def _send(self, data, remote,
stack): # a generator function that does the sending
logger.debug('%r=>%r on type=%r\n%s', stack.sock.getsockname(),
remote, stack.transport.type, data)
try:
if stack.sock.type == socket.SOCK_STREAM: # for TCP send only if a connection exists to the remote.
if stack.transport.type in ('ws', 'wss'):
if len(data) < 126:
init = struct.pack('>BB', 0x81, len(data))
elif len(data) < 65536:
init = struct.pack('>BBH', 0x81, 126, len(data))
else:
raise ValueError, 'cannot send long message'
data = init + data
if remote in self.conn:
yield multitask.send(
self.conn[remote],
data) # and send using that connected TCP socket.
else:
logger.warning(
'ignoring message to %r as no existing connection',
remote)
else: # for UDP send using the stack's UDP socket.
yield multitask.sendto(stack.sock, data, remote)
except StopIteration:
pass
except:
logger.exception('sending')
def sendRequest(sock, m, remote): # serve the send request of TURN
fivetuple = (sock.type, getlocaladdr(sock), remote)
try:
if fivetuple not in binding: # not found
raise ValueError, 'no turn binding found'
newsock = binding[fivetuple]
destaddr = Attribute.DESTINATION_ADDRESS in m and m[Attribute.DESTINATION_ADDRESS].address[1:] or None
data = Attribute.DATA in m and m[Attribute.DATA] or None
if sock.type == socket.SOCK_STREAM:
try:
remote = newsock.getpeername()
except:
remote = None
if not remote:
newsock.connect(destaddr)
remote = destaddr
yield multitask.send(newsock, data)
else:
yield multitask.sendto(newsock, data, destaddr)
# TODO: we don't lock to destaddr. This is a security risk.
result = True
except:
if _debug: print 'sendRequest() exception', sys.exc_info()
result = False
res = Message()
res.method, res.type, res.tid = m.method, (result and Message.RESPONSE or Message.ERROR), m.tid
if not result:
error = Attribute(Attribute.ERROR_CODE)
error.error = (400, 'cannot send request') # TODO: be more explicit.
res.attrs.append(error)
yield respond(sock, str(res), remote)
def _send(self, data, remote, stack): # a generator function that does the sending
if _debug: print '%r=>%r on type=%r\n%s'%(stack.sock.getsockname(), remote, stack.sock.type, data)
if stack.sock.type == socket.SOCK_STREAM: # for TCP send only if a connection exists to the remote.
if remote in self.conn:
yield multitask.send(self.conn[remote], data) # and send using that connected TCP socket.
else: # for UDP send using the stack's UDP socket.
yield multitask.sendto(stack.sock, data, remote)
def _send(self, data, remote, stack): # a generator function that does the sending
if _debug: print '%r=>%r on type=%r\n%s'%(stack.sock.getsockname(), remote, stack.sock.type, data)
if stack.sock.type == socket.SOCK_STREAM: # for TCP send only if a connection exists to the remote.
if remote in self.conn:
yield multitask.send(self.conn[remote], data) # and send using that connected TCP socket.
else: # for UDP send using the stack's UDP socket.
yield multitask.sendto(stack.sock, data, remote)
def sendRTCP(self, data, dest=None):
if self.rtcp:
dest = dest or self.destRTCP
if dest and dest[1] > 0 and dest[0] != '0.0.0.0':
if _debug: print 'sending RTCP %d to %r'%(len(data), dest)
yield multitask.sendto(self.rtcp, data, dest)
elif _debug: print 'ignoring send RTCP'
def sendRTCP(self, data, dest=None):
if self.rtcp:
dest = dest or self.destRTCP
if dest and dest[1] > 0 and dest[0] != '0.0.0.0':
if _debug: print 'sending RTCP %d to %r'%(len(data), dest)
yield multitask.sendto(self.rtcp, data, dest)
elif _debug: print 'ignoring send RTCP'
def _send(self, data, remote, stack): # a generator function that does the sending
logger.debug('%r=>%r on type=%r\n%s', stack.sock.getsockname(), remote, stack.transport.type, data)
try:
if stack.sock.type == socket.SOCK_STREAM: # for TCP send only if a connection exists to the remote.
if stack.transport.type in ('ws', 'wss'):
if len(data) < 126:
init = struct.pack('>BB', 0x81, len(data))
elif len(data) < 65536:
init = struct.pack('>BBH', 0x81, 126, len(data))
else:
raise ValueError, 'cannot send long message'
data = init + data
if remote in self.conn:
yield multitask.send(self.conn[remote], data) # and send using that connected TCP socket.
else:
logger.warning('ignoring message to %r as no existing connection', remote)
else: # for UDP send using the stack's UDP socket.
yield multitask.sendto(stack.sock, data, remote)
except StopIteration: pass
except:
logger.exception('sending')
def respond(sock, data, remote):
if sock.type == socket.SOCK_STREAM:
yield multitask.send(sock, data)
else:
yield multitask.sendto(sock, data, remote)
def request(sock, server=None, **kwargs):
'''Send a STUN client request with retransmissions and return the response.
