Merge branch 'dbus-1.8'

Conflicts:
	NEWS
	configure.ac

3 files changed, 68 insertions, 11 deletions

diff --git a/bus/activation.c b/bus/activation.c
index bdf9cf3d..ffedf4c5 100644
--- a/bus/activation.c
+++ b/bus/activation.c
@@ -1688,6 +1688,31 @@ out:
   return retval;
 }
 
+static void
+child_setup (void *user_data)
+{
+#ifdef DBUS_UNIX
+  BusActivation *activation = user_data;
+  DBusRLimit *initial_fd_limit;
+  DBusError error;
+
+  dbus_error_init (&error);
+  initial_fd_limit = bus_context_get_initial_fd_limit (activation->context);
+
+  if (initial_fd_limit != NULL &&
+      !_dbus_rlimit_restore_fd_limit (initial_fd_limit, &error))
+    {
+      /* unfortunately we don't actually know the service name here */
+      bus_context_log (activation->context,
+                       DBUS_SYSTEM_LOG_INFO,
+                       "Failed to reset fd limit before activating "
+                       "service: %s: %s",
+                       error.name, error.message);
+    }
+#endif
+}
+
+
 dbus_bool_t
 bus_activation_activate_service (BusActivation  *activation,
                                  DBusConnection *connection,
@@ -2121,7 +2146,8 @@ bus_activation_activate_service (BusActivation  *activation,
                                           service_name,
                                           argv,
                                           envp,
-                                          NULL, activation,
+                                          child_setup,
+                                          activation,
                                           &tmp_error))
     {
       _dbus_verbose ("Failed to spawn child\n");
diff --git a/bus/bus.c b/bus/bus.c
index 35d40754..47cc3452 100644
--- a/bus/bus.c
+++ b/bus/bus.c
@@ -64,6 +64,7 @@ struct BusContext
   BusPolicy *policy;
   BusMatchmaker *matchmaker;
   BusLimits limits;
+  DBusRLimit *initial_fd_limit;
   unsigned int fork : 1;
   unsigned int syslog : 1;
   unsigned int keep_umask : 1;
@@ -659,19 +660,38 @@ oom:
 static void
 raise_file_descriptor_limit (BusContext      *context)
 {
+#ifdef DBUS_UNIX
+  DBusError error = DBUS_ERROR_INIT;
 
-  /* I just picked this out of thin air; we need some extra
-   * descriptors for things like any internal pipes we create,
-   * inotify, connections to SELinux, etc.
-   */
-  unsigned int arbitrary_extra_fds = 32;
-  unsigned int limit;
+  /* we only do this once */
+  if (context->initial_fd_limit != NULL)
+    return;
 
-  limit = context->limits.max_completed_connections +
-    context->limits.max_incomplete_connections
-    + arbitrary_extra_fds;
+  context->initial_fd_limit = _dbus_rlimit_save_fd_limit (&error);
+
+  if (context->initial_fd_limit == NULL)
+    {
+      bus_context_log (context, DBUS_SYSTEM_LOG_INFO,
+                       "%s: %s", error.name, error.message);
+      dbus_error_free (&error);
+      return;
+    }
 
-  _dbus_request_file_descriptor_limit (limit);
+  /* We used to compute a suitable rlimit based on the configured number
+   * of connections, but that breaks down as soon as we allow fd-passing,
+   * because each connection is allowed to pass 64 fds to us, and if
+   * they all did, we'd hit kernel limits. We now hard-code 64k as a
+   * good limit, like systemd does: that's enough to avoid DoS from
+   * anything short of multiple uids conspiring against us.
+   */
+  if (!_dbus_rlimit_raise_fd_limit_if_privileged (65536, &error))
+    {
+      bus_context_log (context, DBUS_SYSTEM_LOG_INFO,
+                       "%s: %s", error.name, error.message);
+      dbus_error_free (&error);
+      return;
+    }
+#endif
 }
 
 static dbus_bool_t
@@ -1130,6 +1150,10 @@ bus_context_unref (BusContext *context)
 
           dbus_free (context->pidfile);
 	}
+
+      if (context->initial_fd_limit)
+        _dbus_rlimit_free (context->initial_fd_limit);
+
       dbus_free (context);
 
       dbus_server_free_data_slot (&server_data_slot);
@@ -1294,6 +1318,12 @@ bus_context_get_reply_timeout (BusContext *context)
   return context->limits.reply_timeout;
 }
 
+DBusRLimit *
+bus_context_get_initial_fd_limit (BusContext *context)
+{
+  return context->initial_fd_limit;
+}
+
 void
 bus_context_log (BusContext *context, DBusSystemLogSeverity severity, const char *msg, ...) _DBUS_GNUC_PRINTF (3, 4);
 
diff --git a/bus/bus.h b/bus/bus.h
index 7d0b3697..dac6ea5e 100644
--- a/bus/bus.h
+++ b/bus/bus.h
@@ -116,6 +116,7 @@ int               bus_context_get_max_services_per_connection    (BusContext
 int               bus_context_get_max_match_rules_per_connection (BusContext       *context);
 int               bus_context_get_max_replies_per_connection     (BusContext       *context);
 int               bus_context_get_reply_timeout                  (BusContext       *context);
+DBusRLimit *      bus_context_get_initial_fd_limit               (BusContext       *context);
 void              bus_context_log                                (BusContext       *context,
                                                                   DBusSystemLogSeverity severity,
                                                                   const char       *msg,