reworking messages

1) start 'bin/secop-server test'
2) connect to localhost port 10767
3) enter help<enter>
4) enjoy

Change-Id: I488d5f9cdca8c91c583691ab23f541a4a8759f4e

secop/protocol/framing/__init__.py

@@ -0,0 +1,62 @@
+#!/usr/bin/env 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>
+#
+# *****************************************************************************
+
+"""Encoding/decoding Frames"""
+
+
+# Base class
+class Framer(object):
+    """Frames and unframes an encoded message
+
+    also transforms the encoded message to the 'wire-format' (and vise-versa)
+
+    note: not all MessageEncoders can use all Framers,
+          but the intention is to have this for as many as possible.
+    """
+
+    def encode(self, *frames):
+        """return the wire-data for the given messageframes"""
+        raise NotImplemented
+
+    def decode(self, data):
+        """return a list of messageframes found in data"""
+        raise NotImplemented
+
+    def reset(self):
+        """resets the de/encoding stage (clears internal information)"""
+        raise NotImplemented
+
+
+# now some Implementations
+from null import NullFramer
+from eol import EOLFramer
+from rle import RLEFramer
+from demo import DemoFramer
+
+FRAMERS = {
+    'null': NullFramer,
+    'eol': EOLFramer,
+    'rle': RLEFramer,
+    'demo': DemoFramer,
+}
+
+__ALL__ = ['FRAMERS']

secop/protocol/framing/demo.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env 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>
+#
+# *****************************************************************************
+
+"""Encoding/decoding Frames"""
+
+from secop.protocol.framing import Framer
+
+
+class DemoFramer(Framer):
+    """Text based message framer
+
+    frmes are delimited by '\n'
+    messages are delimited by '\n\n'
+    '\r' is ignored
+    """
+
+    def __init__(self):
+        self.data = b''
+        self.decoded = []
+
+    def encode(self, frames):
+        """add transport layer encapsulation/framing of messages"""
+        if isinstance(frames, (tuple, list)):
+            return b'\n'.join(frames) + b'\n\n'
+        return b'%s\n\n' % frames
+
+    def decode(self, data):
+        """remove transport layer encapsulation/framing of messages
+
+        returns a list of messageframes which got decoded from data!
+        """
+        self.data += data
+        res = []
+        while b'\n' in self.data:
+            frame, self.data = self.data.split(b'\n', 1)
+            if frame.endswith('\r'):
+                frame = frame[:-1]
+            if self.data.startswith('\r'):
+                self.data = self.data[1:]
+            res.append(frame)
+        return res
+
+    def decode2(self, data):
+        """remove transport layer encapsulation/framing of messages
+
+        returns a _list_ of messageframes which got decoded from data!
+        """
+        self.data += data.replace(b'\r', '')
+        while b'\n' in self.data:
+            frame, self.data = self.data.split(b'\n', 1)
+            if frame:
+                # not an empty line -> belongs to this set of messages
+                self.decoded.append(frame)
+            else:
+                # empty line -> our set of messages is finished decoding
+                res = self.decoded
+                self.decoded = []
+                return res
+        return None
+
+    def reset(self):
+        self.data = b''
+        self.decoded = []
+
+

secop/protocol/framing/eol.py

@@ -0,0 +1,57 @@
+#!/usr/bin/env 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>
+#
+# *****************************************************************************
+
+"""Encoding/decoding Frames"""
+
+from secop.protocol.framing import Framer
+
+
+class EOLFramer(Framer):
+    """Text based message framer
+
+    messages are delimited by '\r\n'
+    upon reception the end of a message is detected by '\r\n','\n' or '\n\r'
+    """
+    data = b''
+
+    def encode(self, *frames):
+        """add transport layer encapsulation/framing of messages"""
+        return b'%s\r\n' % b'\r\n'.join(frames)
+
+    def decode(self, data):
+        """remove transport layer encapsulation/framing of messages
+
+        returns a list of messageframes which got decoded from data!
+        """
+        self.data += data
+        res = []
+        while b'\n' in self.data:
+            frame, self.data = self.data.split(b'\n', 1)
+            if frame.endswith('\r'):
+                frame = frame[:-1]
+            if self.data.startswith('\r'):
+                self.data = self.data[1:]
+            res.append(frame)
+        return res
+
+    def reset(self):
+        self.data = b''

secop/protocol/framing/null.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env 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>
+#
+# *****************************************************************************
+
+"""Encoding/decoding Frames"""
+
+from secop.protocol.framing import Framer
+
+
+class NullFramer(Framer):
+    """do-nothing-framer
+
+    assumes messages are framed by themselfs or the interface does it already.
+    """
+
+    def encode(self, *frames):
+        """add transport layer encapsulation/framing of messages"""
+        return ''.join(frames)
+
+    def decode(self, data):
+        """remove transport layer encapsulation/framing of messages"""
+        return [data]

secop/protocol/framing/rle.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env 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>
+#
+# *****************************************************************************
+
+"""Encoding/decoding Frames"""
+
+from secop.protocol.framing import Framer
+
+
+class RLEFramer(Framer):
+    data = b''
+    frames_to_go = 0
+
+    def encode(self, *frames):
+        """add transport layer encapsulation/framing of messages"""
+        # format is 'number of frames:[framelengt:frme]*N'
+        frdata = ['%d:%s' % (len(frame), frame) for frame in frames]
+        return b'%d:' + b''.join(frdata)
+
+    def decode(self, data):
+        """remove transport layer encapsulation/framing of messages
+
+        returns a list of messageframes which got decoded from data!
+        """
+        self.data += data
+        res = []
+        while self.data:
+            if frames_to_go == 0:
+                if ':' in self.data:
+                    # scan for and decode 'number of frames'
+                    frnum, self.data = self.data.split(':', 1)
+                    try:
+                        self.frames_to_go = int(frnum)
+                    except ValueError:
+                        # can not recover, complain!
+                        raise FramingError('invalid start of message found!')
+                else:
+                    # not enough data to decode number of frames,
+                    # return what we have
+                    return res
+            while self.frames_to_go:
+                # there are still some (partial) frames stuck inside self.data
+                frlen, self.data = self.data.split(':', 1)
+                if len(self.data) >= frlen:
+                    res.append(self.data[:frlen])
+                    self.data = self.data[frlen:]
+                    self.frames_to_go -= 1
+                else:
+                    # not enough data for this frame, return what we have
+                    return res
+
+    def reset(self):
+        self.data = b''
+        self.frames_to_go = 0
+
+