VACM contextName memory leakk fix

3 files changed, 30 insertions, 5 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index 57252f44..96a37b9d 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -5,6 +5,7 @@ Revision 4.4.5, released 2018-04-XX
 - Fixed broken InetAddressType rendering caused by a pyasn1 regression
 - Fixed typo in RFC1158 module
 - Fixed possible infinite loop in GETBULK response PDU builder
+- Fixed memory leak in the T`config.delContext()` VACM management harness
 
 Revision 4.4.4, released 2018-01-03
 -----------------------------------
diff --git a/pysnmp/entity/config.py b/pysnmp/entity/config.py
index 06d6c14d..28dfccee 100644
--- a/pysnmp/entity/config.py
+++ b/pysnmp/entity/config.py
@@ -389,13 +389,30 @@ delSocketTransport = delTransport
 
 # VACM shortcuts
 
-def addContext(snmpEngine, contextName):
+def __cookVacmContextInfo(snmpEngine, contextName):
     mibBuilder = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder
-
     vacmContextEntry, = mibBuilder.importSymbols('SNMP-VIEW-BASED-ACM-MIB', 'vacmContextEntry')
     tblIdx = vacmContextEntry.getInstIdFromIndices(contextName)
+    return vacmContextEntry, tblIdx
+
+
+def addContext(snmpEngine, contextName):
+    vacmContextEntry, tblIdx = __cookVacmContextInfo(snmpEngine, contextName)
+
+    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
+        ((vacmContextEntry.name + (5,) + tblIdx, 'destroy'),)
+    )
     snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
-        ((vacmContextEntry.name + (1,) + tblIdx, contextName),)
+        ((vacmContextEntry.name + (1,) + tblIdx, contextName),
+         (vacmContextEntry.name + (2,) + tblIdx, 'createAndGo'))
+    )
+
+
+def delContext(snmpEngine, contextName):
+    vacmContextEntry, tblIdx = __cookVacmContextInfo(snmpEngine, contextName)
+
+    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
+        ((vacmContextEntry.name + (5,) + tblIdx, 'destroy'),)
     )
 
 
@@ -448,7 +465,7 @@ def addVacmAccess(snmpEngine, groupName, contextName, securityModel,
                                                    contextName, securityModel,
                                                    securityLevel)
 
-    addContext(snmpEngine, contextName)  # this is leaky
+    addContext(snmpEngine, contextName)
 
     snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
         ((vacmAccessEntry.name + (9,) + tblIdx, 'destroy'),)
@@ -470,6 +487,9 @@ def delVacmAccess(snmpEngine, groupName, contextName, securityModel,
     vacmAccessEntry, tblIdx = __cookVacmAccessInfo(snmpEngine, groupName,
                                                    contextName, securityModel,
                                                    securityLevel)
+
+    delContext(snmpEngine, contextName)
+
     snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
         ((vacmAccessEntry.name + (9,) + tblIdx, 'destroy'),)
     )
diff --git a/pysnmp/smi/mibs/SNMP-VIEW-BASED-ACM-MIB.py b/pysnmp/smi/mibs/SNMP-VIEW-BASED-ACM-MIB.py
index d8eeffd4..8fbf962e 100644
--- a/pysnmp/smi/mibs/SNMP-VIEW-BASED-ACM-MIB.py
+++ b/pysnmp/smi/mibs/SNMP-VIEW-BASED-ACM-MIB.py
@@ -34,6 +34,10 @@ if mibBuilder.loadTexts: vacmContextEntry.setDescription('Information about a pa
 vacmContextName = MibTableColumn((1, 3, 6, 1, 6, 3, 16, 1, 1, 1, 1), SnmpAdminString().subtype(subtypeSpec=ValueSizeConstraint(0, 32))).setMaxAccess("readonly")
 if mibBuilder.loadTexts: vacmContextName.setStatus('current')
 if mibBuilder.loadTexts: vacmContextName.setDescription('A human readable name identifying a particular context at a particular SNMP entity. The empty contextName (zero length) represents the default context. ')
+# The RowStatus column is not present in the MIB
+vacmContextStatus = MibTableColumn((1, 3, 6, 1, 6, 3, 16, 1, 1, 1, 2), RowStatus()).setMaxAccess("readcreate")
+if mibBuilder.loadTexts: vacmContextStatus.setStatus('current')
+if mibBuilder.loadTexts: vacmContextStatus.setDescription("The status of this conceptual row. Until instances of all corresponding columns are appropriately configured, the value of the corresponding instance of the vacmContextTableStatus column is 'notReady'. In particular, a newly created row cannot be made active until a value has been set for vacmContextName. The RowStatus TC [RFC2579] requires that this DESCRIPTION clause states under which circumstances other objects in this row can be modified: The value of this object has no effect on whether other objects in this conceptual row can be modified. ")
 vacmSecurityToGroupTable = MibTable((1, 3, 6, 1, 6, 3, 16, 1, 2), )
 if mibBuilder.loadTexts: vacmSecurityToGroupTable.setStatus('current')
 if mibBuilder.loadTexts: vacmSecurityToGroupTable.setDescription('This table maps a combination of securityModel and securityName into a groupName which is used to define an access control policy for a group of principals. ')
@@ -122,4 +126,4 @@ vacmMIBCompliance = ModuleCompliance((1, 3, 6, 1, 6, 3, 16, 2, 1, 1)).setObjects
 if mibBuilder.loadTexts: vacmMIBCompliance.setDescription('The compliance statement for SNMP engines which implement the SNMP View-based Access Control Model configuration MIB. ')
 vacmBasicGroup = ObjectGroup((1, 3, 6, 1, 6, 3, 16, 2, 2, 1)).setObjects(("SNMP-VIEW-BASED-ACM-MIB", "vacmContextName"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmGroupName"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmSecurityToGroupStorageType"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmSecurityToGroupStatus"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmAccessContextMatch"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmAccessReadViewName"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmAccessWriteViewName"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmAccessNotifyViewName"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmAccessStorageType"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmAccessStatus"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmViewSpinLock"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmViewTreeFamilyMask"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmViewTreeFamilyType"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmViewTreeFamilyStorageType"), ("SNMP-VIEW-BASED-ACM-MIB", "vacmViewTreeFamilyStatus"))
 if mibBuilder.loadTexts: vacmBasicGroup.setDescription('A collection of objects providing for remote configuration of an SNMP engine which implements the SNMP View-based Access Control Model. ')
-mibBuilder.exportSymbols("SNMP-VIEW-BASED-ACM-MIB", vacmSecurityModel=vacmSecurityModel, vacmSecurityToGroupEntry=vacmSecurityToGroupEntry, vacmMIBConformance=vacmMIBConformance, vacmAccessReadViewName=vacmAccessReadViewName, vacmViewTreeFamilyMask=vacmViewTreeFamilyMask, snmpVacmMIB=snmpVacmMIB, vacmViewTreeFamilyType=vacmViewTreeFamilyType, vacmMIBGroups=vacmMIBGroups, vacmAccessContextMatch=vacmAccessContextMatch, vacmAccessNotifyViewName=vacmAccessNotifyViewName, vacmViewSpinLock=vacmViewSpinLock, vacmAccessWriteViewName=vacmAccessWriteViewName, vacmContextTable=vacmContextTable, PYSNMP_MODULE_ID=snmpVacmMIB, vacmViewTreeFamilyViewName=vacmViewTreeFamilyViewName, vacmMIBObjects=vacmMIBObjects, vacmViewTreeFamilyStatus=vacmViewTreeFamilyStatus, vacmSecurityName=vacmSecurityName, vacmGroupName=vacmGroupName, vacmAccessSecurityLevel=vacmAccessSecurityLevel, vacmBasicGroup=vacmBasicGroup, vacmContextName=vacmContextName, vacmSecurityToGroupStatus=vacmSecurityToGroupStatus, vacmAccessEntry=vacmAccessEntry, vacmMIBViews=vacmMIBViews, vacmAccessStorageType=vacmAccessStorageType, vacmMIBCompliances=vacmMIBCompliances, vacmViewTreeFamilyEntry=vacmViewTreeFamilyEntry, vacmViewTreeFamilyTable=vacmViewTreeFamilyTable, vacmSecurityToGroupStorageType=vacmSecurityToGroupStorageType, vacmAccessTable=vacmAccessTable, vacmAccessContextPrefix=vacmAccessContextPrefix, vacmViewTreeFamilyStorageType=vacmViewTreeFamilyStorageType, vacmMIBCompliance=vacmMIBCompliance, vacmAccessSecurityModel=vacmAccessSecurityModel, vacmAccessStatus=vacmAccessStatus, vacmContextEntry=vacmContextEntry, vacmSecurityToGroupTable=vacmSecurityToGroupTable, vacmViewTreeFamilySubtree=vacmViewTreeFamilySubtree)
+mibBuilder.exportSymbols("SNMP-VIEW-BASED-ACM-MIB", vacmSecurityModel=vacmSecurityModel, vacmSecurityToGroupEntry=vacmSecurityToGroupEntry, vacmMIBConformance=vacmMIBConformance, vacmAccessReadViewName=vacmAccessReadViewName, vacmViewTreeFamilyMask=vacmViewTreeFamilyMask, snmpVacmMIB=snmpVacmMIB, vacmViewTreeFamilyType=vacmViewTreeFamilyType, vacmMIBGroups=vacmMIBGroups, vacmAccessContextMatch=vacmAccessContextMatch, vacmAccessNotifyViewName=vacmAccessNotifyViewName, vacmViewSpinLock=vacmViewSpinLock, vacmAccessWriteViewName=vacmAccessWriteViewName, vacmContextTable=vacmContextTable, PYSNMP_MODULE_ID=snmpVacmMIB, vacmViewTreeFamilyViewName=vacmViewTreeFamilyViewName, vacmMIBObjects=vacmMIBObjects, vacmViewTreeFamilyStatus=vacmViewTreeFamilyStatus, vacmSecurityName=vacmSecurityName, vacmGroupName=vacmGroupName, vacmAccessSecurityLevel=vacmAccessSecurityLevel, vacmBasicGroup=vacmBasicGroup, vacmContextName=vacmContextName, vacmContextStatus=vacmContextStatus, vacmSecurityToGroupStatus=vacmSecurityToGroupStatus, vacmAccessEntry=vacmAccessEntry, vacmMIBViews=vacmMIBViews, vacmAccessStorageType=vacmAccessStorageType, vacmMIBCompliances=vacmMIBCompliances, vacmViewTreeFamilyEntry=vacmViewTreeFamilyEntry, vacmViewTreeFamilyTable=vacmViewTreeFamilyTable, vacmSecurityToGroupStorageType=vacmSecurityToGroupStorageType, vacmAccessTable=vacmAccessTable, vacmAccessContextPrefix=vacmAccessContextPrefix, vacmViewTreeFamilyStorageType=vacmViewTreeFamilyStorageType, vacmMIBCompliance=vacmMIBCompliance, vacmAccessSecurityModel=vacmAccessSecurityModel, vacmAccessStatus=vacmAccessStatus, vacmContextEntry=vacmContextEntry, vacmSecurityToGroupTable=vacmSecurityToGroupTable, vacmViewTreeFamilySubtree=vacmViewTreeFamilySubtree)