1

"""

     2

    Requirements:

     3

        memoized-property

     4

     5

    Setup:

     6

        ./opt/bin/build-pysnmp-mib -o usr/mibs/BRIDGE-MIB.py etc/mibs/rfc1493.mib

     7

     8

    Run:

     9

        PYSNMP_MIB_DIRS=usr/mibs/ ./opt/bin/python ...

    10

    11

    SNMP:

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        BRIDGE-MIB::dot1dTpFdbTable

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        Q-BRIDGE-MIB::dot1qTpFdbTable

    14

        Q-BRIDGE-MIB::dot1qVlanCurrentTable

    15

    16

"""

    17

    18

from pvl.snmp import snmp

    19

from pvl.snmp.snmp import pysnmp

    20

    21

from memoized_property import memoized_property

    22

    23

import logging; log = logging.getLogger('pvl.snmp.vlan')

    24

    25

DOT1D_TP_AGING_TIME = pysnmp.MibVariable('BRIDGE-MIB', 'dot1dTpAgingTime', 0)

    26

DOT1D_TP_FDB_PORT = pysnmp.MibVariable('BRIDGE-MIB', 'dot1dTpFdbPort')

    27

    28

DOT1Q_VLAN_FDB_ID = pysnmp.MibVariable('Q-BRIDGE-MIB', 'dot1qVlanFdbId') # [dot1qVlanIndex]

    29

    30

DOT1Q_TP_FDB_PORT = pysnmp.MibVariable('Q-BRIDGE-MIB', 'dot1qTpFdbPort') # [dot1qFdbId, dot1qTpFdbAddress]

    31

    32

def macaddr (value) :

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    """

    34

        Excepts a MAC address from an SNMP OctetString.

    35

    """

    36

    37

    return ':'.join('{octet:02x}'.format(octet=c) for c in value.asNumbers())

    38

    39

class BridgeAgent (snmp.SNMPAgent) :

    40

    """

    41

        Query Bridge configuration.

    42

    43

        XXX: this is not VLAN-aware!

    44

    """

    45

    46

    def ping (self) :

    47

        for name, value in self.get(DOT1D_TP_AGING_TIME) :

    48

            # XXX: ????

    49

            if value.tagSet == pysnmp.rfc1905.NoSuchInstance.tagSet :

    50

                continue

    51

    52

            return True

    53

    54

    def fdb_ports (self) :

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        """

    56

            Map hosts in the brige FDB to specific ports.

    57

        """

    58

    59

        for idx, data in self.table(DOT1D_TP_FDB_PORT) :

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            addr, = idx

    61

            port = data[DOT1D_TP_FDB_PORT]

    62

    63

            yield macaddr(addr), int(port)

    64

    65

    def vlan_fdb (self) :

    66

        """

    67

            Get FDB id -> vlan mappings.

    68

    69

                (fdb, vlan)

    70

        """

    71

    72

        for idx, data in self.table(DOT1Q_VLAN_FDB_ID) :

    73

            time, vlan = idx

    74

            fdb = int(data[DOT1Q_VLAN_FDB_ID])

    75

    76

            yield fdb, vlan

    77

    78

    def vlan_fdb_ports (self) :

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        """

    80

            Get per-vlan host -> port mappings.

    81

    82

                (macaddr, port, vlan)

    83

        """

    84

    85

        fdb_to_vlan = dict(self.vlan_fdb())

    86

    87

        for idx, data in self.table(DOT1Q_TP_FDB_PORT) :

    88

            fdb, addr = idx

    89

            port = data[DOT1Q_TP_FDB_PORT]

    90

    91

            vlan = fdb_to_vlan.get(fdb)

    92

    93

            yield macaddr(addr), int(port), vlan

    94

    95

    96

if __name__ == '__main__':

    97

    import doctest

    98

    doctest.testmod()