"""Implements asyncore-based generic DGRAM transport"""
import socket, errno
from pysnmp.carrier.asynsock.base import AbstractSocketTransport
from pysnmp.carrier import error
from pysnmp import debug
sockErrors = { # Ignore these socket errors
errno.ESHUTDOWN: 1,
errno.ENOTCONN: 1,
errno.ECONNRESET: 0,
errno.ECONNREFUSED: 0,
errno.EAGAIN: 0,
errno.EWOULDBLOCK: 0
}
try:
# bad FD may happen upon FD closure on n-1 select() event
sockErrors[errno.EBADFD] = 1
except AttributeError:
# Windows sockets do not have EBADFD
pass
class DgramSocketTransport(AbstractSocketTransport):
sockType = socket.SOCK_DGRAM
retryCount = 3; retryInterval = 1
def __init__(self, sock=None, sockMap=None):
self.__outQueue = []
AbstractSocketTransport.__init__(self, sock, sockMap)
def openClientMode(self, iface=None):
if iface is not None:
try:
self.socket.bind(iface)
except socket.error, why:
raise error.CarrierError('bind() failed: %s' % (why,))
return self
def openServerMode(self, iface):
try:
self.socket.bind(iface)
except socket.error, why:
raise error.CarrierError('bind() failed: %s' % (why,))
self._iface = iface
return self
def sendMessage(self, outgoingMessage, transportAddress):
self.__outQueue.append(
(outgoingMessage, transportAddress)
)
# asyncore API
def handle_connect(self): pass
def writable(self): return self.__outQueue
def handle_write(self):
outgoingMessage, transportAddress = self.__outQueue.pop()
debug.logger & debug.flagIO and debug.logger('handle_write: transportAddress %s outgoingMessage %s' % (transportAddress, repr(outgoingMessage)))
try:
self.socket.sendto(outgoingMessage, transportAddress)
except socket.error, why:
if sockErrors.has_key(why[0]):
debug.logger & debug.flagIO and debug.logger('handle_write: ignoring socket error %s' % (why,))
else:
raise socket.error, why
def readable(self): return 1
def handle_read(self):
try:
incomingMessage, transportAddress = self.socket.recvfrom(65535)
debug.logger & debug.flagIO and debug.logger('handle_read: transportAddress %s incomingMessage %s' % (transportAddress, repr(incomingMessage)))
if not incomingMessage:
self.handle_close()
return
else:
self._cbFun(self, transportAddress, incomingMessage)
return
except socket.error, why:
if sockErrors.has_key(why[0]):
debug.logger & debug.flagIO and debug.logger('handle_read: known socket error %s' % (why,))
sockErrors[why[0]] and self.handle_close()
return
else:
raise socket.error, why
def handle_close(self): pass # no datagram connection
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