1 files changed, 92 insertions, 0 deletions
diff --git a/src/core/or/orconn_event.c b/src/core/or/orconn_event.c
new file mode 100644
index 0000000000..c30e2dd22f
--- /dev/null
+++ b/src/core/or/orconn_event.c
@@ -0,0 +1,92 @@
+/* Copyright (c) 2007-2020, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file orconn_event.c
+ * \brief Publish state change messages for OR connections
+ *
+ * Implements a basic publish-subscribe framework for messages about
+ * the state of OR connections.  The publisher calls the subscriber
+ * callback functions synchronously.
+ *
+ * Although the synchronous calls might not simplify the call graph,
+ * this approach improves data isolation because the publisher doesn't
+ * need knowledge about the internals of subscribing subsystems.  It
+ * also avoids race conditions that might occur in asynchronous
+ * frameworks.
+ **/
+
+#include "core/or/or.h"
+#include "lib/pubsub/pubsub.h"
+#include "lib/subsys/subsys.h"
+
+#define ORCONN_EVENT_PRIVATE
+#include "core/or/orconn_event.h"
+#include "core/or/or_sys.h"
+
+DECLARE_PUBLISH(orconn_state);
+DECLARE_PUBLISH(orconn_status);
+
+static void
+orconn_event_free(msg_aux_data_t u)
+{
+  tor_free_(u.ptr);
+}
+
+static char *
+orconn_state_fmt(msg_aux_data_t u)
+{
+  orconn_state_msg_t *msg = (orconn_state_msg_t *)u.ptr;
+  char *s = NULL;
+
+  tor_asprintf(&s, "<gid=%"PRIu64" chan=%"PRIu64" proxy_type=%d state=%d>",
+               msg->gid, msg->chan, msg->proxy_type, msg->state);
+  return s;
+}
+
+static char *
+orconn_status_fmt(msg_aux_data_t u)
+{
+  orconn_status_msg_t *msg = (orconn_status_msg_t *)u.ptr;
+  char *s = NULL;
+
+  tor_asprintf(&s, "<gid=%"PRIu64" status=%d reason=%d>",
+               msg->gid, msg->status, msg->reason);
+  return s;
+}
+
+static dispatch_typefns_t orconn_state_fns = {
+  .free_fn = orconn_event_free,
+  .fmt_fn = orconn_state_fmt,
+};
+
+static dispatch_typefns_t orconn_status_fns = {
+  .free_fn = orconn_event_free,
+  .fmt_fn = orconn_status_fmt,
+};
+
+int
+orconn_add_pubsub(struct pubsub_connector_t *connector)
+{
+  if (DISPATCH_REGISTER_TYPE(connector, orconn_state, &orconn_state_fns))
+    return -1;
+  if (DISPATCH_REGISTER_TYPE(connector, orconn_status, &orconn_status_fns))
+    return -1;
+  if (DISPATCH_ADD_PUB(connector, orconn, orconn_state) != 0)
+    return -1;
+  if (DISPATCH_ADD_PUB(connector, orconn, orconn_status) != 0)
+    return -1;
+  return 0;
+}
+
+void
+orconn_state_publish(orconn_state_msg_t *msg)
+{
+  PUBLISH(orconn_state, msg);
+}
+
+void
+orconn_status_publish(orconn_status_msg_t *msg)
+{
+  PUBLISH(orconn_status, msg);
+}