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b0cfbfce IJ |
1 | # -*- python -*- |
2 | ||
37ab4cdc IJ |
3 | import signal |
4 | signal.signal(signal.SIGINT, signal.SIG_DFL) | |
5 | ||
040ff511 IJ |
6 | import twisted |
7 | from twisted.internet import reactor | |
ae7c7784 | 8 | from twisted.logger import LogLevel |
1d023c89 | 9 | import twisted.internet.endpoints |
b0cfbfce IJ |
10 | |
11 | import ipaddress | |
12 | from ipaddress import AddressValueError | |
13 | ||
040ff511 IJ |
14 | import hippotat.slip as slip |
15 | ||
ae7c7784 IJ |
16 | from optparse import OptionParser |
17 | from configparser import ConfigParser | |
18 | from configparser import NoOptionError | |
19 | ||
20 | import collections | |
21 | ||
87a7c0c7 | 22 | # these need to be defined here so that they can be imported by import * |
ae7c7784 IJ |
23 | cfg = ConfigParser() |
24 | optparser = OptionParser() | |
25 | ||
87a7c0c7 IJ |
26 | class ConfigResults: |
27 | def __init__(self, d = { }): | |
28 | self.__dict__ = d | |
29 | def __repr__(self): | |
30 | return 'ConfigResults('+repr(self.__dict__)+')' | |
31 | ||
32 | c = ConfigResults() | |
33 | ||
b0cfbfce IJ |
34 | #---------- packet parsing ---------- |
35 | ||
36 | def packet_addrs(packet): | |
37 | version = packet[0] >> 4 | |
38 | if version == 4: | |
39 | addrlen = 4 | |
40 | saddroff = 3*4 | |
41 | factory = ipaddress.IPv4Address | |
42 | elif version == 6: | |
43 | addrlen = 16 | |
44 | saddroff = 2*4 | |
45 | factory = ipaddress.IPv6Address | |
46 | else: | |
47 | raise ValueError('unsupported IP version %d' % version) | |
48 | saddr = factory(packet[ saddroff : saddroff + addrlen ]) | |
49 | daddr = factory(packet[ saddroff + addrlen : saddroff + addrlen*2 ]) | |
50 | return (saddr, daddr) | |
51 | ||
52 | #---------- address handling ---------- | |
53 | ||
54 | def ipaddr(input): | |
55 | try: | |
56 | r = ipaddress.IPv4Address(input) | |
57 | except AddressValueError: | |
58 | r = ipaddress.IPv6Address(input) | |
59 | return r | |
60 | ||
61 | def ipnetwork(input): | |
62 | try: | |
63 | r = ipaddress.IPv4Network(input) | |
64 | except NetworkValueError: | |
65 | r = ipaddress.IPv6Network(input) | |
66 | return r | |
040ff511 IJ |
67 | |
68 | #---------- ipif (SLIP) subprocess ---------- | |
69 | ||
70 | class _IpifProcessProtocol(twisted.internet.protocol.ProcessProtocol): | |
71 | def __init__(self, router): | |
72 | self._buffer = b'' | |
73 | self._router = router | |
74 | def connectionMade(self): pass | |
75 | def outReceived(self, data): | |
034284c3 | 76 | #print('IPIF-GOT ', repr(data)) |
040ff511 IJ |
77 | self._buffer += data |
78 | packets = slip.decode(self._buffer) | |
79 | self._buffer = packets.pop() | |
80 | for packet in packets: | |
81 | if not len(packet): continue | |
82 | (saddr, daddr) = packet_addrs(packet) | |
83 | self._router(packet, saddr, daddr) | |
84 | def processEnded(self, status): | |
85 | status.raiseException() | |
86 | ||
87 | def start_ipif(command, router): | |
88 | global ipif | |
89 | ipif = _IpifProcessProtocol(router) | |
90 | reactor.spawnProcess(ipif, | |
91 | '/bin/sh',['sh','-xc', command], | |
92 | childFDs={0:'w', 1:'r', 2:2}) | |
93 | ||
94 | def queue_inbound(packet): | |
95 | ipif.transport.write(slip.delimiter) | |
96 | ipif.transport.write(slip.encode(packet)) | |
97 | ipif.transport.write(slip.delimiter) | |
98 | ||
650a3251 IJ |
99 | #---------- packet queue ---------- |
100 | ||
101 | class PacketQueue(): | |
102 | def __init__(self, max_queue_time): | |
103 | self._max_queue_time = max_queue_time | |
104 | self._pq = collections.deque() # packets | |
105 | ||
106 | def append(self, packet): | |
107 | self._pq.append((time.monotonic(), packet)) | |
108 | ||
109 | def nonempty(self): | |
110 | while True: | |
111 | try: (queuetime, packet) = self._pq[0] | |
112 | except IndexError: return False | |
113 | ||
