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6005ef9b MW |
1 | #! @PYTHON@ |
2 | ### -*-python-*- | |
3 | ### | |
4 | ### Build a CDB file from configuration file | |
5 | ### | |
6 | ### (c) 2007 Straylight/Edgeware | |
7 | ### | |
8 | ||
9 | ###----- Licensing notice --------------------------------------------------- | |
10 | ### | |
11 | ### This file is part of Trivial IP Encryption (TrIPE). | |
12 | ### | |
11ad66c2 MW |
13 | ### TrIPE is free software: you can redistribute it and/or modify it under |
14 | ### the terms of the GNU General Public License as published by the Free | |
15 | ### Software Foundation; either version 3 of the License, or (at your | |
16 | ### option) any later version. | |
6005ef9b | 17 | ### |
11ad66c2 MW |
18 | ### TrIPE is distributed in the hope that it will be useful, but WITHOUT |
19 | ### ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
20 | ### FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
21 | ### for more details. | |
6005ef9b MW |
22 | ### |
23 | ### You should have received a copy of the GNU General Public License | |
11ad66c2 | 24 | ### along with TrIPE. If not, see <https://www.gnu.org/licenses/>. |
6005ef9b MW |
25 | |
26 | VERSION = '@VERSION@' | |
27 | ||
28 | ###-------------------------------------------------------------------------- | |
29 | ### External dependencies. | |
30 | ||
6005ef9b MW |
31 | import mLib as M |
32 | from optparse import OptionParser | |
33 | import cdb as CDB | |
34 | from sys import stdin, stdout, exit, argv | |
bf495093 | 35 | import subprocess as SUB |
6005ef9b MW |
36 | import re as RX |
37 | import os as OS | |
bf495093 MW |
38 | import errno as E |
39 | import fcntl as F | |
97567475 | 40 | import socket as S |
b7e5aa06 | 41 | from cStringIO import StringIO |
6005ef9b MW |
42 | |
43 | ###-------------------------------------------------------------------------- | |
44 | ### Utilities. | |
45 | ||
46 | class CDBFake (object): | |
47 | """Like cdbmake, but just outputs data suitable for cdb-map.""" | |
48 | def __init__(me, file = stdout): | |
49 | me.file = file | |
50 | def add(me, key, value): | |
51 | me.file.write('%s:%s\n' % (key, value)) | |
52 | def finish(me): | |
53 | pass | |
54 | ||
1c4623dd MW |
55 | class ExpectedError (Exception): pass |
56 | ||
6005ef9b MW |
57 | ###-------------------------------------------------------------------------- |
58 | ### A bulk DNS resolver. | |
59 | ||
1c4623dd | 60 | class ResolverFailure (ExpectedError): |
6f48da4a MW |
61 | def __init__(me, host, msg): |
62 | me.host = host | |
63 | me.msg = msg | |
64 | def __str__(me): | |
65 | return "failed to resolve `%s': %s" % (me.host, me.msg) | |
66 | ||
660564a1 MW |
67 | class ResolvingHost (object): |
68 | """ | |
69 | A host name which is being looked up by a bulk-resolver instance. | |
ef7d7afb MW |
70 | |
71 | Most notably, this is where the flag-handling logic lives for the | |
72 | $FLAGS[HOSTNAME] syntax. | |
660564a1 MW |
73 | """ |
74 | ||
75 | def __init__(me, name): | |
76 | """Make a new resolving-host object for the host NAME.""" | |
77 | me.name = name | |
97567475 | 78 | me.addr = { 'INET': [], 'INET6': [] } |
660564a1 MW |
79 | me.failure = None |
80 | ||
cc72e4b3 MW |
81 | def addaddr(me, af, addr): |
82 | """ | |
83 | Add the address ADDR with address family AF. | |
84 | ||
97567475 | 85 | The address family may be `INET' or `INET6'. |
cc72e4b3 MW |
86 | """ |
87 | me.addr[af].append(addr) | |
660564a1 MW |
88 | |
89 | def failed(me, msg): | |
90 | """ | |
91 | Report that resolution of this host failed, with a human-readable MSG. | |
92 | """ | |
93 | me.failure = msg | |
94 | ||
ef7d7afb MW |
95 | def get(me, flags): |
96 | """Return a list of addresses according to the FLAGS string.""" | |
660564a1 | 97 | if me.failure is not None: raise ResolverFailure(me.name, me.failure) |
