""" BFD protocol implementation """

from random import randint
from socket import AF_INET, AF_INET6, inet_pton
from scapy.all import bind_layers
from scapy.layers.inet import UDP
from scapy.packet import Packet
from scapy.fields import BitField, BitEnumField, XByteField, FlagsField,\
    ConditionalField, StrField
from vpp_object import VppObject
from util import NumericConstant


class BFDDiagCode(NumericConstant):
    """ BFD Diagnostic Code """
    no_diagnostic = 0
    control_detection_time_expired = 1
    echo_function_failed = 2
    neighbor_signaled_session_down = 3
    forwarding_plane_reset = 4
    path_down = 5
    concatenated_path_down = 6
    administratively_down = 7
    reverse_concatenated_path_down = 8

    desc_dict = {
        no_diagnostic: "No diagnostic",
        control_detection_time_expired: "Control Detection Time Expired",
        echo_function_failed: "Echo Function Failed",
        neighbor_signaled_session_down: "Neighbor Signaled Session Down",
        forwarding_plane_reset: "Forwarding Plane Reset",
        path_down: "Path Down",
        concatenated_path_down: "Concatenated Path Down",
        administratively_down: "Administratively Down",
        reverse_concatenated_path_down: "Reverse Concatenated Path Down",
    }


class BFDState(NumericConstant):
    """ BFD State """
    admin_down = 0
    down = 1
    init = 2
    up = 3

    desc_dict = {
        admin_down: "AdminDown",
        down: "Down",
        init: "Init",
        up: "Up",
    }


class BFDAuthType(NumericConstant):
    """ BFD Authentication Type """
    no_auth = 0
    simple_pwd = 1
    keyed_md5 = 2
    meticulous_keyed_md5 = 3
    keyed_sha1 = 4
    meticulous_keyed_sha1 = 5

    desc_dict = {
        no_auth: "No authentication",
        simple_pwd: "Simple Password",
        keyed_md5: "Keyed MD5",
        meticulous_keyed_md5: "Meticulous Keyed MD5",
        keyed_sha1: "Keyed SHA1",
        meticulous_keyed_sha1: "Meticulous Keyed SHA1",
    }


def bfd_is_auth_used(pkt):
    """ is packet authenticated? """
    return "A" in pkt.sprintf("%BFD.flags%")


def bfd_is_simple_pwd_used(pkt):
    """ is simple password authentication used? """
    return bfd_is_auth_used(pkt) and pkt.auth_type == BFDAuthType.simple_pwd


def bfd_is_sha1_used(pkt):
    """ is sha1 authentication used? """
    return bfd_is_auth_used(pkt) and pkt.auth_type in \
        (BFDAuthType.keyed_sha1, BFDAuthType.meticulous_keyed_sha1)


def bfd_is_md5_used(pkt):
    """ is md5 authentication used? """
    return bfd_is_auth_used(pkt) and pkt.auth_type in \
        (BFDAuthType.keyed_md5, BFDAuthType.meticulous_keyed_md5)


def bfd_is_md5_or_sha1_used(pkt):
    """ is md5 or sha1 used? """
    return bfd_is_md5_used(pkt) or bfd_is_sha1_used(pkt)


class BFD(Packet):
    """ BFD protocol layer for scapy """

    udp_dport = 3784  #: BFD destination port per RFC 5881
    udp_dport_echo = 3785  # : BFD destination port for ECHO per RFC 5881
    udp_sport_min = 49152  #: BFD source port min value per RFC 5881
    udp_sport_max = 65535  #: BFD source port max value per RFC 5881
    bfd_pkt_len = 24  # : length of BFD pkt without authentication section
    sha1_auth_len = 28  # : length of authentication section if SHA1 used

    name = "BFD"

