class CoAP(object):
"""
Implementation of the Reverse Proxy
"""
def __init__(self,
server_address,
xml_file,
multicast=False,
starting_mid=None,
cache=False,
sock=None):
"""
Initialize the Reverse Proxy.
:param server_address: Server address for incoming connections
:param xml_file: the xml file that describe remote servers
:param multicast: if the ip is a multicast address
:param starting_mid: used for testing purposes
:param cache: if a cache must be used
:param sock: if a socket has been created externally, it can be used directly
"""
self.stopped = threading.Event()
self.stopped.clear()
self.to_be_stopped = []
self.purge = threading.Thread(target=self.purge)
self.purge.start()
self._messageLayer = MessageLayer(starting_mid)
self._blockLayer = BlockLayer()
self._observeLayer = ObserveLayer()
self._forwardLayer = ForwardLayer(self)
self.resourceLayer = ResourceLayer(self)
self.cache_enable = cache
if self.cache_enable:
self._cacheLayer = CacheLayer(defines.REVERSE_PROXY)
else:
self._cacheLayer = None
# Resource directory
root = Resource('root',
self,
visible=False,
observable=False,
allow_children=True)
root.path = '/'
self.root = Tree()
self.root["/"] = root
self._serializer = None
self.server_address = server_address
self.multicast = multicast
self.file_xml = xml_file
self._mapping = {}
addrinfo = socket.getaddrinfo(self.server_address[0], None)[0]
if sock is not None:
# Use given socket, could be a DTLS socket
self._socket = sock
elif self.multicast: # pragma: no cover
# Create a socket
# self._socket.setsockopt(socket.SOL_IP, socket.IP_MULTICAST_TTL, 255)
# self._socket.setsockopt(socket.SOL_IP, socket.IP_MULTICAST_LOOP, 1)
# Join group
if addrinfo[0] == socket.AF_INET: # IPv4
self._socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM,
socket.IPPROTO_UDP)
# Allow multiple copies of this program on one machine
# (not strictly needed)
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR,
1)
self._socket.bind(
(defines.ALL_COAP_NODES, self.server_address[1]))
mreq = struct.pack("4sl",
socket.inet_aton(defines.ALL_COAP_NODES),
socket.INADDR_ANY)
self._socket.setsockopt(socket.IPPROTO_IP,
socket.IP_ADD_MEMBERSHIP, mreq)
self._unicast_socket = socket.socket(socket.AF_INET,
socket.SOCK_DGRAM)
self._unicast_socket.setsockopt(socket.SOL_SOCKET,
socket.SO_REUSEADDR, 1)
self._unicast_socket.bind(self.server_address)
else:
self._socket = socket.socket(socket.AF_INET6,
socket.SOCK_DGRAM,
socket.IPPROTO_UDP)
# Allow multiple copies of this program on one machine
# (not strictly needed)
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR,
1)
self._socket.bind(
(defines.ALL_COAP_NODES_IPV6, self.server_address[1]))
addrinfo_multicast = socket.getaddrinfo(
defines.ALL_COAP_NODES_IPV6, 5683)[0]
group_bin = socket.inet_pton(socket.AF_INET6,
addrinfo_multicast[4][0])
mreq = group_bin + struct.pack('@I', 0)
self._socket.setsockopt(socket.IPPROTO_IPV6,
socket.IPV6_JOIN_GROUP, mreq)
self._unicast_socket = socket.socket(socket.AF_INET6,
socket.SOCK_DGRAM)
self._unicast_socket.setsockopt(socket.SOL_SOCKET,
socket.SO_REUSEADDR, 1)
self._unicast_socket.bind(self.server_address)
else:
if addrinfo[0] == socket.AF_INET: # IPv4
self._socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR,
1)
else:
self._socket = socket.socket(socket.AF_INET6,
socket.SOCK_DGRAM)
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR,
1)
self._socket.bind(self.server_address)
# self.parse_config()
def parse_config(self):
"""
Parse the xml file with remote servers and discover resources on each found server.
"""
tree = ElementTree.parse(self.file_xml)
root = tree.getroot()
for server in root.findall('server'):
destination = server.text
name = server.get("name")
self.discover_remote(destination, name)
def discover_remote(self, destination, name):
"""
Discover resources on remote servers.
:param destination: the remote server (ip, port)
:type destination: tuple
:param name: the name of the remote server
:type name: String
"""
assert (isinstance(destination, str))
if destination.startswith("["):
split = destination.split("]", 1)
host = split[0][1:]
port = int(split[1][1:])
else:
split = destination.split(":", 1)
host = split[0]
port = int(split[1])
server = (host, port)
client = HelperClient(server)
response = client.discover()
client.stop()
self.discover_remote_results(response, name)
def discover_remote_results(self, response, name):
"""
Create a new remote server resource for each valid discover response.
:param response: the response to the discovery request
:param name: the server name
"""
host, port = response.source
if response.code == defines.Codes.CONTENT.number:
resource = Resource('server',
self,
visible=True,
observable=False,
allow_children=True)
self.add_resource(name, resource)
self._mapping[name] = (host, port)
self.parse_core_link_format(response.payload, name, (host, port))
else:
logger.error("Server: " + response.source + " isn't valid.")
def parse_core_link_format(self, link_format, base_path, remote_server):
"""
Parse discovery results.