cc72e4b3 MW |
98 | aa = [] |
99 | a4 = me.addr['INET'] | |
97567475 | 100 | a6 = me.addr['INET6'] |
cc72e4b3 | 101 | all, any = False, False |
ef7d7afb MW |
102 | for ch in flags: |
103 | if ch == '*': all = True | |
cc72e4b3 | 104 | elif ch == '4': aa += a4; any = True |
97567475 | 105 | elif ch == '6': aa += a6; any = True |
ef7d7afb | 106 | else: raise ValueError("unknown address-resolution flag `%s'" % ch) |
97567475 | 107 | if not any: aa = a4 + a6 |
ef7d7afb MW |
108 | if not aa: raise ResolverFailure(me.name, 'no matching addresses found') |
109 | if not all: aa = [aa[0]] | |
110 | return aa | |
660564a1 | 111 | |
ad367891 | 112 | class BaseBulkResolver (object): |
6005ef9b MW |
113 | """ |
114 | Resolve a number of DNS names in parallel. | |
115 | ||
116 | The BulkResovler resolves a number of hostnames in parallel. Using it | |
117 | works in three phases: | |
118 | ||
119 | 1. You call prepare(HOSTNAME) a number of times, to feed in the hostnames | |
120 | you're interested in. | |
121 | ||
122 | 2. You call run() to actually drive the resolver. | |
123 | ||
124 | 3. You call lookup(HOSTNAME) to get the address you wanted. This will | |
125 | fail with KeyError if the resolver couldn't resolve the HOSTNAME. | |
126 | """ | |
127 | ||
128 | def __init__(me): | |
129 | """Initialize the resolver.""" | |
6005ef9b | 130 | me._namemap = {} |
81b1fdde | 131 | |
660564a1 MW |
132 | def prepare(me, name): |
133 | """Prime the resolver to resolve the given host NAME.""" | |
134 | if name not in me._namemap: | |
135 | me._namemap[name] = host = ResolvingHost(name) | |
97567475 MW |
136 | try: |
137 | ailist = S.getaddrinfo(name, None, S.AF_UNSPEC, S.SOCK_DGRAM, 0, | |
138 | S.AI_NUMERICHOST | S.AI_NUMERICSERV) | |
139 | except S.gaierror: | |
140 | me._prepare(host, name) | |
141 | else: | |
142 | for af, skty, proto, cname, sa in ailist: | |
143 | if af == S.AF_INET: host.addaddr('INET', sa[0]) | |
144 | elif af == S.AF_INET6: host.addaddr('INET6', sa[0]) | |
6005ef9b | 145 | |
ef7d7afb | 146 | def lookup(me, name, flags): |
660564a1 | 147 | """Fetch the address corresponding to the host NAME.""" |
ef7d7afb | 148 | return me._namemap[name].get(flags) |
6005ef9b | 149 | |
ad367891 MW |
150 | class BresBulkResolver (BaseBulkResolver): |
151 | """ | |
152 | A BulkResolver using mLib's `bres' background resolver. | |
153 | ||
154 | This is always available (and might use ADNS), but only does IPv4. | |
155 | """ | |
156 | ||
157 | def __init__(me): | |
158 | super(BresBulkResolver, me).__init__() | |
159 | """Initialize the resolver.""" | |
160 | me._noutstand = 0 | |
161 | ||
162 | def _prepare(me, host, name): | |
163 | """Arrange to resolve a NAME, reporting the results to HOST.""" | |
164 | host._resolv = M.SelResolveByName( | |
165 | name, | |
166 | lambda cname, alias, addr: me._resolved(host, cname, addr), | |
167 | lambda: me._resolved(host, None, [])) | |
168 | me._noutstand += 1 | |
169 | ||
170 | def run(me): | |
171 | """Run the background DNS resolver until it's finished.""" | |
172 | while me._noutstand: M.select() | |
173 | ||
3c8803fa | 174 | def _resolved(me, host, cname, addr): |
ef7d7afb MW |
175 | """Callback function: remember that ADDRs are the addresses for HOST.""" |
176 | if not addr: | |
660564a1 MW |
177 | host.failed('(unknown failure)') |
178 | else: | |
3c8803fa | 179 | if cname is not None: host.name = cname |
cc72e4b3 | 180 | for a in addr: host.addaddr('INET', a) |
660564a1 MW |
181 | host._resolv = None |
182 | me._noutstand -= 1 | |
6005ef9b | 183 | |
bf495093 MW |
184 | class AdnsBulkResolver (BaseBulkResolver): |
185 | """ | |
186 | A BulkResolver using ADNS, via the `adnshost' command-line tool. | |
187 | ||
188 | This can do simultaneous IPv4 and IPv6 lookups and is quite shiny. | |
