// OpenVPN -- An application to securely tunnel IP networks
// over a single port, with support for SSL/TLS-based
// session authentication and key exchange,
// packet encryption, packet authentication, and
// packet compression.
//
// Copyright (C) 2012-2017 OpenVPN Inc.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License Version 3
// 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program in the COPYING file.
// If not, see .
// Define the ICMPv4 header
#pragma once
#include // for std::uint32_t, uint16_t, uint8_t
#include
#pragma pack(push)
#pragma pack(1)
namespace openvpn {
struct ICMPv4 {
enum {
ECHO_REQUEST = 8,
ECHO_REPLY = 0,
DEST_UNREACH = 3,
FRAG_NEEDED = 4,
MIN_DATA_SIZE = 8
};
struct IPv4Header head;
union {
struct {
std::uint8_t type;
std::uint8_t code;
};
std::uint16_t type_code;
};
std::uint16_t checksum;
union {
struct {
std::uint16_t id;
std::uint16_t seq_num;
};
struct {
std::uint16_t unused;
std::uint16_t nexthop_mtu;
};
};
};
}
#pragma pack(pop)