Imported Upstream version 1.2.24upstream/1.2.24

1 files changed, 279 insertions, 0 deletions

diff --git a/bus/dir-watch-inotify.c b/bus/dir-watch-inotify.c
new file mode 100644
index 00000000..094993bb
--- /dev/null
+++ b/bus/dir-watch-inotify.c
@@ -0,0 +1,279 @@
+/* -*- mode: C; c-file-style: "gnu" -*- */
+/* dir-watch-inotify.c  OS specific directory change notification for message bus
+ *
+ * Copyright (C) 2003 Red Hat, Inc.
+ *           (c) 2006 Mandriva
+ *
+ * Licensed under the Academic Free License version 2.1
+ * 
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include <config.h>
+
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/inotify.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <errno.h>
+
+#include <dbus/dbus-internals.h>
+#include <dbus/dbus-list.h>
+#include <dbus/dbus-watch.h>
+#include "dir-watch.h"
+
+#define MAX_DIRS_TO_WATCH 128
+#define INOTIFY_EVENT_SIZE (sizeof(struct inotify_event))
+#define INOTIFY_BUF_LEN (1024 * (INOTIFY_EVENT_SIZE + 16))
+
+/* use a static array to avoid handling OOM */
+static int wds[MAX_DIRS_TO_WATCH];
+static char *dirs[MAX_DIRS_TO_WATCH];
+static int num_wds = 0;
+static int inotify_fd = -1;
+static DBusWatch *watch = NULL;
+static DBusLoop *loop = NULL;
+
+static dbus_bool_t
+_inotify_watch_callback (DBusWatch *watch, unsigned int condition, void *data)
+{
+  return dbus_watch_handle (watch, condition);
+}
+
+static dbus_bool_t
+_handle_inotify_watch (DBusWatch *passed_watch, unsigned int flags, void *data)
+{
+  char buffer[INOTIFY_BUF_LEN];
+  ssize_t ret = 0;
+  int i = 0;
+  pid_t pid;
+  dbus_bool_t have_change = FALSE;
+
+  ret = read (inotify_fd, buffer, INOTIFY_BUF_LEN);
+  if (ret < 0)
+    _dbus_verbose ("Error reading inotify event: '%s'\n", _dbus_strerror(errno));
+  else if (!ret)
+    _dbus_verbose ("Error reading inotify event: buffer too small\n");
+
+  while (i < ret)
+    {
+      struct inotify_event *ev;
+      pid = _dbus_getpid ();
+
+      ev = (struct inotify_event *) &buffer[i];
+      i += INOTIFY_EVENT_SIZE + ev->len;
+#ifdef DBUS_ENABLE_VERBOSE_MODE
+      if (ev->len)
+        _dbus_verbose ("event name: '%s'\n", ev->name);
+      _dbus_verbose ("inotify event: wd=%d mask=%u cookie=%u len=%u\n", ev->wd, ev->mask, ev->cookie, ev->len);
+#endif
+      _dbus_verbose ("Sending SIGHUP signal on reception of a inotify event\n");
+      have_change = TRUE;
+    }
+  if (have_change)
+    (void) kill (pid, SIGHUP);
+
+  return TRUE;
+}
+
+#include <stdio.h>
+
+static void
+_set_watched_dirs_internal (DBusList **directories)
+{
+  int new_wds[MAX_DIRS_TO_WATCH];
+  char *new_dirs[MAX_DIRS_TO_WATCH];
+  DBusList *link;
+  int i, j, wd;
+
+  for (i = 0; i < MAX_DIRS_TO_WATCH; i++)
+    {
+      new_wds[i] = -1;
+      new_dirs[i] = NULL;
+    }
+
+  i = 0;
+  link = _dbus_list_get_first_link (directories);
+  while (link != NULL)
+    {
+      new_dirs[i++] = (char *)link->data;
+      link = _dbus_list_get_next_link (directories, link);
+    }
+
+  /* Look for directories in both the old and new sets, if
+   * we find one, move its data into the new set.
+   */
+  for (i = 0; new_dirs[i]; i++)
+    {
+      for (j = 0; j < num_wds; j++)
+        {
+          if (dirs[j] && strcmp (new_dirs[i], dirs[j]) == 0)
+            {
+              new_wds[i] = wds[j];
+              new_dirs[i] = dirs[j];
+              wds[j] = -1;
+              dirs[j] = NULL;
+              break;
+            }
+        }
+    }
+
+  /* Any directories we find in "wds" with a nonzero fd must
+   * not be in the new set, so perform cleanup now.
