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CoAP/coapthon/layers/messagelayer.py

315 lines
13 KiB
Python

import logging
import random
import time
import socket
from coapthon import utils
from coapthon.messages.message import Message
from coapthon import defines
from coapthon.messages.request import Request
from coapthon.transaction import Transaction
__author__ = 'Giacomo Tanganelli'
logger = logging.getLogger(__name__)
class MessageLayer(object):
"""
Handles matching between messages (Message ID) and request/response (Token)
"""
def __init__(self, starting_mid):
"""
Set the layer internal structure.
:param starting_mid: the first mid used to send messages.
"""
self._transactions = {}
self._transactions_token = {}
if starting_mid is not None:
self._current_mid = starting_mid
else:
self._current_mid = random.randint(1, 1000)
def fetch_mid(self):
"""
Gets the next valid MID.
:return: the mid to use
"""
current_mid = self._current_mid
self._current_mid += 1
self._current_mid %= 65535
return current_mid
def purge(self, timeout_time=defines.EXCHANGE_LIFETIME):
for k in list(self._transactions.keys()):
now = time.time()
transaction = self._transactions[k]
if transaction.timestamp + timeout_time < now:
logger.debug("Delete transaction")
del self._transactions[k]
for k in list(self._transactions_token.keys()):
now = time.time()
transaction = self._transactions_token[k]
if transaction.timestamp + timeout_time < now:
logger.debug("Delete transaction")
del self._transactions_token[k]
def receive_request(self, request):
"""
Handle duplicates and store received messages.
:type request: Request
:param request: the incoming request
:rtype : Transaction
:return: the edited transaction
"""
logger.info("receive_request - " + str(request))
try:
host, port = request.source
except AttributeError:
return
key_mid = utils.str_append_hash(host, port, request.mid)
key_token = utils.str_append_hash(host, port, request.token)
if key_mid in list(self._transactions.keys()):
# Duplicated
self._transactions[key_mid].request.duplicated = True
transaction = self._transactions[key_mid]
else:
request.timestamp = time.time()
transaction = Transaction(request=request, timestamp=request.timestamp)
with transaction:
self._transactions[key_mid] = transaction
self._transactions_token[key_token] = transaction
return transaction
def receive_response(self, response):
"""
Pair responses with requests.
:type response: Response
:param response: the received response
:rtype : Transaction
:return: the transaction to which the response belongs to
"""
logger.info("receive_response - " + str(response))
try:
host, port = response.source
except AttributeError:
return
all_coap_nodes = defines.ALL_COAP_NODES_IPV6 if socket.getaddrinfo(host, None)[0][0] == socket.AF_INET6 else defines.ALL_COAP_NODES
key_mid = utils.str_append_hash(host, port, response.mid)
key_mid_multicast = utils.str_append_hash(all_coap_nodes, port, response.mid)
key_token = utils.str_append_hash(host, port, response.token)
key_token_multicast = utils.str_append_hash(all_coap_nodes, port, response.token)
if key_mid in list(self._transactions.keys()):
transaction = self._transactions[key_mid]
if response.token != transaction.request.token:
logger.warning("Tokens does not match - response message " + str(host) + ":" + str(port))
return None, False
elif key_token in self._transactions_token:
transaction = self._transactions_token[key_token]
elif key_mid_multicast in list(self._transactions.keys()):
transaction = self._transactions[key_mid_multicast]
elif key_token_multicast in self._transactions_token:
transaction = self._transactions_token[key_token_multicast]
if response.token != transaction.request.token:
logger.warning("Tokens does not match - response message " + str(host) + ":" + str(port))
return None, False
else:
logger.warning("Un-Matched incoming response message " + str(host) + ":" + str(port))
return None, False
send_ack = False
if response.type == defines.Types["CON"]:
send_ack = True
transaction.request.acknowledged = True
transaction.completed = True
transaction.response = response
if transaction.retransmit_stop is not None:
transaction.retransmit_stop.set()
return transaction, send_ack
def receive_empty(self, message):
"""
Pair ACKs with requests.
