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/*
* 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) 2002-2010 OpenVPN Technologies, 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 (see the file COPYING included with this
* distribution); if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#elif defined(_MSC_VER)
#include "config-msvc.h"
#endif
#include "syshead.h"
#include "ping.h"
#include "memdbg.h"
#include "ping-inline.h"
/*
* This random string identifies an OpenVPN ping packet.
* It should be of sufficient length and randomness
* so as not to collide with other tunnel data.
*
* PING_STRING_SIZE must be sizeof (ping_string)
*/
const uint8_t ping_string[] = {
0x2a, 0x18, 0x7b, 0xf3, 0x64, 0x1e, 0xb4, 0xcb,
0x07, 0xed, 0x2d, 0x0a, 0x98, 0x1f, 0xc7, 0x48
};
/*
* Should we exit or restart due to ping (or other authenticated packet)
* not received in n seconds?
*/
void
check_ping_restart_dowork (struct context *c)
{
struct gc_arena gc = gc_new ();
switch (c->options.ping_rec_timeout_action)
{
case PING_EXIT:
msg (M_INFO, "%sInactivity timeout (--ping-exit), exiting",
format_common_name (c, &gc));
c->sig->signal_received = SIGTERM;
c->sig->signal_text = "ping-exit";
break;
case PING_RESTART:
msg (M_INFO, "%sInactivity timeout (--ping-restart), restarting",
format_common_name (c, &gc));
c->sig->signal_received = SIGUSR1; /* SOFT-SIGUSR1 -- Ping Restart */
c->sig->signal_text = "ping-restart";
break;
default:
ASSERT (0);
}
gc_free (&gc);
}
/*
* Should we ping the remote?
*/
void
check_ping_send_dowork (struct context *c)
{
c->c2.buf = c->c2.buffers->aux_buf;
ASSERT (buf_init (&c->c2.buf, FRAME_HEADROOM (&c->c2.frame)));
ASSERT (buf_safe (&c->c2.buf, MAX_RW_SIZE_TUN (&c->c2.frame)));
ASSERT (buf_write (&c->c2.buf, ping_string, sizeof (ping_string)));
/*
* We will treat the ping like any other outgoing packet,
* encrypt, sign, etc.
*/
encrypt_sign (c, true);
/* Set length to 0, so it won't be counted as activity */
c->c2.buf.len = 0;
dmsg (D_PING, "SENT PING");
}
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