189 | """ | |
190 | ||
191 | def __init__(me): | |
192 | """Initialize the resolver.""" | |
193 | ||
194 | super(AdnsBulkResolver, me).__init__() | |
195 | ||
196 | ## Start the external resolver process. | |
197 | me._kid = SUB.Popen(['adnshost', '-afs'], | |
198 | stdin = SUB.PIPE, stdout = SUB.PIPE) | |
199 | ||
200 | ## Set up the machinery for feeding input to the resolver. | |
201 | me._in = me._kid.stdin | |
202 | M.fdflags(me._in, fbic = OS.O_NONBLOCK, fxor = OS.O_NONBLOCK) | |
203 | me._insel = M.SelFile(me._in.fileno(), M.SEL_WRITE, me._write) | |
204 | me._inbuf, me._inoff, me._inlen = '', 0, 0 | |
205 | me._idmap = {} | |
206 | me._nextid = 0 | |
207 | ||
208 | ## Set up the machinery for collecting the resolver's output. | |
209 | me._out = me._kid.stdout | |
210 | M.fdflags(me._out, fbic = OS.O_NONBLOCK, fxor = OS.O_NONBLOCK) | |
211 | me._outline = M.SelLineBuffer(me._out, | |
212 | lineproc = me._hostline, eofproc = me._eof) | |
213 | me._outline.enable() | |
214 | ||
215 | ## It's not finished yet. | |
216 | me._done = False | |
217 | ||
218 | def _prepare(me, host, name): | |
219 | """Arrange for the resolver to resolve the name NAME.""" | |
220 | ||
221 | ## Work out the next job id, and associate that with the host record. | |
222 | host.id = me._nextid; me._nextid += 1 | |
223 | me._namemap[name] = me._idmap[host.id] = host | |
224 | ||
225 | ## Feed the name to the resolver process. | |
226 | me._inbuf += name + '\n' | |
227 | me._inlen += len(name) + 1 | |
228 | if not me._insel.activep: me._insel.enable() | |
229 | while me._inoff < me._inlen: M.select() | |
230 | ||
231 | def _write(me): | |
232 | """Write material from `_inbuf' to the resolver when it's ready.""" | |
233 | ||
234 | ## Try to feed some more material to the resolver. | |
235 | try: n = OS.write(me._in.fileno(), me._inbuf[me._inoff:]) | |
236 | except OSError, e: | |
237 | if e.errno == E.EAGAIN or e.errno == E.EWOULDBLOCK: return | |
238 | else: raise | |
239 | ||
240 | ## If we're done, then clear the buffer. | |
241 | me._inoff += n | |
242 | if me._inoff >= me._inlen: | |
243 | me._insel.disable() | |
244 | me._inbuf, me._inoff, me._inlen = '', 0, 0 | |
245 | ||
246 | def _eof(me): | |
247 | """Notice that the resolver has finished.""" | |
248 | me._outline.disable() | |
249 | me._done = True | |
250 | me._kid.wait() | |
251 | ||
252 | def run(me): | |
253 | """ | |
254 | Tell the resolver it has all of our input now, and wait for it to finish. | |
255 | """ | |
256 | me._in.close() | |
257 | while not me._done: M.select() | |
258 | if me._idmap: | |
259 | raise Exception('adnshost failed to process all the requests') | |
260 | ||
261 | def _hostline(me, line): | |
262 | """Handle a host line from the resolver.""" | |
263 | ||
264 | ## Parse the line into fields. | |
265 | (id, nrrs, stty, stocde, stmsg, owner, cname, ststr), _ = \ | |
266 | M.split(line, quotep = True) | |
267 | id, nrrs = int(id), int(nrrs) | |
268 | ||
269 | ## Find the right record. | |
270 | host = me._idmap[id] | |
271 | if stty != 'ok': host.failed(ststr) | |
272 | ||
273 | ## Stash away the canonical name of the host. | |
274 | host.name = cname == '$' and owner or cname | |
275 | ||
276 | ## If there are no record lines to come, then remove this record from the | |
277 | ## list of outstanding jobs. Otherwise, switch to the handler for record | |
278 | ## lines. | |
279 | if not nrrs: | |
280 | del me._idmap[id] | |
281 | else: | |
282 | me._outline.lineproc = me._rrline | |
283 | me._nrrs = nrrs | |
284 | me._outhost = host | |
285 | ||
286 | def _rrline(me, line): | |
287 | """Handle a record line from the resolver.""" | |
288 | ||
289 | ## Parse the line into fields. | |
290 | ww, _ = M.split(line, quotep = True) | |
291 | owner, type, af = ww[:3] | |
292 | ||