:param link_format: the payload of the response to the discovery request
:param base_path: the base path used to create child resources discovered on the remote server
:param remote_server: the (ip, port) of the remote server
"""
while len(link_format) > 0:
pattern = "<([^>]*)>;"
result = re.match(pattern, link_format)
path = result.group(1)
path = path.split("/")
path = path[1:][0]
link_format = link_format[result.end(1) + 2:]
pattern = "([^<,])*"
result = re.match(pattern, link_format)
attributes = result.group(0)
dict_att = {}
if len(attributes) > 0:
attributes = attributes.split(";")
for att in attributes:
a = att.split("=")
if len(a) > 1:
dict_att[a[0]] = a[1]
else:
dict_att[a[0]] = a[0]
link_format = link_format[result.end(0) + 1:]
# TODO handle observing
resource = RemoteResource('server',
remote_server,
path,
coap_server=self,
visible=True,
observable=False,
allow_children=True)
resource.attributes = dict_att
self.add_resource(base_path + "/" + path, resource)
logger.info(self.root.dump())
def purge(self):
"""
Clean old transactions
"""
while not self.stopped.isSet():
self.stopped.wait(timeout=defines.EXCHANGE_LIFETIME)
self._messageLayer.purge()
def listen(self, timeout=10):
"""
Listen for incoming messages. Timeout is used to check if the server must be switched off.
:param timeout: Socket Timeout in seconds
"""
self._socket.settimeout(float(timeout))
while not self.stopped.isSet():
try:
data, client_address = self._socket.recvfrom(4096)
except socket.timeout:
continue
try:
self.receive_datagram((data, client_address))
except RuntimeError:
logger.exception("Exception with Executor")
self._socket.close()
def close(self):
"""
Stop the server.
"""
logger.info("Stop server")
self.stopped.set()
for event in self.to_be_stopped:
event.set()
self._socket.close()
def receive_datagram(self, args):
"""
Handle messages coming from the udp socket.
:param args: (data, client_address)
"""
data, client_address = args
serializer = Serializer()
message = serializer.deserialize(data, client_address)
if isinstance(message, int):
logger.error("receive_datagram - BAD REQUEST")
rst = Message()
rst.destination = client_address
rst.type = defines.Types["RST"]
rst.code = message
self.send_datagram(rst)
return
logger.debug("receive_datagram - " + str(message))
if isinstance(message, Request):
transaction = self._messageLayer.receive_request(message)
if transaction.request.duplicated and transaction.completed:
logger.debug("message duplicated,transaction completed")
transaction = self._observeLayer.send_response(transaction)
transaction = self._blockLayer.send_response(transaction)
transaction = self._messageLayer.send_response(transaction)
self.send_datagram(transaction.response)
return
elif transaction.request.duplicated and not transaction.completed:
logger.debug("message duplicated,transaction NOT completed")
self._send_ack(transaction)
return
transaction.separate_timer = self._start_separate_timer(
transaction)
transaction = self._blockLayer.receive_request(transaction)
if transaction.block_transfer:
self._stop_separate_timer(transaction.separate_timer)
transaction = self._messageLayer.send_response(transaction)
self.send_datagram(transaction.response)
return
transaction = self._observeLayer.receive_request(transaction)
"""
call to the cache layer to check if there's a cached response for the request
if not, call the forward layer
"""
if self._cacheLayer is not None:
transaction = self._cacheLayer.receive_request(transaction)
if transaction.cacheHit is False:
logger.debug(transaction.request)
transaction = self._forwardLayer.receive_request_reverse(
transaction)
logger.debug(transaction.response)
transaction = self._observeLayer.send_response(transaction)
transaction = self._blockLayer.send_response(transaction)
transaction = self._cacheLayer.send_response(transaction)
else:
transaction = self._forwardLayer.receive_request_reverse(
transaction)
transaction = self._observeLayer.send_response(transaction)
transaction = self._blockLayer.send_response(transaction)
self._stop_separate_timer(transaction.separate_timer)
transaction = self._messageLayer.send_response(transaction)
if transaction.response is not None:
if transaction.response.type == defines.Types["CON"]:
self._start_retrasmission(transaction,
transaction.response)
self.send_datagram(transaction.response)
elif isinstance(message, Message):
transaction = self._messageLayer.receive_empty(message)
if transaction is not None:
transaction = self._blockLayer.receive_empty(
message, transaction)
self._observeLayer.receive_empty(message, transaction)
else: # pragma: no cover
logger.error("Received response from %s", message.source)
def send_datagram(self, message):
"""
Send a message through the udp socket.
:type message: Message
:param message: the message to send
"""
if not self.stopped.isSet():
host, port = message.destination
logger.debug("send_datagram - " + str(message))
serializer = Serializer()
message = serializer.serialize(message)
self._socket.sendto(message, (host, port))
def add_resource(self, path, resource):
""""
Helper function to add resources to the resource directory during server initialization.
:param path: the path for the new created resource
:type resource: Resource
:param resource: the resource to be added
"""
assert isinstance(resource, Resource)
path = path.strip("/")
paths = path.split("/")
actual_path = ""
i = 0
for p in paths:
i += 1
actual_path += "/" + p
try:
res = self.root[actual_path]
except KeyError:
res = None
if res is None:
if len(paths) != i:
return False
resource.path = actual_path
self.root[actual_path] = resource
return True
def _start_retrasmission(self, transaction, message):
"""
Start the retransmission task.
