Revision 4.1.16a
----------------

- Extended Security Options (3DESEDE, AES192, AES256) privacy
  protocols implemented.
- The error-indication codes moved from literals to objects for reliability
  and clarity
- Fix to v1.TrapPDUAPI.getVarBinds() to address PDU component at the right
  position.
- Fix to rfc1902.Bits initialization from named bits sequence.
- Fix to MIB builder by-extension module filtering code to cope with .pyw
  files.
- Internal caches structure improved.
- Sync versions of oneliner apps split off async implementation for clarity.
- Randomize initial in various numeric sequences.
- MsgAndPduDsp expectResponse parameters passing reworked.
- GetNext/GetBulk response processing logic moved to getNextVarBinds()
- Changes towards performance improvement:
  + all dict.has_key() & dict.get() invocations replaced with modern syntax
    (this breaks compatibility with Python 2.1 and older).
  + introduce the MibInstrumControlle.readVarsFast() method (which skips
    the "testing" phase of MIB value readin) for dealing with internal
    configuration (LCD).
  + default debug.logger is now just a zero value instead of an object
    what saves big on frequent calls
  + SNMPv2-SMI columnar indices <-> index values convertion code optimized.
  + pre-compute and re-use some of ASN.1 structures.
  + avoid setting PDU defaults to save on unnecessary initialization.
  + skip ASN.1 types verification where possible.
  + at oneliner Command Generator, avoid looking up pure OID arguments
    at MIB as it's pointless but takes time.
  + cache MIB columnar objects instance ID <-> symbolic index representation
    mapping

Revision 4.1.15a
----------------

- SNMP Proxy example added.
- End-of-MIB condition detection reworked what caused backward
  incompatibility at v1arch GETNEXT API. Previous pysnmp versions
  used value = None in var-binds as returned by getVarBindTable()
  API method. This version uses rfc1905 exception values (v2c/v3)
  or pyasn1 Null (v1).
  Built-in GETNEXT/GETBULK apps now do not require user to track
  end-of-mib conditions anymore -- this is now done automatically.
- CommandResponder API now supports async mode of operation.
- SNMP exception values now exported from rfc1905 module, and made
  pretty printable.
- Lexicographic walking mode is now supported at oneliner CommandGenerator.
- ContextEngineId&ContextName parameters passing implemented at
  v3arch oneliner API.
- Multiple instances of the same transport domain now supported.
- Initial snmpEngineId value generation improved not to accidentally
  collide within an administrative domain.
- MibTableColumn instances now build value-to-column-instance map
  to speedup by-value search.
- SNMPv2-CONF::AgentCapabilities macro implemented.
- The libsmi2pysnmp tool handles some more MACROs.
- Void access control module implemented to let apps disabling [default] VACM.
- Allow standard SNMP apps to choose access control method to use.
- Twisted-based CommandResponder example added.
- Fix/rework of Twisted GETNEXT/BULK CommandGenerator callback API to
  make it simpler and uniform with other CommandGenerators
- Fix to SNMPv3 security module to store peer SNMP engine timeline
  only if taken from an authenticated message. Prior to this fix
  SNMP engine was not been protected from spoofing.
- Fix to $SMIPATH initialization at build-pysnmp-mib.
- Fix to maxSizeResponseScopedPDU calculation.
- Fix to Next/Bulk CommandGenerators to catch a non-increasing OID
  error condition (what prevents looping).
- Fix to Opaque value tagging at rfc1155.Opaque type.
- Fix to handle (fail gracefully) zero-length user password.
- Fix to SNMP error propagation at Twisted driver (SF tracker ID #3054505).
- Fix to Agent-role snmpEngineId discovery procedure that allows
  authenticated ReportPDU generation.
- Fix to SNMPv1 PDU handling at CommandResponder & NotificationReceiver
  apps.
- Fix to CommandResponder app to skip Counter64 SMI values when responding
  to SNMPv1 Manager.
- Fix to protocol translator code (rfc2576) to handle Counter64 type
  in v2c-to-v1 PDU translation.
- Fix to non-response var-binds translation in rfc2576.v2ToV1().
- Fix to wrong exceptions used in pysnmp/entity modules.
- Fix to noauth/nopriv security module so that it would not crash SNMP
  engine if called accidentally.
- Fix to CommandResponder not to return out-of-range errorIndex along
  with genErr
- Fix to GETBULK CommandResponder to do a by-column MIB walk, not by-raw.
- Fix to getVarBindTable() API function logic.
- Fix to example Manager scripts to use errorIndex when available.
- Fix to dummy encryptData()/decryptData() API
- Fix to oneliner GETBULK table collection code to make it stripping
  uneven rows off table tail.

