From b4eda69d07b26b97bebefd0163651470e3ece333 Mon Sep 17 00:00:00 2001
From: Erik Reid <erik.reid@geant.org>
Date: Thu, 14 Jan 2021 13:42:17 +0100
Subject: [PATCH] added utils for capturing bgp peer state info
---
inventory_provider/snmp.py | 152 ++++++++++++++++++++++++++++++++++---
1 file changed, 140 insertions(+), 12 deletions(-)
diff --git a/inventory_provider/snmp.py b/inventory_provider/snmp.py
index 92cc3a83..319cc044 100644
--- a/inventory_provider/snmp.py
+++ b/inventory_provider/snmp.py
@@ -1,14 +1,19 @@
+import ipaddress
import logging
import re
+import struct
from pysnmp.hlapi import nextCmd, SnmpEngine, CommunityData, \
- UdpTransportTarget, ContextData, ObjectType, ObjectIdentity
+ UdpTransportTarget, ContextData, ObjectType, ObjectIdentity
from pysnmp.smi import builder, compiler
+
# from pysnmp.smi import view, rfc1902
RFC1213_MIB_IFDESC = '1.3.6.1.2.1.2.2.1.2'
-
+# BGP4-V2-MIB-JUNIPER::jnxBgpM2PeerState
+JNX_BGP_M2_PEER_STATE = '1.3.6.1.4.1.2636.5.1.1.2.1.1.1.2'
+logger = logging.getLogger(__name__)
class SNMPWalkError(ConnectionError):
pass
@@ -35,8 +40,6 @@ def walk(agent_hostname, community, base_oid): # pragma: no cover
:return:
"""
- logger = logging.getLogger(__name__)
-
mibBuilder = builder.MibBuilder()
# mibViewController = view.MibViewController(mibBuilder)
compiler.addMibCompiler(
@@ -54,14 +57,14 @@ def walk(agent_hostname, community, base_oid): # pragma: no cover
pduErrorIndication,
errorIndex,
varBinds) in nextCmd(
- SnmpEngine(),
- CommunityData(community),
- UdpTransportTarget((agent_hostname, 161)),
- ContextData(),
- ObjectType(ObjectIdentity(base_oid)),
- lexicographicMode=False,
- lookupNames=True,
- lookupValues=True):
+ SnmpEngine(),
+ CommunityData(community),
+ UdpTransportTarget((agent_hostname, 161)),
+ ContextData(),
+ ObjectType(ObjectIdentity(base_oid)),
+ lexicographicMode=False,
+ lookupNames=True,
+ lookupValues=True):
# cf. http://snmplabs.com/
# pysnmp/examples/hlapi/asyncore/sync/contents.html
@@ -97,3 +100,128 @@ def get_router_snmp_indexes(hostname, community):
'name': ifc['value'],
'index': int(m.group(1))
}
+
+
+def _v6bytes(l):
+ assert len(l) == 16
+ return struct.pack('!16B', *map(int, l))
+
+
+def _v4str(l):
+ assert len(l) == 4
+ return '.'.join(l)
+
+
+def get_peer_state_info(hostname, community):
+ oid_prefix = f'.{JNX_BGP_M2_PEER_STATE}.'
+ for ifc in walk(hostname, community, JNX_BGP_M2_PEER_STATE):
+ assert ifc['oid'].startswith(oid_prefix), \
+ f'{ifc["oid"]}: {JNX_BGP_M2_PEER_STATE}'
+ rest = ifc['oid'][len(oid_prefix):]
+ splits = rest.split('.')
+ splits.pop(0) # no idea what this integer is ...
+ if splits[0] == splits[5] == '1': # v4 should peer with v4
+ # ipv4
+ assert len(splits) == 10
+ local = ipaddress.ip_address(_v4str(splits[1:5]))
+ remote = ipaddress.ip_address(_v4str(splits[6:]))
+ elif splits[0] == splits[17] == '2': # v6 should peer with v6
+ assert len(splits) == 34
+ local = ipaddress.ip_address(_v6bytes(splits[1:17]))
+ remote = ipaddress.ip_address(_v6bytes(splits[18:]))
+ else:
+ logger.error()
+
+ yield {
+ 'local': local.exploded,
+ 'remote': remote.exploded,
+ 'oid': ifc['oid'][1:],
+ 'value': ifc['value'],
+ }
+
+############################
+from pysnmp.hlapi import getCmd
+
+def _construct_object_types(oids):
+ return [ObjectType(ObjectIdentity(oid)) for oid in oids]
+
+
+def _cast_snmp_value(value):
+ """
+ Boilerplate method for explicitly casting returned snmp value types.
+
+ Copied from the tutorial - negligible performance
+ impact since in our case we'll always return in the
+ first condition. This method is in fact totally useless
+ and should be removed.
+
+ :param value:
+ :return:
+ """
+ try:
+ return int(value)
+ except (ValueError, TypeError):
+ try:
+ return float(value)
+ except (ValueError, TypeError):
+ try:
+ return str(value)
+ except (ValueError, TypeError):
+ pass
+ return value
+
+
+def _fetch(handler):
+ """
+ yields (oid, value) from the response handler
+
+ :param handler:
+ :return: a dict like {oid: value}, or None if there's any error
+ """
+
+ for (error_indication, error_status, error_index, var_binds) in handler:
+
+ if error_indication or error_status:
+ # raise RuntimeError(
+ # 'Got SNMP error: {0}'.format(error_indication))
+ logger.error(f'SNMP error: {error_indication}')
+ return
+
+ for oid, value in var_binds:
+ yield [str(oid), _cast_snmp_value(value)]
+
+
+def get(
+ router_hostname: str,
+ community_string: str,
+ oids) -> dict:
+ """
+ Sends SNMP get requests for each oid and returns the results in a dict.
+
+ :param router_hostname:
+ :param community_string:
+ :param oids:
+ :return: a dict like {oid: value}, or None if there's any error
+ """
+ handler = getCmd(
+ SnmpEngine(),
+ CommunityData(community_string),
+ UdpTransportTarget((router_hostname, 161)),
+ ContextData(),
+ *_construct_object_types(oids)
+ )
+
+ return {oid: val for oid, val in _fetch(handler)}
+##############
+
+if __name__ == '__main__':
+
+ # for x in get_peer_state_oids('mx1.kau.lt.geant.net', '0pBiFbD'):
+ # print(x)
+
+ oids = [x['oid'] for x in get_peer_state_info('mx1.kau.lt.geant.net', '0pBiFbD')]
+ oids = list(oids)
+ for i in range(0, len(oids), 3):
+ print('*' * 20)
+ for x in get('mx1.kau.lt.geant.net', '0pBiFbD', oids[i:i+3]).items():
+ print(x)
--
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