[PATCH 2/2] systemd-logind: don't second guess D-Bus default timeout

Ray Strode rstrode at redhat.com
Thu Apr 16 08:28:16 PDT 2015


At the moment, the X server uses a non-default timeout for D-Bus
messages to systemd-logind. The only timeouts normally used with
D-Bus are:

1) Infinite
2) Default

Anything else is just as arbitrary as Default, and so rarely makes
sense to use instead of Default.

Put another way, there's little reason to be fault tolerant against
a local root running daemon (logind), that in some configurations, the
X server already depends on for proper functionality.

This commit changes systemd-logind to just use the default timeouts.

Downstream-bug: https://bugzilla.redhat.com/show_bug.cgi?id=1209347
Signed-off-by: Ray Strode <rstrode at redhat.com>
---
 hw/xfree86/os-support/linux/systemd-logind.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/hw/xfree86/os-support/linux/systemd-logind.c b/hw/xfree86/os-support/linux/systemd-logind.c
index 57c87c0..4ad41a3 100644
--- a/hw/xfree86/os-support/linux/systemd-logind.c
+++ b/hw/xfree86/os-support/linux/systemd-logind.c
@@ -13,62 +13,60 @@
  * Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  *
  * Author: Hans de Goede <hdegoede at redhat.com>
  */
 
 #ifdef HAVE_XORG_CONFIG_H
 #include <xorg-config.h>
 #endif
 
 #include <dbus/dbus.h>
 #include <string.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include "os.h"
 #include "dbus-core.h"
 #include "xf86.h"
 #include "xf86platformBus.h"
 #include "xf86Xinput.h"
 
 #include "systemd-logind.h"
 
-#define DBUS_TIMEOUT 500 /* Wait max 0.5 seconds */
-
 struct systemd_logind_info {
     DBusConnection *conn;
     char *session;
     Bool active;
     Bool vt_active;
 };
 
 static struct systemd_logind_info logind_info;
 
 static InputInfoPtr
 systemd_logind_find_info_ptr_by_devnum(InputInfoPtr start,
                                        int major, int minor)
 {
     InputInfoPtr pInfo;
 
     for (pInfo = start; pInfo; pInfo = pInfo->next)
         if (pInfo->major == major && pInfo->minor == minor &&
                 (pInfo->flags & XI86_SERVER_FD))
             return pInfo;
 
     return NULL;
 }
 
 static void
 systemd_logind_set_input_fd_for_all_devs(int major, int minor, int fd,
                                          Bool enable)
 {
     InputInfoPtr pInfo;
 
     pInfo = systemd_logind_find_info_ptr_by_devnum(xf86InputDevs, major, minor);
@@ -103,61 +101,61 @@ systemd_logind_take_fd(int _major, int _minor, const char *path,
     if (strstr(path, "mouse"))
         return -1;
 
     /* Check if we already have an InputInfo entry with this major, minor
      * (shared device-nodes happen ie with Wacom tablets). */
     pInfo = systemd_logind_find_info_ptr_by_devnum(xf86InputDevs, major, minor);
     if (pInfo) {
         LogMessage(X_INFO, "systemd-logind: returning pre-existing fd for %s %u:%u\n",
                path, major, minor);
         *paused_ret = FALSE;
         return pInfo->fd;
     }
 
     dbus_error_init(&error);
 
     msg = dbus_message_new_method_call("org.freedesktop.login1", info->session,
             "org.freedesktop.login1.Session", "TakeDevice");
     if (!msg) {
         LogMessage(X_ERROR, "systemd-logind: out of memory\n");
         goto cleanup;
     }
 
     if (!dbus_message_append_args(msg, DBUS_TYPE_UINT32, &major,
                                        DBUS_TYPE_UINT32, &minor,
                                        DBUS_TYPE_INVALID)) {
         LogMessage(X_ERROR, "systemd-logind: out of memory\n");
         goto cleanup;
     }
 
     reply = dbus_connection_send_with_reply_and_block(info->conn, msg,
-                                                      DBUS_TIMEOUT, &error);
+                                                      DBUS_TIMEOUT_USE_DEFAULT, &error);
     if (!reply) {
         LogMessage(X_ERROR, "systemd-logind: failed to take device %s: %s\n",
                    path, error.message);
         goto cleanup;
     }
 
     if (!dbus_message_get_args(reply, &error,
                                DBUS_TYPE_UNIX_FD, &fd,
                                DBUS_TYPE_BOOLEAN, &paused,
                                DBUS_TYPE_INVALID)) {
         LogMessage(X_ERROR, "systemd-logind: TakeDevice %s: %s\n",
                    path, error.message);
         goto cleanup;
     }
 
     *paused_ret = paused;
 
