+/*
+ * Check if a connection is attached to a session.
+ * Return 1 if attached, 0 if not attached, a negative value on error.
+ */
+static
+int session_attached(struct relay_connection *conn, uint64_t session_id)
+{
+ struct relay_session *session;
+ int found = 0;
+
+ if (!conn->viewer_session) {
+ goto end;
+ }
+ cds_list_for_each_entry(session,
+ &conn->viewer_session->sessions_head,
+ viewer_session_list) {
+ if (session->id == session_id) {
+ found = 1;
+ goto end;
+ }
+ }
+
+end:
+ return found;
+}
+
+/*
+ * Delete all streams for a specific session ID.
+ */
+static void destroy_viewer_streams_by_session(struct relay_session *session)
+{
+ struct relay_viewer_stream *stream;
+ struct lttng_ht_iter iter;
+
+ assert(session);
+
+ rcu_read_lock();
+ cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, stream,
+ stream_n.node) {
+ struct ctf_trace *ctf_trace;
+
+ health_code_update();
+ if (stream->session_id != session->id) {
+ continue;
+ }
+
+ ctf_trace = ctf_trace_find_by_path(session->ctf_traces_ht,
+ stream->path_name);
+ assert(ctf_trace);
+
+ viewer_stream_delete(stream);
+
+ if (stream->metadata_flag) {
+ ctf_trace->metadata_sent = 0;
+ ctf_trace->viewer_metadata_stream = NULL;
+ }
+
+ viewer_stream_destroy(ctf_trace, stream);
+ }
+ rcu_read_unlock();
+}
+
+static void try_destroy_streams(struct relay_session *session)
+{
+ struct ctf_trace *ctf_trace;
+ struct lttng_ht_iter iter;
+
+ assert(session);
+
+ cds_lfht_for_each_entry(session->ctf_traces_ht->ht, &iter.iter, ctf_trace,
+ node.node) {
+ /* Attempt to destroy the ctf trace of that session. */
+ ctf_trace_try_destroy(session, ctf_trace);
+ }
+}
+
+/*
+ * Cleanup a session.
+ */
+static void cleanup_session(struct relay_connection *conn,
+ struct relay_session *session)
+{
+ /*
+ * Very important that this is done before destroying the session so we
+ * can put back every viewer stream reference from the ctf_trace.
+ */
+ destroy_viewer_streams_by_session(session);
+ try_destroy_streams(session);
+ cds_list_del(&session->viewer_session_list);
+ session_viewer_try_destroy(conn->sessions_ht, session);
+}
+