293 | ## If this is an address record, and it looks like an interesting address | |
294 | ## type, then stash the address. | |
295 | if type == 'A' and (af == 'INET' or af == 'INET6'): | |
296 | me._outhost.addaddr(af, ww[3]) | |
297 | ||
298 | ## Update the parser state. If there are no more records for this job | |
299 | ## then mark the job as done and switch back to expecting a host line. | |
300 | me._nrrs -= 1 | |
301 | if not me._nrrs: | |
302 | me._outline.lineproc = me._hostline | |
303 | del me._idmap[me._outhost.id] | |
304 | me._outhost = None | |
305 | ||
306 | ## Select a bulk resolver. If `adnshost' exists then we might as well use | |
307 | ## it. | |
ad367891 | 308 | BulkResolver = BresBulkResolver |
bf495093 MW |
309 | try: |
310 | p = SUB.Popen(['adnshost', '--version'], | |
311 | stdin = SUB.PIPE, stdout = SUB.PIPE, stderr = SUB.PIPE) | |
312 | _out, _err = p.communicate() | |
313 | st = p.wait() | |
314 | if st == 0: BulkResolver = AdnsBulkResolver | |
315 | except OSError: | |
316 | pass | |
ad367891 | 317 | |
6005ef9b MW |
318 | ###-------------------------------------------------------------------------- |
319 | ### The configuration parser. | |
320 | ||
b7e5aa06 MW |
321 | ## Match a comment or empty line. |
322 | RX_COMMENT = RX.compile(r'(?x) ^ \s* (?: $ | [;#])') | |
323 | ||
324 | ## Match a section group header. | |
325 | RX_GRPHDR = RX.compile(r'(?x) ^ \s* \[ (.*) \] \s* $') | |
326 | ||
327 | ## Match an assignment line. | |
328 | RX_ASSGN = RX.compile(r'''(?x) ^ | |
329 | ([^\s:=] (?: [^:=]* [^\s:=])?) | |
330 | \s* [:=] \s* | |
331 | (| \S | \S.*\S) | |
332 | \s* $''') | |
333 | ||
334 | ## Match a continuation line. | |
335 | RX_CONT = RX.compile(r'''(?x) ^ \s+ | |
336 | (| \S | \S.*\S) | |
337 | \s* $''') | |
338 | ||
6005ef9b | 339 | ## Match a $(VAR) configuration variable reference; group 1 is the VAR. |
2d51bc9f | 340 | RX_REF = RX.compile(r'(?x) \$ \( ([^)]+) \)') |
6005ef9b | 341 | |
ef7d7afb MW |
342 | ## Match a $FLAGS[HOST] name resolution reference; group 1 are the flags; |
343 | ## group 2 is the HOST. | |
97567475 | 344 | RX_RESOLVE = RX.compile(r'(?x) \$ ([46*]*) \[ ([^]]+) \]') |
6005ef9b | 345 | |
1c4623dd | 346 | class ConfigSyntaxError (ExpectedError): |
b7e5aa06 MW |
347 | def __init__(me, fname, lno, msg): |
348 | me.fname = fname | |
349 | me.lno = lno | |
350 | me.msg = msg | |
351 | def __str__(me): | |
352 | return '%s:%d: %s' % (me.fname, me.lno, me.msg) | |
353 | ||
bd3db76c MW |
354 | def _fmt_path(path): |
355 | return ' -> '.join(["`%s'" % hop for hop in path]) | |
356 | ||
1c4623dd | 357 | class AmbiguousOptionError (ExpectedError): |
bd3db76c MW |
358 | def __init__(me, key, patha, vala, pathb, valb): |
359 | me.key = key | |
360 | me.patha, me.vala = patha, vala | |
361 | me.pathb, me.valb = pathb, valb | |
362 | def __str__(me): | |
363 | return "Ambiguous answer resolving key `%s': " \ | |
364 | "path %s yields `%s' but %s yields `%s'" % \ | |
365 | (me.key, _fmt_path(me.patha), me.vala, _fmt_path(me.pathb), me.valb) | |
366 | ||
1c4623dd | 367 | class InheritanceCycleError (ExpectedError): |
bd3db76c MW |
368 | def __init__(me, key, path): |
369 | me.key = key | |
370 | me.path = path | |
371 | def __str__(me): | |
372 | return "Found a cycle %s looking up key `%s'" % \ | |
373 | (_fmt_path(me.path), me.key) | |
374 | ||
1c4623dd | 375 | class MissingSectionException (ExpectedError): |
e3ec3a3a | 376 | def __init__(me, sec): |
260dce8e | 377 | me.sec = sec |
e3ec3a3a MW |
378 | def __str__(me): |
379 | return "Section `%s' not found" % (me.sec) | |
380 | ||
1c4623dd | 381 | class MissingKeyException (ExpectedError): |
bd3db76c MW |
382 | def __init__(me, sec, key): |
383 | me.sec = sec | |
384 | me.key = key | |
385 | def __str__(me): | |
386 | return "Key `%s' not found in section `%s'" % (me.key, me.sec) | |