:type transaction: Transaction
:param transaction: the transaction that owns the message that needs retransmission
:type message: Message
:param message: the message that needs the retransmission task
"""
with transaction:
if message.type == defines.Types['CON']:
future_time = random.uniform(
defines.ACK_TIMEOUT,
(defines.ACK_TIMEOUT * defines.ACK_RANDOM_FACTOR))
transaction.retransmit_thread = threading.Thread(
target=self._retransmit,
args=(transaction, message, future_time, 0))
transaction.retransmit_stop = threading.Event()
self.to_be_stopped.append(transaction.retransmit_stop)
transaction.retransmit_thread.start()
def _retransmit(self, transaction, message, future_time, retransmit_count):
"""
Thread function to retransmit the message in the future
:param transaction: the transaction that owns the message that needs retransmission
:param message: the message that needs the retransmission task
:param future_time: the amount of time to wait before a new attempt
:param retransmit_count: the number of retransmissions
"""
with transaction:
while retransmit_count < defines.MAX_RETRANSMIT and (not message.acknowledged and not message.rejected) \
and not self.stopped.isSet():
transaction.retransmit_stop.wait(timeout=future_time)
if not message.acknowledged and not message.rejected and not self.stopped.isSet(
):
retransmit_count += 1
future_time *= 2
self.send_datagram(message)
if message.acknowledged or message.rejected:
message.timeouted = False
else:
logger.warning("Give up on message {message}".format(
message=message.line_print))
message.timeouted = True
if message.observe is not None:
self._observeLayer.remove_subscriber(message)
try:
self.to_be_stopped.remove(transaction.retransmit_stop)
except ValueError:
pass
transaction.retransmit_stop = None
transaction.retransmit_thread = None
def _start_separate_timer(self, transaction):
"""
Start a thread to handle separate mode.
:type transaction: Transaction
:param transaction: the transaction that is in processing
:rtype : the Timer object
"""
t = threading.Timer(defines.ACK_TIMEOUT, self._send_ack,
(transaction, ))
t.start()
return t
@staticmethod
def _stop_separate_timer(timer):
"""
Stop the separate Thread if an answer has been already provided to the client.
:param timer: The Timer object
"""
timer.cancel()
def _send_ack(self, transaction):
"""
Sends an ACK message for the request.
:param transaction: the transaction that owns the request
"""
ack = Message()
ack.type = defines.Types['ACK']
if not transaction.request.acknowledged:
ack = self._messageLayer.send_empty(transaction,
transaction.request, ack)
self.send_datagram(ack)
class CoAP(object):
def __init__(self, server_address, xml_file, multicast=False, starting_mid=None, cache=False):
self.stopped = threading.Event()
self.stopped.clear()
self.to_be_stopped = []
self.purge = threading.Thread(target=self.purge)
self.purge.start()
self._messageLayer = MessageLayer(starting_mid)
self._blockLayer = BlockLayer()
self._observeLayer = ObserveLayer()
self._forwardLayer = ForwardLayer(self)
self.resourceLayer = ResourceLayer(self)
self.cache_enable = cache
if self.cache_enable:
self._cacheLayer = CacheLayer(defines.REVERSE_PROXY)
else:
self._cacheLayer = None
# Resource directory
root = Resource('root', self, visible=False, observable=False, allow_children=True)
root.path = '/'
self.root = Tree()
self.root["/"] = root
self._serializer = None
self.server_address = server_address
self.multicast = multicast
self.file_xml = xml_file
self._mapping = {}
addrinfo = socket.getaddrinfo(self.server_address[0], None)[0]
if self.multicast: # pragma: no cover
# Create a socket
self._socket = socket.socket(addrinfo[1], socket.SOCK_DGRAM)
# Allow multiple copies of this program on one machine
# (not strictly needed)
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
# Bind it to the port
self._socket.bind(('', self.server_address[1]))
group_bin = socket.inet_pton(addrinfo[1], addrinfo[4][0])
# Join group
if addrinfo[0] == socket.AF_INET: # IPv4
mreq = group_bin + struct.pack('=I', socket.INADDR_ANY)
self._socket.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
else:
mreq = group_bin + struct.pack('@I', 0)
self._socket.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_JOIN_GROUP, mreq)
else:
if addrinfo[0] == socket.AF_INET: # IPv4
self._socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
else:
self._socket = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
self._socket.bind(self.server_address)
self.parse_config()
def parse_config(self):
tree = ElementTree.parse(self.file_xml)
root = tree.getroot()
for server in root.findall('server'):
destination = server.text
name = server.get("name")
self.discover_remote(destination, name)
def discover_remote(self, destination, name):
assert (isinstance(destination, str))
if destination.startswith("["):
split = destination.split("]", 1)
host = split[0][1:]
port = int(split[1][1:])
else:
split = destination.split(":", 1)
host = split[0]
port = int(split[1])
server = (host, port)
client = HelperClient(server)
response = client.discover()
client.stop()
self.discover_remote_results(response, name)
def discover_remote_results(self, response, name):
host, port = response.source
if response.code == defines.Codes.CONTENT.number:
resource = Resource('server', self, visible=True, observable=False, allow_children=True)
self.add_resource(name, resource)
self._mapping[name] = (host, port)
self.parse_core_link_format(response.payload, name, (host, port))
else:
logger.error("Server: " + response.source + " isn't valid.")
