summaryrefslogtreecommitdiffstats
path: root/openbsc/contrib/ipa.py
blob: 71cbf45a4671038a87d59fb270b7b37113ba2599 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
#!/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)