Max | c3b94f9 | 2016-11-14 18:46:40 +0100 | [diff] [blame] | 1 | #!/usr/bin/python3 |
| 2 | # -*- mode: python-mode; py-indent-tabs-mode: nil -*- |
| 3 | """ |
| 4 | /* |
| 5 | * Copyright (C) 2016 sysmocom s.f.m.c. GmbH |
| 6 | * |
| 7 | * All Rights Reserved |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation; either version 3 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
Max | c3b94f9 | 2016-11-14 18:46:40 +0100 | [diff] [blame] | 18 | */ |
| 19 | """ |
| 20 | |
| 21 | import struct, random, sys |
| 22 | |
| 23 | class IPA(object): |
| 24 | """ |
| 25 | Stateless IPA protocol multiplexer: add/remove/parse (extended) header |
| 26 | """ |
| 27 | version = "0.0.5" |
| 28 | TCP_PORT_OML = 3002 |
| 29 | TCP_PORT_RSL = 3003 |
| 30 | # OpenBSC extensions: OSMO, MGCP_OLD |
| 31 | PROTO = dict(RSL=0x00, CCM=0xFE, SCCP=0xFD, OML=0xFF, OSMO=0xEE, MGCP_OLD=0xFC) |
| 32 | # ...OML Router Control, GSUP GPRS extension, Osmocom Authn Protocol |
| 33 | EXT = dict(CTRL=0, MGCP=1, LAC=2, SMSC=3, ORC=4, GSUP=5, OAP=6) |
| 34 | # OpenBSC extension: SCCP_OLD |
| 35 | MSGT = dict(PING=0x00, PONG=0x01, ID_GET=0x04, ID_RESP=0x05, ID_ACK=0x06, SCCP_OLD=0xFF) |
| 36 | _IDTAG = dict(SERNR=0, UNITNAME=1, LOCATION=2, TYPE=3, EQUIPVERS=4, SWVERSION=5, IPADDR=6, MACADDR=7, UNIT=8) |
| 37 | CTRL_GET = 'GET' |
| 38 | CTRL_SET = 'SET' |
| 39 | CTRL_REP = 'REPLY' |
| 40 | CTRL_ERR = 'ERR' |
| 41 | CTRL_TRAP = 'TRAP' |
| 42 | |
| 43 | def _l(self, d, p): |
| 44 | """ |
| 45 | Reverse dictionary lookup: return key for a given value |
| 46 | """ |
| 47 | if p is None: |
| 48 | return 'UNKNOWN' |
| 49 | return list(d.keys())[list(d.values()).index(p)] |
| 50 | |
| 51 | def _tag(self, t, v): |
| 52 | """ |
| 53 | Create TAG as TLV data |
| 54 | """ |
| 55 | return struct.pack(">HB", len(v) + 1, t) + v |
| 56 | |
| 57 | def proto(self, p): |
| 58 | """ |
| 59 | Lookup protocol name |
| 60 | """ |
| 61 | return self._l(self.PROTO, p) |
| 62 | |
| 63 | def ext(self, p): |
| 64 | """ |
| 65 | Lookup protocol extension name |
| 66 | """ |
| 67 | return self._l(self.EXT, p) |
| 68 | |
| 69 | def msgt(self, p): |
| 70 | """ |
| 71 | Lookup message type name |
| 72 | """ |
| 73 | return self._l(self.MSGT, p) |
| 74 | |
| 75 | def idtag(self, p): |
| 76 | """ |
| 77 | Lookup ID tag name |
| 78 | """ |
| 79 | return self._l(self._IDTAG, p) |
| 80 | |
| 81 | def ext_name(self, proto, exten): |
| 82 | """ |
| 83 | Return proper extension byte name depending on the protocol used |
| 84 | """ |
| 85 | if self.PROTO['CCM'] == proto: |
| 86 | return self.msgt(exten) |
| 87 | if self.PROTO['OSMO'] == proto: |
| 88 | return self.ext(exten) |
| 89 | return None |
| 90 | |
| 91 | def add_header(self, data, proto, ext=None): |
| 92 | """ |
| 93 | Add IPA header (with extension if necessary), data must be represented as bytes |
| 94 | """ |
| 95 | if ext is None: |
| 96 | return struct.pack(">HB", len(data) + 1, proto) + data |
| 97 | return struct.pack(">HBB", len(data) + 1, proto, ext) + data |
| 98 | |
| 99 | def del_header(self, data): |
| 100 | """ |
| 101 | Strip IPA protocol header correctly removing extension if present |
