def handle_udp(self, conn, name, enip_process, **kwds):
"""
Process UDP packets from multiple clients
"""
with parser.enip_machine(name=name, context='enip') as machine:
while not kwds['server']['control']['done'] and not kwds['server']['control']['disable']:
try:
source = cpppo.rememberable()
data = cpppo.dotdict()
# If no/partial EtherNet/IP header received, parsing will fail with a NonTerminal
# Exception (dfa exits in non-terminal state). Build data.request.enip:
begun = cpppo.timer() # waiting for next transaction
addr, stats = None, None
with contextlib.closing(machine.run(
path='request', source=source, data=data)) as engine:
# PyPy compatibility; avoid deferred destruction of generators
for mch, sta in engine:
if sta is not None:
# No more transitions available. Wait for input.
continue
assert not addr, "Incomplete UDP request from client %r" % (addr)
msg = None
while msg is None:
# For UDP, we'll allow no input only at the start of a new request parse
# (addr is None); anything else will be considered a failed request Back
# to the trough for more symbols, after having already received a packet
# from a peer? No go!
wait = (kwds['server']['control']['latency']
if source.peek() is None else 0)
brx = cpppo.timer()
msg, frm = network.recvfrom(conn, timeout=wait)
now = cpppo.timer()
if not msg:
if kwds['server']['control']['done'] or kwds['server']['control']['disable']:
return
(logger.info if msg else logger.debug)(
"Transaction receive after %7.3fs (%5s bytes in %7.3f/%7.3fs): %r",
now - begun, len(msg) if msg is not None else "None",
now - brx, wait, self.stats_for(frm)[0])
# If we're at a None (can't proceed), and we haven't yet received input,
# then this is where we implement "Blocking"; we just loop for input.
# We have received exactly one packet from an identified peer!
begun = now
addr = frm
stats, _ = self.stats_for(addr)
# For UDP, we don't ever receive incoming EOF, or set stats['eof'].
# However, we can respond to a manual eof (eg. from web interface) by
# ignoring the peer's packets.
assert stats and not stats.get('eof'), \
"Ignoring UDP request from client %r: %r" % (addr, msg)
stats['received'] += len(msg)
logger.debug("%s recv: %5d: %s", machine.name_centered(), len(msg), cpppo.reprlib.repr(msg))
source.chain(msg)
# Terminal state and EtherNet/IP header recognized; process and return response
assert stats
if 'request' in data:
stats['requests'] += 1
# enip_process must be able to handle no request (empty data), indicating the
# clean termination of the session if closed from this end (not required if
# enip_process returned False, indicating the connection was terminated by
# request.)
if enip_process(addr, data=data, **kwds):
# Produce an EtherNet/IP response carrying the encapsulated response data.
# If no encapsulated data, ensure we also return a non-zero EtherNet/IP
# status. A non-zero status indicates the end of the session.
assert 'response.enip' in data, "Expected EtherNet/IP response; none found"
if 'input' not in data.response.enip or not data.response.enip.input:
logger.warning("Expected EtherNet/IP response encapsulated message; none found")
assert data.response.enip.status, "If no/empty response payload, expected non-zero EtherNet/IP status"
rpy = parser.enip_encode(data.response.enip)
logger.debug("%s send: %5d: %s", machine.name_centered(),
len(rpy), cpppo.reprlib.repr(rpy))
conn.sendto(rpy, addr)
logger.debug("Transaction complete after %7.3fs", cpppo.timer() - begun)
stats['processed'] = source.sent
except:
# Parsing failure. Suck out some remaining input to give us some context, but don't re-raise
if stats:
stats['processed'] = source.sent
memory = bytes(bytearray(source.memory))
pos = len(source.memory)
future = bytes(bytearray(b for b in source))
where = "at %d total bytes:\n%s\n%s (byte %d)" % (
stats.get('processed', 0) if stats else 0,
repr(memory + future), '-' * (len(repr(memory)) - 1) + '^', pos)
logger.error("Client %r EtherNet/IP error %s\n\nFailed with exception:\n%s\n", addr, where, ''.join(
traceback.format_exception(*sys.exc_info())))
def handle_udp(self, conn, name, enip_process, **kwds):
"""
Process UDP packets from multiple clients
"""
with parser.enip_machine(name=name, context='enip') as machine:
while not kwds['server']['control']['done'] and not kwds['server']['control']['disable']:
try:
source = cpppo.rememberable()
data = cpppo.dotdict()
# If no/partial EtherNet/IP header received, parsing will fail with a NonTerminal
# Exception (dfa exits in non-terminal state). Build data.request.enip:
begun = cpppo.timer() # waiting for next transaction
addr, stats = None, None
with contextlib.closing(machine.run(
path='request', source=source, data=data)) as engine:
# PyPy compatibility; avoid deferred destruction of generators
for mch, sta in engine:
if sta is not None:
