'", devnode);
+        wd = inotify_add_watch(inotify_fd, devnode, IN_CLOSE_WRITE);
+        if (wd < 0)
+                return log_error_errno(errno, "Failed to add device '%s' to watch: %m", devnode);
+
+        device_set_watch_handle(dev, wd);
 
         xsprintf(filename, "/run/udev/watch/%d", wd);
-        mkdir_parents(filename, 0755);
-        unlink(filename);
-        r = symlink(udev_device_get_id_filename(dev), filename);
+        r = mkdir_parents(filename, 0755);
         if (r < 0)
-                log_error_errno(errno, "Failed to create symlink %s: %m", filename);
+                return log_error_errno(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_error_errno(r, "Failed to get device id-filename: %m");
+
+        if (symlink(id_filename, filename) < 0)
+                return log_error_errno(errno, "Failed to create symlink %s: %m", filename);
 
-        udev_device_set_watch_handle(dev, wd);
+        return 0;
 }
 
-void udev_watch_end(struct udev_device *dev) {
-        int wd;
-        char filename[sizeof("/run/udev/watch/") + DECIMAL_STR_MAX(int)];
+int udev_watch_end(sd_device *dev) {
+        char filename[STRLEN("/run/udev/watch/") + DECIMAL_STR_MAX(int)];
+        const char *devnode;
+        int wd, r;
 
         if (inotify_fd < 0)
-                return;
+                return log_error_errno(EINVAL, "Invalid inotify descriptor.");
 
-        wd = udev_device_get_watch_handle(dev);
-        if (wd < 0)
-                return;
+        r = device_get_watch_handle(dev, &wd);
+        if (r == -ENOENT)
+                return 0;
+        if (r < 0)
+                return log_error_errno(r, "Failed to get watch handle for device '%s', ignoring: %m", devnode);
+
+        r = sd_device_get_devname(dev, &devnode);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get device name: %m");
 
-        log_debug("removing watch on '%s'", udev_device_get_devnode(dev));
-        inotify_rm_watch(inotify_fd, wd);
+        log_debug("Removing watch on '%s'", devnode);
+        (void) inotify_rm_watch(inotify_fd, wd);
 
         xsprintf(filename, "/run/udev/watch/%d", wd);
-        unlink(filename);
+        (void) unlink(filename);
 
-        udev_device_set_watch_handle(dev, -1);
+        device_set_watch_handle(dev, -1);
+
+        return 0;
 }
 
-struct udev_device *udev_watch_lookup(int wd) {
-        char filename[sizeof("/run/udev/watch/") + DECIMAL_STR_MAX(int)];
-        char device[UTIL_NAME_SIZE];
+int udev_watch_lookup(int wd, sd_device **ret) {
+        char filename[STRLEN("/run/udev/watch/") + DECIMAL_STR_MAX(int)], device[PATH_MAX];
         ssize_t len;
+        int r;
+
+        assert(ret);
+
+        if (inotify_fd < 0)
+                return log_error_errno(EINVAL, "Invalid inotify descriptor.");
 
-        if (inotify_fd < 0 || wd < 0)
-                return NULL;
+        if (wd < 0)
+                return log_error_errno(EINVAL, "Invalid watch handle.");
 
         xsprintf(filename, "/run/udev/watch/%d", wd);
         len = readlink(filename, device, sizeof(device));
-        if (len <= 0 || (size_t)len == sizeof(device))
-                return NULL;
+        if (len <= 0) {
+                if (errno != ENOENT)
+                        return log_error_errno(errno, "Failed to read link '%s': %m", filename);
+                return 0;
+        } else if (len >= (ssize_t) sizeof(device))
+                return log_error_errno(ENAMETOOLONG, "Path specified by link '%s' is truncated.", filename);
         device[len] = '\0';
 
-        return udev_device_new_from_device_id(NULL, device);
+        r = sd_device_new_from_device_id(ret, device);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create sd_device object for '%s': %m", device);
+
+        return 0;
 }