--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mncc/outcall.c	Sat Jun 08 23:12:12 2024 +0000
@@ -0,0 +1,69 @@
+/*
+ * In this module we handle routing of outbound MO calls
+ * to the outcall socket provided by themwi-sip-out.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <syslog.h>
+#include <unistd.h>
+#include "../include/mncc.h"
+#include "../include/gsm48_const.h"
+#include "struct.h"
+
+extern struct socket_conn outcall_conn;
+
+static char outcall_socket_pathname[] = "/var/gsm/outcall_socket";
+
+connect_outcall_socket()
+{
+	struct sockaddr_un sa;
+	unsigned sa_len;
+	int fd, rc;
+
+	if (outcall_conn.fd >= 0)
+		return(0);
+	fd = socket(AF_UNIX, SOCK_SEQPACKET, 0);
+	if (fd < 0) {
+		syslog(LOG_CRIT, "socket(AF_UNIX, SOCK_SEQPACKET, 0): %m");
+		return(-1);
+	}
+	fill_sockaddr_un(outcall_socket_pathname, &sa, &sa_len);
+	rc = connect(fd, (struct sockaddr *) &sa, sa_len);
+	if (rc < 0) {
+		syslog(LOG_ERR, "connect to %s: %m", outcall_socket_pathname);
+		close(fd);
+		return(-1);
+	}
+	update_max_fd(fd);
+	outcall_conn.fd = fd;
+	return(0);
+}
+
+void
+outbound_mo_setup(call, msg)
+	struct gsm_call *call;
+	struct gsm_mncc *msg;
+{
+	int rc;
+
+	rc = connect_outcall_socket();
+	if (rc < 0) {
+		syslog(LOG_ERR, "rejecting MO call 0x%x: outbound gateway down",
+			msg->callref);
+		reject_mo_call(msg->callref, GSM48_CAUSE_LOC_PRN_S_LU,
+				GSM48_CC_CAUSE_DEST_OOO);
+		call->gc_flag = 1;
+		return;
+	}
+	call->socket = &outcall_conn;
+	call->socket_ref = msg->callref;
+	outcall_conn.ncalls++;
+	mncc_signal_to_socket(call, msg);
+}