:type message: Message
:param message: the received message
:rtype : Transaction
:return: the transaction to which the message belongs to
"""
logger.info("receive_empty - " + str(message))
try:
host, port = message.source
except AttributeError:
return
all_coap_nodes = defines.ALL_COAP_NODES_IPV6 if socket.getaddrinfo(host, None)[0][0] == socket.AF_INET6 else defines.ALL_COAP_NODES
key_mid = utils.str_append_hash(host, port, message.mid)
key_mid_multicast = utils.str_append_hash(all_coap_nodes, port, message.mid)
key_token = utils.str_append_hash(host, port, message.token)
key_token_multicast = utils.str_append_hash(all_coap_nodes, port, message.token)
if key_mid in list(self._transactions.keys()):
transaction = self._transactions[key_mid]
elif key_token in self._transactions_token:
transaction = self._transactions_token[key_token]
elif key_mid_multicast in list(self._transactions.keys()):
transaction = self._transactions[key_mid_multicast]
elif key_token_multicast in self._transactions_token:
transaction = self._transactions_token[key_token_multicast]
else:
logger.warning("Un-Matched incoming empty message " + str(host) + ":" + str(port))
return None
if message.type == defines.Types["ACK"]:
if not transaction.request.acknowledged:
transaction.request.acknowledged = True
elif (transaction.response is not None) and (not transaction.response.acknowledged):
transaction.response.acknowledged = True
elif message.type == defines.Types["RST"]:
if not transaction.request.acknowledged:
transaction.request.rejected = True
elif not transaction.response.acknowledged:
transaction.response.rejected = True
elif message.type == defines.Types["CON"]:
#implicit ACK (might have been lost)
logger.debug("Implicit ACK on received CON for waiting transaction")
transaction.request.acknowledged = True
else:
logger.warning("Unhandled message type...")
if transaction.retransmit_stop is not None:
transaction.retransmit_stop.set()
return transaction
def send_request(self, request):
"""
Create the transaction and fill it with the outgoing request.
:type request: Request
:param request: the request to send
:rtype : Transaction
:return: the created transaction
"""
logger.info("send_request - " + str(request))
assert isinstance(request, Request)
try:
host, port = request.destination
except AttributeError:
return
request.timestamp = time.time()
transaction = Transaction(request=request, timestamp=request.timestamp)
if transaction.request.type is None:
transaction.request.type = defines.Types["CON"]
if transaction.request.mid is None:
transaction.request.mid = self.fetch_mid()
key_mid = utils.str_append_hash(host, port, request.mid)
self._transactions[key_mid] = transaction
key_token = utils.str_append_hash(host, port, request.token)
self._transactions_token[key_token] = transaction
return self._transactions[key_mid]
def send_response(self, transaction):
"""
Set the type, the token and eventually the MID for the outgoing response
:type transaction: Transaction
:param transaction: the transaction that owns the response
:rtype : Transaction
:return: the edited transaction
"""
logger.info("send_response - " + str(transaction.response))
if transaction.response.type is None:
if transaction.request.type == defines.Types["CON"] and not transaction.request.acknowledged:
transaction.response.type = defines.Types["ACK"]
transaction.response.mid = transaction.request.mid
transaction.response.acknowledged = True
transaction.completed = True
elif transaction.request.type == defines.Types["NON"]:
transaction.response.type = defines.Types["NON"]
else:
transaction.response.type = defines.Types["CON"]
transaction.response.token = transaction.request.token
if transaction.response.mid is None:
transaction.response.mid = self.fetch_mid()
try:
host, port = transaction.response.destination
except AttributeError:
return
key_mid = utils.str_append_hash(host, port, transaction.response.mid)
self._transactions[key_mid] = transaction
transaction.request.acknowledged = True
return transaction
def send_empty(self, transaction, related, message):
"""
Manage ACK or RST related to a transaction. Sets if the transaction has been acknowledged or rejected.
:param transaction: the transaction
:param related: if the ACK/RST message is related to the request or the response. Must be equal to
transaction.request or to transaction.response or None
:type message: Message
:param message: the ACK or RST message to send
"""
logger.info("send_empty - " + str(message))
if transaction is None:
try:
host, port = message.destination
except AttributeError:
return
key_mid = utils.str_append_hash(host, port, message.mid)
key_token = utils.str_append_hash(host, port, message.token)
if key_mid in self._transactions:
transaction = self._transactions[key_mid]
related = transaction.response
elif key_token in self._transactions_token:
transaction = self._transactions_token[key_token]
related = transaction.response
else:
return message
if message.type == defines.Types["ACK"]:
if transaction.request == related:
transaction.request.acknowledged = True
transaction.completed = True
message.mid = transaction.request.mid
message.code = 0
message.destination = transaction.request.source
elif transaction.response == related:
transaction.response.acknowledged = True
transaction.completed = True
message.mid = transaction.response.mid
message.code = 0
message.token = transaction.response.token
message.destination = transaction.response.source
elif message.type == defines.Types["RST"]:
if transaction.request == related:
transaction.request.rejected = True
message._mid = transaction.request.mid
if message.mid is None:
message.mid = self.fetch_mid()
message.code = 0
message.token = transaction.request.token
message.destination = transaction.request.source
elif transaction.response == related:
transaction.response.rejected = True
transaction.completed = True
message._mid = transaction.response.mid
if message.mid is None:
message.mid = self.fetch_mid()
message.code = 0
message.token = transaction.response.token
message.destination = transaction.response.source
return message