stuff
[oweals/gnunet.git] / src / util / client.c
index 86b36bfbba10b0d3c4b2e6849858dec5c973e708..55eb68d13ca2f58cdc2a584c1b7a810f56517b85 100644 (file)
@@ -136,6 +136,46 @@ struct TransmitGetResponseContext
   void *rn_cls;
 };
 
+/**
+ * Context for handling the shutdown of a service.
+ */
+struct ShutdownContext
+{
+  /**
+   * Scheduler to be used to call continuation
+   */
+  struct GNUNET_SCHEDULER_Handle *sched;
+  /**
+   * Connection to the service that is being shutdown.
+   */
+  struct GNUNET_CLIENT_Connection *sock;
+
+  /**
+   * Time allowed for shutdown to happen.
+   */
+  struct GNUNET_TIME_Absolute timeout;
+
+  /**
+   * Task set up to cancel the shutdown request on timeout.
+   */
+  GNUNET_SCHEDULER_TaskIdentifier cancel_task;
+
+  /**
+   * Task to call once shutdown complete
+   */
+  GNUNET_CLIENT_ShutdownTask cont;
+
+  /**
+   * Closure for shutdown continuation
+   */
+  void *cont_cls;
+
+  /**
+   * We received a confirmation that the service will shut down.
+   */
+  int confirmed;
+
+};
 
 /**
  * Struct to refer to a GNUnet TCP connection.
@@ -540,6 +580,94 @@ GNUNET_CLIENT_receive (struct GNUNET_CLIENT_Connection *sock,
 }
 
 
+/**
+ * Handler receiving response to service shutdown requests.
+ * First call with NULL: service misbehaving, or something.
+ * First call with GNUNET_MESSAGE_TYPE_SHUTDOWN_ACK:
+ *   - service will shutdown
+ * First call with GNUNET_MESSAGE_TYPE_SHUTDOWN_REFUSE:
+ *   - service will not be stopped!
+ *
+ * Second call with NULL:
+ *   - service has now really shut down.
+ *
+ * @param cls closure
+ * @param msg NULL, indicating socket closure.
+ */
+static void
+service_shutdown_handler (void *cls, const struct GNUNET_MessageHeader *msg)
+{
+  struct ShutdownContext *shutdown_ctx = cls;
+
+  if ((msg == NULL) && (shutdown_ctx->confirmed != GNUNET_YES))   
+    {
+      /* Means the other side closed the connection and never confirmed a shutdown */
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING, 
+                 "Service handle shutdown before ACK!\n");
+      if (shutdown_ctx->cont != NULL)
+        shutdown_ctx->cont(shutdown_ctx->cont_cls, GNUNET_SYSERR);      
+      GNUNET_SCHEDULER_cancel(shutdown_ctx->sched, shutdown_ctx->cancel_task);
+      GNUNET_CLIENT_disconnect (shutdown_ctx->sock, GNUNET_NO);
+      GNUNET_free(shutdown_ctx);
+    }
+  else if ((msg == NULL) && (shutdown_ctx->confirmed == GNUNET_YES))
+    {
+      GNUNET_log(GNUNET_ERROR_TYPE_WARNING, 
+                "Service shutdown complete.\n");
+      if (shutdown_ctx->cont != NULL)
+        shutdown_ctx->cont(shutdown_ctx->cont_cls, GNUNET_NO);
+
+      GNUNET_SCHEDULER_cancel(shutdown_ctx->sched, shutdown_ctx->cancel_task);
+      GNUNET_CLIENT_disconnect (shutdown_ctx->sock, GNUNET_NO);
+      GNUNET_free(shutdown_ctx);
+    }
+  else
+    {
+      GNUNET_assert(ntohs(msg->size) == sizeof(struct GNUNET_MessageHeader));
+
+      switch (ntohs(msg->type))
+      {
+      case GNUNET_MESSAGE_TYPE_SHUTDOWN_ACK:
+        GNUNET_log(GNUNET_ERROR_TYPE_WARNING,
+                  "Received confirmation for service shutdown.\n");
+        shutdown_ctx->confirmed = GNUNET_YES;
+        GNUNET_CLIENT_receive (shutdown_ctx->sock, 
+                              &service_shutdown_handler, 
+                              shutdown_ctx, 
+                              GNUNET_TIME_UNIT_FOREVER_REL);
+        break;
+      case GNUNET_MESSAGE_TYPE_SHUTDOWN_REFUSE:
+      default: /* Fall through */
+        GNUNET_log(GNUNET_ERROR_TYPE_WARNING, 
+                  "Service shutdown refused!\n");
+        if (shutdown_ctx->cont != NULL)
+          shutdown_ctx->cont(shutdown_ctx->cont_cls, GNUNET_YES);
+
+        GNUNET_SCHEDULER_cancel(shutdown_ctx->sched, shutdown_ctx->cancel_task);
+        GNUNET_CLIENT_disconnect (shutdown_ctx->sock, GNUNET_NO);
+        GNUNET_free(shutdown_ctx);
+        break;
+      }
+    }
+}
+
+/**
+ * Shutting down took too long, cancel receive and return error.
+ *
+ * @param cls closure
+ * @param tc context information (why was this task triggered now)
+ */
+void service_shutdown_cancel (void *cls,
+                              const struct GNUNET_SCHEDULER_TaskContext * tc)
+{
+  struct ShutdownContext *shutdown_ctx = cls;
+  GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "service_shutdown_cancel called!\n");
+  shutdown_ctx->cont(shutdown_ctx->cont_cls, GNUNET_SYSERR);
+  GNUNET_CLIENT_disconnect (shutdown_ctx->sock, GNUNET_NO);
+  GNUNET_free(shutdown_ctx);
+}
+
+
 /**
  * If possible, write a shutdown message to the target
  * buffer and destroy the client connection.
@@ -553,15 +681,25 @@ static size_t
 write_shutdown (void *cls, size_t size, void *buf)
 {
   struct GNUNET_MessageHeader *msg;
-  struct GNUNET_CLIENT_Connection *sock = cls;
+  struct ShutdownContext *shutdown_ctx = cls;
 
