ObjectIdentity.resolveWithMib()无法解析具有InetAddressIPv4类型的实例索引

Question

在使用TCP-MIB::tcpConnectionTable时，我注意到它们的表索引在调用resolveWithMib()之后仍未得到解决；启动MIB工具调试显示，大小约束检查应用于文本IP地址值，而不是应用于原始(4字节)值。非IP地址表索引(如IF-MIB::ifIndex )不会出现此问题.

复制：

from pysnmp.smi.rfc1902 import ObjectIdentity
from pysnmp.smi.builder import MibBuilder
from pysnmp.smi.compiler import addMibCompiler
from pysnmp.smi.view import MibViewController
from pysnmp.debug import Debug, setLogger

builder = MibBuilder()
addMibCompiler(builder)
builder.loadModules('IF-MIB')
builder.loadModules('TCP-MIB')
view = MibViewController(builder)

def doit(*poargs):
    print(ObjectIdentity(*poargs).resolveWithMib(view).getMibSymbol())

setLogger(Debug('all'))
doit('.1.3.6.1.2.1.2.2.1.2.1')
doit('.1.3.6.1.2.1.6.19.1.7.1.9.49.48.46.48.46.48.46.49.49.22.1.14.49.57.50.46.49.54.57.46.50.48.46.49.53.52.2629')

返回：

2017-09-28 19:14:35,045 pysnmp: running pysnmp version 4.3.9
2017-09-28 19:14:35,045 pysnmp: debug category 'all' enabled
2017-09-28 19:14:35,045 pysnmp: resolving .1.3.6.1.2.1.2.2.1.2.1 as OID or label
2017-09-28 19:14:35,046 pysnmp: indexMib: re-indexing MIB view
2017-09-28 19:14:35,049 pysnmp: getNodeNameByOid: resolved :1.3.6.1.2.1.2.2.1.2.1 -> ('iso', 'org', 'dod', 'internet', 'mgmt', 'mib-2', 'interfaces', 'ifTable', 'ifEntry', 'ifDescr').1
2017-09-28 19:14:35,049 pysnmp: resolved ('.1.3.6.1.2.1.2.2.1.2.1',) into prefix ObjectName('1.3.6.1.2.1.2.2.1.2') and suffix ObjectName('1')
2017-09-28 19:14:35,049 pysnmp: getNodeNameByOid: resolved :1.3.6.1.2.1.2.2.1.2 -> ('iso', 'org', 'dod', 'internet', 'mgmt', 'mib-2', 'interfaces', 'ifTable', 'ifEntry', 'ifDescr').()
2017-09-28 19:14:35,049 pysnmp: resolved prefix ObjectName('1.3.6.1.2.1.2.2.1.2') into MIB node MibTableColumn((1, 3, 6, 1, 2, 1, 2, 2, 1, 2), DisplayString(subtypeSpec=ConstraintsIntersection(ValueSizeConstraint(0, 65535), ValueSizeConstraint(0, 255), ValueSizeConstraint(0, 255))))
2017-09-28 19:14:35,049 pysnmp: getNodeNameByOid: resolved :(1, 3, 6, 1, 2, 1, 2, 2, 1) -> ('iso', 'org', 'dod', 'internet', 'mgmt', 'mib-2', 'interfaces', 'ifTable', 'ifEntry').()
2017-09-28 19:14:35,049 pysnmp: resolved indices are (InterfaceIndex(1),)
('IF-MIB', 'ifDescr', (InterfaceIndex(1),))
2017-09-28 19:14:35,050 pysnmp: resolving .1.3.6.1.2.1.6.19.1.7.1.9.49.48.46.48.46.48.46.49.49.22.1.14.49.57.50.46.49.54.57.46.50.48.46.49.53.52.2629 as OID or label
2017-09-28 19:14:35,051 pysnmp: getNodeNameByOid: resolved :1.3.6.1.2.1.6.19.1.7.1.9.49.48.46.48.46.48.46.49.49.22.1.14.49.57.50.46.49.54.57.46.50.48.46.49.53.52.2629 -> ('iso', 'org', 'dod', 'internet', 'mgmt', 'mib-2', 'tcp', 'tcpConnectionTable', 'tcpConnectionEntry', 'tcpConnectionState').1.9.49.48.46.48.46.48.46.49.49.22.1.14.49.57.50.46.49.54.57.46.50.48.46.49.53.52.2629
2017-09-28 19:14:35,051 pysnmp: resolved ('.1.3.6.1.2.1.6.19.1.7.1.9.49.48.46.48.46.48.46.49.49.22.1.14.49.57.50.46.49.54.57.46.50.48.46.49.53.52.2629',) into prefix ObjectName('1.3.6.1.2.1.6.19.1.7') and suffix ObjectName('1.9.49.48.46.48.46.48.46.49.49.22.1.14.49.57.50.46.49.54.57.46.50.48.46.49.53.52.2629')
2017-09-28 19:14:35,051 pysnmp: getNodeNameByOid: resolved :1.3.6.1.2.1.6.19.1.7 -> ('iso', 'org', 'dod', 'internet', 'mgmt', 'mib-2', 'tcp', 'tcpConnectionTable', 'tcpConnectionEntry', 'tcpConnectionState').()
2017-09-28 19:14:35,051 pysnmp: resolved prefix ObjectName('1.3.6.1.2.1.6.19.1.7') into MIB node MibTableColumn((1, 3, 6, 1, 2, 1, 6, 19, 1, 7), Integer32(subtypeSpec=ConstraintsIntersection(ValueRangeConstraint(-2147483648, 2147483647), ConstraintsUnion(SingleValueConstraint(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12))), NamedValues((('synReceived', 4), ('established', 5), ('finWait2', 7), ('timeWait', 11), ('finWait1', 6), ('lastAck', 9), ('closeWait', 8), ('deleteTCB', 12), ('closed', 1), ('closing', 10), ('listen', 2), ('synSent', 3)))))
2017-09-28 19:14:35,051 pysnmp: getNodeNameByOid: resolved :(1, 3, 6, 1, 2, 1, 6, 19, 1) -> ('iso', 'org', 'dod', 'internet', 'mgmt', 'mib-2', 'tcp', 'tcpConnectionTable', 'tcpConnectionEntry').()
2017-09-28 19:14:35,052 pysnmp: error resolving table indices at MibTableRow, (9, 49, 48, 46, 48, 46, 48, 46, 49, 49, 22, 1, 14, 49, 57, 50, 46, 49, 54, 57, 46, 50, 48, 46, 49, 53, 52, 2629): ConstraintsIntersection(ValueSizeConstraint(0, 65535), ValueSizeConstraint(4, 4)) failed at: ValueConstraintError("ValueSizeConstraint(4, 4) failed at: ValueConstraintError('10.0.0.11',)",) at InetAddressIPv4
2017-09-28 19:14:35,052 pysnmp: resolved indices are ((9, 49, 48, 46, 48, 46, 48, 46, 49, 49, 22, 1, 14, 49, 57, 50, 46, 49, 54, 57, 46, 50, 48, 46, 49, 53, 52, 2629),)
('TCP-MIB', 'tcpConnectionState', ((9, 49, 48, 46, 48, 46, 48, 46, 49, 49, 22, 1, 14, 49, 57, 50, 46, 49, 54, 57, 46, 50, 48, 46, 49, 53, 52, 2629),))

