dhcp.hpp

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//    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- OpenVPN Inc.
//
//    SPDX-License-Identifier: MPL-2.0 OR AGPL-3.0-only WITH openvpn3-openssl-exception
//
 
#ifndef OPENVPN_IP_DHCP_H
#define OPENVPN_IP_DHCP_H
 
#include <openvpn/ip/eth.hpp>
#include <openvpn/ip/ip4.hpp>
#include <openvpn/ip/udp.hpp>
 
#pragma pack(push)
#pragma pack(1)
 
namespace openvpn {
struct DHCP
{
    enum
    {
        /* DHCP Option types */
        DHCP_PAD = 0,
        DHCP_NETMASK = 1,
        DHCP_ROUTER = 3,
        DHCP_DNS = 6,
        DHCP_MSG_TYPE = 53 /* message type (u8) */,
        DHCP_END = 255,
 
        /* DHCP Messages types */
        DHCPDISCOVER = 1,
        DHCPOFFER = 2,
        DHCPREQUEST = 3,
        DHCPDECLINE = 4,
        DHCPACK = 5,
        DHCPNAK = 6,
        DHCPRELEASE = 7,
        DHCPINFORM = 8,
 
        /* DHCP UDP port numbers */
        BOOTPS_PORT = 67,
        BOOTPC_PORT = 68,
 
        /* DHCP message op */
        BOOTREQUEST = 1,
        BOOTREPLY = 2,
    };
 
    std::uint8_t op;    /* message op */
    std::uint8_t htype; /* hardware address type (e.g. '1' = 10Mb Ethernet) */
    std::uint8_t hlen;  /* hardware address length (e.g. '6' for 10Mb Ethernet) */
    std::uint8_t hops;  /* client sets to 0, may be used by relay agents */
    std::uint32_t xid;  /* transaction ID, chosen by client */
    std::uint16_t secs; /* seconds since request process began, set by client */
    std::uint16_t flags;
    std::uint32_t ciaddr;    /* client IP address, client sets if known */
    std::uint32_t yiaddr;    /* 'your' IP address -- server's response to client */
    std::uint32_t siaddr;    /* server IP address */
    std::uint32_t giaddr;    /* relay agent IP address */
    std::uint8_t chaddr[16]; /* client hardware address */
    std::uint8_t sname[64];  /* optional server host name */
    std::uint8_t file[128];  /* boot file name */
    std::uint32_t magic;     /* must be 0x63825363 (network order) */
};
 
struct DHCPPacket
{
    EthHeader eth;
    IPv4Header ip;
    UDPHeader udp;
    DHCP dhcp;
    std::uint8_t options[];
};
} // namespace openvpn
 
#pragma pack(pop)
 
#endif