    fields_desc = [
        BitField("version", 1, 3),
        BitEnumField("diag", 0, 5, BFDDiagCode.desc_dict),
        BitEnumField("state", 0, 2, BFDState.desc_dict),
        FlagsField("flags", 0, 6, ['M', 'D', 'A', 'C', 'F', 'P']),
        XByteField("detect_mult", 0),
        BitField("length", bfd_pkt_len, 8),
        BitField("my_discriminator", 0, 32),
        BitField("your_discriminator", 0, 32),
        BitField("desired_min_tx_interval", 0, 32),
        BitField("required_min_rx_interval", 0, 32),
        BitField("required_min_echo_rx_interval", 0, 32),
        ConditionalField(
            BitEnumField("auth_type", 0, 8, BFDAuthType.desc_dict),
            bfd_is_auth_used),
        ConditionalField(BitField("auth_len", 0, 8), bfd_is_auth_used),
        ConditionalField(BitField("auth_key_id", 0, 8), bfd_is_auth_used),
        ConditionalField(BitField("auth_reserved", 0, 8),
                         bfd_is_md5_or_sha1_used),
        ConditionalField(
            BitField("auth_seq_num", 0, 32), bfd_is_md5_or_sha1_used),
        ConditionalField(StrField("auth_key_hash", "0" * 16), bfd_is_md5_used),
        ConditionalField(
            StrField("auth_key_hash", "0" * 20), bfd_is_sha1_used),
    ]

    def mysummary(self):
        return self.sprintf("BFD(my_disc=%BFD.my_discriminator%,"
                            "your_disc=%BFD.your_discriminator%)")


# glue the BFD packet class to scapy parser
bind_layers(UDP, BFD, dport=BFD.udp_dport)


class BFD_vpp_echo(Packet):
    """ BFD echo packet as used by VPP (non-rfc, as rfc doesn't define one) """

    udp_dport = 3785  #: BFD echo destination port per RFC 5881
    name = "BFD_VPP_ECHO"

    fields_desc = [
        BitField("discriminator", 0, 32),
        BitField("expire_time_clocks", 0, 64),
        BitField("checksum", 0, 64)
    ]

    def mysummary(self):
        return self.sprintf(
            "BFD_VPP_ECHO(disc=%BFD_VPP_ECHO.discriminator%,"
            "expire_time_clocks=%BFD_VPP_ECHO.expire_time_clocks%)")


