sockopt.hpp

//    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_COMMON_SOCKOPT_H
#define OPENVPN_COMMON_SOCKOPT_H

#include <openvpn/common/platform.hpp>

#if !defined(OPENVPN_PLATFORM_WIN)

#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>

#include <openvpn/common/exception.hpp>

namespace openvpn::SockOpt {

#ifdef SO_REUSEPORT
// set SO_REUSEPORT for inter-thread load balancing
inline void reuseport(const int fd)
{
    int on = 1;
    if (::setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, (void *)&on, sizeof(on)) < 0)
        throw Exception("error setting SO_REUSEPORT on socket");
}
#endif

// set SO_REUSEADDR for TCP
inline void reuseaddr(const int fd)
{
    int on = 1;
    if (::setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)) < 0)
        throw Exception("error setting SO_REUSEADDR on socket");
}

// set TCP_NODELAY for TCP
inline void tcp_nodelay(const int fd)
{
    int state = 1;
    if (::setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, (void *)&state, sizeof(state)) != 0)
        throw Exception("error setting TCP_NODELAY on socket");
}

// set FD_CLOEXEC to prevent fd from being passed across execs
inline void set_cloexec(const int fd)
{
    if (::fcntl(fd, F_SETFD, FD_CLOEXEC) < 0)
        throw Exception("error setting FD_CLOEXEC on file-descriptor/socket");
}

// set non-block mode on socket
static inline void set_nonblock(const int fd)
{
    if (::fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
        throw Exception("error setting socket to non-blocking mode");
}
} // namespace openvpn::SockOpt

#endif
#endif