def send (self, request=None):
"""
send([message])
Send SNMP message (the specified one or previously submitted
with store() method) to remote SNMP process specified on
session object creation.
"""
# Message must present
if not request and not self.request:
raise error.BadArgument('Empty SNMP message')
# Make sure we are given a message
if request:
# Store new request
self.store (request)
# Make sure the connection is established, open it otherwise
if not self.socket:
self.open()
try:
self.socket.send(self.request)
except socket.error, why:
raise error.TransportError('send() error: ' + str(why))
def open (self):
"""
open()
Initialize transport layer (UDP socket) to be used
for further communication with remote SNMP process.
"""
try:
self.socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
except socket.error, why:
raise error.TransportError('socket() error: ' + str(why))
def close (self):
"""
close()
Close UDP socket used to communicate with remote SNMP agent.
"""
# See if it's opened
if self.socket:
try:
self.socket.close()
except socket.error, why:
raise error.TransportError('close() error: ' + str(why))
# Initialize it to None to indicate it's closed
self.socket = None
def read (self):
"""
read() -> message
Read data from the socket (assuming there's some data ready
for reading), return SNMP message (as string).
"""
# Make sure the connection exists
if not self.socket:
raise error.NotConnected
try:
self.response = self.socket.recv(65536)
except socket.error, why:
raise error.TransportError('recv() error: ' + str(why))
def receive (self):
"""
receive() -> message
Receive SNMP message from remote SNMP process or timeout
(and return None).
"""
# Initialize sockets map
r, w, x = [self.socket], [], []
# Wait for response
r, w, x = select.select(r, w, x, self.timeout)
# Timeout occurred?
if r:
try:
self.response = self.socket.recv(65536)
except socket.error, why:
raise error.TransportError('recv() error: ' + str(why))
return self.response
class session (message.message):
"""Build & send SNMP request, receive & parse SNMP response
"""
def __init__ (self, agent, community='public'):
# Call message class constructor
message.message.__init__ (self, community)
# Make sure we get all these arguments
if not agent:
raise error.BadArgument ('Empty SNMP agent name')
# Initialize SNMP session
self.agent = agent
self.port = 161
self.timeout = 1.0
self.retries = 3
self.iface = None
# This is a provision for multisession superclass
self.request = None
self.response = None
# Initialize socket
self.socket = None
def store (self, request):
"""
store(message)
Store SNMP message for later transmission.
"""
if not request:
raise error.BadArgument('Empty SNMP message')
# Otherwise, store the message to be sent
self.request = request
def get_socket (self):
"""
get_socket() -> socket
Return socket object previously created with open() method.
"""
return self.socket
def open (self):
"""
open()
Initialize transport layer (UDP socket) to be used
for further communication with remote SNMP process.
"""
try:
self.socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
except socket.error, why:
raise error.TransportError('socket() error: ' + str(why))
# See if we need to bind to specific interface at SNMP
# manager machine
if self.iface:
try:
self.socket.bind((self.iface[0], 0))
except socket.error, why:
raise error.TransportError('bind() error: ' + str(why))
raise error.TransportError('socket() error: ' + str(why))
# See if we need to bind to specific interface at SNMP
# manager machine
if self.iface:
try:
self.socket.bind((self.iface[0], 0))
except socket.error, why:
raise error.TransportError('bind() error: ' + str(why))
try:
self.socket.connect((self.agent, self.port))
except socket.error, why:
raise error.TransportError('connect() error: ' + str(why))
return self.socket
def send (self, request=None):
"""
send([message])
Send SNMP message (the specified one or previously submitted
with store() method) to remote SNMP process specified on
session object creation.
"""
# Message must present
if not request and not self.request:
raise error.BadArgument('Empty SNMP message')