Revision 4.1.14a
----------------

- Fix to maxSizeResponseScopedPDU calculation at USM security module: now
  more precise and robust against screwed values on input.
- Fix to MIB loading logic that used to load same-name modules at
  disticts search paths on each loadModules() call.
- Fix to AsynsockDispatcher.runDispatcher() to make use of optional
  non-default select() timeout value.
- AbstractTransportDispatcher now allows user application registering
  multiple timer callbacks each with dedicated call period.
- Asynsock mainloop default idle period reduced to 0.5 sec for better
  timer resolution.
- Fix to SNMPv1->SNMPv2c error status handling at proxy module. This
  defect may have caused an infinite loop on a multiple var-bind
  SNMPv1 GetNext operation.
- Fix to contextName processing at config.addV1System -- typo rendered
  passed contextName not committed into LCD.
- Fix to unknown ContextName exception handling at CommandResponder App.
- config.addVacmUser() now accepts an optional contextName what makes
  it usable for configuring multiple contextName-bound bases of Managed
  Objects to SnmpEngine.
- MP pending states cache management re-worked so that SNMP engine will
  now handle an unlimited number of pending request/responses.
- Fix to SNMP discovery procedure: include ContentName in SNMP discovery
  messaging.
- Many fixes to AES crypto code that makes it actually working.
- Fix to SNMPv2-SMI createUndo operations.
- Fix to INFORM sending error handling at oneliner.
- Fix to mismatched response PDU handling at CommandGenerator application.
- Debug category 'app' (for Application) added to facilitate
  Standard SNMP Applications debugging.
- The retryCount semantic of CommandGenerator application changed to include
  sole retries and do not include initial request. Thus, retryCount=1 will
  now send up to two packets, not just one as it used to be.
- Debugging printout now escapes non-printable characters.

Revision 4.1.13a
----------------

- UDP over IPv6 transport implemented.
- Fix to MIB tree walking code that used to fail on table columns where
  indices have identical leading parts.
- SNMPv1/v2c snmpCommunityTransportTag-based imcoming message filtering
  implemented (rfc2576).

Revision 4.1.12a
----------------

- API versioning retired (pysnmp.v4 -> pysnmp).
- MIB loading mechanics re-designed to allow ZIP import.
- MIB loader supports code objects (py[co])
- Installer now uses setuptools for package management whenever available.
- The libsmi2pysnmp tool improved to build constraints of more than
  256 items (Python has a limit on the number of function params).
- Missing SNMPTrap PDU API implemented at proto.api.v2c, RFC2576 proxy
  code reworked.
- Fix to sysUpTime OID at SNMPv2 TRAP PDU.

Revision 4.1.11a
----------------

- Twisted integration implemented.
- Attempt to use hashlib whenever available.
- Fix to oneliner Manager code on < Python 2.4.
- Let NotificationReceiver and CommandResponder Apps browsing request details
  (transport information at the moment) at SNMP engine.
- Fix to config.addV1System() to allow multiple systems to co-exist in LCD.
- Fix to wrongly succeeding user-parameters-by-community-name searching code
  in rfc2576 processIncomingMsg() method.
- Do sanity checking on PYSNMP_MODULE_ID, Groups and Notifications in
  libsmi2pysnmp (SF bug #2122489).
- Fix to oneliner Notification Originator that sometimes used to send multiple
  requests at once.
- Oneliners LCD names generation code reworked to avoid accidental clashes.
- Fix and re-work of sysUpTime value management in LCD.
- Fix to pending inform request data caching in mpmod/rfc2576.py -- previous
  code led to cache data corruption on multple outstanding requests.
- In SMI configuration wrapper functions, catch access to non-configured
  entries and raise an exception.
- Allow multuple callback timer functions in all transport dispatchers.
- Fix to libsmi2pysnmp code to preserve more underscored object names and
  to guess the right type between indistinguishable ObjectGroup &
  NotificationGroup
- Fix to MibScalarInstance value setting logic - previous code failed
  when modifying the same OID multiple times within a single SET operation.
- Minor usability improvements to tools/build-pysnmp-mib.
- Made MIB objects unexport feature operational.