| 102 | Returns data length, IPA protocol, extension (or None if not defined for a give protocol) and the data without header |
| 103 | """ |
| 104 | if not len(data): |
| 105 | return None, None, None, None |
| 106 | (dlen, proto) = struct.unpack('>HB', data[:3]) |
| 107 | if self.PROTO['OSMO'] == proto or self.PROTO['CCM'] == proto: # there's extension which we have to unpack |
| 108 | return struct.unpack('>HBB', data[:4]) + (data[4:], ) # length, protocol, extension, data |
| 109 | return dlen, proto, None, data[3:] # length, protocol, _, data |
| 110 | |
| 111 | def split_combined(self, data): |
| 112 | """ |
| 113 | Split the data which contains multiple concatenated IPA messages into tuple (first, rest) where rest contains remaining messages, first is the single IPA message |
| 114 | """ |
| 115 | (length, _, _, _) = self.del_header(data) |
| 116 | return data[:(length + 3)], data[(length + 3):] |
| 117 | |
| 118 | def tag_serial(self, data): |
| 119 | """ |
| 120 | Make TAG for serial number |
| 121 | """ |
| 122 | return self._tag(self._IDTAG['SERNR'], data) |
| 123 | |
| 124 | def tag_name(self, data): |
| 125 | """ |
| 126 | Make TAG for unit name |
| 127 | """ |
| 128 | return self._tag(self._IDTAG['UNITNAME'], data) |
| 129 | |
| 130 | def tag_loc(self, data): |
| 131 | """ |
| 132 | Make TAG for location |
| 133 | """ |
| 134 | return self._tag(self._IDTAG['LOCATION'], data) |
| 135 | |
| 136 | def tag_type(self, data): |
| 137 | """ |
| 138 | Make TAG for unit type |
| 139 | """ |
| 140 | return self._tag(self._IDTAG['TYPE'], data) |
| 141 | |
| 142 | def tag_equip(self, data): |
| 143 | """ |
| 144 | Make TAG for equipment version |
| 145 | """ |
| 146 | return self._tag(self._IDTAG['EQUIPVERS'], data) |
| 147 | |
| 148 | def tag_sw(self, data): |
| 149 | """ |
| 150 | Make TAG for software version |
| 151 | """ |
| 152 | return self._tag(self._IDTAG['SWVERSION'], data) |
| 153 | |
| 154 | def tag_ip(self, data): |
| 155 | """ |
| 156 | Make TAG for IP address |
| 157 | """ |
| 158 | return self._tag(self._IDTAG['IPADDR'], data) |
| 159 | |
| 160 | def tag_mac(self, data): |
| 161 | """ |
| 162 | Make TAG for MAC address |
| 163 | """ |
| 164 | return self._tag(self._IDTAG['MACADDR'], data) |
| 165 | |
| 166 | def tag_unit(self, data): |
| 167 | """ |
| 168 | Make TAG for unit ID |
| 169 | """ |
| 170 | return self._tag(self._IDTAG['UNIT'], data) |
| 171 | |
| 172 | def identity(self, unit=b'', mac=b'', location=b'', utype=b'', equip=b'', sw=b'', name=b'', serial=b''): |
| 173 | """ |
| 174 | Make IPA IDENTITY tag list, by default returns empty concatenated bytes of tag list |
| 175 | """ |
| 176 | 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) |
| 177 | |
| 178 | def ping(self): |
| 179 | """ |
| 180 | Make PING message |
| 181 | """ |
| 182 | return self.add_header(b'', self.PROTO['CCM'], self.MSGT['PING']) |
| 183 | |
| 184 | def pong(self): |
| 185 | """ |
| 186 | Make PONG message |
| 187 | """ |
| 188 | return self.add_header(b'', self.PROTO['CCM'], self.MSGT['PONG']) |
| 189 | |
| 190 | def id_ack(self): |
