diff options
Diffstat (limited to 'pysnmp/smi/instrum.py')
| -rw-r--r-- | pysnmp/smi/instrum.py | 221 |
1 files changed, 135 insertions, 86 deletions
diff --git a/pysnmp/smi/instrum.py b/pysnmp/smi/instrum.py index d84493ac..cec737d6 100644 --- a/pysnmp/smi/instrum.py +++ b/pysnmp/smi/instrum.py @@ -6,6 +6,8 @@ # import sys import traceback +import functools +from pysnmp import nextid from pysnmp.smi import error from pysnmp import debug @@ -24,39 +26,59 @@ class AbstractMibInstrumController(object): class MibInstrumController(AbstractMibInstrumController): + STATUS_OK = 'ok' + STATUS_ERROR = 'err' + + STATE_START = 'start' + STATE_STOP = 'stop' + STATE_ANY = '*' + # These states are actually methods of the MIB objects + STATE_READ_TEST = 'readTest' + STATE_READ_GET = 'readGet' + STATE_READ_TEST_NEXT = 'readTestNext' + STATE_READ_GET_NEXT = 'readGetNext' + STATE_WRITE_TEST = 'writeTest' + STATE_WRITE_COMMIT = 'writeCommit' + STATE_WRITE_CLEANUP = 'writeCleanup' + STATE_WRITE_UNDO = 'writeUndo' + fsmReadVar = { # ( state, status ) -> newState - ('start', 'ok'): 'readTest', - ('readTest', 'ok'): 'readGet', - ('readGet', 'ok'): 'stop', - ('*', 'err'): 'stop' + (STATE_START, STATUS_OK): STATE_READ_TEST, + (STATE_READ_TEST, STATUS_OK): STATE_READ_GET, + (STATE_READ_GET, STATUS_OK): STATE_STOP, + (STATE_ANY, STATUS_ERROR): STATE_STOP } fsmReadNextVar = { # ( state, status ) -> newState - ('start', 'ok'): 'readTestNext', - ('readTestNext', 'ok'): 'readGetNext', - ('readGetNext', 'ok'): 'stop', - ('*', 'err'): 'stop' + (STATE_START, STATUS_OK): STATE_READ_TEST_NEXT, + (STATE_READ_TEST_NEXT, STATUS_OK): STATE_READ_GET_NEXT, + (STATE_READ_GET_NEXT, STATUS_OK): STATE_STOP, + (STATE_ANY, STATUS_ERROR): STATE_STOP } fsmWriteVar = { # ( state, status ) -> newState - ('start', 'ok'): 'writeTest', - ('writeTest', 'ok'): 'writeCommit', - ('writeCommit', 'ok'): 'writeCleanup', - ('writeCleanup', 'ok'): 'readTest', + (STATE_START, STATUS_OK): STATE_WRITE_TEST, + (STATE_WRITE_TEST, STATUS_OK): STATE_WRITE_COMMIT, + (STATE_WRITE_COMMIT, STATUS_OK): STATE_WRITE_CLEANUP, + (STATE_WRITE_CLEANUP, STATUS_OK): STATE_READ_TEST, # Do read after successful write - ('readTest', 'ok'): 'readGet', - ('readGet', 'ok'): 'stop', + (STATE_READ_TEST, STATUS_OK): STATE_READ_GET, + (STATE_READ_GET, STATUS_OK): STATE_STOP, # Error handling - ('writeTest', 'err'): 'writeCleanup', - ('writeCommit', 'err'): 'writeUndo', - ('writeUndo', 'ok'): 'readTest', + (STATE_WRITE_TEST, STATUS_ERROR): STATE_WRITE_CLEANUP, + (STATE_WRITE_COMMIT, STATUS_ERROR): STATE_WRITE_UNDO, + (STATE_WRITE_UNDO, STATUS_OK): STATE_READ_TEST, # Ignore read errors (removed columns) - ('readTest', 'err'): 'stop', - ('readGet', 'err'): 'stop', - ('*', 'err'): 'stop' + (STATE_READ_TEST, STATUS_ERROR): STATE_STOP, + (STATE_READ_GET, STATUS_ERROR): STATE_STOP, + (STATE_ANY, STATUS_ERROR): STATE_STOP } + FSM_CONTEXT = '_fsmContext' + + FSM_SESSION_ID = nextid.Integer(0xffffffff) + def __init__(self, mibBuilder): self.mibBuilder = mibBuilder self.lastBuildId = -1 @@ -183,88 +205,115 @@ class MibInstrumController(AbstractMibInstrumController): # MIB instrumentation - def flipFlopFsm(self, fsmTable, *varBinds, **context): + def _flipFlopFsmCb(self, varBind, **context): + fsmContext = context[self.FSM_CONTEXT] + + varBinds = fsmContext['varBinds'] + + idx = context.pop('idx') + + if idx >= 0: + fsmContext['count'] += 1 + + varBinds[idx] = varBind + + debug.logger & debug.flagIns and debug.logger( + '_flipFlopFsmCb: var-bind %d, processed %d, expected %d' % (idx, fsmContext['count'], len(varBinds))) + if fsmContext['count'] < len(varBinds): + return + + debug.logger & debug.flagIns and debug.logger( + '_flipFlopFsmCb: finished, output %r' % (varBinds,)) + + fsmCallable = fsmContext['fsmCallable'] + + fsmCallable(**context) + + def flipFlopFsm(self, fsmTable, *varBinds, **context): try: - fsmContext = context['fsmState'] + fsmContext = context[self.FSM_CONTEXT] except KeyError: self.