Revision 4.1.10a
----------------

- Internal MIB indexing method __indexMib() unmangled to facilitate
  setting up mutex there for sharing MIB stuff between threads.
- Fixed broken IpAddress value handling in SET operation.
- Broken MibBuilder.unloadModules() method now works.
- Use getLabel() SMI object method when building MIB tree (in builder.py)
  in addition to direct attribute access for clearer object protocol.
- The MIB building tools updated to match significantly improved
  smidump tool (libsmi version > 0.4.5).
- Made libsmi2pysnmp tool optionally building MIB text fields into pysnmp
  MIB code (enabled by default) and MibBuilder conditionally loading them 
  up (disabled by default).
- SnmpEngine and MsgAndPduDispatcher constructors now optionally
  take msgAndPduDspr and mibInstrumController class instances
  respectively to facilitate these objects sharing within a process.
- Unique integers, for various parts of the system, are now generated
  by a nextid.py module. This fixes possible issues with duplicate
  request IDs and handlers.
- Built-in MIBs re-generated to include text fields.

Revision 4.1.9a
---------------

- UNSTABLE ALPHA RELEASE.
- At onliner CommandGenerator, close transport on destruction to
  prevent socket leak. Implicit async transports registration at
  default asyncore's socket map has been disabled to avoid side
  effects.
- Fix to rfc2576.v1ToV2c() PDU converter to perform noSuchName error code
  translation.
- Fixes to Notification PDU convertion code at rfc2576 in part of
  snmpTrapOID handling.
- Fix to nonRepeaters object use as sequence slicer (must be int) at
  cmdrsp.CommandResponderApplication
- Make AsynsockDispatcher using its own socket map by default for 
  threading safety. This will break asyncore apps that rely on pysnmp 
  sharing the same socket map with them. A solution would  be to either
  set asyncore map to pysnmp (AsynsockDispatcher.setSocketMap()) or pass
  pysnmp map (AsynsockDispatcher.getSocketMap()) to asyncore.
- Fix to response timeout roundup bug at CommandGenerator and
  NotificationOriginator code.
- Oneline configuration classes made hashable to prevent memory leaks
  when committing them into CommandGenerator/NotificationOriginator
  internal repository.
- Security information is now released properly in all MP modules.
  This might fix a significant memory leak.
- Typo fix to rfc3411 confirmed class PDU members.

Revision 4.1.8a
---------------

- UNSTABLE ALPHA RELEASE.
- SMI/dispatcher timeout convertion multiplier is actually 100 (1/100 sec)
  rather than 1/1000. This fix affects timeouts specified through SMI.
- __repr__() implemented for UdpTransportTarget, CommunityData, UsmUserData
  in oneliner module.
- Automatically initialize table index values on table management
  operations (SF bug ID #1671989).
- Fix to carrier code: ignore BADFD socket error as it may happen upon 
  FD closure on n-1 select() event.
- Fix to MibBuilder.setMibPath() to preserve previously loaded modules
  intact. Otherwise loadModules() called after setMibPath() might fail
  with 'MIB file not found in search path' exception.
- Fix to oneliner classes that now invoke unconfiguration methods on
  destruction. This might have caused memory leaks.
- Automatically initialize SNMP-USER-BASED-SM-MIB::UsmUserSecurityName
  columnar object instance on creation, as stated in DESCRIPTION (SF
  tracker ID #1620392).
- Fix to USM timeframe arithmetics (SF bug #1649032).
- VACM shortcuts merged into universal add/delVacmUser() to let notifications
  and requests to co-exist for the same user.
- At oneliners, build LCD tables keys from a hashed mix of input parameters
  to make sure these automatic entries won't interfere or exceed constraints
  on keys values.
- Made use of notificationType parameter of the sendNotification method
  in NotificationOriginator applications. This parameter used to be
  ignored in the past. Note, that previously used (and ignored) syntax
  has been changed in an incompatible way.
- Allow plain Python values in setCmd() and sendNotification()
  methods in CommandGenerator and NotificationOriginator applications
  respectively.
- Multi-target oneliner API-based example script added.
- Ignore more socket errors in datagram-type async socket code.
- AES cipher now supported (rfc3826).
- Fix to messed up tagIDs of noSuchInstance and noSuchObject types.
- SET Command Responder fixed to obscure access to non-existing variables
  by returning notWritable error (SF bug #1764839).
- AsynsockDispatcher.setSocketMap() method added to facilitate pysnmp
  transport integration into third-party asyncore-based applications.
- Fix to errorIndex generation at CommandResponder application, the value
  should be a one-based.

