core: introduce common handler class

- make RequestHanlder based on socketserver.BaserequestHandler
- split handle() into subfunctions
- rework TCPRequestHandler

Change-Id: I62452e21c03b9cb9937673ce9c8663765798f863
Reviewed-on: https://forge.frm2.tum.de/review/c/secop/frappy/+/32984
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Alexander Zaft <a.zaft@fz-juelich.de>
This commit is contained in:
Alexander Zaft 2024-01-30 17:10:56 +01:00 committed by Markus Zolliker
parent c63f98f3cb
commit 118e22ee44
2 changed files with 284 additions and 116 deletions

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@ -0,0 +1,231 @@
# *****************************************************************************
# 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>
#
# *****************************************************************************
"""The common parts of the SECNodes outside interfaces"""
import sys
import threading
from frappy.errors import SECoPError
from frappy.lib import formatException, formatExtendedStack, \
formatExtendedTraceback
from frappy.protocol.messages import ERRORPREFIX, HELPREPLY, HELPREQUEST, \
HelpMessage
class DecodeError(Exception):
def __init__(self, message, raw_msg):
super().__init__(message)
self._raw_msg = raw_msg
@property
def raw_msg(self):
return self._raw_msg
class ConnectionClose(Exception):
"""Indicates that receive quit due to an error."""
class RequestHandler:
"""Base class for the request handlers.
This is an extended copy of the BaseRequestHandler from socketserver.
To make a new interface, implement these methods:
ingest, next_message, decode_message, receive, send_reply and format
and extend (override) setup() and finish() if needed.
For an example, have a look at TCPRequestHandler.
"""
# Methods from BaseRequestHandler
def __init__(self, request, client_address, server):
self.request = request
self.client_address = client_address
self.server = server
self.setup()
try:
self.handle()
finally:
self.finish()
def setup(self):
self.log = self.server.log
self.log.info("new connection %s", self.format())
# notify dispatcher of us
self.server.dispatcher.add_connection(self)
self.send_lock = threading.Lock()
self.running = True
# overwrite this with an appropriate buffer if needed
self.data = None
def handle(self):
"""handle a new connection"""
# copy state info
serverobj = self.server
# copy relevant settings from Interface
detailed_errors = serverobj.detailed_errors
# start serving
while self.running:
try:
newdata = self.receive()
if newdata is None:
# no new data during read, continue
continue
self.ingest(newdata)
except ConnectionClose:
# either normal close or error in receive
return
# put data into (de-) framer,
# de-frame data with next_message() and decode it
# call dispatcher.handle_request(self, message)
# dispatcher will queue the reply before returning
while self.running:
try:
msg = self.next_message()
if msg is None:
break # no more messages to process
except DecodeError as err:
# we have to decode 'origin' here
# use latin-1, as utf-8 or ascii may lead to encoding errors
msg = err.raw_msg.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:
if msg[0] == HELPREQUEST:
self.handle_help()
result = (HELPREPLY, None, None)
else:
result = serverobj.dispatcher.handle_request(self,
msg)
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.send_reply(result)
def handle_help(self):
for idx, line in enumerate(HelpMessage.splitlines()):
# not sending HELPREPLY here, as there should be only one reply for
# every request
self.send_reply(('_', f'{idx + 1}', line))
def finish(self):
"""called when handle() terminates, i.e. the socket closed"""
self.log.info('closing connection %s', self.format())
# notify dispatcher
self.server.dispatcher.remove_connection(self)
# Methods for implementing in derived classes:
def ingest(self, newdata):
"""Put the new data into the buffer."""
raise NotImplementedError
def next_message(self):
"""Get the next decoded message from the buffer.
Has to return a triple of (MESSAGE, specifier, data) or None, in case
there are no further messages in the receive queue.
If there is an Error during decoding, this method has to raise a
DecodeError.
"""
raise NotImplementedError
def receive(self):
"""Receive data from the link.
Should return the received data or None if there was nothing new. Has
to raise a ConnectionClose on shutdown of the connection or on errors
that are not recoverable.
"""
raise NotImplementedError
def send_reply(self, data):
"""send reply
stops recv loop on error
"""
raise NotImplementedError
def format(self):
"""
Format available connection data into something recognizable for
logging.
For example, the remote IP address or a connection identifier.
"""
raise NotImplementedError
# TODO: server baseclass?

