1 files changed, 121 insertions, 0 deletions
diff --git a/src/core/or/ocirc_event.c b/src/core/or/ocirc_event.c
new file mode 100644
index 0000000000..fa16459175
--- /dev/null
+++ b/src/core/or/ocirc_event.c
@@ -0,0 +1,121 @@
+/* Copyright (c) 2007-2020, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file ocirc_event.c
+ * \brief Publish state change messages for origin circuits
+ *
+ * Implements a basic publish-subscribe framework for messages about
+ * the state of origin circuits.  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"
+
+#define OCIRC_EVENT_PRIVATE
+
+#include "core/or/cpath_build_state_st.h"
+#include "core/or/ocirc_event.h"
+#include "core/or/or_sys.h"
+#include "core/or/origin_circuit_st.h"
+#include "lib/subsys/subsys.h"
+
+DECLARE_PUBLISH(ocirc_state);
+DECLARE_PUBLISH(ocirc_chan);
+DECLARE_PUBLISH(ocirc_cevent);
+
+static void
+ocirc_event_free(msg_aux_data_t u)
+{
+  tor_free_(u.ptr);
+}
+
+static char *
+ocirc_state_fmt(msg_aux_data_t u)
+{
+  ocirc_state_msg_t *msg = (ocirc_state_msg_t *)u.ptr;
+  char *s = NULL;
+
+  tor_asprintf(&s, "<gid=%"PRIu32" state=%d onehop=%d>",
+               msg->gid, msg->state, msg->onehop);
+  return s;
+}
+
+static char *
+ocirc_chan_fmt(msg_aux_data_t u)
+{
+  ocirc_chan_msg_t *msg = (ocirc_chan_msg_t *)u.ptr;
+  char *s = NULL;
+
+  tor_asprintf(&s, "<gid=%"PRIu32" chan=%"PRIu64" onehop=%d>",
+               msg->gid, msg->chan, msg->onehop);
+  return s;
+}
+
+static char *
+ocirc_cevent_fmt(msg_aux_data_t u)
+{
+  ocirc_cevent_msg_t *msg = (ocirc_cevent_msg_t *)u.ptr;
+  char *s = NULL;
+
+  tor_asprintf(&s, "<gid=%"PRIu32" evtype=%d reason=%d onehop=%d>",
+               msg->gid, msg->evtype, msg->reason, msg->onehop);
+  return s;
+}
+
+static dispatch_typefns_t ocirc_state_fns = {
+  .free_fn = ocirc_event_free,
+  .fmt_fn = ocirc_state_fmt,
+};
+
+static dispatch_typefns_t ocirc_chan_fns = {
+  .free_fn = ocirc_event_free,
+  .fmt_fn = ocirc_chan_fmt,
+};
+
+static dispatch_typefns_t ocirc_cevent_fns = {
+  .free_fn = ocirc_event_free,
+  .fmt_fn = ocirc_cevent_fmt,
+};
+
+int
+ocirc_add_pubsub(struct pubsub_connector_t *connector)
+{
+  if (DISPATCH_REGISTER_TYPE(connector, ocirc_state, &ocirc_state_fns))
+    return -1;
+  if (DISPATCH_REGISTER_TYPE(connector, ocirc_chan, &ocirc_chan_fns))
+    return -1;
+  if (DISPATCH_REGISTER_TYPE(connector, ocirc_cevent, &ocirc_cevent_fns))
+    return -1;
+  if (DISPATCH_ADD_PUB(connector, ocirc, ocirc_state))
+    return -1;
+  if (DISPATCH_ADD_PUB(connector, ocirc, ocirc_chan))
+    return -1;
+  if (DISPATCH_ADD_PUB(connector, ocirc, ocirc_cevent))
+    return -1;
+  return 0;
+}
+
+void
+ocirc_state_publish(ocirc_state_msg_t *msg)
+{
+  PUBLISH(ocirc_state, msg);
+}
+
+void
+ocirc_chan_publish(ocirc_chan_msg_t *msg)
+{
+  PUBLISH(ocirc_chan, msg);
+}
+
+void
+ocirc_cevent_publish(ocirc_cevent_msg_t *msg)
+{
+  PUBLISH(ocirc_cevent, msg);
+}