     LogMessage(X_INFO, "systemd-logind: got fd for %s %u:%u fd %d paused %d\n",
                path, major, minor, fd, paused);
 
 cleanup:
     if (msg)
         dbus_message_unref(msg);
     if (reply)
         dbus_message_unref(reply);
     dbus_error_free(&error);
 
     return fd;
 }
 
@@ -180,61 +178,61 @@ systemd_logind_release_fd(int _major, int _minor, int fd)
      * and minor, otherwise other InputInfo's are still referencing the fd. */
     pInfo = systemd_logind_find_info_ptr_by_devnum(xf86InputDevs, major, minor);
     while (pInfo) {
         matches++;
         pInfo = systemd_logind_find_info_ptr_by_devnum(pInfo->next, major, minor);
     }
     if (matches > 1) {
         LogMessage(X_INFO, "systemd-logind: not releasing fd for %u:%u, still in use\n", major, minor);
         return;
     }
 
     LogMessage(X_INFO, "systemd-logind: releasing fd for %u:%u\n", major, minor);
 
     dbus_error_init(&error);
 
     msg = dbus_message_new_method_call("org.freedesktop.login1", info->session,
             "org.freedesktop.login1.Session", "ReleaseDevice");
     if (!msg) {
         LogMessage(X_ERROR, "systemd-logind: out of memory\n");
         goto cleanup;
     }
 
     if (!dbus_message_append_args(msg, DBUS_TYPE_UINT32, &major,
                                        DBUS_TYPE_UINT32, &minor,
                                        DBUS_TYPE_INVALID)) {
         LogMessage(X_ERROR, "systemd-logind: out of memory\n");
         goto cleanup;
     }
 
     reply = dbus_connection_send_with_reply_and_block(info->conn, msg,
-                                                      DBUS_TIMEOUT, &error);
+                                                      DBUS_TIMEOUT_USE_DEFAULT, &error);
     if (!reply)
         LogMessage(X_ERROR, "systemd-logind: failed to release device: %s\n",
                    error.message);
 
 cleanup:
     if (msg)
         dbus_message_unref(msg);
     if (reply)
         dbus_message_unref(reply);
     dbus_error_free(&error);
 close:
     if (fd != -1)
         close(fd);
 }
 
 int
 systemd_logind_controls_session(void)
 {
     return logind_info.session ? 1 : 0;
 }
 
 void
 systemd_logind_vtenter(void)
 {
     struct systemd_logind_info *info = &logind_info;
     InputInfoPtr pInfo;
     int i;
 
     if (!info->session)
         return; /* Not using systemd-logind */
@@ -262,61 +260,61 @@ systemd_logind_vtenter(void)
 
     /* Do delayed input probing, this must be done after the above enabling */
     xf86InputEnableVTProbe();
 }
 
 static void
 systemd_logind_ack_pause(struct systemd_logind_info *info,
                          dbus_int32_t minor, dbus_int32_t major)
 {
     DBusError error;
     DBusMessage *msg = NULL;
     DBusMessage *reply = NULL;
 
     dbus_error_init(&error);
 
     msg = dbus_message_new_method_call("org.freedesktop.login1", info->session,
             "org.freedesktop.login1.Session", "PauseDeviceComplete");
     if (!msg) {
         LogMessage(X_ERROR, "systemd-logind: out of memory\n");
         goto cleanup;
     }
 
     if (!dbus_message_append_args(msg, DBUS_TYPE_UINT32, &major,
                                        DBUS_TYPE_UINT32, &minor,
                                        DBUS_TYPE_INVALID)) {
         LogMessage(X_ERROR, "systemd-logind: out of memory\n");
         goto cleanup;
     }
 
     reply = dbus_connection_send_with_reply_and_block(info->conn, msg,
-                                                      DBUS_TIMEOUT, &error);
+                                                      DBUS_TIMEOUT_USE_DEFAULT, &error);
     if (!reply)
         LogMessage(X_ERROR, "systemd-logind: failed to ack pause: %s\n",
                    error.message);
 
 cleanup:
     if (msg)
         dbus_message_unref(msg);
     if (reply)
         dbus_message_unref(reply);
     dbus_error_free(&error);
 }
 
 static DBusHandlerResult
 message_filter(DBusConnection * connection, DBusMessage * message, void *data)
 {
     struct systemd_logind_info *info = data;
     struct xf86_platform_device *pdev = NULL;
     InputInfoPtr pInfo = NULL;
     int ack = 0, pause = 0, fd = -1;
     DBusError error;
     dbus_int32_t major, minor;
     char *pause_str;
 
     if (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_SIGNAL)
         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 
     dbus_error_init(&error);
 
     if (dbus_message_is_signal(message,
                                "org.freedesktop.DBus", "NameOwnerChanged")) {
@@ -430,96 +428,96 @@ message_filter(DBusConnection * connection, DBusMessage * message, void *data)
 }
 
 static void
 connect_hook(DBusConnection *connection, void *data)
 {
     struct systemd_logind_info *info = data;
     DBusError error;
     DBusMessage *msg = NULL;
     DBusMessage *reply = NULL;
     dbus_int32_t arg;
     char *session = NULL;
 
     dbus_error_init(&error);
 
     msg = dbus_message_new_method_call("org.freedesktop.login1",
             "/org/freedesktop/login1", "org.freedesktop.login1.Manager",
             "GetSessionByPID");
     if (!msg) {
         LogMessage(X_ERROR, "systemd-logind: out of memory\n");
         goto cleanup;
     }
 