387 | ||
e3ec3a3a MW |
388 | class ConfigSection (object): |
389 | """ | |
390 | A section in a configuration parser. | |
391 | ||
392 | This is where a lot of the nitty-gritty stuff actually happens. The | |
393 | `MyConfigParser' knows a lot about the internals of this class, which saves | |
394 | on building a complicated interface. | |
395 | """ | |
396 | ||
397 | def __init__(me, name, cp): | |
398 | """Initialize a new, empty section with a given NAME and parent CP.""" | |
886350e8 MW |
399 | |
400 | ## The cache maps item keys to entries, which consist of a pair of | |
401 | ## objects. There are four possible states for a cache entry: | |
402 | ## | |
403 | ## * missing -- there is no entry at all with this key, so we must | |
404 | ## search for it; | |
405 | ## | |
406 | ## * None, None -- we are actively trying to resolve this key, so if we | |
407 | ## encounter this state, we have found a cycle in the inheritance | |
408 | ## graph; | |
409 | ## | |
410 | ## * None, [] -- we know that this key isn't reachable through any of | |
411 | ## our parents; | |
412 | ## | |
413 | ## * VALUE, PATH -- we know that the key resolves to VALUE, along the | |
414 | ## PATH from us (exclusive) to the defining parent (inclusive). | |
e3ec3a3a MW |
415 | me.name = name |
416 | me._itemmap = dict() | |
886350e8 | 417 | me._cache = dict() |
e3ec3a3a MW |
418 | me._cp = cp |
419 | ||
420 | def _expand(me, string, resolvep): | |
421 | """ | |
ef7d7afb | 422 | Expands $(...) and (optionally) $FLAGS[...] placeholders in STRING. |
e3ec3a3a MW |
423 | |
424 | RESOLVEP is a boolean switch: do we bother to tax the resolver or not? | |
425 | This is turned off by MyConfigParser's resolve() method while it's | |
426 | collecting hostnames to be resolved. | |
427 | """ | |
ef7d7afb | 428 | string = RX_REF.sub(lambda m: me.get(m.group(1), resolvep), string) |
e3ec3a3a | 429 | if resolvep: |
ef7d7afb MW |
430 | string = RX_RESOLVE.sub( |
431 | lambda m: ' '.join(me._cp._resolver.lookup(m.group(2), m.group(1))), | |
432 | string) | |
e3ec3a3a MW |
433 | return string |
434 | ||
4251f8ad MW |
435 | def _parents(me): |
436 | """Yield this section's parents.""" | |
437 | try: names = me._itemmap['@inherit'] | |
438 | except KeyError: return | |
439 | for name in names.replace(',', ' ').split(): | |
440 | yield me._cp.section(name) | |
441 | ||
886350e8 | 442 | def _get(me, key, path = None): |
e3ec3a3a MW |
443 | """ |
444 | Low-level option-fetching method. | |
445 | ||
446 | Fetch the value for the named KEY in this section, or maybe (recursively) | |
447 | a section which it inherits from. | |
448 | ||
449 | Returns a pair VALUE, PATH. The value is not expanded; nor do we check | |
450 | for the special `name' key. The caller is expected to do these things. | |
451 | Returns None if no value could be found. | |
452 | """ | |
453 | ||
886350e8 | 454 | ## If we weren't given a path, then we'd better make one. |
e3ec3a3a MW |
455 | if path is None: path = [] |
456 | ||
457 | ## Extend the path to cover us, but remember to remove us again when | |
458 | ## we've finished. If we need to pass the current path back upwards, | |
459 | ## then remember to take a copy. | |
460 | path.append(me.name) | |
461 | try: | |
462 | ||
f82066a0 MW |
463 | ## If we've been this way before on another pass through then return |
464 | ## the value we found then. If we're still thinking about it then | |
465 | ## we've found a cycle. | |
886350e8 | 466 | try: v, p = me._cache[key] |
e3ec3a3a MW |
467 | except KeyError: pass |
468 | else: | |
886350e8 MW |
469 | if p is None: raise InheritanceCycleError(key, path[:]) |
470 | else: return v, path + p | |
e3ec3a3a MW |
471 | |
472 | ## See whether the answer is ready waiting for us. | |
473 | try: v = me._itemmap[key] | |