-  GNUNET_CLIENT_disconnect (sock, GNUNET_YES);
   if (size < sizeof (struct GNUNET_MessageHeader))
     {
-      GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                   _("Failed to transmit shutdown request to client.\n"));
+      shutdown_ctx->cont(shutdown_ctx->cont_cls, GNUNET_SYSERR);
+      GNUNET_CLIENT_disconnect (shutdown_ctx->sock, GNUNET_NO);
+      GNUNET_free(shutdown_ctx);
       return 0;                 /* client disconnected */
     }
+
+  GNUNET_CLIENT_receive (shutdown_ctx->sock,
+                        &service_shutdown_handler, shutdown_ctx, 
+                        GNUNET_TIME_UNIT_FOREVER_REL);
+  shutdown_ctx->cancel_task = GNUNET_SCHEDULER_add_delayed (shutdown_ctx->sched, 
+                                                           GNUNET_TIME_absolute_get_remaining(shutdown_ctx->timeout), 
+                                                           &service_shutdown_cancel, 
+                                                           shutdown_ctx);
   msg = (struct GNUNET_MessageHeader *) buf;
   msg->type = htons (GNUNET_MESSAGE_TYPE_SHUTDOWN);
   msg->size = htons (sizeof (struct GNUNET_MessageHeader));
@@ -576,16 +714,32 @@ write_shutdown (void *cls, size_t size, void *buf)
  * be used by the caller after this call
  * (calling this function frees "sock" after a while).
  *
+ * @param sched the scheduler to use for calling shutdown continuation
  * @param sock the socket connected to the service
+ * @param timeout how long to wait before giving up on transmission
+ * @param cont continuation to call once the service is really down
+ * @param cont_cls closure for continuation
+ *
  */
 void
-GNUNET_CLIENT_service_shutdown (struct GNUNET_CLIENT_Connection *sock)
+GNUNET_CLIENT_service_shutdown (struct GNUNET_SCHEDULER_Handle *sched,
+                                struct GNUNET_CLIENT_Connection *sock,
+                                struct GNUNET_TIME_Relative timeout,
+                                GNUNET_CLIENT_ShutdownTask cont,
+                                void *cont_cls)
 {
+  struct ShutdownContext *shutdown_ctx;
+  shutdown_ctx = GNUNET_malloc(sizeof(struct ShutdownContext));
+  shutdown_ctx->sched = sched;
+  shutdown_ctx->cont = cont;
+  shutdown_ctx->cont_cls = cont_cls;
+  shutdown_ctx->sock = sock;
+  shutdown_ctx->timeout = GNUNET_TIME_relative_to_absolute(timeout);
   GNUNET_CONNECTION_notify_transmit_ready (sock->sock,
                                            sizeof (struct
                                                    GNUNET_MessageHeader),
-                                           GNUNET_TIME_UNIT_FOREVER_REL,
-                                           &write_shutdown, sock);
+                                           timeout,
+                                           &write_shutdown, shutdown_ctx);
 }
 
 
@@ -648,6 +802,7 @@ write_test (void *cls, size_t size, void *buf)
                   _("Failure to transmit TEST request.\n"));
 #endif
       service_test_error (conn->sched, conn->test_cb, conn->test_cb_cls);
+      GNUNET_CLIENT_disconnect (conn, GNUNET_NO);
       return 0;                 /* client disconnected */
     }
 #if DEBUG_CLIENT