/sys$common/syshlp/helplib.hlb TCPIP Services, Programming Interfaces, Sockets API, recvfrom(), Errors  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    EBADF              The socket descriptor is invalid.
    ECONNRESET         A connection was forcibly closed by a peer.
    EFAULT             A valid message buffer was not specified.
                       Nonexistent or protected address space is
                       specified for the message buffer.
    EINTR              A signal interrupted the recvfrom() function
                       before any data was available.
    EINVAL             The MSG_OOB flag is set, and no out-of-band
                       data is available.
    ENOBUFS            The system has insufficient resources to
                       complete the call.
    ENOMEM             The system did not have sufficient memory to
                       fulfill the request.
    ENOTCONN           A receive is attempted on a connection-
                       oriented socket that is not connected.
    ENOTSOCK           The socket descriptor is invalid.
    EOPNOTSUPP         The specified flags are not supported for this
                       socket type.
    ETIMEDOUT          The connection timed out when trying to
                       establish a connection or when a transmission
                       timed out on an active connection.
    EWOULDBLOCK        The NBIO (nonblocking) flag is set for the
                       socket descriptor and the process delayed
                       during the write operation.