474 | except KeyError: pass | |
886350e8 MW |
475 | else: |
476 | p = path[:] | |
477 | me._cache[key] = v, [] | |
478 | return v, p | |
e3ec3a3a | 479 | |
e3ec3a3a MW |
480 | ## Initially we have no idea. |
481 | value = None | |
886350e8 | 482 | winner = [] |
e3ec3a3a MW |
483 | |
484 | ## Go through our parents and ask them what they think. | |
886350e8 | 485 | me._cache[key] = None, None |
4251f8ad | 486 | for p in me._parents(): |
e3ec3a3a MW |
487 | |
488 | ## See whether we get an answer. If not, keep on going. | |
886350e8 | 489 | v, pp = p._get(key, path) |
e3ec3a3a MW |
490 | if v is None: continue |
491 | ||
492 | ## If we got an answer, check that it matches any previous ones. | |
493 | if value is None: | |
494 | value = v | |
495 | winner = pp | |
496 | elif value != v: | |
497 | raise AmbiguousOptionError(key, winner, value, pp, v) | |
498 | ||
499 | ## That's the best we could manage. | |
886350e8 | 500 | me._cache[key] = value, winner[len(path):] |
e3ec3a3a MW |
501 | return value, winner |
502 | ||
503 | finally: | |
504 | ## Remove us from the path again. | |
505 | path.pop() | |
506 | ||
507 | def get(me, key, resolvep = True): | |
508 | """ | |
509 | Retrieve the value of KEY from this section. | |
510 | """ | |
511 | ||
512 | ## Special handling for the `name' key. | |
513 | if key == 'name': | |
514 | value = me._itemmap.get('name', me.name) | |
7dd9d51f MW |
515 | elif key == '@inherits': |
516 | try: return me._itemmap['@inherits'] | |
517 | except KeyError: raise MissingKeyException(me.name, key) | |
e3ec3a3a MW |
518 | else: |
519 | value, _ = me._get(key) | |
520 | if value is None: | |
521 | raise MissingKeyException(me.name, key) | |
522 | ||
523 | ## Expand the value and return it. | |
524 | return me._expand(value, resolvep) | |
525 | ||
526 | def items(me, resolvep = True): | |
527 | """ | |
85341d9c | 528 | Yield a list of item names in the section. |
e3ec3a3a MW |
529 | """ |
530 | ||
531 | ## Initialize for a depth-first walk of the inheritance graph. | |
4063c2b5 | 532 | seen = { 'name': True } |
f417591a | 533 | visiting = { me.name: True } |
4251f8ad | 534 | stack = [me] |
e3ec3a3a MW |
535 | |
536 | ## Visit nodes, collecting their keys. Don't believe the values: | |
537 | ## resolving inheritance is too hard to do like this. | |
538 | while stack: | |
4251f8ad | 539 | sec = stack.pop() |
f417591a MW |
540 | for p in sec._parents(): |
541 | if p.name not in visiting: | |
542 | stack.append(p); visiting[p.name] = True | |
e3ec3a3a | 543 | |
7dd9d51f | 544 | for key in sec._itemmap.iterkeys(): seen[key] = None |
e3ec3a3a | 545 | |
e3ec3a3a | 546 | ## And we're done. |
6e5794ef | 547 | return seen.iterkeys() |
e3ec3a3a | 548 | |
b7e5aa06 | 549 | class MyConfigParser (object): |
6005ef9b MW |
550 | """ |
551 | A more advanced configuration parser. | |
552 | ||
b7e5aa06 | 553 | This has four major enhancements over the standard ConfigParser which are |
6005ef9b MW |
554 | relevant to us. |
555 | ||
556 | * It recognizes `@inherits' keys and follows them when expanding a | |
557 | value. | |
558 | ||
559 | * It recognizes `$(VAR)' references to configuration variables during | |
560 | expansion and processes them correctly. | |
561 | ||
ef7d7afb | 562 | * It recognizes `$FLAGS[HOST]' name-resolver requests and handles them |
97567475 MW |
563 | correctly. FLAGS consists of characters `4' (IPv4 addresses), `6' |
564 | (IPv6 addresses), and `*' (all, space-separated, rather than just the | |
565 | first). | |
6005ef9b | 566 | |
b7e5aa06 MW |
567 | * Its parsing behaviour is well-defined. |
568 | ||
6005ef9b MW |
569 | Use: |
570 | ||
b7e5aa06 | 571 | 1. Call parse(FILENAME) to slurp in the configuration data. |
6005ef9b MW |
572 | |
573 | 2. Call resolve() to collect the hostnames which need to be resolved and | |