def parse_core_link_format(self, link_format, base_path, remote_server):
while len(link_format) > 0:
pattern = "<([^>]*)>;"
result = re.match(pattern, link_format)
path = result.group(1)
path = path.split("/")
path = path[1:][0]
link_format = link_format[result.end(1) + 2:]
pattern = "([^<,])*"
result = re.match(pattern, link_format)
attributes = result.group(0)
dict_att = {}
if len(attributes) > 0:
attributes = attributes.split(";")
for att in attributes:
a = att.split("=")
# TODO check correctness
dict_att[a[0]] = a[1]
link_format = link_format[result.end(0) + 1:]
# TODO handle observing
resource = RemoteResource('server', remote_server, path, coap_server=self, visible=True, observable=False,
allow_children=True)
resource.attributes = dict_att
self.add_resource(base_path + "/" + path, resource)
logger.info(self.root.dump())
def purge(self):
while not self.stopped.isSet():
self.stopped.wait(timeout=defines.EXCHANGE_LIFETIME)
self._messageLayer.purge()
def listen(self, timeout=10):
"""
Listen for incoming messages. Timeout is used to check if the server must be switched off.
:param timeout: Socket Timeout in seconds
"""
self._socket.settimeout(float(timeout))
while not self.stopped.isSet():
try:
data, client_address = self._socket.recvfrom(4096)
except socket.timeout:
continue
try:
self.receive_datagram((data, client_address))
except RuntimeError:
print "Exception with Executor"
self._socket.close()
def close(self):
"""
Stop the server.
"""
logger.info("Stop server")
self.stopped.set()
for event in self.to_be_stopped:
event.set()
self._socket.close()
def receive_datagram(self, args):
"""
Receive datagram from the udp socket.
:rtype : Message
"""
data, client_address = args
serializer = Serializer()
message = serializer.deserialize(data, client_address)
if isinstance(message, int):
logger.error("receive_datagram - BAD REQUEST")
rst = Message()
rst.destination = client_address
rst.type = defines.Types["RST"]
rst.code = message
self.send_datagram(rst)
return
logger.debug("receive_datagram - " + str(message))
if isinstance(message, Request):
transaction = self._messageLayer.receive_request(message)
if transaction.request.duplicated and transaction.completed:
logger.debug("message duplicated,transaction completed")
transaction = self._observeLayer.send_response(transaction)
transaction = self._blockLayer.send_response(transaction)
transaction = self._messageLayer.send_response(transaction)
self.send_datagram(transaction.response)
return
elif transaction.request.duplicated and not transaction.completed:
logger.debug("message duplicated,transaction NOT completed")
self._send_ack(transaction)
return
transaction.separate_timer = self._start_separate_timer(transaction)
transaction = self._blockLayer.receive_request(transaction)
if transaction.block_transfer:
self._stop_separate_timer(transaction.separate_timer)
transaction = self._messageLayer.send_response(transaction)
self.send_datagram(transaction.response)
return
transaction = self._observeLayer.receive_request(transaction)
"""
call to the cache layer to check if there's a cached response for the request
if not, call the forward layer
"""
if self._cacheLayer is not None:
transaction = self._cacheLayer.receive_request(transaction)
if transaction.cacheHit is False:
print transaction.request
transaction = self._forwardLayer.receive_request_reverse(transaction)
print transaction.response
transaction = self._observeLayer.send_response(transaction)
transaction = self._blockLayer.send_response(transaction)
transaction = self._cacheLayer.send_response(transaction)
else:
transaction = self._forwardLayer.receive_request_reverse(transaction)
transaction = self._observeLayer.send_response(transaction)
transaction = self._blockLayer.send_response(transaction)
self._stop_separate_timer(transaction.separate_timer)
transaction = self._messageLayer.send_response(transaction)
if transaction.response is not None:
if transaction.response.type == defines.Types["CON"]:
self._start_retrasmission(transaction, transaction.response)
self.send_datagram(transaction.response)
elif isinstance(message, Message):
transaction = self._messageLayer.receive_empty(message)
if transaction is not None:
transaction = self._blockLayer.receive_empty(message, transaction)
self._observeLayer.receive_empty(message, transaction)
else: # pragma: no cover
logger.error("Received response from %s", message.source)
def send_datagram(self, message):
"""
:type message: Message
:param message:
"""
if not self.stopped.isSet():
host, port = message.destination
logger.debug("send_datagram - " + str(message))
serializer = Serializer()
message = serializer.serialize(message)
self._socket.sendto(message, (host, port))
def add_resource(self, path, resource):
"""
Helper function to add resources to the resource directory during server initialization.