     arg = getpid();
     if (!dbus_message_append_args(msg, DBUS_TYPE_UINT32, &arg,
                                   DBUS_TYPE_INVALID)) {
         LogMessage(X_ERROR, "systemd-logind: out of memory\n");
         goto cleanup;
     }
 
     reply = dbus_connection_send_with_reply_and_block(connection, msg,
-                                                      DBUS_TIMEOUT, &error);
+                                                      DBUS_TIMEOUT_USE_DEFAULT, &error);
     if (!reply) {
         LogMessage(X_ERROR, "systemd-logind: failed to get session: %s\n",
                    error.message);
         goto cleanup;
     }
     dbus_message_unref(msg);
 
     if (!dbus_message_get_args(reply, &error, DBUS_TYPE_OBJECT_PATH, &session,
                                DBUS_TYPE_INVALID)) {
         LogMessage(X_ERROR, "systemd-logind: GetSessionByPID: %s\n",
                    error.message);
         goto cleanup;
     }
     session = XNFstrdup(session);
 
     dbus_message_unref(reply);
     reply = NULL;
 
 
     msg = dbus_message_new_method_call("org.freedesktop.login1",
             session, "org.freedesktop.login1.Session", "TakeControl");
     if (!msg) {
         LogMessage(X_ERROR, "systemd-logind: out of memory\n");
         goto cleanup;
     }
 
     arg = FALSE; /* Don't forcibly take over over the session */
     if (!dbus_message_append_args(msg, DBUS_TYPE_BOOLEAN, &arg,
                                   DBUS_TYPE_INVALID)) {
         LogMessage(X_ERROR, "systemd-logind: out of memory\n");
         goto cleanup;
     }
 
     reply = dbus_connection_send_with_reply_and_block(connection, msg,
-                                                      DBUS_TIMEOUT, &error);
+                                                      DBUS_TIMEOUT_USE_DEFAULT, &error);
     if (!reply) {
         LogMessage(X_ERROR, "systemd-logind: TakeControl failed: %s\n",
                    error.message);
         goto cleanup;
     }
 
     dbus_bus_add_match(connection,
         "type='signal',sender='org.freedesktop.DBus',interface='org.freedesktop.DBus',member='NameOwnerChanged',path='/org/freedesktop/DBus'",
         &error);
     if (dbus_error_is_set(&error)) {
         LogMessage(X_ERROR, "systemd-logind: could not add match: %s\n",
                    error.message);
         goto cleanup;
     }
 
     /*
      * HdG: This is not useful with systemd <= 208 since the signal only
      * contains invalidated property names there, rather than property, val
      * pairs as it should.  Instead we just use the first resume / pause now.
      */
 #if 0
     snprintf(match, sizeof(match),
         "type='signal',sender='org.freedesktop.login1',interface='org.freedesktop.DBus.Properties',member='PropertiesChanged',path='%s'",
         session);
     dbus_bus_add_match(connection, match, &error);
     if (dbus_error_is_set(&error)) {
         LogMessage(X_ERROR, "systemd-logind: could not add match: %s\n",
                    error.message);
         goto cleanup;
     }
@@ -537,61 +535,61 @@ connect_hook(DBusConnection *connection, void *data)
     info->session = session;
     info->vt_active = info->active = TRUE; /* The server owns the vt during init */
     session = NULL;
 
 cleanup:
     free(session);
     if (msg)
         dbus_message_unref(msg);
     if (reply)
         dbus_message_unref(reply);
     dbus_error_free(&error);
 }
 
 static void
 systemd_logind_release_control(struct systemd_logind_info *info)
 {
     DBusError error;
     DBusMessage *msg = NULL;
     DBusMessage *reply = NULL;
 
     dbus_error_init(&error);
 
     msg = dbus_message_new_method_call("org.freedesktop.login1",
             info->session, "org.freedesktop.login1.Session", "ReleaseControl");
     if (!msg) {
         LogMessage(X_ERROR, "systemd-logind: out of memory\n");
         goto cleanup;
     }
 
     reply = dbus_connection_send_with_reply_and_block(info->conn, msg,
-                                                      DBUS_TIMEOUT, &error);
+                                                      DBUS_TIMEOUT_USE_DEFAULT, &error);
     if (!reply) {
         LogMessage(X_ERROR, "systemd-logind: ReleaseControl failed: %s\n",
                    error.message);
         goto cleanup;
     }
 
 cleanup:
     if (msg)
         dbus_message_unref(msg);
     if (reply)
         dbus_message_unref(reply);
     dbus_error_free(&error);
 }
 
 static void
 disconnect_hook(void *data)
 {
     struct systemd_logind_info *info = data;
 
     free(info->session);
     info->session = NULL;
     info->conn = NULL;
 }
 
 static struct dbus_core_hook core_hook = {
     .connect = connect_hook,
     .disconnect = disconnect_hook,
     .data = &logind_info,
 };
 
-- 
2.3.5



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