114 | age = time.monotonic() - queuetime | |
115 | if age > self.max_queue_time: | |
116 | # strip old packets off the front | |
117 | self._pq.popleft() | |
118 | continue | |
119 | ||
120 | return True | |
121 | ||
122 | def popleft(self): | |
123 | # caller must have checked nonempty | |
124 | try: (dummy, packet) = self._pq[0] | |
125 | except IndexError: return None | |
126 | return packet | |
ae7c7784 IJ |
127 | |
128 | #---------- error handling ---------- | |
129 | ||
130 | def crash(err): | |
131 | print('CRASH ', err, file=sys.stderr) | |
132 | try: reactor.stop() | |
133 | except twisted.internet.error.ReactorNotRunning: pass | |
134 | ||
135 | def crash_on_defer(defer): | |
136 | defer.addErrback(lambda err: crash(err)) | |
137 | ||
138 | def crash_on_critical(event): | |
139 | if event.get('log_level') >= LogLevel.critical: | |
140 | crash(twisted.logger.formatEvent(event)) | |
141 | ||
87a7c0c7 IJ |
142 | #---------- config processing ---------- |
143 | ||
144 | def process_cfg_common_always(): | |
145 | global mtu | |
146 | c.mtu = cfg.get('virtual','mtu') | |
147 | ||
88487243 IJ |
148 | def process_cfg_ipif(section, varmap): |
149 | for d, s in varmap: | |
150 | try: v = getattr(c, s) | |
034284c3 | 151 | except AttributeError: continue |
88487243 IJ |
152 | setattr(c, d, v) |
153 | ||
154 | print(repr(c)) | |
155 | ||
156 | c.ipif_command = cfg.get(section,'ipif', vars=c.__dict__) | |
157 | ||
158 | def process_cfg_network(): | |
159 | c.network = ipnetwork(cfg.get('virtual','network')) | |
160 | if c.network.num_addresses < 3 + 2: | |
161 | raise ValueError('network needs at least 2^3 addresses') | |
162 | ||
163 | def process_cfg_server(): | |
164 | try: | |
165 | c.server = cfg.get('virtual','server') | |
166 | except NoOptionError: | |
167 | process_cfg_network() | |
168 | c.server = next(c.network.hosts()) | |
169 | ||
170 | class ServerAddr(): | |
171 | def __init__(self, port, addrspec): | |
172 | self.port = port | |
173 | # also self.addr | |
174 | try: | |
175 | self.addr = ipaddress.IPv4Address(addrspec) | |
176 | self._endpointfactory = twisted.internet.endpoints.TCP4ServerEndpoint | |
177 | self._inurl = '%s' | |
178 | except AddressValueError: | |
179 | self.addr = ipaddress.IPv6Address(addrspec) | |
180 | self._endpointfactory = twisted.internet.endpoints.TCP6ServerEndpoint | |
181 | self._inurl = '[%s]' | |
182 | def make_endpoint(self): | |
183 | return self._endpointfactory(reactor, self.port, self.addr) | |
184 | def url(self): | |
185 | url = 'http://' + (self._inurl % self.addr) | |
186 | if self.port != 80: url += ':%d' % self.port | |
187 | url += '/' | |
188 | return url | |
189 | ||
190 | def process_cfg_saddrs(): | |
1d023c89 IJ |
191 | try: port = cfg.getint('server','port') |
192 | except NoOptionError: port = 80 | |
88487243 IJ |
193 | |
194 | c.saddrs = [ ] | |
195 | for addrspec in cfg.get('server','addrs').split(): | |
196 | sa = ServerAddr(port, addrspec) | |
197 | c.saddrs.append(sa) | |
198 | ||
199 | def process_cfg_clients(constructor): | |
200 | c.clients = [ ] | |
201 | for cs in cfg.sections(): | |
202 | if not (':' in cs or '.' in cs): continue | |
203 | ci = ipaddr(cs) | |
204 | pw = cfg.get(cs, 'password') | |
205 | constructor(ci,cs,pw) | |
206 | ||
ae7c7784 IJ |
207 | #---------- startup ---------- |
208 | ||
209 | def common_startup(defcfg): | |
210 | twisted.logger.globalLogPublisher.addObserver(crash_on_critical) | |
211 | ||
212 | optparser.add_option('-c', '--config', dest='configfile', | |
213 | default='/etc/hippotat/config') | |
214 | (opts, args) = optparser.parse_args() | |
215 | if len(args): optparser.error('no non-option arguments please') | |
216 | ||
217 | cfg.read_string(defcfg) | |
218 | cfg.read(opts.configfile) | |
219 | ||
220 | def common_run(): | |
221 | reactor.run() | |
222 | print('CRASHED (end)', file=sys.stderr) |