Revision 4.1.7a
---------------

- UNSTABLE ALPHA RELEASE.
- Low-level debugging facility implemented.
- Support UdpTransportTarget timeout and retries parameters in oneliner API.
- Fix to snmpTrapOID construction at ...proxy.rfc2576.v1ToV2() 
  function.
- Fix to MibViewController.getNodeName() to take MIB module name
  into account (SF bug #1505847).
- Do explicit check for Counter32,Unsigned32,TimeTicks,Counter64 value types
  in MibTableRow index convertion and in TextualConvention.prettyPrint()
  methods (SF bug #1506341). Handle Bits in indices as RFC2578 suggests.
- Apply read-create column status to libsmi2pysnmp-generated code
  whenever MIB text specifies that (SF bug #1508955).
- Honor and apply DISPLAY-HINT specification when building TextualConvention
  class at libsmi2pysnmp.
- Managed Objects Instances files (smi/mibs/instances/) are now 
  double-underscore prefixed to make them imported explicitly by these
  prefixed names. They used to be imported as a side-effect of
  Managed Objects files import what is way too hackerish.
- The libsmi2pysnmp now supports future libsmi bugfix that would generate 
  "ranges" subtree along with the legacy and ambiguous "range" one.
- SMI support for fixed-length string indices implemented (SF bug #1584799,
  #1653908).
- Managed Object Instances may now have smiRead, smiWrite, smiCreate methods
  to support specific value mangling. These methods, if present, would be 
  invoked from SNMP [Agent] core instead of conventional clone() method.
  The reason is to separate trivial value duplication from specific
  Instance value mangling that may have Agent-specific side effects
  (such as RowStatus).
- MIB table row destruction now works (SF bug #1555010).
- LCD unconfiguration functions for oneliners implemented (SF bug #1635270).
- unloadModules() and unexportSymbols() implemented at MibBuilder
- Notification type PDU proxy code fixed to produce symmetrical
  convertion.
- Various SNMP engine-internal caches expiration implemented.
- SMI-level access control now takes effect only if AC object is
  passed to MIB instrumentation API.
- LCD management code now uses generic MIB instrumentation features.
- Fix to oneliner manager code to have individual UdpSocketTransport
  instance per each SnmpEngine. Multithreaded apps might fail otherwise.
  (SF bug ID #1586420).
- Exclude the PYSNMP_MODULE_ID symbol from MIB view index, as it may get
  resolved into OID label instead of actual MIB object name.
- Memory leak fixed in indices.OidOrderedDict implementation.
- Fix to VACM shortcuts to let notifications and requests to co-exist 
  for the same user otherwise.
- Fix to ...oneliner.cmdgen.UsmUserData to support non-default ciphers.
- USM now uses local notion of snmpEngineBoots/Time when authoritative
  and cached estimate otherwise. Also, a security fix applied to to USM 
  time-window verification (SF bug #1649032).
- Fix to notification objects resolution code at
  NotificationOriginator.sendNotification()
- Do not raise securityLevel for USM error reports that lacks user
  information, as these reports could never be ciphered (SF bug #1624720).
- Non-default BULK PDU params now actually applied.
- SnmpEngineID default value generation algorithmic function changed
  to allow multiple SNMP engines running on the same host.
- Documentation updated.
- A handful of minor fixes applied (SourceForge tracker IDs #1537592,
  #1537600, #1537659, #1548208, #1560939, #1563715, #1575697, #1599220,
  #1615077, #1615365, #1616579).