:type resource: Resource
:param resource:
"""
assert isinstance(resource, Resource)
path = path.strip("/")
paths = path.split("/")
actual_path = ""
i = 0
for p in paths:
i += 1
actual_path += "/" + p
try:
res = self.root[actual_path]
except KeyError:
res = None
if res is None:
if len(paths) != i:
return False
resource.path = actual_path
self.root[actual_path] = resource
return True
def _start_retrasmission(self, transaction, message):
"""
:type transaction: Transaction
:param transaction:
:type message: Message
:param message:
:rtype : Future
"""
if message.type == defines.Types['CON']:
future_time = random.uniform(defines.ACK_TIMEOUT, (defines.ACK_TIMEOUT * defines.ACK_RANDOM_FACTOR))
transaction.retransmit_thread = threading.Thread(target=self._retransmit,
args=(transaction, message, future_time, 0))
transaction.retransmit_stop = threading.Event()
self.to_be_stopped.append(transaction.retransmit_stop)
transaction.retransmit_thread.start()
def _retransmit(self, transaction, message, future_time, retransmit_count):
while retransmit_count < defines.MAX_RETRANSMIT and (not message.acknowledged and not message.rejected) \
and not self.stopped.isSet():
transaction.retransmit_stop.wait(timeout=future_time)
if not message.acknowledged and not message.rejected and not self.stopped.isSet():
retransmit_count += 1
future_time *= 2
self.send_datagram(message)
if message.acknowledged or message.rejected:
message.timeouted = False
else:
logger.warning("Give up on message {message}".format(message=message.line_print))
message.timeouted = True
if message.observe is not None:
self._observeLayer.remove_subscriber(message)
try:
self.to_be_stopped.remove(transaction.retransmit_stop)
except ValueError:
pass
transaction.retransmit_stop = None
transaction.retransmit_thread = None
def _start_separate_timer(self, transaction):
"""
:type transaction: Transaction
:param transaction:
:type message: Message
:param message:
:rtype : Future
"""
t = threading.Timer(defines.ACK_TIMEOUT, self._send_ack, (transaction,))
t.start()
return t
@staticmethod
def _stop_separate_timer(timer):
"""
:type future: Future
:param future:
"""
timer.cancel()
def _send_ack(self, transaction):
# Handle separate
"""
Sends an ACK message for the request.
:param request: [request, sleep_time] or request
"""
ack = Message()
ack.type = defines.Types['ACK']
if not transaction.request.acknowledged:
ack = self._messageLayer.send_empty(transaction, transaction.request, ack)
self.send_datagram(ack)
class CoAP(object):
def __init__(self,
server_address,
xml_file,
multicast=False,
starting_mid=None):
self.stopped = threading.Event()
self.stopped.clear()
self.to_be_stopped = []
self.purge = threading.Thread(target=self.purge)
self.purge.start()
self._messageLayer = MessageLayer(starting_mid)
self._blockLayer = BlockLayer()
self._observeLayer = ObserveLayer()
self._forwardLayer = ForwardLayer(self)
self.resourceLayer = ResourceLayer(self)
# Resource directory
root = Resource('root',
self,
visible=False,
observable=False,
allow_children=True)
root.path = '/'
self.root = Tree()
self.root["/"] = root
self._serializer = None
self.server_address = server_address
self.multicast = multicast
self.file_xml = xml_file
self._mapping = {}
addrinfo = socket.getaddrinfo(self.server_address[0], None)[0]
if self.multicast: # pragma: no cover
# Create a socket
self._socket = socket.socket(addrinfo[1], socket.SOCK_DGRAM)
# Allow multiple copies of this program on one machine
# (not strictly needed)
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
# Bind it to the port
self._socket.bind(('', self.server_address[1]))
group_bin = socket.inet_pton(addrinfo[1], addrinfo[4][0])
# Join group
if addrinfo[0] == socket.AF_INET: # IPv4
mreq = group_bin + struct.pack('=I', socket.INADDR_ANY)
self._socket.setsockopt(socket.IPPROTO_IP,
socket.IP_ADD_MEMBERSHIP, mreq)
else:
mreq = group_bin + struct.pack('@I', 0)
self._socket.setsockopt(socket.IPPROTO_IPV6,
socket.IPV6_JOIN_GROUP, mreq)
else:
if addrinfo[0] == socket.AF_INET: # IPv4
self._socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR,
1)
else:
self._socket = socket.socket(socket.AF_INET6,
socket.SOCK_DGRAM)
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR,
1)
self._socket.bind(self.server_address)
self.parse_config()
def parse_config(self):
tree = ElementTree.parse(self.file_xml)
root = tree.getroot()
for server in root.findall('server'):
destination = server.text
name = server.get("name")
self.discover_remote(destination, name)
def discover_remote(self, destination, name):
assert (isinstance(destination, str))
split = destination.split(":", 1)
host = split[0]
port = int(split[1])
server = (host, port)
client = HelperClient(server)
response = client.discover()
client.stop()
self.discover_remote_results(response, name)
def discover_remote_results(self, response, name):
host, port = response.source
if response.code == defines.Codes.CONTENT.number:
resource = Resource('server',
self,
visible=True,
observable=False,
allow_children=True)
self.add_resource(name, resource)
self._mapping[name] = (host, port)
self.parse_core_link_format(response.payload, name, (host, port))
else:
logger.error("Server: " + response.source + " isn't valid.")
def parse_core_link_format(self, link_format, base_path, remote_server):
while len(link_format) > 0:
pattern = "<([^>]*)>;"
result = re.match(pattern, link_format)
path = result.group(1)
path = path.split("/")
path = path[1:][0]
link_format = link_format[result.end(1) + 2:]
pattern = "([^<,])*"
result = re.match(pattern, link_format)
attributes = result.group(0)
dict_att = {}
if len(attributes) > 0:
attributes = attributes.split(";")
for att in attributes:
a = att.split("=")
# TODO check correctness
dict_att[a[0]] = a[1]
link_format = link_format[result.end(0) + 1:]
# TODO handle observing
resource = RemoteResource('server',
remote_server,
path,
coap_server=self,
visible=True,
observable=False,
allow_children=True)
resource.attributes = dict_att
self.add_resource(base_path + "/" + path, resource)
logger.info(self.root.dump())
def purge(self):
while not self.stopped.isSet():
self.stopped.wait(timeout=defines.EXCHANGE_LIFETIME)
self._messageLayer.purge()
def listen(self, timeout=10):
"""
Listen for incoming messages. Timeout is used to check if the server must be switched off.
