1 files changed, 81 insertions, 0 deletions
diff --git a/examples/v3arch/asyncore/oneliner/manager/cmdgen/get-v3-with-specific-engine-id.py b/examples/v3arch/asyncore/oneliner/manager/cmdgen/get-v3-with-specific-engine-id.py
new file mode 100644
index 0000000..ca1d1fe
--- /dev/null
+++ b/examples/v3arch/asyncore/oneliner/manager/cmdgen/get-v3-with-specific-engine-id.py
@@ -0,0 +1,81 @@
+#
+# Command Generator
+#
+# Send SNMP GET request using the following scenario and options:
+#
+# * try to communicate with a SNMPv3 Engine using:
+# ** a non-existing user
+# ** over IPv4/UDP
+# ** to an Agent at demo.snmplabs.com:161
+# * if remote SNMP Engine ID is discovered, send SNMP GET request:
+# ** with SNMPv3, user 'usr-md5-none', MD5 authentication, no privacy
+#    at discovered securityEngineId
+# ** to the same SNMP Engine ID
+# ** for an OID in text form
+#
+from pysnmp.entity.rfc3413.oneliner.cmdgen import *
+
+snmpEngine = SnmpEngine()
+
+transportTarget = UdpTransportTarget(('demo.snmplabs.com', 161))
+
+#
+# To discover remote SNMP EngineID we will tap on SNMP engine inner workings
+# by setting up execution point observer setup on INTERNAL class PDU processing
+#
+
+observerContext = {}
+
+# Register a callback to be invoked at specified execution point of 
+# SNMP Engine and passed local variables at execution point's local scope
+snmpEngine.observer.registerObserver(
+    lambda e,p,v,c: c.update(securityEngineId=v['securityEngineId']),
+    'rfc3412.prepareDataElements:internal',
+    cbCtx=observerContext
+)
+
+# Send probe SNMP request with invalid credentials
+
+authData = UsmUserData('non-existing-user')
+
+for errorIndication, errorStatus, errorIndex, \
+        varBinds in getCmd(snmpEngine, authData,
+                           transportTarget, ContextData()):
+    break
+
+# See if our SNMP engine received REPORT PDU containing securityEngineId
+
+if 'securityEngineId' not in observerContext:
+    print("Can't discover peer EngineID, errorIndication: %s" % errorIndication)
+    raise Exception()
+
+securityEngineId = observerContext.pop('securityEngineId')
+
+print('Remote securityEngineId = %s' % securityEngineId.prettyPrint())
+
+#
+# Query remote SNMP Engine using usmUserTable entry configured for it
+#
+
+authData = UsmUserData('usr-md5-none', 'authkey1', 
+                       securityEngineId=securityEngineId)
+
+for errorIndication, errorStatus, errorIndex, \
+        varBinds in getCmd(snmpEngine, authData, \
+                           transportTarget, ContextData(), \
+                           ObjectType(ObjectIdentity('1.3.6.1.2.1.1.1.0'))):
+    break
+
+# Check for errors and print out results
+if errorIndication:
+    print(errorIndication)
+else:
+    if errorStatus:
+        print('%s at %s' % (
+            errorStatus.prettyPrint(),
+            errorIndex and varBinds[int(errorIndex)-1][0] or '?'
+            )
+        )
+    else:
+        for name, val in varBinds:
+            print('%s = %s' % (name.prettyPrint(), val.prettyPrint()))