Function CreateSockOS

src/netbase.cpp:522–575

}

std::unique_ptr<Sock> CreateSockOS(int domain, int type, int protocol)
{
    // Not IPv4, IPv6 or UNIX
    if (domain == AF_UNSPEC) return nullptr;

    // Create a socket in the specified address family.
    SOCKET hSocket = socket(domain, type, protocol);
    if (hSocket == INVALID_SOCKET) {
        return nullptr;
    }

    auto sock = std::make_unique<Sock>(hSocket);

    if (domain != AF_INET && domain != AF_INET6 && domain != AF_UNIX) {
        return sock;
    }

    // Ensure that waiting for I/O on this socket won't result in undefined
    // behavior.
    if (!sock->IsSelectable()) {
        LogInfo("Cannot create connection: non-selectable socket created (fd >= FD_SETSIZE ?)\n");
        return nullptr;
    }

#ifdef SO_NOSIGPIPE
    int set = 1;
    // Set the no-sigpipe option on the socket for BSD systems, other UNIXes
    // should use the MSG_NOSIGNAL flag for every send.
    if (sock->SetSockOpt(SOL_SOCKET, SO_NOSIGPIPE, &set, sizeof(int)) == SOCKET_ERROR) {
        LogInfo("Error setting SO_NOSIGPIPE on socket: %s, continuing anyway\n",
                  NetworkErrorString(WSAGetLastError()));
    }
#endif

    // Set the non-blocking option on the socket.
    if (!sock->SetNonBlocking()) {
        LogInfo("Error setting socket to non-blocking: %s\n", NetworkErrorString(WSAGetLastError()));
        return nullptr;
    }

#ifdef HAVE_SOCKADDR_UN
    if (domain == AF_UNIX) return sock;
#endif

    if (protocol == IPPROTO_TCP) {
        // Set the no-delay option (disable Nagle's algorithm) on the TCP socket.
        const int on{1};
        if (sock->SetSockOpt(IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) == SOCKET_ERROR) {
            LogDebug(BCLog::NET, "Unable to set TCP_NODELAY on a newly created socket, continuing anyway\n");
        }
    }

    return sock;
}

std::function<std::unique_ptr<Sock>(int, int, int)> CreateSock = CreateSockOS;