:param timeout: Socket Timeout in seconds
"""
self._socket.settimeout(float(timeout))
while not self.stopped.isSet():
try:
data, client_address = self._socket.recvfrom(4096)
except socket.timeout:
continue
try:
self.receive_datagram((data, client_address))
except RuntimeError:
print "Exception with Executor"
self._socket.close()
def close(self):
"""
Stop the server.
"""
logger.info("Stop server")
self.stopped.set()
for event in self.to_be_stopped:
event.set()
self._socket.close()
def receive_datagram(self, args):
"""
Receive datagram from the udp socket.
:rtype : Message
"""
data, client_address = args
serializer = Serializer()
message = serializer.deserialize(data, client_address)
if isinstance(message, int):
logger.error("receive_datagram - BAD REQUEST")
rst = Message()
rst.destination = client_address
rst.type = defines.Types["RST"]
rst.code = message
self.send_datagram(rst)
return
logger.debug("receive_datagram - " + str(message))
if isinstance(message, Request):
transaction = self._messageLayer.receive_request(message)
if transaction.request.duplicated and transaction.completed:
logger.debug("message duplicated,transaction completed")
transaction = self._observeLayer.send_response(transaction)
transaction = self._blockLayer.send_response(transaction)
transaction = self._messageLayer.send_response(transaction)
self.send_datagram(transaction.response)
return
elif transaction.request.duplicated and not transaction.completed:
logger.debug("message duplicated,transaction NOT completed")
self._send_ack(transaction)
return
transaction.separate_timer = self._start_separate_timer(
transaction)
transaction = self._blockLayer.receive_request(transaction)
if transaction.block_transfer:
self._stop_separate_timer(transaction.separate_timer)
transaction = self._messageLayer.send_response(transaction)
self.send_datagram(transaction.response)
return
transaction = self._observeLayer.receive_request(transaction)
transaction = self._forwardLayer.receive_request_reverse(
transaction)
transaction = self._observeLayer.send_response(transaction)
transaction = self._blockLayer.send_response(transaction)
self._stop_separate_timer(transaction.separate_timer)
transaction = self._messageLayer.send_response(transaction)
if transaction.response is not None:
if transaction.response.type == defines.Types["CON"]:
self._start_retrasmission(transaction,
transaction.response)
self.send_datagram(transaction.response)
elif isinstance(message, Message):
transaction = self._messageLayer.receive_empty(message)
if transaction is not None:
transaction = self._blockLayer.receive_empty(
message, transaction)
self._observeLayer.receive_empty(message, transaction)
else: # pragma: no cover
logger.error("Received response from %s", message.source)
def send_datagram(self, message):
"""
:type message: Message
:param message:
"""
if not self.stopped.isSet():
host, port = message.destination
logger.debug("send_datagram - " + str(message))
serializer = Serializer()
message = serializer.serialize(message)
self._socket.sendto(message, (host, port))
def add_resource(self, path, resource):
"""
Helper function to add resources to the resource directory during server initialization.
:type resource: Resource
:param resource:
"""
assert isinstance(resource, Resource)
path = path.strip("/")
paths = path.split("/")
actual_path = ""
i = 0
for p in paths:
i += 1
actual_path += "/" + p
try:
res = self.root[actual_path]
except KeyError:
res = None
if res is None:
if len(paths) != i:
return False
resource.path = actual_path
self.root[actual_path] = resource
return True
def _start_retrasmission(self, transaction, message):
"""
:type transaction: Transaction
:param transaction:
:type message: Message
:param message:
:rtype : Future
"""
if message.type == defines.Types['CON']:
future_time = random.uniform(
defines.ACK_TIMEOUT,
(defines.ACK_TIMEOUT * defines.ACK_RANDOM_FACTOR))
transaction.retransmit_thread = threading.Thread(
target=self._retransmit,
args=(transaction, message, future_time, 0))
transaction.retransmit_stop = threading.Event()
self.to_be_stopped.append(transaction.retransmit_stop)
transaction.retransmit_thread.start()
def _retransmit(self, transaction, message, future_time, retransmit_count):
while retransmit_count < defines.MAX_RETRANSMIT and (not message.acknowledged and not message.rejected) \
and not self.stopped.isSet():
transaction.retransmit_stop.wait(timeout=future_time)
if not message.acknowledged and not message.rejected and not self.stopped.isSet(
):
retransmit_count += 1
future_time *= 2
self.send_datagram(message)
if message.acknowledged or message.rejected:
message.timeouted = False
else:
logger.warning("Give up on message {message}".format(
message=message.line_print))
message.timeouted = True
if message.observe is not None:
self._observeLayer.remove_subscriber(message)
try:
self.to_be_stopped.remove(transaction.retransmit_stop)
except ValueError:
pass
transaction.retransmit_stop = None
transaction.retransmit_thread = None
def _start_separate_timer(self, transaction):
"""
:type transaction: Transaction
:param transaction:
:type message: Message
:param message:
:rtype : Future
"""
t = threading.Timer(defines.ACK_TIMEOUT, self._send_ack,
(transaction, ))
t.start()
return t
@staticmethod
def _stop_separate_timer(timer):
"""
:type future: Future
:param future:
"""
timer.cancel()
def _send_ack(self, transaction):
# Handle separate
"""
Sends an ACK message for the request.