574 | actually do the name resolution. | |
575 | ||
e3ec3a3a MW |
576 | 3. Call sections() to get a list of the configuration sections, or |
577 | section(NAME) to find a named section. | |
578 | ||
579 | 4. Call get(ITEM) on a section to collect the results, or items() to | |
6005ef9b MW |
580 | iterate over them. |
581 | """ | |
582 | ||
583 | def __init__(me): | |
584 | """ | |
585 | Initialize a new, empty configuration parser. | |
586 | """ | |
b7e5aa06 | 587 | me._sectmap = dict() |
6005ef9b MW |
588 | me._resolver = BulkResolver() |
589 | ||
b7e5aa06 MW |
590 | def parse(me, f): |
591 | """ | |
592 | Parse configuration from a file F. | |
593 | """ | |
594 | ||
595 | ## Initial parser state. | |
596 | sect = None | |
597 | key = None | |
598 | val = None | |
599 | lno = 0 | |
600 | ||
601 | ## An unpleasant hack. Python makes it hard to capture a value in a | |
602 | ## variable and examine it in a single action, and this is the best that | |
603 | ## I came up with. | |
604 | m = [None] | |
605 | def match(rx): m[0] = rx.match(line); return m[0] | |
606 | ||
607 | ## Commit a key's value when we've determined that there are no further | |
608 | ## continuation lines. | |
609 | def flush(): | |
e3ec3a3a | 610 | if key is not None: sect._itemmap[key] = val.getvalue() |
b7e5aa06 MW |
611 | |
612 | ## Work through all of the input lines. | |
613 | for line in f: | |
614 | lno += 1 | |
615 | ||
616 | if match(RX_COMMENT): | |
617 | ## A comment or a blank line. Nothing doing. (This means that we | |
618 | ## leave out blank lines which look like they might be continuation | |
619 | ## lines.) | |
620 | ||
621 | pass | |
622 | ||
623 | elif match(RX_GRPHDR): | |
624 | ## A section header. Flush out any previous value and set up the new | |
625 | ## group. | |
626 | ||
627 | flush() | |
628 | name = m[0].group(1) | |
629 | try: sect = me._sectmap[name] | |
e3ec3a3a | 630 | except KeyError: sect = me._sectmap[name] = ConfigSection(name, me) |
b7e5aa06 MW |
631 | key = None |
632 | ||
633 | elif match(RX_ASSGN): | |
634 | ## A new assignment. Flush out the old one, and set up to store this | |
635 | ## one. | |
636 | ||
637 | if sect is None: | |
638 | raise ConfigSyntaxError(f.name, lno, 'no active section to update') | |
639 | flush() | |
640 | key = m[0].group(1) | |
641 | val = StringIO(); val.write(m[0].group(2)) | |
642 | ||
643 | elif match(RX_CONT): | |
644 | ## A continuation line. Accumulate the value. | |
645 | ||
646 | if key is None: | |
647 | raise ConfigSyntaxError(f.name, lno, 'no config value to continue') | |
648 | val.write('\n'); val.write(m[0].group(1)) | |
649 | ||
650 | else: | |
651 | ## Something else. | |
652 | ||
653 | raise ConfigSyntaxError(f.name, lno, 'incomprehensible line') | |
654 | ||
655 | ## Don't forget to commit any final value material. | |
656 | flush() | |
657 | ||
e3ec3a3a MW |
658 | def section(me, name): |
659 | """Return a ConfigSection with the given NAME.""" | |
660 | try: return me._sectmap[name] | |
661 | except KeyError: raise MissingSectionException(name) | |
662 | ||
b7e5aa06 | 663 | def sections(me): |
e3ec3a3a MW |
664 | """Yield the known sections.""" |
665 | return me._sectmap.itervalues() | |
b7e5aa06 | 666 | |
6005ef9b MW |
667 | def resolve(me): |
668 | """ | |
669 | Works out all of the hostnames which need resolving and resolves them. | |
670 | ||
671 | Until you call this, attempts to fetch configuration items which need to | |
672 | resolve hostnames will fail! | |
673 | """ | |
e3ec3a3a | 674 | for sec in me.sections(): |
85341d9c MW |
675 | for key in sec.items(): |
676 | value = sec.get(key, resolvep = False) | |
2d51bc9f | 677 | for match in RX_RESOLVE.finditer(value): |
ef7d7afb | 678 | me._resolver.prepare(match.group(2)) |
6005ef9b MW |
679 | me._resolver.run() |
680 | ||
6005ef9b MW |