| 191 | """ |
| 192 | Make ID_ACK CCM message |
| 193 | """ |
| 194 | return self.add_header(b'', self.PROTO['CCM'], self.MSGT['ID_ACK']) |
| 195 | |
| 196 | def id_get(self): |
| 197 | """ |
| 198 | Make ID_GET CCM message |
| 199 | """ |
| 200 | return self.add_header(self.identity(), self.PROTO['CCM'], self.MSGT['ID_GET']) |
| 201 | |
| 202 | def id_resp(self, data): |
| 203 | """ |
| 204 | Make ID_RESP CCM message |
| 205 | """ |
| 206 | return self.add_header(data, self.PROTO['CCM'], self.MSGT['ID_RESP']) |
| 207 | |
| 208 | class Ctrl(IPA): |
| 209 | """ |
| 210 | Osmocom CTRL protocol implemented on top of IPA multiplexer |
| 211 | """ |
| 212 | def __init__(self): |
| 213 | random.seed() |
| 214 | |
| 215 | def add_header(self, data): |
| 216 | """ |
| 217 | Add CTRL header |
| 218 | """ |
| 219 | return super(Ctrl, self).add_header(data.encode('utf-8'), IPA.PROTO['OSMO'], IPA.EXT['CTRL']) |
| 220 | |
| 221 | def rem_header(self, data): |
| 222 | """ |
| 223 | Remove CTRL header, check for appropriate protocol and extension |
| 224 | """ |
| 225 | (_, proto, ext, d) = super(Ctrl, self).del_header(data) |
| 226 | if self.PROTO['OSMO'] != proto or self.EXT['CTRL'] != ext: |
| 227 | return None |
| 228 | return d |
| 229 | |
| 230 | def parse(self, data, op=None): |
| 231 | """ |
| 232 | Parse Ctrl string returning (var, value) pair |
| 233 | var could be None in case of ERROR message |
| 234 | value could be None in case of GET message |
| 235 | """ |
| 236 | (s, i, v) = data.split(' ', 2) |
| 237 | if s == self.CTRL_ERR: |
| 238 | return None, v |
| 239 | if s == self.CTRL_GET: |
| 240 | return v, None |
| 241 | (s, i, var, val) = data.split(' ', 3) |
| 242 | if s == self.CTRL_TRAP and i != '0': |
| 243 | return None, '%s with non-zero id %s' % (s, i) |
| 244 | if op is not None and i != op: |
| 245 | if s == self.CTRL_GET + '_' + self.CTRL_REP or s == self.CTRL_SET + '_' + self.CTRL_REP: |
| 246 | return None, '%s with unexpected id %s' % (s, i) |
| 247 | return var, val |
| 248 | |
| 249 | def trap(self, var, val): |
| 250 | """ |
| 251 | Make TRAP message with given (vak, val) pair |
| 252 | """ |
| 253 | return self.add_header("%s 0 %s %s" % (self.CTRL_TRAP, var, val)) |
| 254 | |
| 255 | def cmd(self, var, val=None): |
| 256 | """ |
| 257 | Make SET/GET command message: returns (r, m) tuple where r is random operation id and m is assembled message |
| 258 | """ |
| 259 | r = random.randint(1, sys.maxsize) |
| 260 | if val is not None: |
| 261 | return r, self.add_header("%s %s %s %s" % (self.CTRL_SET, r, var, val)) |
| 262 | return r, self.add_header("%s %s %s" % (self.CTRL_GET, r, var)) |
| 263 | |
| 264 | def verify(self, reply, r, var, val=None): |
| 265 | """ |
| 266 | Verify reply to SET/GET command: returns (b, v) tuple where v is True/False verification result and v is the variable value |
| 267 | """ |
| 268 | (k, v) = self.parse(reply) |
| 269 | if k != var or (val is not None and v != val): |
| 270 | return False, v |
| 271 | return True, v |
| 272 | |
| 273 | if __name__ == '__main__': |
| 274 | print("IPA multiplexer v%s loaded." % IPA.version) |