1 files changed, 100 insertions, 0 deletions
diff --git a/examples/v3arch/asyncore/manager/cmdgen/get-v2c-spoof-source-address.py b/examples/v3arch/asyncore/manager/cmdgen/get-v2c-spoof-source-address.py
new file mode 100644
index 0000000..998d40f
--- /dev/null
+++ b/examples/v3arch/asyncore/manager/cmdgen/get-v2c-spoof-source-address.py
@@ -0,0 +1,100 @@
+"""
+Spoof source address
+++++++++++++++++++++
+
+Send a SNMP GET request
+* with SNMPv2c, community 'public'
+* over IPv4/UDP
+* to an Agent at 195.218.195.228:161
+* from a non-local, spoofed IP 1.2.3.4 (root and Python 3.3+ required)
+* for an OID in tuple form
+
+This script performs similar to the following Net-SNMP command:
+
+| $ snmpget -v2c -c public -ObentU 195.218.195.228 1.3.6.1.2.1.1.1.0
+
+But unlike the above command, this script issues SNMP request from 
+a non-default, non-local IP address.
+
+It is indeed possible to originate SNMP traffic from any valid local
+IP addresses. It could be a secondary IP interface, for instance. 
+Superuser privileges are only required to send spoofed packets. 
+Alternatively, sending from local interface could also be achieved by
+binding to it (via openClientMode() parameter).
+
+"""#
+from pysnmp.entity import engine, config
+from pysnmp.carrier.asyncore.dgram import udp
+from pysnmp.entity.rfc3413 import cmdgen
+
+# Create SNMP engine instance
+snmpEngine = engine.SnmpEngine()
+
+#
+# SNMPv1 setup
+#
+
+# SecurityName <-> CommunityName mapping
+config.addV1System(snmpEngine, 'my-area', 'public')
+
+# Specify security settings per SecurityName (SNMPv1 - 0, SNMPv2c - 1)
+config.addTargetParams(snmpEngine, 'my-creds', 'my-area', 'noAuthNoPriv', 0)
+
+#
+# Setup transport endpoint and bind it with security settings yielding
+# a target name
+#
+
+# Initialize asyncore-based UDP/IPv4 transport
+udpSocketTransport = udp.UdpSocketTransport().openClientMode()
+
+# Use sendmsg()/recvmsg() for socket communication (required for
+# IP source spoofing functionality)
+udpSocketTransport.enablePktInfo()
+
+# Enable IP source spoofing (requires root privileges)
+udpSocketTransport.enableTransparent()
+
+# Register this transport at SNMP Engine
+config.addTransport(
+    snmpEngine,
+    udp.domainName,
+    udpSocketTransport
+)
+
+# Configure destination IPv4 address as well as source IPv4 address
+config.addTargetAddr(
+    snmpEngine, 'my-router',
+    udp.domainName, ('195.218.195.228', 161),
+    'my-creds',
+    sourceAddress=('1.2.3.4', 0)
+)
+
+# Error/response receiver
+def cbFun(snmpEngine, sendRequestHandle, errorIndication,
+          errorStatus, errorIndex, varBinds, cbCtx):
+    if errorIndication:
+        print(errorIndication)
+    # SNMPv1 response may contain noSuchName error *and* SNMPv2c exception,
+    # so we ignore noSuchName error here
+    elif errorStatus and errorStatus != 2:
+        print('%s at %s' % (
+            errorStatus.prettyPrint(),
+            errorIndex and varBinds[int(errorIndex)-1][0] or '?'
+            )
+        )
+    else:
+        for oid, val in varBinds:
+            print('%s = %s' % (oid.prettyPrint(), val.prettyPrint()))
+
+# Prepare and send a request message
+cmdgen.GetCommandGenerator().sendVarBinds(
+    snmpEngine,
+    'my-router',
+    None, '',  # contextEngineId, contextName
+    [ ((1,3,6,1,2,1,1,1,0), None) ],
+    cbFun
+)
+
+# Run I/O dispatcher which would send pending queries and process responses
+snmpEngine.transportDispatcher.runDispatcher()