:param request: [request, sleep_time] or request
"""
ack = Message()
ack.type = defines.Types['ACK']
if not transaction.request.acknowledged:
ack = self._messageLayer.send_empty(transaction,
transaction.request, ack)
self.send_datagram(ack)
class CoAP(object):
def __init__(self, server_address, xml_file, multicast=False, starting_mid=None):
self.stopped = threading.Event()
self.stopped.clear()
self.to_be_stopped = []
self.purge = threading.Thread(target=self.purge)
self.purge.start()
host, port = server_address
ret = socket.getaddrinfo(host, port)
family, socktype, proto, canonname, sockaddr = ret[0]
self._messageLayer = MessageLayer(starting_mid)
self._blockLayer = BlockLayer()
self._observeLayer = ObserveLayer()
self._forwardLayer = ForwardLayer(self)
self.resourceLayer = ResourceLayer(self)
# Resource directory
root = Resource('root', self, visible=False, observable=False, allow_children=True)
root.path = '/'
self.root = Tree()
self.root["/"] = root
self._serializer = None
self.server_address = server_address
self.multicast = multicast
self.file_xml = xml_file
self._mapping = {}
# IPv4 or IPv6
if len(sockaddr) == 4:
self._socket = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
else:
self._socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
if self.multicast:
# Set some options to make it multicast-friendly
try:
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
except AttributeError:
pass # Some systems don't support SO_REUSEPORT
self._socket.setsockopt(socket.SOL_IP, socket.IP_MULTICAST_TTL, 20)
self._socket.setsockopt(socket.SOL_IP, socket.IP_MULTICAST_LOOP, 1)
# Bind to the port
self._socket.bind(self.server_address)
# Set some more multicast options
interface = socket.gethostbyname(socket.gethostname())
self._socket.setsockopt(socket.SOL_IP, socket.IP_MULTICAST_IF, socket.inet_aton(interface))
self._socket.setsockopt(socket.SOL_IP, socket.IP_ADD_MEMBERSHIP, socket.inet_aton(self.server_address)
+ socket.inet_aton(interface))
else:
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
self._socket.bind(self.server_address)
self.parse_config()
def parse_config(self):
tree = ElementTree.parse(self.file_xml)
root = tree.getroot()
for server in root.findall('server'):
destination = server.text
name = server.get("name")
self.discover_remote(destination, name)
def discover_remote(self, destination, name):
assert (isinstance(destination, str))
split = destination.split(":", 1)
host = split[0]
port = int(split[1])
server = (host, port)
client = HelperClient(server)
response = client.discover()
client.stop()
self.discover_remote_results(response, name)
def discover_remote_results(self, response, name):
host, port = response.source
if response.code == defines.Codes.CONTENT.number:
resource = Resource('server', self, visible=True, observable=False, allow_children=True)
self.add_resource(name, resource)
self._mapping[name] = (host, port)
self.parse_core_link_format(response.payload, name, (host, port))
else:
logger.error("Server: " + response.source + " isn't valid.")
def parse_core_link_format(self, link_format, base_path, remote_server):
while len(link_format) > 0:
pattern = "<([^>]*)>;"
result = re.match(pattern, link_format)
path = result.group(1)
path = path.split("/")
path = path[1:][0]
link_format = link_format[result.end(1) + 2:]
pattern = "([^<,])*"
result = re.match(pattern, link_format)
attributes = result.group(0)
dict_att = {}
if len(attributes) > 0:
attributes = attributes.split(";")
for att in attributes:
a = att.split("=")
# TODO check correctness
dict_att[a[0]] = a[1]
link_format = link_format[result.end(0) + 1:]
# TODO handle observing
resource = RemoteResource('server', remote_server, path, coap_server=self, visible=True, observable=False,
allow_children=True)
resource.attributes = dict_att
self.add_resource(base_path + "/" + path, resource)
logger.info(self.root.dump())
def purge(self):
while not self.stopped.isSet():
self.stopped.wait(timeout=defines.EXCHANGE_LIFETIME)
self._messageLayer.purge()
def listen(self, timeout=10):
"""
Listen for incoming messages. Timeout is used to check if the server must be switched off.
:param timeout: Socket Timeout in seconds
"""
self._socket.settimeout(float(timeout))
while not self.stopped.isSet():
try:
data, client_address = self._socket.recvfrom(4096)
except socket.timeout:
continue
try:
self.receive_datagram((data, client_address))
except RuntimeError:
print "Exception with Executor"
self._socket.close()
def close(self):
"""
Stop the server.
"""
logger.info("Stop server")
self.stopped.set()
for event in self.to_be_stopped:
event.set()
self._socket.close()
def receive_datagram(self, args):
"""
Receive datagram from the udp socket.