__indexMib() - fsmContext = context['fsmState'] = dict(varBinds=[], state='start', status='ok') + fsmContext = context[self.FSM_CONTEXT] = dict( + sessionId=self.FSM_SESSION_ID(), + varBinds=list(varBinds[:]), + fsmCallable=functools.partial(self.flipFlopFsm, fsmTable, *varBinds), + state=self.STATE_START, status=self.STATUS_OK + ) debug.logger & debug.flagIns and debug.logger('flipFlopFsm: input var-binds %r' % (varBinds,)) mibTree, = self.mibBuilder.importSymbols('SNMPv2-SMI', 'iso') - outputVarBinds = fsmContext['varBinds'] state = fsmContext['state'] status = fsmContext['status'] - origExc = origTraceback = None + debug.logger & debug.flagIns and debug.logger( + 'flipFlopFsm: current state %s, status %s' % (state, status)) + + try: + newState = fsmTable[(state, status)] + + except KeyError: + try: + newState = fsmTable[(self.STATE_ANY, status)] + + except KeyError: + raise error.SmiError('Unresolved FSM state %s, %s' % (state, status)) + + debug.logger & debug.flagIns and debug.logger( + 'flipFlopFsm: state %s status %s -> new state %s' % (state, status, newState)) + + state = newState + + if state == self.STATE_STOP: + context.pop(self.FSM_CONTEXT, None) + + cbFun = context.get('cbFun') + if cbFun: + varBinds = fsmContext['varBinds'] + cbFun(varBinds, **context) + + return + + fsmContext.update(state=state, count=0) + + # the case of no var-binds + if not varBinds: + return self._flipFlopFsmCb(None, idx=-1, **context) + + mgmtFun = getattr(mibTree, state, None) + if not mgmtFun: + raise error.SmiError( + 'Unsupported state handler %s at %s' % (state, self) + ) + + for idx, varBind in enumerate(varBinds): + try: + # TODO: managed objects to run asynchronously + #mgmtFun(varBind, idx=idx, **context) + self._flipFlopFsmCb(mgmtFun(varBind, idx=idx, **context), idx=idx, **context) + + except error.SmiError: + exc = sys.exc_info() + debug.logger & debug.flagIns and debug.logger( + 'flipFlopFsm: fun %s exception %s for %r with traceback: %s' % ( + mgmtFun, exc[0], varBind, traceback.format_exception(*exc))) + + varBind = varBind[0], exc + + fsmContext['status'] = self.STATUS_ERROR + + self._flipFlopFsmCb(varBind, idx=idx, **context) + + return - while True: - k = state, status - if k in fsmTable: - fsmState = fsmTable[k] - else: - k = '*', status - if k in fsmTable: - fsmState = fsmTable[k] - else: - raise error.SmiError( - 'Unresolved FSM state %s, %s' % (state, status) - ) - debug.logger & debug.flagIns and debug.logger( - 'flipFlopFsm: state %s status %s -> fsmState %s' % (state, status, fsmState)) - state = fsmState - status = 'ok' - if state == 'stop': - break - - for idx, (name, val) in enumerate(varBinds): - mgmtFun = getattr(mibTree, state, None) - if not mgmtFun: - raise error.SmiError( - 'Unsupported state handler %s at %s' % (state, self) - ) - - context['idx'] = idx - - try: - # Convert to tuple to avoid ObjectName instantiation - # on subscription - rval = mgmtFun((tuple(name), val), **context) - - except error.SmiError: - exc_t, exc_v, exc_tb = sys.exc_info() - debug.logger & debug.flagIns and debug.logger( - 'flipFlopFsm: fun %s exception %s for %s=%r with traceback: %s' % ( - mgmtFun, exc_t, name, val, traceback.format_exception(exc_t, exc_v, exc_tb))) - if origExc is None: # Take the first exception - origExc, origTraceback = exc_v, exc_tb - status = 'err' - break - else: - debug.logger & debug.flagIns and debug.logger( - 'flipFlopFsm: fun %s succeeded for %s=%r' % (mgmtFun, name, val)) - if rval is not None: - outputVarBinds.append((rval[0], rval[1])) - - if origExc: - if sys.version_info[0] <= 2: - raise origExc else: - try: - raise origExc.with_traceback(origTraceback) - finally: - # Break cycle between locals and traceback object - # (seems to be irrelevant on Py3 but just in case) - del origTraceback - - cbFun = context.get('cbFun') - if cbFun: - cbFun(outputVarBinds, **context) + debug.logger & debug.flagIns and debug.logger( + 'flipFlopFsm: func %s initiated for %r' % (mgmtFun, varBind)) def readVars(self, *varBinds, **context): self.flipFlopFsm(self.fsmReadVar, *varBinds, **context) |