Osmocom's Base Station Controller for 2G mobile networks https://osmocom.org/projects/osmobsc
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# -*- mode: python-mode; py-indent-tabs-mode: nil -*-
* Copyright (C) 2016 sysmocom s.f.m.c. GmbH
* All Rights Reserved
* 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 3 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
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
import struct, random, sys
class IPA(object):
Stateless IPA protocol multiplexer: add/remove/parse (extended) header
version = "0.0.5"
# OpenBSC extensions: OSMO, MGCP_OLD
PROTO = dict(RSL=0x00, CCM=0xFE, SCCP=0xFD, OML=0xFF, OSMO=0xEE, MGCP_OLD=0xFC)
# ...OML Router Control, GSUP GPRS extension, Osmocom Authn Protocol
EXT = dict(CTRL=0, MGCP=1, LAC=2, SMSC=3, ORC=4, GSUP=5, OAP=6)
# OpenBSC extension: SCCP_OLD
MSGT = dict(PING=0x00, PONG=0x01, ID_GET=0x04, ID_RESP=0x05, ID_ACK=0x06, SCCP_OLD=0xFF)
def _l(self, d, p):
Reverse dictionary lookup: return key for a given value
if p is None:
return 'UNKNOWN'
return list(d.keys())[list(d.values()).index(p)]
def _tag(self, t, v):
Create TAG as TLV data
return struct.pack(">HB", len(v) + 1, t) + v
def proto(self, p):
Lookup protocol name
return self._l(self.PROTO, p)
def ext(self, p):
Lookup protocol extension name
return self._l(self.EXT, p)
def msgt(self, p):
Lookup message type name
return self._l(self.MSGT, p)
def idtag(self, p):
Lookup ID tag name
return self._l(self._IDTAG, p)
def ext_name(self, proto, exten):
Return proper extension byte name depending on the protocol used
if self.PROTO['CCM'] == proto:
return self.msgt(exten)
if self.PROTO['OSMO'] == proto:
return self.ext(exten)
return None
def add_header(self, data, proto, ext=None):
Add IPA header (with extension if necessary), data must be represented as bytes
if ext is None:
return struct.pack(">HB", len(data) + 1, proto) + data
return struct.pack(">HBB", len(data) + 1, proto, ext) + data
def del_header(self, data):
Strip IPA protocol header correctly removing extension if present
Returns data length, IPA protocol, extension (or None if not defined for a give protocol) and the data without header
if not len(data):
return None, None, None, None
(dlen, proto) = struct.unpack('>HB', data[:3])
if self.PROTO['OSMO'] == proto or self.PROTO['CCM'] == proto: # there's extension which we have to unpack
return struct.unpack('>HBB', data[:4]) + (data[4:], ) # length, protocol, extension, data
return dlen, proto, None, data[3:] # length, protocol, _, data
def split_combined(self, data):
Split the data which contains multiple concatenated IPA messages into tuple (first, rest) where rest contains remaining messages, first is the single IPA message
(length, _, _, _) = self.del_header(data)
return data[:(length + 3)], data[(length + 3):]
def tag_serial(self, data):
Make TAG for serial number
return self._tag(self._IDTAG['SERNR'], data)
def tag_name(self, data):
Make TAG for unit name
return self._tag(self._IDTAG['UNITNAME'], data)
def tag_loc(self, data):
Make TAG for location
return self._tag(self._IDTAG['LOCATION'], data)
def tag_type(self, data):
Make TAG for unit type
return self._tag(self._IDTAG['TYPE'], data)
def tag_equip(self, data):
Make TAG for equipment version
return self._tag(self._IDTAG['EQUIPVERS'], data)
def tag_sw(self, data):
Make TAG for software version
return self._tag(self._IDTAG['SWVERSION'], data)
def tag_ip(self, data):
Make TAG for IP address
return self._tag(self._IDTAG['IPADDR'], data)
def tag_mac(self, data):
Make TAG for MAC address
return self._tag(self._IDTAG['MACADDR'], data)
def tag_unit(self, data):
Make TAG for unit ID
return self._tag(self._IDTAG['UNIT'], data)
def identity(self, unit=b'', mac=b'', location=b'', utype=b'', equip=b'', sw=b'', name=b'', serial=b''):
Make IPA IDENTITY tag list, by default returns empty concatenated bytes of tag list
return self.tag_unit(unit) + self.tag_mac(mac) + self.tag_loc(location) + self.tag_type(utype) + self.tag_equip(equip) + self.tag_sw(sw) + self.tag_name(name) + self.tag_serial(serial)
def ping(self):
Make PING message
return self.add_header(b'', self.PROTO['CCM'], self.MSGT['PING'])
def pong(self):
Make PONG message
return self.add_header(b'', self.PROTO['CCM'], self.MSGT['PONG'])
def id_ack(self):
Make ID_ACK CCM message
return self.add_header(b'', self.PROTO['CCM'], self.MSGT['ID_ACK'])
def id_get(self):
Make ID_GET CCM message
return self.add_header(self.identity(), self.PROTO['CCM'], self.MSGT['ID_GET'])
def id_resp(self, data):
Make ID_RESP CCM message
return self.add_header(data, self.PROTO['CCM'], self.MSGT['ID_RESP'])
class Ctrl(IPA):
Osmocom CTRL protocol implemented on top of IPA multiplexer
def __init__(self):
def add_header(self, data):
Add CTRL header
return super(Ctrl, self).add_header(data.encode('utf-8'), IPA.PROTO['OSMO'], IPA.EXT['CTRL'])
def rem_header(self, data):
Remove CTRL header, check for appropriate protocol and extension
(_, proto, ext, d) = super(Ctrl, self).del_header(data)
if self.PROTO['OSMO'] != proto or self.EXT['CTRL'] != ext:
return None
return d
def parse(self, data, op=None):
Parse Ctrl string returning (var, value) pair
var could be None in case of ERROR message
value could be None in case of GET message
(s, i, v) = data.split(' ', 2)
if s == self.CTRL_ERR:
return None, v
if s == self.CTRL_GET:
return v, None
(s, i, var, val) = data.split(' ', 3)
if s == self.CTRL_TRAP and i != '0':
return None, '%s with non-zero id %s' % (s, i)
if op is not None and i != op:
if s == self.CTRL_GET + '_' + self.CTRL_REP or s == self.CTRL_SET + '_' + self.CTRL_REP:
return None, '%s with unexpected id %s' % (s, i)
return var, val
def trap(self, var, val):
Make TRAP message with given (vak, val) pair
return self.add_header("%s 0 %s %s" % (self.CTRL_TRAP, var, val))
def cmd(self, var, val=None):
Make SET/GET command message: returns (r, m) tuple where r is random operation id and m is assembled message
r = random.randint(1, sys.maxsize)
if val is not None:
return r, self.add_header("%s %s %s %s" % (self.CTRL_SET, r, var, val))
return r, self.add_header("%s %s %s" % (self.CTRL_GET, r, var))
def verify(self, reply, r, var, val=None):
Verify reply to SET/GET command: returns (b, v) tuple where v is True/False verification result and v is the variable value
(k, v) = self.parse(reply)
if k != var or (val is not None and v != val):
return False, v
return True, v
if __name__ == '__main__':
print("IPA multiplexer v%s loaded." % IPA.version)