681 | ###-------------------------------------------------------------------------- |
682 | ### Command-line handling. | |
683 | ||
684 | def inputiter(things): | |
685 | """ | |
686 | Iterate over command-line arguments, returning corresponding open files. | |
687 | ||
688 | If none were given, or one is `-', assume standard input; if one is a | |
689 | directory, scan it for files other than backups; otherwise return the | |
690 | opened files. | |
691 | """ | |
692 | ||
693 | if not things: | |
694 | if OS.isatty(stdin.fileno()): | |
695 | M.die('no input given, and stdin is a terminal') | |
696 | yield stdin | |
697 | else: | |
698 | for thing in things: | |
699 | if thing == '-': | |
700 | yield stdin | |
701 | elif OS.path.isdir(thing): | |
702 | for item in OS.listdir(thing): | |
703 | if item.endswith('~') or item.endswith('#'): | |
704 | continue | |
705 | name = OS.path.join(thing, item) | |
706 | if not OS.path.isfile(name): | |
707 | continue | |
708 | yield file(name) | |
709 | else: | |
710 | yield file(thing) | |
711 | ||
712 | def parse_options(argv = argv): | |
713 | """ | |
714 | Parse command-line options, returning a pair (OPTS, ARGS). | |
715 | """ | |
716 | M.ego(argv[0]) | |
717 | op = OptionParser(usage = '%prog [-c CDB] INPUT...', | |
718 | version = '%%prog (tripe, version %s)' % VERSION) | |
719 | op.add_option('-c', '--cdb', metavar = 'CDB', | |
720 | dest = 'cdbfile', default = None, | |
721 | help = 'Compile output into a CDB file.') | |
722 | opts, args = op.parse_args(argv) | |
723 | return opts, args | |
724 | ||
725 | ###-------------------------------------------------------------------------- | |
726 | ### Main code. | |
727 | ||
728 | def getconf(args): | |
729 | """ | |
730 | Read the configuration files and return the accumulated result. | |
731 | ||
732 | We make sure that all hostnames have been properly resolved. | |
733 | """ | |
734 | conf = MyConfigParser() | |
735 | for f in inputiter(args): | |
b7e5aa06 | 736 | conf.parse(f) |
6005ef9b MW |
737 | conf.resolve() |
738 | return conf | |
739 | ||
740 | def output(conf, cdb): | |
741 | """ | |
742 | Output the configuration information CONF to the database CDB. | |
743 | ||
744 | This is where the special `user' and `auto' database entries get set. | |
745 | """ | |
746 | auto = [] | |
e3ec3a3a MW |
747 | for sec in sorted(conf.sections(), key = lambda sec: sec.name): |
748 | if sec.name.startswith('@'): | |
6005ef9b | 749 | continue |
e3ec3a3a MW |
750 | elif sec.name.startswith('$'): |
751 | label = sec.name | |
6005ef9b | 752 | else: |
e3ec3a3a | 753 | label = 'P%s' % sec.name |
fd1ba90c MW |
754 | try: a = sec.get('auto') |
755 | except MissingKeyException: pass | |
756 | else: | |
757 | if a in ('y', 'yes', 't', 'true', '1', 'on'): auto.append(sec.name) | |
758 | try: u = sec.get('user') | |
759 | except MissingKeyException: pass | |
7af8eef8 | 760 | else: cdb.add('U%s' % u, sec.name) |
6090fc43 | 761 | url = M.URLEncode(semip = True) |
85341d9c | 762 | for key in sorted(sec.items()): |
6005ef9b | 763 | if not key.startswith('@'): |
6090fc43 | 764 | url.encode(key, sec.get(key)) |
6005ef9b MW |
765 | cdb.add(label, url.result) |
766 | cdb.add('%AUTO', ' '.join(auto)) | |
767 | cdb.finish() | |
768 | ||
769 | def main(): | |
770 | """Main program.""" | |
771 | opts, args = parse_options() | |
772 | if opts.cdbfile: | |
773 | cdb = CDB.cdbmake(opts.cdbfile, opts.cdbfile + '.new') | |
774 | else: | |
775 | cdb = CDBFake() | |
1c4623dd MW |
776 | try: |
777 | conf = getconf(args[1:]) | |
778 | output(conf, cdb) | |
779 | except ExpectedError, e: | |
780 | M.moan(str(e)) | |
781 | exit(2) | |
6005ef9b MW |
782 | |
783 | if __name__ == '__main__': | |
784 | main() | |
785 | ||
786 | ###----- That's all, folks -------------------------------------------------- |