# No more transitions available. Wait for input.
continue
assert not addr, "Incomplete UDP request from client %r" % (addr)
msg = None
while msg is None:
# For UDP, we'll allow no input only at the start of a new request parse
# (addr is None); anything else will be considered a failed request Back
# to the trough for more symbols, after having already received a packet
# from a peer? No go!
wait = (kwds['server']['control']['latency']
if source.peek() is None else 0)
brx = cpppo.timer()
msg, frm = network.recvfrom(conn, timeout=wait)
now = cpppo.timer()
(logger.info if msg else logger.debug)(
"Transaction receive after %7.3fs (%5s bytes in %7.3f/%7.3fs): %r",
now - begun, len(msg) if msg is not None else "None",
now - brx, wait, self.stats_for(frm)[0])
# If we're at a None (can't proceed), and we haven't yet received input,
# then this is where we implement "Blocking"; we just loop for input.
# We have received exactly one packet from an identified peer!
begun = now
addr = frm
stats, _ = self.stats_for(addr)
# For UDP, we don't ever receive incoming EOF, or set stats['eof'].
# However, we can respond to a manual eof (eg. from web interface) by
# ignoring the peer's packets.
assert stats and not stats.get('eof'), \
"Ignoring UDP request from client %r: %r" % (addr, msg)
stats['received'] += len(msg)
logger.debug("%s recv: %5d: %s", machine.name_centered(), len(msg), cpppo.reprlib.repr(msg))
source.chain(msg)
# Terminal state and EtherNet/IP header recognized; process and return response
assert stats
if 'request' in data:
stats['requests'] += 1
# enip_process must be able to handle no request (empty data), indicating the
# clean termination of the session if closed from this end (not required if
# enip_process returned False, indicating the connection was terminated by
# request.)
if enip_process(addr, data=data, **kwds):
# Produce an EtherNet/IP response carrying the encapsulated response data.
# If no encapsulated data, ensure we also return a non-zero EtherNet/IP
# status. A non-zero status indicates the end of the session.
assert 'response.enip' in data, "Expected EtherNet/IP response; none found"
if 'input' not in data.response.enip or not data.response.enip.input:
logger.warning("Expected EtherNet/IP response encapsulated message; none found")
assert data.response.enip.status, "If no/empty response payload, expected non-zero EtherNet/IP status"
rpy = parser.enip_encode(data.response.enip)
logger.debug("%s send: %5d: %s", machine.name_centered(),
len(rpy), cpppo.reprlib.repr(rpy))
conn.sendto(rpy, addr)
logger.debug("Transaction complete after %7.3fs", cpppo.timer() - begun)
stats['processed'] = source.sent
except:
# Parsing failure. Suck out some remaining input to give us some context, but don't re-raise
if stats:
stats['processed'] = source.sent
memory = bytes(bytearray(source.memory))
pos = len(source.memory)
future = bytes(bytearray(b for b in source))
where = "at %d total bytes:\n%s\n%s (byte %d)" % (
stats.get('processed', 0) if stats else 0,
repr(memory + future), '-' * (len(repr(memory)) - 1) + '^', pos)
logger.error("Client %r EtherNet/IP error %s\n\nFailed with exception:\n%s\n", addr, where, ''.join(
traceback.format_exception(*sys.exc_info())))