--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mgw/ctrl_prot.c	Sat Jul 09 22:51:44 2022 -0800
@@ -0,0 +1,65 @@
+/*
+ * In this module we implement our control socket protocol.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <syslog.h>
+#include <unistd.h>
+#include "../include/tmgw_ctrl.h"
+#include "struct.h"
+#include "select.h"
+
+struct endpoint *
+find_ep_by_id(conn, id)
+	struct ctrl_conn *conn;
+	unsigned id;
+{
+	struct endpoint *ep;
+
+	for (ep = conn->endp_list; ep; ep = ep->next)
+		if (ep->ep_id == id)
+			return ep;
+	return 0;
+}
+
+void
+ctrl_message_handler(fd, conn)
+	struct ctrl_conn *conn;
+{
+	struct tmgw_ctrl_req req;
+	struct tmgw_ctrl_resp resp;
+	int rc;
+
+	rc = recv(fd, &req, sizeof req, 0);
+	if (rc < sizeof req) {
+		syslog(LOG_INFO, "ctrl connection closing %s active endpoints",
+			conn->endp_list ? "with" : "without");
+		close(fd);
+		FD_CLR(fd, &select_for_read);
+		dlcx_all_on_conn(conn);
+		free(conn);
+		return;
+	}
+	bzero(&resp, sizeof resp);
+	resp.transact_ref = req.transact_ref;
+	switch (req.opcode) {
+	case TMGW_CTRL_OP_CRCX:
+		process_crcx(conn, &req, &resp);
+		break;
+	case TMGW_CTRL_OP_MDCX:
+		process_mdcx(conn, &req, &resp);
+		break;
+	case TMGW_CTRL_OP_DLCX:
+		process_dlcx(conn, &req, &resp);
+		break;
+	default:
+		resp.res = TMGW_RESP_ERR_PROT;
+	}
+	send(fd, &resp, sizeof resp, 0);
+}