This is a generator function, and can be called as
response, external = yield request(sock, ('stun.iptel.org', 3478))
It raises ValueError in case of failure and multitask.Timeout in case of timeout
or failure to connect TCP or invalid response received. For TCP, the sock remains
connected after successful return or exception from this function.
Arguments are as follows:
sock: the socket to use for sending request and receiving response.
server: optional server (ip, port), defaults to defaultServers[0]. For TCP if sock
is already connected, then server argument is ignored.
method: optional STUN method, defaults to Message.BINDING.
tid: optional transaction id, by default generates a new.
attrs: optional attributes, by default empty list [].
rto: optional RTO, defaults to 0.1 for UDP and 9.3 for TCP.
retry: optional retry count, defaults to 7 for UDP and 1 for TCP.
maxsize: optional maximum packet size, defaults to 1500.
handler: optional handler function, that receives any message that was received
but not handled by the request method.
The handler argument allows demultiplexing other types of received messages on the
same socket. Note that raising an exception is not good, because we still want to
wait for response instead of exiting. The handler is invoked as
handler(sock, remote, data) where data is raw data string and remote is usually
server (ip, port). If no handler is specified, then invalid data raises a ValueError.
'''
server = server or defaultServers[0] # use first server if missing
handler = kwargs.get('handler', None)
maxsize = kwargs.get('maxsize', 1500)
m = Message()
m.method = kwargs.get('method', Message.BINDING)
m.type = Message.REQUEST
m.tid = kwargs.get('tid', urandom(12))
m.attrs = kwargs.get('attrs', [])
mstr = str(m) # formatted message bytes to send
if len(mstr) >= maxsize: raise ValueError, 'Cannot send packet of length>%d'%(maxsize)
if sock.type == socket.SOCK_STREAM:
remote = None
try: remote = sock.getpeername()
except: pass
if not remote:
try:
sock.connect(server)
remote = server # connect if not already connected.
except:
raise multitask.Timeout() # can't connect, then raise a timeout error.
tcp, rto, retry = True, kwargs.get('rto', 9.3), kwargs.get('retry', 1)
else:
tcp, rto, retry = False, kwargs.get('rto', 0.100), kwargs.get('retry', 7)
while retry>0:
retry = retry - 1
if _debug: print 'sending STUN request method=%d, len=%d, remaining-retry=%d'%(m.method, len(mstr), retry)
if tcp:
yield multitask.send(sock, mstr) # send the request
else:
yield multitask.sendto(sock, mstr, server)
try:
if tcp: # receiving a TCP packet is complicated. remote is already set
data = (yield multitask.recv(sock, maxsize, timeout=rto))
if not data: break
if _debug: print 'request() received data'
type, length, magic = struct.unpack('!HHL', data[:8])
if type & 0xC000 != 0 or magic != Message.MAGIC:
raise ValueError, 'invalid STUN response from server type=0x%x, magic=0x%x'%(type, magic)
if length > (maxsize-8):
raise ValueError, 'very large response length[%d]>%d'%(length+8, maxsize)
else: # receive a UDP datagram
data, remote = (yield multitask.recvfrom(sock, maxsize, timeout=rto))
if data:
try:
response = Message(data) # parse the message if any
if _debug: print 'received STUN message method=%d, type=%d'%(response.method, response.type)
except:
if _debug: print 'received invalid STUN message len=%d'%(len(response))
if handler:
handler(sock, remote, data) # allow app to demultiplex
continue # retry next
else:
raise ValueError, 'Invalid response from server'
if response.tid != m.tid:
if _debug: print 'The tid does not match. ignoring'
if handler: handler(sock, remote, data)
continue # probably a old response, don't raise exception.
external = None
for attr in response.attrs:
if not attr.optional and attr.type not in Attribute.knownTypes:
raise ValueError, 'Attribute 0x%04x not understood in response'%attr.type
if response.type == Message.RESPONSE: # success response
for attr in response.attrs:
if m.method == Message.BINDING:
if attr.type == Attribute.XOR_MAPPED_ADDRESS:
external = attr.xorAddress # (family, ip, port)
elif attr.type == Attribute.MAPPED_ADDRESS: # for backward compatibility with RFC 3489
external = attr.address
elif response.type == Message.ERROR: # error response
error = None
for attr in response.attrs:
if attrs.type == Attribute.ERROR_CODE:
error = attrs.error # (code, reason)
break
raise ValueError, 'Request failed with error %r'%error
if external:
external = external[1:] # ignore the address family
raise StopIteration(response, external) # result to the caller
# TODO: else do we continue or raise an error?
except multitask.Timeout:
rto = rto * 2 # double the rto
except StopIteration:
if _debug: print 'request() returning external=' + str(external)
raise
except: # any other exception, fall back to Timeout exception
if _debug: print 'Some ValueError exception', sys.exc_info()
break
raise multitask.Timeout # no response after all retransmissions