import copy
from coapthon.messages.request import Request
from coapclient import HelperClient
from coapthon.messages.response import Response
from coapthon import defines
from coapthon.resources.remoteResource import RemoteResource
from coapthon.utils import parse_uri
__author__ = 'Giacomo Tanganelli'
[docs]class ForwardLayer(object):
"""
Class used by Proxies to forward messages.
"""
def __init__(self, server):
self._server = server
[docs] def receive_request(self, transaction):
"""
Setup the transaction for forwarding purposes on Forward Proxies.
:type transaction: Transaction
:param transaction: the transaction that owns the request
:rtype : Transaction
:return: the edited transaction
"""
uri = transaction.request.proxy_uri
host, port, path = parse_uri(uri)
path = str("/" + path)
transaction.response = Response()
transaction.response.destination = transaction.request.source
transaction.response.token = transaction.request.token
return self._forward_request(transaction, (host, port), path)
[docs] def receive_request_reverse(self, transaction):
"""
Setup the transaction for forwarding purposes on Reverse Proxies.
:type transaction: Transaction
:param transaction: the transaction that owns the request
:rtype : Transaction
:return: the edited transaction
"""
path = str("/" + transaction.request.uri_path)
transaction.response = Response()
transaction.response.destination = transaction.request.source
transaction.response.token = transaction.request.token
if path == defines.DISCOVERY_URL:
transaction = self._server.resourceLayer.discover(transaction)
else:
new = False
if transaction.request.code == defines.Codes.POST.number:
new_paths = self._server.root.with_prefix(path)
new_path = "/"
for tmp in new_paths:
if len(tmp) > len(new_path):
new_path = tmp
if path != new_path:
new = True
path = new_path
try:
resource = self._server.root[path]
except KeyError:
resource = None
if resource is None or path == '/':
# Not Found
transaction.response.code = defines.Codes.NOT_FOUND.number
else:
transaction.resource = resource
transaction = self._handle_request(transaction, new)
return transaction
@staticmethod
def _forward_request(transaction, destination, path):
"""
Forward requests.
:type transaction: Transaction
:param transaction: the transaction that owns the request
:param destination: the destination of the request (IP, port)
:param path: the path of the request.
:rtype : Transaction
:return: the edited transaction
"""
client = HelperClient(destination)
request = Request()
request.options = copy.deepcopy(transaction.request.options)
del request.block2
del request.block1
del request.uri_path
del request.proxy_uri
del request.proxy_schema
# TODO handle observing
del request.observe
# request.observe = transaction.request.observe
request.uri_path = path
request.destination = destination
request.payload = transaction.request.payload
request.code = transaction.request.code
response = client.send_request(request)
client.stop()
if response is not None:
transaction.response.payload = response.payload
transaction.response.code = response.code
transaction.response.options = response.options
else:
transaction.response.code = defines.Codes.SERVICE_UNAVAILABLE.number
return transaction
def _handle_request(self, transaction, new_resource):
"""
Forward requests. Used by reverse proxies to also create new virtual resources on the proxy
in case of created resources
:type new_resource: bool
:type transaction: Transaction
:param transaction: the transaction that owns the request
:rtype : Transaction
:param new_resource: if the request will generate a new resource
:return: the edited transaction
"""
client = HelperClient(transaction.resource.remote_server)
request = Request()
request.options = copy.deepcopy(transaction.request.options)
del request.block2
del request.block1
del request.uri_path
del request.proxy_uri
del request.proxy_schema
# TODO handle observing
del request.observe
# request.observe = transaction.request.observe
request.uri_path = "/".join(transaction.request.uri_path.split("/")[1:])
request.destination = transaction.resource.remote_server
request.payload = transaction.request.payload
request.code = transaction.request.code
response = client.send_request(request)
client.stop()
transaction.response.payload = response.payload
transaction.response.code = response.code
transaction.response.options = response.options
if response.code == defines.Codes.CREATED.number:
lp = transaction.response.location_path
del transaction.response.location_path
transaction.response.location_path = transaction.request.uri_path.split("/")[0] + "/" + lp
# TODO handle observing
if new_resource:
resource = RemoteResource('server', transaction.resource.remote_server, lp, coap_server=self,
visible=True,
observable=False,
allow_children=True)
self._server.add_resource(transaction.response.location_path, resource)
if response.code == defines.Codes.DELETED.number:
del self._server.root["/" + transaction.request.uri_path]
return transaction