# glue the BFD echo packet class to scapy parser
bind_layers(UDP, BFD_vpp_echo, dport=BFD_vpp_echo.udp_dport)


c<style>
@media only all and (prefers-color-scheme: dark) {
.highlight .hll { background-color: #49483e }
.highlight .c { color: #75715e } /* Comment */
.highlight .err { color: #960050; background-color: #1e0010 } /* Error */
.highlight .k { color: #66d9ef } /* Keyword */
.highlight .l { color: #ae81ff } /* Literal */
.highlight .n { color: #f8f8f2 } /* Name */
.highlight .o { color: #f92672 } /* Operator */
.highlight .p { color: #f8f8f2 } /* Punctuation */
.highlight .ch { color: #75715e } /* Comment.Hashbang */
.highlight .cm { color: #75715e } /* Comment.Multiline */
.highlight .cp { color: #75715e } /* Comment.Preproc */
.highlight .cpf { color: #75715e } /* Comment.PreprocFile */
.highlight .c1 { color: #75715e } /* Comment.Single */
.highlight .cs { color: #75715e } /* Comment.Special */
.highlight .gd { color: #f92672 } /* Generic.Deleted */
.highlight .ge { font-style: italic } /* Generic.Emph */
.highlight .gi { color: #a6e22e } /* Generic.Inserted */
.highlight .gs { font-weight: bold } /* Generic.Strong */
.highlight .gu { color: #75715e } /* Generic.Subheading */
.highlight .kc { color: #66d9ef } /* Keyword.Constant */
.highlight .kd { color: #66d9ef } /* Keyword.Declaration */
.highlight .kn { color: #f92672 } /* Keyword.Namespace */
.highlight .kp { color: #66d9ef } /* Keyword.Pseudo */
.highlight .kr { color: #66d9ef } /* Keyword.Reserved */
.highlight .kt { color: #66d9ef } /* Keyword.Type */
.highlight .ld { color: #e6db74 } /* Literal.Date */
.highlight .m { color: #ae81ff } /* Literal.Number */
.highlight .s { color: #e6db74 } /* Literal.String */
.highlight .na { color: #a6e22e } /* Name.Attribute */
.highlight .nb { color: #f8f8f2 } /* Name.Builtin */
.highlight .nc { color: #a6e22e } /* Name.Class */
.highlight .no { color: #66d9ef } /* Name.Constant */
.highlight .nd { color: #a6e22e } /* Name.Decorator */
.highlight .ni { color: #f8f8f2 } /* Name.Entity */
.highlight .ne { color: #a6e22e } /* Name.Exception */
.highlight .nf { color: #a6e22e } /* Name.Function */
.highlight .nl { color: #f8f8f2 } /* Name.Label */
.highlight .nn { color: #f8f8f2 } /* Name.Namespace */
.highlight .nx { color: #a6e22e } /* Name.Other */
.highlight .py { color: #f8f8f2 } /* Name.Property */
.highlight .nt { color: #f92672 } /* Name.Tag */
.highlight .nv { color: #f8f8f2 } /* Name.Variable */
.highlight .ow { color: #f92672 } /* Operator.Word */
.highlight .w { color: #f8f8f2 } /* Text.Whitespace */
.highlight .mb { color: #ae81ff } /* Literal.Number.Bin */
.highlight .mf { color: #ae81ff } /* Literal.Number.Float */
.highlight .mh { color: #ae81ff } /* Literal.Number.Hex */
.highlight .mi { color: #ae81ff } /* Literal.Number.Integer */
.highlight .mo { color: #ae81ff } /* Literal.Number.Oct */
.highlight .sa { color: #e6db74 } /* Literal.String.Affix */
.highlight .sb { color: #e6db74 } /* Literal.String.Backtick */
.highlight .sc { color: #e6db74 } /* Literal.String.Char */
.highlight .dl { color: #e6db74 } /* Literal.String.Delimiter */
.highlight .sd { color: #e6db74 } /* Literal.String.Doc */
.highlight .s2 { color: #e6db74 } /* Literal.String.Double */
.highlight .se { color: #ae81ff } /* Literal.String.Escape */
.highlight .sh { color: #e6db74 } /* Literal.String.Heredoc */
.highlight .si { color: #e6db74 } /* Literal.String.Interpol */
.highlight .sx { color: #e6db74 } /* Literal.String.Other */
.highlight .sr { color: #e6db74 } /* Literal.String.Regex */
.highlight .s1 { color: #e6db74 } /* Literal.String.Single */
.highlight .ss { color: #e6db74 } /* Literal.String.Symbol */
.highlight .bp { color: #f8f8f2 } /* Name.Builtin.Pseudo */
.highlight .fm { color: #a6e22e } /* Name.Function.Magic */
.highlight .vc { color: #f8f8f2 } /* Name.Variable.Class */
.highlight .vg { color: #f8f8f2 } /* Name.Variable.Global */
.highlight .vi { color: #f8f8f2 } /* Name.Variable.Instance */
.highlight .vm { color: #f8f8f2 } /* Name.Variable.Magic */
.highlight .il { color: #ae81ff } /* Literal.Number.Integer.Long */
}
@media (prefers-color-scheme: light) {
.highlight .hll { background-color: #ffffcc }
.highlight .c { color: #888888 } /* Comment */
.highlight .err { color: #a61717; background-color: #e3d2d2 } /* Error */
.highlight .k { color: #008800; font-weight: bold } /* Keyword */
.highlight .ch { color: #888888 } /* Comment.Hashbang */
.highlight .cm { color: #888888 } /* Comment.Multiline */
.highlight .cp { color: #cc0000; font-weight: bold } /* Comment.Preproc */
.highlight .cpf { color: #888888 } /* Comment.PreprocFile */
.highlight .c1 { color: #888888 } /* Comment.Single */
.highlight .cs { color: #cc0000; font-weight: bold; background-color: #fff0f0 } /* Comment.Special */
.highlight .gd { color: #000000; background-color: #ffdddd } /* Generic.Deleted */
.highlight .ge { font-style: italic } /* Generic.Emph */
.highlight .gr { color: #aa0000 } /* Generic.Error */
.highlight .gh { color: #333333 } /* Generic.Heading */
