/*
 * In this module we implement low-level handling
 * of the main MNCC socket that connects to OsmoMSC.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <syslog.h>
#include "../include/mncc.h"

static char mncc_socket_pathname[] = "/var/gsm/mncc_socket";

int mncc_socket;

open_mncc_socket()
{
	struct sockaddr_un sa;
	unsigned sa_len;
	int rc;

	mncc_socket = socket(AF_UNIX, SOCK_SEQPACKET, 0);
	if (mncc_socket < 0) {
		syslog(LOG_CRIT, "socket(AF_UNIX, SOCK_SEQPACKET, 0): %m");
		return(-1);
	}
	fill_sockaddr_un(mncc_socket_pathname, &sa, &sa_len);
	rc = connect(mncc_socket, (struct sockaddr *) &sa, sa_len);
	if (rc < 0) {
		syslog(LOG_ERR, "connect to %s: %m", mncc_socket_pathname);
		return(-1);
	}
	update_max_fd(mncc_socket);
	return(0);
}

void
mncc_socket_select()
{
	union mncc_msg msg;
	int rc;

	rc = recv(mncc_socket, &msg, sizeof msg, 0);
	if (rc < 0) {
		syslog(LOG_CRIT, "error reading from MNCC socket: %m");
		exit(1);
	}
	if (rc < 4) {
		syslog(LOG_CRIT, "short read from MNCC socket: %d bytes", rc);
		exit(1);
	}
	mncc_msg_from_gsm(&msg, rc);
}

send_mncc_to_gsm(msg, msglen)
	union mncc_msg *msg;
	unsigned msglen;
{
	return send(mncc_socket, msg, msglen, 0);
}