VMS Help TCPIP Services, Programming Interfaces, Sockets API, getpeername(), Errors  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    EBADF              The descriptor is invalid.
    EFAULT             The name argument is not a valid part of the
                       user address space.
    EINVAL             The socket has been shut down.
    ENOBUFS            The system has insufficient resources to
                       complete the call.
    ENOTCONN           The socket is not connected.
    ENOTSOCK           The socket descriptor is invalid.
    EOPNOTSUPP         The operation is not supported for the socket
                       protocol.