Revision 4.1.6a
---------------

- UNSTABLE ALPHA RELEASE.
- pysnmpUsmSecretAuthKey and pysnmpUsmSecretPrivKey length increased
  up to 256 octets. There seems no limit on this in RFC, though.
- A workaround for probably broken Agents: SNMPv3 Manager code defaults
  ContextEngineId to SecurityEngineId whenever ContextEngineId is not 
  reported by authoritative SNMP engine on discovery.
- Use empty PDU in engine-discovery report at mpmod/rfc3412.py.
- MibBuilder.loadModules() now fails on missing MIB files.
- MibBuilder.exportSymbols() now accepts unnamed objects (likely Managed
  Objects Instances)
- SNMPv2-SMI.MibScalarInstance objects now support create*/destroy*
  Management Instrumentation methods to pass Columnar Object creation and
  removal events. MibTableColumn class invoke these methods accordingly.
- Fix to AsynNotificationOriginator.asyncSendNotification() callback
  formal parameters
- Initial VACM configuration implemented according to rfc3415 Appendix 1
- tools/buildmibs.sh split-up and re-implemented as tools/build-pysnmp-mib
  and pysnmp-mibs/tools/rebuild-pysnmp-mibs for better usability. These
  and libsmi2pysnmp scripts made installable.
- Types/Notifications/Groups exportSymbols() call chunking implemented
  in tools/libsmi2pysnmp
- Initial values specified to pyasn1 types to comply with latest pyasn1 API.
- Documentation improved
- Minor fixes towards Python 1.5 compatibility

Revision 4.1.5a
---------------

- UNSTABLE ALPHA RELEASE.
- Multi-lingual SNMP Trap/Inform Applications completed; examples added
- SMI model re-designed to make a clear separation between
  Managed Objects and their specification (AKA Agent and Manager side)
- SNMP SET Application support completed
- Minor, though backward incompatible, changes to one-liner API
- Many bugfixes

Revision 4.1.4a
---------------

- UNSTABLE ALPHA RELEASE.
- SHA-based authentication fixed and privacy implemented
- ...oneliner.cmdgen.UsmUserData constructor now takes 
  authProtocol and privProtocol parameters in a backward incompatible
  manner.

Revision 4.1.3a
---------------

- UNSTABLE ALPHA RELEASE.
- rfc3413 applications API changes (related to callback function
  behaviour).
- TransportDispatcher now provides "jobs" interface to clients
  for better control of dispatcher's execution.
- Many minor fixes.

Revision 4.1.2a
---------------

- UNSTABLE ALPHA RELEASE.
- Top-level application classes renamed into longer, self descripting names
  for clarity.
- CommandResponder & NotificationOriginator applications now uses 
  stand-alone SnmpContext for application registration.
- Many minor fixes (inspired by testing on WinXP)

Revision 4.1.1a
---------------

- UNSTABLE ALPHA RELEASE.
- SNMPv3 code first published
- SNMP engine and applications implemented on library level
- Major re-design towards SNMPv3-style API.

Release 4.0.2a
--------------

- Adopted to slightly changed asyncore API (as shipped with python 2,4)

Release 4.0.1a
--------------

- Minor bug/typo fixes, mostly in example/ scripts.

Release 4.0.0a
--------------

- UNSTABLE EARLY ALPHA RELEASE.
- Major re-design and re-implementation.
- Rudimental API versioning implemented to let incompatible package
  branches to co-exist within the same Python installation.
- SMI framework designed and implemented. This framework provides 
  1) various access to MIB data 2) a way to implement custom MIB
  instrumentation objects. There's also a tool for building SMI classes
  from libsmi(3) output (smidump -f python).
- ASN.1 subtyping machinery implemented. Now dynamic ASN.1 instances
  subtyping and quering becomes available. Previously, this has been done
  through Python classes inheritance what proved to be a wrong concept.
- ASN.1 codecs framework re-designed and re-implemented aimed at a more
  consistent design and better performance. Highlights include abstract
  codec interface and serialized data caching (at encoder).
- Asn1Item constraints machinery re-implemented based on Mike C. Fletcher's
  design and code. Now various constrains are implemented as stand-alone
  objects serving interested Asn1Object derivatives through some abstract
  protocol (that's probably the Decorator design pattern).
- ASN.1 tagging facility re-implemented along the client-server design
  pattern. Besides this seems to be a more appropriate design, it allows
  an easier way for dynamic subtyping.
