selftests: bpf: log direct file writes

    """

    Class for netdevsim bus device and its attributes.

    """

    @staticmethod

    def ctrl_write(path, val):

        fullpath = os.path.join("/sys/bus/netdevsim/", path)

        try:

            with open(fullpath, "w") as f:

                f.write(val)

        except OSError as e:

            log("WRITE %s: %r" % (fullpath, val), -e.errno)

            raise e

        log("WRITE %s: %r" % (fullpath, val), 0)

    def __init__(self, port_count=1):

        addr = 0

        while True:

            try:

                with open("/sys/bus/netdevsim/new_device", "w") as f:

                    f.write("%u %u" % (addr, port_count))

                self.ctrl_write("new_device", "%u %u" % (addr, port_count))

            except OSError as e:

                if e.errno == errno.ENOSPC:

                    addr += 1

        return progs

    def remove(self):

        with open("/sys/bus/netdevsim/del_device", "w") as f:

            f.write("%u" % self.addr)

        self.ctrl_write("del_device", "%u" % (self.addr, ))

        devs.remove(self)

    def remove_nsim(self, nsim):

        self.nsims.remove(nsim)

        with open("/sys/bus/netdevsim/devices/netdevsim%u/del_port" % self.addr ,"w") as f:

            f.write("%u" % nsim.port_index)

        self.ctrl_write("devices/netdevsim%u/del_port" % (self.addr, ),

                        "%u" % (nsim.port_index, ))

class NetdevSim:

    """