:rtype : Message
"""
data, client_address = args
serializer = Serializer()
message = serializer.deserialize(data, client_address)
logger.debug("receive_datagram - " + str(message))
if isinstance(message, Request):
transaction = self._messageLayer.receive_request(message)
if transaction.request.duplicated and transaction.completed:
logger.debug("message duplicated,transaction completed")
transaction = self._observeLayer.send_response(transaction)
transaction = self._blockLayer.send_response(transaction)
transaction = self._messageLayer.send_response(transaction)
self.send_datagram(transaction.response)
return
elif transaction.request.duplicated and not transaction.completed:
logger.debug("message duplicated,transaction NOT completed")
self._send_ack(transaction)
return
transaction.separate_timer = self._start_separate_timer(transaction)
transaction = self._blockLayer.receive_request(transaction)
if transaction.block_transfer:
self._stop_separate_timer(transaction.separate_timer)
transaction = self._messageLayer.send_response(transaction)
self.send_datagram(transaction.response)
return
transaction = self._observeLayer.receive_request(transaction)
transaction = self._forwardLayer.receive_request_reverse(transaction)
if transaction.resource is not None and transaction.resource.changed:
self.notify(transaction.resource)
transaction.resource.changed = False
elif transaction.resource is not None and transaction.resource.deleted:
self.notify(transaction.resource)
transaction.resource.deleted = False
transaction = self._observeLayer.send_response(transaction)
transaction = self._blockLayer.send_response(transaction)
self._stop_separate_timer(transaction.separate_timer)
transaction = self._messageLayer.send_response(transaction)
if transaction.response is not None:
if transaction.response.type == defines.Types["CON"]:
self._start_retrasmission(transaction, transaction.response)
self.send_datagram(transaction.response)
elif isinstance(message, Message):
transaction = self._messageLayer.receive_empty(message)
if transaction is not None:
transaction = self._blockLayer.receive_empty(message, transaction)
transaction = self._observeLayer.receive_empty(message, transaction)
else: # is Response
logger.error("Received response from %s", message.source)
def send_datagram(self, message):
"""
:type message: Message
:param message:
"""
if not self.stopped.isSet():
host, port = message.destination
logger.debug("send_datagram - " + str(message))
serializer = Serializer()
message = serializer.serialize(message)
self._socket.sendto(message, (host, port))
def add_resource(self, path, resource):
"""
Helper function to add resources to the resource directory during server initialization.
:type resource: Resource
:param resource:
"""
assert isinstance(resource, Resource)
path = path.strip("/")
paths = path.split("/")
actual_path = ""
i = 0
for p in paths:
i += 1
actual_path += "/" + p
try:
res = self.root[actual_path]
except KeyError:
res = None
if res is None:
if len(paths) != i:
return False
resource.path = actual_path
self.root[actual_path] = resource
return True
def _start_retrasmission(self, transaction, message):
"""
:type transaction: Transaction
:param transaction:
:type message: Message
:param message:
:rtype : Future
"""
if message.type == defines.Types['CON']:
future_time = random.uniform(defines.ACK_TIMEOUT, (defines.ACK_TIMEOUT * defines.ACK_RANDOM_FACTOR))
transaction.retransmit_thread = threading.Thread(target=self._retransmit,
args=(transaction, message, future_time, 0))
transaction.retransmit_stop = threading.Event()
self.to_be_stopped.append(transaction.retransmit_stop)
transaction.retransmit_thread.start()
def _retransmit(self, transaction, message, future_time, retransmit_count):
while retransmit_count < defines.MAX_RETRANSMIT and (not message.acknowledged and not message.rejected) \
and not self.stopped.isSet():
transaction.retransmit_stop.wait(timeout=future_time)
if not message.acknowledged and not message.rejected and not self.stopped.isSet():
retransmit_count += 1
future_time *= 2
self.send_datagram(message)
if message.acknowledged or message.rejected:
message.timeouted = False
else:
logger.warning("Give up on message {message}".format(message=message.line_print))
message.timeouted = True
if message.observe is not None:
self._observeLayer.remove_subscriber(message)
try:
self.to_be_stopped.remove(transaction.retransmit_stop)
except ValueError:
pass
transaction.retransmit_stop = None
transaction.retransmit_thread = None
def _start_separate_timer(self, transaction):
"""
:type transaction: Transaction
:param transaction:
:type message: Message
:param message:
:rtype : Future
"""
t = threading.Timer(defines.ACK_TIMEOUT, self._send_ack, (transaction,))
t.start()
return t
@staticmethod
def _stop_separate_timer(timer):
"""
:type future: Future
:param future:
"""
if not timer.finished:
timer.cancel()
def _send_ack(self, transaction):
# Handle separate
"""
Sends an ACK message for the request.
:param request: [request, sleep_time] or request
"""
ack = Message()
ack.type = defines.Types['ACK']
if not transaction.request.acknowledged:
ack = self._messageLayer.send_empty(transaction, transaction.request, ack)
self.send_datagram(ack)
def notify(self, resource):
observers = self._observeLayer.notify(resource)
logger.debug("Notify")
for transaction in observers:
transaction.response = None
transaction = self._requestLayer.receive_request(transaction)
transaction = self._observeLayer.send_response(transaction)
transaction = self._blockLayer.send_response(transaction)
transaction = self._messageLayer.send_response(transaction)
if transaction.response is not None:
if transaction.response.type == defines.Types["CON"]:
self._start_retrasmission(transaction, transaction.response)
self.send_datagram(transaction.response)