Markus Zolliker 7953826fac improve error handling on client connections
- send a heartbeat, if no events for 5 sec.
  an interrupted connection (not closed by the other end) may
  not be detected for a long time when nothing is sent
+ make the error reply on a non SECoPEror more verbose
  e.g. "KeyError('foo')" instead of just "foo"
+ allow cfg file without nodeinterface
+ shorter logger name in HasIodev

Change-Id: I6b1ff23f9bf8c96feb25af44935596437b7d726f
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/23098
Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>
2020-05-15 15:49:36 +02:00

214 lines
9.1 KiB
Python

# -*- coding: utf-8 -*-
# *****************************************************************************
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# Module authors:
# Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
# Markus Zolliker <markus.zolliker@psi.ch>
#
# *****************************************************************************
"""provides tcp interface to the SECoP Server"""
import sys
import socket
import collections
import socketserver
from secop.datatypes import StringType, BoolType
from secop.errors import SECoPError
from secop.lib import formatException, \
formatExtendedStack, formatExtendedTraceback
from secop.properties import Property
from secop.protocol.interface import decode_msg, encode_msg_frame, get_msg
from secop.protocol.messages import ERRORPREFIX, \
HELPREPLY, HELPREQUEST, HelpMessage
DEF_PORT = 10767
MESSAGE_READ_SIZE = 1024
HELP = HELPREQUEST.encode()
class OutputBufferOverflow(Exception):
pass
class TCPRequestHandler(socketserver.BaseRequestHandler):
def setup(self):
self.log = self.server.log
# Queue of msgObjects to send
self._queue = collections.deque() # do not use maxlen, as items might get lost
# self.framing = self.server.framingCLS()
# self.encoding = self.server.encodingCLS()
def handle(self):
"""handle a new tcp-connection"""
# copy state info
mysocket = self.request
clientaddr = self.client_address
serverobj = self.server
self.log.info("handling new connection from %s:%d" % clientaddr)
data = b''
# notify dispatcher of us
serverobj.dispatcher.add_connection(self)
# copy relevant settings from Interface
detailed_errors = serverobj.detailed_errors
mysocket.settimeout(.3)
# mysocket.setblocking(False)
# start serving
while True:
# send replys first, then listen for requests, timing out after 0.1s
while self._queue:
# put message into encoder to get frame(s)
# put frame(s) into framer to get bytestring
# send bytestring
outmsg = self._queue.popleft()
if not outmsg:
outmsg = ('error', 'InternalError', ['<unknown origin>', 'trying to send none-data', {}])
if len(outmsg) > 3:
outmsg = ('error', 'InternalError', ['<unknown origin>', 'bad message format', {'msg': outmsg}])
outdata = encode_msg_frame(*outmsg)
try:
mysocket.sendall(outdata)
except Exception as e:
self.log.error('error on sendall: %r', e)
return
# XXX: improve: use polling/select here?
try:
newdata = mysocket.recv(MESSAGE_READ_SIZE)
if not newdata:
# no timeout error, but no new data -> connection closed
return
data = data + newdata
except socket.timeout:
continue
except socket.error as e:
self.log.exception(e)
return
# XXX: should use select instead of busy polling
if not data:
continue
# put data into (de-) framer,
# put frames into (de-) coder and if a message appear,
# call dispatcher.handle_request(self, message)
# dispatcher will queue the reply before returning
while True:
origin, data = get_msg(data)
if origin is None:
break # no more messages to process
origin = origin.strip()
if origin in (HELP, b''): # empty string -> send help message
for idx, line in enumerate(HelpMessage.splitlines()):
# not sending HELPREPLY here, as there should be only one reply for every request
self.queue_async_reply(('_', '%d' % (idx+1), line))
# ident matches request
self.queue_async_reply((HELPREPLY, None, None))
continue
try:
msg = decode_msg(origin)
except Exception as err:
# we have to decode 'origin' here
# use latin-1, as utf-8 or ascii may lead to encoding errors
msg = origin.decode('latin-1').split(' ', 3) + [None] # make sure len(msg) > 1
result = (ERRORPREFIX + msg[0], msg[1], ['InternalError', str(err),
{'exception': formatException(),
'traceback': formatExtendedStack()}])
print('--------------------')
print(formatException())
print('--------------------')
print(formatExtendedTraceback(sys.exc_info()))
print('====================')
else:
try:
result = serverobj.dispatcher.handle_request(self, msg)
except OutputBufferOverflow:
raise
except SECoPError as err:
result = (ERRORPREFIX + msg[0], msg[1], [err.name, str(err),
{'exception': formatException(),
'traceback': formatExtendedStack()}])
except Exception as err:
# create Error Obj instead
result = (ERRORPREFIX + msg[0], msg[1], ['InternalError', repr(err),
{'exception': formatException(),
'traceback': formatExtendedStack()}])
print('--------------------')
print(formatException())
print('--------------------')
print(formatExtendedTraceback(sys.exc_info()))
print('====================')
if not result:
self.log.error('empty result upon msg %s' % repr(msg))
if result[0].startswith(ERRORPREFIX) and not detailed_errors:
# strip extra information
result[2][2].clear()
self.queue_async_reply(result)
def queue_async_reply(self, data):
"""called by dispatcher for async data units"""
if data:
# avoid queue growing to infinity. the needed size of the queue might be
# a multiple of the total number of parameters -> use a big number
if len(self._queue) > 10000:
self.log.error('output message buffer overflow')
raise OutputBufferOverflow()
self._queue.append(data)
else:
self.log.error('should async_queue empty data!')
def finish(self):
"""called when handle() terminates, i.e. the socket closed"""
self.log.info('closing connection from %s:%d' % self.client_address)
# notify dispatcher
self.server.dispatcher.remove_connection(self)
# close socket
try:
self.request.shutdown(socket.SHUT_RDWR)
except Exception:
pass
finally:
self.request.close()
class TCPServer(socketserver.ThreadingTCPServer):
daemon_threads = True
allow_reuse_address = True
# for cfg-editor
configurables = {
'uri': Property('hostname or ip address for binding', StringType(),
default='tcp://%d' % DEF_PORT, export=False),
'detailed_errors': Property('Flag to enable detailed Errorreporting.', BoolType(),
default=False, export=False),
}
def __init__(self, name, logger, options, srv): # pylint: disable=super-init-not-called
self.dispatcher = srv.dispatcher
self.name = name
self.log = logger
port = int(options.pop('uri').split('://', 1)[-1])
self.detailed_errors = options.pop('detailed_errors', False)
self.allow_reuse_address = True
self.log.info("TCPServer %s binding to port %d" % (name, port))
socketserver.ThreadingTCPServer.__init__(
self, ('0.0.0.0', port), TCPRequestHandler, bind_and_activate=True)
self.log.info("TCPServer initiated")