first cut at a vlan manager utility.

.gitignore

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+*.pyc
+p
+.coverage

Makefile

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+MODULES=vlanmang.py
+
+test:
+	(echo $(MODULES) | entr sh -c 'python -m coverage run -m unittest $(basename $(MODULES)) && coverage report --omit=p/\* -m -i')
+
+env:
+	(virtualenv p && . ./p/bin/activate && pip install -r requirements.txt)

requirements.txt

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+pysnmp
+coverage

vlanmang.py

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+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from pysnmp.hlapi import *
+from pysnmp.smi.builder import MibBuilder
+from pysnmp.smi.view import MibViewController
+
+import random
+import unittest
+
+_mbuilder = MibBuilder()
+_mvc = MibViewController(_mbuilder)
+
+# received packages
+# pvid: dot1qPvid
+#
+# tx packets:
+# dot1qVlanStaticEgressPorts
+# dot1qVlanStaticUntaggedPorts
+#
+# vlans:
+# dot1qVlanCurrentTable
+#	lists ALL vlans, including baked in ones
+#
+# note that even though an snmpwalk of dot1qVlanStaticEgressPorts
+# skips over other vlans (only shows statics), the other vlans (1,2,3)
+# are still accessible via that oid
+#
+# LLDP:
+# 1.0.8802.1.1.2.1.4.1.1 aka LLDP-MIB, lldpRemTable
+
+class SNMPSwitch(object):
+	def __init__(self, host, community):
+		self._eng = SnmpEngine()
+		self._cd = CommunityData(community, mpModel=0)
+		self._targ = UdpTransportTarget((host, 161))
+
+	def _get(self, oid):
+		oid = ObjectIdentity(*oid)
+		oid.resolveWithMib(_mvc)
+
+		errorInd, errorStatus, errorIndex, varBinds = \
+		    next(getCmd(self._eng, self._cd, self._targ, ContextData(), ObjectType(oid)))
+
+		if errorInd: # pragma: no cover
+			raise ValueError(errorIndication)
+		elif errorStatus:
+			raise ValueError('%s at %s' %
+			    (errorStatus.prettyPrint(), errorIndex and
+			    varBinds[int(errorIndex)-1][0] or '?'))
+		else:
+			if len(varBinds) != 1: # pragma: no cover
+				raise ValueError('too many return values')
+
+			varBind = varBinds[0]
+			return varBind[1]
+
+	def _set(self, oid, value):
+		oid = ObjectIdentity(*oid)
+		oid.resolveWithMib(_mvc)
+
+		if isinstance(value, (int, long)):
+			value = Integer(value)
+		elif isinstance(value, str):
+			value = OctetString(value)
+
+		errorInd, errorStatus, errorIndex, varBinds = \
+		    next(setCmd(self._eng, self._cd, self._targ, ContextData(), ObjectType(oid, value)))
+
+		if errorInd: # pragma: no cover
+			raise ValueError(errorIndication)
+		elif errorStatus: # pragma: no cover
+			raise ValueError('%s at %s' %
+			    (errorStatus.prettyPrint(), errorIndex and
+			    varBinds[int(errorIndex)-1][0] or '?'))
+		else:
+			for varBind in varBinds:
+				if varBind[1] != value: # pragma: no cover
+					raise RuntimeError('failed to set: %s' % ' = '.join([x.prettyPrint() for x in varBind]))
+
+	def _walk(self, *oid):
+		oid = ObjectIdentity(*oid)
+		# XXX - keep these, this might stop working, no clue what managed to magically make things work
+		# ref: http://snmplabs.com/pysnmp/examples/smi/manager/browsing-mib-tree.html#mib-objects-to-pdu-var-binds
+		# mibdump.py --mib-source '/Users/jmg/Nextcloud/Documents/user manuals/netgear/gs7xxt-v6.3.1.19-mibs' --mib-source /usr/share/snmp/mibs  --rebuild rfc1212 pbridge vlan
+		#oid.addAsn1MibSource('/usr/share/snmp/mibs', '/Users/jmg/Nextcloud/Documents/user manuals/netgear/gs7xxt-v6.3.1.19-mibs')
+
+		oid.resolveWithMib(_mvc)
+
+		for (errorInd, errorStatus, errorIndex, varBinds) in nextCmd(
+		    self._eng, self._cd, self._targ, ContextData(),
+		    ObjectType(oid),
+		    lexicographicMode=False):
+			if errorInd: # pragma: no cover
+				raise ValueError(errorIndication)
+			elif errorStatus: # pragma: no cover
+				raise ValueError('%s at %s' % (errorStatus.prettyPrint(), errorIndex and varBinds[int(errorIndex)-1][0] or '?'))
+			else:
+				for varBind in varBinds:
+					yield varBind
+
+	def findport(self, name):
+		return [ x[0][-1] for x in self._walk('IF-MIB', 'ifName') if str(x[1]) == name ][0]
+
+	def getvlanname(self, vlan):
+		v = self._get(('Q-BRIDGE-MIB', 'dot1qVlanStaticName', vlan))
+
+		return str(v).decode('utf-8')
+
+	def createvlan(self, vlan, name):
+		# createAndGo(4)
+		self._set(('Q-BRIDGE-MIB', 'dot1qVlanStaticRowStatus',
+		    int(vlan)), 4)
+		self._set(('Q-BRIDGE-MIB', 'dot1qVlanStaticName', int(vlan)),
+		    name)
+
+	def deletevlan(self, vlan):
+		self._set(('Q-BRIDGE-MIB', 'dot1qVlanStaticRowStatus',
+		    int(vlan)), 6) # destroy(6)
+
+	def getvlans(self):
+		return (x[0][-1] for x in self._walk('Q-BRIDGE-MIB', 'dot1qVlanStatus'))
+
+	def staticvlans(self):
+		return (x[0][-1] for x in self._walk('Q-BRIDGE-MIB', 'dot1qVlanStaticName'))
+
+class Test(unittest.TestCase):
+	def setUp(self):
+		args = open('test.creds').read().split()
+		self.switch = SNMPSwitch(*args)
+
+	def test_unpacktable(self):
+		pass
+
+	def test_misc(self):
+		switch = self.switch
+
+		self.assertEqual(switch.findport('g1'), 1)
+		self.assertEqual(switch.findport('l1'), 14)
+
+	def test_vlan(self):
+		switch = self.switch
+
+		existingvlans = set(switch.getvlans())
+
+		while True:
+			testvlan = random.randint(1,4095)
+			if testvlan not in existingvlans:
+				break
+
+		# Test that getting a non-existant vlans raises an exception
+		self.assertRaises(ValueError, switch.getvlanname, testvlan)
+
+		self.assertTrue(set(switch.staticvlans()).issubset(existingvlans))
+
+		testname = 'Sometestname'
+
+		# Create test vlan
+		switch.createvlan(testvlan, testname)
+		try:
+			# make sure the test vlan was created
+			self.assertIn(testvlan, set(switch.staticvlans()))
+
+			self.assertEqual(testname, switch.getvlanname(testvlan))
+		finally:
+			switch.deletevlan(testvlan)