src/openvpn/ping.h

/*
 *  OpenVPN -- An application to securely tunnel IP networks
 *             over a single TCP/UDP port, with support for SSL/TLS-based
 *             session authentication and key exchange,
 *             packet encryption, packet authentication, and
 *             packet compression.
 *
 *  Copyright (C) 2002-2021 OpenVPN Inc <sales@openvpn.net>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef PING_H
#define PING_H

#include "init.h"
#include "forward.h"

/*
 * Initial default --ping-restart before --pull
 */
#define PRE_PULL_INITIAL_PING_RESTART 120  /* in seconds */

extern const uint8_t ping_string[];

/* PING_STRING_SIZE must be sizeof (ping_string) */
#define PING_STRING_SIZE 16

static inline bool
is_ping_msg(const struct buffer *buf)
{
    return buf_string_match(buf, ping_string, PING_STRING_SIZE);
}

/**
 * Trigger the correct signal on a --ping timeout
 * depending if --ping-exit is set (SIGTERM) or not
 * (SIGUSR1)
 */
void trigger_ping_timeout_signal(struct context *c);

void check_ping_send_dowork(struct context *c);

/*
 * Should we exit or restart due to ping (or other authenticated packet)
 * not received in n seconds?
 */
static inline void
check_ping_restart(struct context *c)
{
    if (c->options.ping_rec_timeout
        && event_timeout_trigger(&c->c2.ping_rec_interval,
                                 &c->c2.timeval,
                                 (!c->options.ping_timer_remote
                                  || link_socket_actual_defined(&c->c1.link_socket_addr.actual))
                                 ? ETT_DEFAULT : 15))
    {
        trigger_ping_timeout_signal(c);
    }
}

/*
 * Should we ping the remote?
 */
static inline void
check_ping_send(struct context *c)
{
    if (c->options.ping_send_timeout
        && event_timeout_trigger(&c->c2.ping_send_interval,
                                 &c->c2.timeval,
                                 !TO_LINK_DEF(c) ? ETT_DEFAULT : 1))
    {
        check_ping_send_dowork(c);
    }
}

#endif /* ifndef PING_H */