| #!/usr/bin/python3 |
| # -*- 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 |
| * 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., |
| * 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" |
| TCP_PORT_OML = 3002 |
| TCP_PORT_RSL = 3003 |
| # 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) |
| _IDTAG = dict(SERNR=0, UNITNAME=1, LOCATION=2, TYPE=3, EQUIPVERS=4, SWVERSION=5, IPADDR=6, MACADDR=7, UNIT=8) |
| CTRL_GET = 'GET' |
| CTRL_SET = 'SET' |
| CTRL_REP = 'REPLY' |
| CTRL_ERR = 'ERR' |
| CTRL_TRAP = 'TRAP' |
| |
| 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): |
| random.seed() |
| |
| 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) |