X-Git-Url: https://git.distorted.org.uk/~mdw/tripe/blobdiff_plain/6005ef9bfba49124a25825a5b044d4f4cbf02792..6f48da4ac71b5944d0464dd940ced3baf0d4311b:/peerdb/tripe-newpeers.in diff --git a/peerdb/tripe-newpeers.in b/peerdb/tripe-newpeers.in index d7205845..0ba9cb61 100644 --- a/peerdb/tripe-newpeers.in +++ b/peerdb/tripe-newpeers.in @@ -10,32 +10,31 @@ ### ### This file is part of Trivial IP Encryption (TrIPE). ### -### TrIPE 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 2 of the License, or -### (at your option) any later version. +### TrIPE 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. ### -### TrIPE 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. +### TrIPE 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 TrIPE; if not, write to the Free Software Foundation, -### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. +### along with TrIPE. If not, see . VERSION = '@VERSION@' ###-------------------------------------------------------------------------- ### External dependencies. -import ConfigParser as CP import mLib as M from optparse import OptionParser import cdb as CDB from sys import stdin, stdout, exit, argv import re as RX import os as OS +from cStringIO import StringIO ###-------------------------------------------------------------------------- ### Utilities. @@ -52,6 +51,13 @@ class CDBFake (object): ###-------------------------------------------------------------------------- ### A bulk DNS resolver. +class ResolverFailure (Exception): + def __init__(me, host, msg): + me.host = host + me.msg = msg + def __str__(me): + return "failed to resolve `%s': %s" % (me.host, me.msg) + class BulkResolver (object): """ Resolve a number of DNS names in parallel. @@ -75,11 +81,12 @@ class BulkResolver (object): def prepare(me, host): """Prime the resolver to resolve the name HOST.""" - me._resolvers[host] = M.SelResolveByName \ - (host, - lambda name, alias, addr: - me._resolved(host, addr[0]), - lambda: me._resolved(host, None)) + if host not in me._resolvers: + me._resolvers[host] = M.SelResolveByName \ + (host, + lambda name, alias, addr: + me._resolved(host, addr[0]), + lambda: me._resolved(host, None)) def run(me): """Run the background DNS resolver until it's finished.""" @@ -92,7 +99,7 @@ class BulkResolver (object): """ addr = me._namemap[host] if addr is None: - raise KeyError, host + raise ResolverFailure(host, '(unknown failure)') return addr def _resolved(me, host, addr): @@ -103,17 +110,238 @@ class BulkResolver (object): ###-------------------------------------------------------------------------- ### The configuration parser. +## Match a comment or empty line. +RX_COMMENT = RX.compile(r'(?x) ^ \s* (?: $ | [;#])') + +## Match a section group header. +RX_GRPHDR = RX.compile(r'(?x) ^ \s* \[ (.*) \] \s* $') + +## Match an assignment line. +RX_ASSGN = RX.compile(r'''(?x) ^ + ([^\s:=] (?: [^:=]* [^\s:=])?) + \s* [:=] \s* + (| \S | \S.*\S) + \s* $''') + +## Match a continuation line. +RX_CONT = RX.compile(r'''(?x) ^ \s+ + (| \S | \S.*\S) + \s* $''') + ## Match a $(VAR) configuration variable reference; group 1 is the VAR. -r_ref = RX.compile(r'\$\(([^)]+)\)') +RX_REF = RX.compile(r'(?x) \$ \( ([^)]+) \)') ## Match a $[HOST] name resolution reference; group 1 is the HOST. -r_resolve = RX.compile(r'\$\[([^]]+)\]') +RX_RESOLVE = RX.compile(r'(?x) \$ \[ ([^]]+) \]') + +class ConfigSyntaxError (Exception): + def __init__(me, fname, lno, msg): + me.fname = fname + me.lno = lno + me.msg = msg + def __str__(me): + return '%s:%d: %s' % (me.fname, me.lno, me.msg) + +def _fmt_path(path): + return ' -> '.join(["`%s'" % hop for hop in path]) + +class AmbiguousOptionError (Exception): + def __init__(me, key, patha, vala, pathb, valb): + me.key = key + me.patha, me.vala = patha, vala + me.pathb, me.valb = pathb, valb + def __str__(me): + return "Ambiguous answer resolving key `%s': " \ + "path %s yields `%s' but %s yields `%s'" % \ + (me.key, _fmt_path(me.patha), me.vala, _fmt_path(me.pathb), me.valb) + +class InheritanceCycleError (Exception): + def __init__(me, key, path): + me.key = key + me.path = path + def __str__(me): + return "Found a cycle %s looking up key `%s'" % \ + (_fmt_path(me.path), me.key) + +class MissingSectionException (Exception): + def __init__(me, sec): + me.key = key + def __str__(me): + return "Section `%s' not found" % (me.sec) + +class MissingKeyException (Exception): + def __init__(me, sec, key): + me.sec = sec + me.key = key + def __str__(me): + return "Key `%s' not found in section `%s'" % (me.key, me.sec) + +class ConfigSection (object): + """ + A section in a configuration parser. + + This is where a lot of the nitty-gritty stuff actually happens. The + `MyConfigParser' knows a lot about the internals of this class, which saves + on building a complicated interface. + """ + + def __init__(me, name, cp): + """Initialize a new, empty section with a given NAME and