openvpn/include/openvpn-msg.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) 2013-2025 Heiko Hund <heiko.hund@sophos.com>
 *
 *  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, see <https://www.gnu.org/licenses/>.
 */

#ifndef OPENVPN_MSG_H_
#define OPENVPN_MSG_H_

#include <windef.h>
#include <ws2tcpip.h>

typedef enum {
    msg_acknowledgement,
    msg_add_address,
    msg_del_address,
    msg_add_route,
    msg_del_route,
    msg_add_dns_cfg,
    msg_del_dns_cfg,
    msg_add_nrpt_cfg,
    msg_del_nrpt_cfg,
    msg_add_nbt_cfg,
    msg_del_nbt_cfg,
    msg_flush_neighbors,
    msg_add_wfp_block,
    msg_del_wfp_block,
    msg_register_dns,
    msg_enable_dhcp,
    deprecated_msg_register_ring_buffers,
    msg_set_mtu,
    msg_add_wins_cfg,
    msg_del_wins_cfg,
    msg_create_adapter
} message_type_t;

typedef struct {
    message_type_t type;
    size_t size;
    int message_id;
} message_header_t;

typedef union {
    struct in_addr ipv4;
    struct in6_addr ipv6;
} inet_address_t;

typedef struct {
    int index;
    char name[256];
} interface_t;

typedef enum {
    wfp_block_local = 1<<0,
    wfp_block_dns = 1<<1
} wfp_block_flags_t;

typedef struct {
    message_header_t header;
    short family;
    inet_address_t address;
    int prefix_len;
    interface_t iface;
} address_message_t;

typedef struct {
    message_header_t header;
    short family;
    inet_address_t prefix;
    int prefix_len;
    inet_address_t gateway;
    interface_t iface;
    int metric;
} route_message_t;

typedef struct {
    message_header_t header;
    interface_t iface;
    char domains[512];
    short family;
    int addr_len;
    inet_address_t addr[4]; /* support up to 4 dns addresses */
} dns_cfg_message_t;


typedef enum {
    nrpt_dnssec
} nrpt_flags_t;

#define NRPT_ADDR_NUM 8   /* Max. number of addresses */
#define NRPT_ADDR_SIZE 48 /* Max. address strlen + some */
typedef char nrpt_address_t[NRPT_ADDR_SIZE];
typedef struct {
    message_header_t header;
    interface_t iface;
    nrpt_address_t addresses[NRPT_ADDR_NUM];
    char resolve_domains[512]; /* double \0 terminated */
    char search_domains[512];
    nrpt_flags_t flags;
} nrpt_dns_cfg_message_t;

typedef struct {
    message_header_t header;
    interface_t iface;
    int addr_len;
    inet_address_t addr[4]; /* support up to 4 dns addresses */
} wins_cfg_message_t;

typedef struct {
    message_header_t header;
    interface_t iface;
    int disable_nbt;
    int nbt_type;
    char scope_id[256];
    struct in_addr primary_nbns;
    struct in_addr secondary_nbns;
} nbt_cfg_message_t;

/* TODO: NTP */

typedef struct {
    message_header_t header;
    short family;
    interface_t iface;
} flush_neighbors_message_t;

typedef struct {
    message_header_t header;
    int error_number;
} ack_message_t;

typedef struct {
    message_header_t header;
    wfp_block_flags_t flags;
    interface_t iface;
} wfp_block_message_t;

typedef struct {
    message_header_t header;
    interface_t iface;
} enable_dhcp_message_t;

typedef struct {
    message_header_t header;
    interface_t iface;
    short family;
    int mtu;
} set_mtu_message_t;

typedef enum {
    ADAPTER_TYPE_DCO,
    ADAPTER_TYPE_TAP,
} adapter_type_t;

typedef struct {
    message_header_t header;
    adapter_type_t adapter_type;
} create_adapter_message_t;

#endif /* ifndef OPENVPN_MSG_H_ */