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@ -18,122 +18,77 @@
# Markus Zolliker <markus.zolliker@psi.ch>
#
# *****************************************************************************
"""provides tcp interface to the SECoP Server"""
"""TCP interface to the SECoP Server"""
import errno
import os
import socket
import socketserver
import sys
import threading
import time
from frappy.datatypes import BoolType, StringType
from frappy.errors import SECoPError
from frappy.lib import formatException, formatExtendedStack, \
formatExtendedTraceback, SECoP_DEFAULT_PORT
from frappy.lib import SECoP_DEFAULT_PORT
from frappy.properties import Property
from frappy.protocol.interface import decode_msg, encode_msg_frame, get_msg
from frappy.protocol.messages import ERRORPREFIX, HELPREPLY, HELPREQUEST, \
HelpMessage
from frappy.protocol.interface.handler import ConnectionClose, \
RequestHandler, DecodeError
from frappy.protocol.messages import HELPREQUEST
MESSAGE_READ_SIZE = 1024
HELP = HELPREQUEST.encode()
class TCPRequestHandler(socketserver.BaseRequestHandler):
def format_address(addr):
if len(addr) == 2:
return '%s:%d' % addr
address, port = addr[0:2]
if address.startswith('::ffff'):
return '%s:%d' % (address[7:], port)
return '[%s]:%d' % (address, port)
class TCPRequestHandler(RequestHandler):
def setup(self):
self.log = self.server.log
self.running = True
self.send_lock = threading.Lock()
super().setup()
self.request.settimeout(1)
self.data = b''
def handle(self):
"""handle a new tcp-connection"""
# copy state info
mysocket = self.request
clientaddr = self.client_address
serverobj = self.server
def finish(self):
"""called when handle() terminates, i.e. the socket closed"""
super().finish()
# close socket
try:
self.request.shutdown(socket.SHUT_RDWR)
except Exception:
pass
finally:
self.request.close()
self.log.info("handling new connection from %s", format_address(clientaddr))
data = b''
def ingest(self, newdata):
self.data += newdata
# notify dispatcher of us
serverobj.dispatcher.add_connection(self)
def next_message(self):
try:
message, self.data = get_msg(self.data)
if message is None:
return None
if message.strip() == b'':
return (HELPREQUEST, None, None)
return decode_msg(message)
except Exception as e:
raise DecodeError('exception in receive', raw_msg=message) from e
# copy relevant settings from Interface
detailed_errors = serverobj.detailed_errors
mysocket.settimeout(1)
# start serving
while self.running:
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
def receive(self):
try:
data = self.request.recv(MESSAGE_READ_SIZE)
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 self.running:
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.send_reply(('_', f'{idx + 1}', line))
# ident matches request
self.send_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 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.send_reply(result)
raise ConnectionClose('socket was closed')
return data
except socket.timeout:
return None
except socket.error as e:
self.log.exception(e)
raise ConnectionClose() from e
def send_reply(self, data):
"""send reply
@ -156,18 +111,9 @@ class TCPRequestHandler(socketserver.BaseRequestHandler):
self.log.error('ERROR in send_reply %r', e)
self.running = False
def finish(self):
"""called when handle() terminates, i.e. the socket closed"""
self.log.info('closing connection from %s', format_address(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()
def format(self):
return f'from {format_address(self.client_address)}'
class DualStackTCPServer(socketserver.ThreadingTCPServer):
"""Subclassed to provide IPv6 capabilities as socketserver only uses IPv4"""
@ -230,12 +176,3 @@ class TCPServer(DualStackTCPServer):
if ntry:
self.log.warning('tried again %d times after "Address already in use"', ntry)
self.log.info("TCPServer initiated")
def format_address(addr):
if len(addr) == 2:
return '%s:%d' % addr
address, port = addr[0:2]
if address.startswith('::ffff'):
return '%s:%d' % (address[7:], port)
return '[%s]:%d' % (address, port)