请注意IF-MIB::ifDescr的实例索引是如何正确地解析为(InterfaceIndex(1),)的，而TCP-MIB::tcpConnectionState的实例索引是如何作为((9, 49, 48, 46, ...),)未解决的。

我如何解决或解决这个问题？

Answer 1

在我看来你好像是在传递畸形的索引。例如，46 ASCII序数以IPv4虚线符号表示小数点。这个点不应该被编码到OID中。

以下是tcpConnectionTable的索引结构

INDEX   { tcpConnectionLocalAddressType,
          tcpConnectionLocalAddress,
          tcpConnectionLocalPort,
          tcpConnectionRemAddressType,
          tcpConnectionRemAddress,
          tcpConnectionRemPort }

所有这些组件都应该在任何有效的索引中结束。如果我使用您的复制器并尝试反向转换，例如从符号索引(这很容易手工构建)转换为OID并返回：

oid = ObjectIdentity('TCP-MIB', 'tcpConnectionState', 
                     'ipv4', '10.0.0.11', 22,
                     'ipv4', '10.0.0.11', 1024).resolveWithMib(view)
print(oid)
mib_obj = ObjectIdentity(oid).resolveWithMib(view)
print(mib_obj.getMibSymbol())

我可以看到索引是如何被编码到OID中的，并证明这个pysnmp可以将它们解码回来：

1.3.6.1.2.1.6.19.1.7.1.4.10.0.0.11.22.1.4.10.0.0.11.1024
('TCP-MIB', 'tcpConnectionState', 
 (InetAddressType('ipv4'), InetAddressIPv4(hexValue='0a00000b'), InetPortNumber(22),
  InetAddressType('ipv4'), InetAddressIPv4(hexValue='0a00000b'), InetPortNumber(1024)))