+   */
+  for (j = 0; j < num_wds; j++)
+    {
+      if (wds[j] != -1)
+        {
+          inotify_rm_watch (inotify_fd, wds[j]);
+          dbus_free (dirs[j]);
+          wds[j] = -1;
+          dirs[j] = NULL;
+        }
+    }
+
+  for (i = 0; new_dirs[i]; i++)
+    {
+      if (new_wds[i] == -1)
+        {
+          /* FIXME - less lame error handling for failing to add a watch; we may need to sleep. */
+          wd = inotify_add_watch (inotify_fd, new_dirs[i], IN_CLOSE_WRITE | IN_DELETE | IN_MOVED_TO | IN_MOVED_FROM);
+          if (wd < 0)
+            {
+              /* Not all service directories need to exist. */
+              if (errno != ENOENT)
+                {
+                  _dbus_warn ("Cannot setup inotify for '%s'; error '%s'\n", new_dirs[i], _dbus_strerror (errno));
+                  goto out;
+                }
+              else
+                {
+                  new_wds[i] = -1;
+                  new_dirs[i] = NULL;
+                  continue;
+                }
+            }
+          new_wds[i] = wd;
+          new_dirs[i] = _dbus_strdup (new_dirs[i]);
+          if (!new_dirs[i])
+            {
+              /* FIXME have less lame handling for OOM, we just silently fail to
+               * watch.  (In reality though, the whole OOM handling in dbus is stupid
+               * but we won't go into that in this comment =) )
+               */
+              inotify_rm_watch (inotify_fd, wd);
+              new_wds[i] = -1;
+            }
+        }
+    }
+
+  num_wds = i;
+
+  for (i = 0; i < MAX_DIRS_TO_WATCH; i++)
+    {
+      wds[i] = new_wds[i];
+      dirs[i] = new_dirs[i];
+    }
+
+ out:;
+}
+
+#include <stdio.h>
+static void
+_shutdown_inotify (void *data)
+{
+  DBusList *empty = NULL;
+
+  if (inotify_fd == -1)
+    return;
+
+  _set_watched_dirs_internal (&empty);
+
+  close (inotify_fd);
+  inotify_fd = -1;
+  if (watch != NULL)
+    {
+      _dbus_loop_remove_watch (loop, watch, _inotify_watch_callback, NULL);
+      _dbus_watch_unref (watch);
+      _dbus_loop_unref (loop);
+    }
+  watch = NULL;
+  loop = NULL;
+}
+
+static int
+_init_inotify (BusContext *context)
+{
+  int ret = 0;
+
+  if (inotify_fd == -1)
+    {
+#ifdef HAVE_INOTIFY_INIT1
+      inotify_fd = inotify_init1 (IN_CLOEXEC);
+      /* This ensures we still run on older Linux kernels.
+       * https://bugs.freedesktop.org/show_bug.cgi?id=23957
+       */
+      if (inotify_fd < 0)
+        inotify_fd = inotify_init ();
+#else
+      inotify_fd = inotify_init ();
+#endif
+      if (inotify_fd <= 0)
+        {
+          _dbus_warn ("Cannot initialize inotify\n");
+          goto out;
+        }
+      loop = bus_context_get_loop (context);
+      _dbus_loop_ref (loop);
+
+      watch = _dbus_watch_new (inotify_fd, DBUS_WATCH_READABLE, TRUE,
+                               _handle_inotify_watch, NULL, NULL);
+
+      if (watch == NULL)
+        {
+          _dbus_warn ("Unable to create inotify watch\n");
+          goto out;
+        }
+
+      if (!_dbus_loop_add_watch (loop, watch, _inotify_watch_callback,
+                                 NULL, NULL))
+        {
+          _dbus_warn ("Unable to add reload watch to main loop");
+          _dbus_watch_unref (watch);
+          watch = NULL;
+          goto out;
+        }
+
+      _dbus_register_shutdown_func (_shutdown_inotify, NULL);
+    }
+
+  ret = 1;
+
+out:
+  return ret;
+}
+
+void
+bus_set_watched_dirs (BusContext *context, DBusList **directories)
+{
+  if (!_init_inotify (context))
+    return;
+
+  _set_watched_dirs_internal (directories);
+}