.highlight .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */
.highlight .go { color: #888888 } /* Generic.Output */
.highlight .gp { color: #555555 } /* Generic.Prompt */
.highlight .gs { font-weight: bold } /* Generic.Strong */
.highlight .gu { color: #666666 } /* Generic.Subheading */
.highlight .gt { color: #aa0000 } /* Generic.Traceback */
.highlight .kc { color: #008800; font-weight: bold } /* Keyword.Constant */
.highlight .kd { color: #008800; font-weight: bold } /* Keyword.Declaration */
.highlight .kn { color: #008800; font-weight: bold } /* Keyword.Namespace */
.highlight .kp { color: #008800 } /* Keyword.Pseudo */
.highlight .kr { color: #008800; font-weight: bold } /* Keyword.Reserved */
.highlight .kt { color: #888888; font-weight: bold } /* Keyword.Type */
.highlight .m { color: #0000DD; font-weight: bold } /* Literal.Number */
.highlight .s { color: #dd2200; background-color: #fff0f0 } /* Literal.String */
.highlight .na { color: #336699 } /* Name.Attribute */
.highlight .nb { color: #003388 } /* Name.Builtin */
.highlight .nc { color: #bb0066; font-weight: bold } /* Name.Class */
.highlight .no { color: #003366; font-weight: bold } /* Name.Constant */
.highlight .nd { color: #555555 } /* Name.Decorator */
.highlight .ne { color: #bb0066; font-weight: bold } /* Name.Exception */
.highlight .nf { color: #0066bb; font-weight: bold } /* Name.Function */
.highlight .nl { color: #336699; font-style: italic } /* Name.Label */
.highlight .nn { color: #bb0066; font-weight: bold } /* Name.Namespace */
.highlight .py { color: #336699; font-weight: bold } /* Name.Property */
.highlight .nt { color: #bb0066; font-weight: bold } /* Name.Tag */
.highlight .nv { color: #336699 } /* Name.Variable */
.highlight .ow { color: #008800 } /* Operator.Word */
.highlight .w { color: #bbbbbb } /* Text.Whitespace */
.highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */
.highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */
.highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */
.highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */
.highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */
.highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */
.highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */
.highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */
.highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */
.highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */
.highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */
.highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */
.highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */
.highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */
.highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */
.highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */
.highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */
.highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */
.highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */
.highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */
.highlight .vc { color: #336699 } /* Name.Variable.Class */
.highlight .vg { color: #dd7700 } /* Name.Variable.Global */
.highlight .vi { color: #3333bb } /* Name.Variable.Instance */
.highlight .vm { color: #336699 } /* Name.Variable.Magic */
.highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
}
</style><div class="highlight"><pre><span></span><span class="cm">/*</span>
<span class="cm"> * Copyright (c) 2017 SUSE LLC.</span>
<span class="cm"> * Licensed under the Apache License, Version 2.0 (the &quot;License&quot;);</span>
<span class="cm"> * you may not use this file except in compliance with the License.</span>
<span class="cm"> * You may obtain a copy of the License at:</span>
<span class="cm"> *</span>
<span class="cm"> *     http://www.apache.org/licenses/LICENSE-2.0</span>
<span class="cm"> *</span>
<span class="cm"> * Unless required by applicable law or agreed to in writing, software</span>
<span class="cm"> * distributed under the License is distributed on an &quot;AS IS&quot; BASIS,</span>
<span class="cm"> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.</span>
<span class="cm"> * See the License for the specific language governing permissions and</span>
<span class="cm"> * limitations under the License.</span>
<span class="cm"> */</span>

<span class="n">geneve_error</span> <span class="p">(</span><span class="n">DECAPSULATED</span><span class="p">,</span> <span class="s">&quot;good packets decapsulated&quot;</span><span class="p">)</span>
<span class="n">geneve_error</span> <span class="p">(</span><span class="n">NO_SUCH_TUNNEL</span><span class="p">,</span> <span class="s">&quot;no such tunnel packets&quot;</span><span class="p">)</span>
<span class="n">geneve_error</span> <span class="p">(</span><span class="n">BAD_FLAGS</span><span class="p">,</span> <span class="s">&quot;packets with bad flags field in geneve header&quot;</span><span class="p">)</span>
</pre></div>
</code></pre></td></tr><