parent CP.""" + + ## The cache maps item keys to entries, which consist of a pair of + ## objects. There are four possible states for a cache entry: + ## + ## * missing -- there is no entry at all with this key, so we must + ## search for it; + ## + ## * None, None -- we are actively trying to resolve this key, so if we + ## encounter this state, we have found a cycle in the inheritance + ## graph; + ## + ## * None, [] -- we know that this key isn't reachable through any of + ## our parents; + ## + ## * VALUE, PATH -- we know that the key resolves to VALUE, along the + ## PATH from us (exclusive) to the defining parent (inclusive). + me.name = name + me._itemmap = dict() + me._cache = dict() + me._cp = cp + + def _expand(me, string, resolvep): + """ + Expands $(...) and (optionally) $[...] placeholders in STRING. + + RESOLVEP is a boolean switch: do we bother to tax the resolver or not? + This is turned off by MyConfigParser's resolve() method while it's + collecting hostnames to be resolved. + """ + string = RX_REF.sub \ + (lambda m: me.get(m.group(1), resolvep), string) + if resolvep: + string = RX_RESOLVE.sub(lambda m: me._cp._resolver.lookup(m.group(1)), + string) + return string + + def _parents(me): + """Yield this section's parents.""" + try: names = me._itemmap['@inherit'] + except KeyError: return + for name in names.replace(',', ' ').split(): + yield me._cp.section(name) + + def _get(me, key, path = None): + """ + Low-level option-fetching method. + + Fetch the value for the named KEY in this section, or maybe (recursively) + a section which it inherits from. + + Returns a pair VALUE, PATH. The value is not expanded; nor do we check + for the special `name' key. The caller is expected to do these things. + Returns None if no value could be found. + """ + + ## If we weren't given a path, then we'd better make one. + if path is None: path = [] + + ## Extend the path to cover us, but remember to remove us again when + ## we've finished. If we need to pass the current path back upwards, + ## then remember to take a copy. + path.append(me.name) + try: + + ## If we've been this way before on another pass through then return the + ## value we found then. If we're still thinking about it then we've + ## found a cycle. + try: v, p = me._cache[key] + except KeyError: pass + else: + if p is None: raise InheritanceCycleError(key, path[:]) + else: return v, path + p + + ## See whether the answer is ready waiting for us. + try: v = me._itemmap[key] + except KeyError: pass + else: + p = path[:] + me._cache[key] = v, [] + return v, p + + ## Initially we have no idea. + value = None + winner = [] + + ## Go through our parents and ask them what they think. + me._cache[key] = None, None + for p in me._parents(): + + ## See whether we get an answer. If not, keep on going. + v, pp = p._get(key, path) + if v is None: continue + + ## If we got an answer, check that it matches any previous ones. + if value is None: + value = v + winner = pp + elif value != v: + raise AmbiguousOptionError(key, winner, value, pp, v) + + ## That's the best we could manage. + me._cache[key] = value, winner[len(path):] + return value, winner + + finally: + ## Remove us from the path again. + path.pop() + + def get(me, key, resolvep = True): + """ + Retrieve the value of KEY from this section. + """ + + ## Special handling for the `name' key. + if key == 'name': + value = me._itemmap.get('name', me.name) + elif key == '@inherits': + try: return me._itemmap['@inherits'] + except KeyError: raise MissingKeyException(me.name, key) + else: + value, _ = me._get(key) + if value is None: + raise MissingKeyException(me.name, key) + + ## Expand the value and return it. + return me._expand(value, resolvep) + + def items(me, resolvep = True): + """ + Yield a list of item names in the section. + """ + + ## Initialize for a depth-first walk of the inheritance graph. + seen = { 'name': True } + visiting = { me.name: True } + stack = [me] + + ## Visit nodes, collecting their keys. Don't believe the values: + ## resolving inheritance is too hard to do like this. + while stack: + sec = stack.pop() + for p in sec._parents(): + if p.name not in visiting: + stack.append(p); visiting[p.name] = True -class MyConfigParser (CP.RawConfigParser): + for key in sec._itemmap.iterkeys(): seen[key] = None + + ## And we're done. + return seen.iterkeys() + +class MyConfigParser (object): """ A more advanced configuration parser. - This has two major enhancements over the standard ConfigParser which are + This has four major enhancements over the standard ConfigParser which are relevant to us. * It recognizes `@inherits' keys and follows them when expanding a @@ -125,15 +353,19 @@ class MyConfigParser (CP.RawConfigParser): * It recognizes `$[HOST]' name-resolver requests and handles them correctly. + * Its parsing behaviour is well-defined. + Use: - 1. Call read(FILENAME) and/or read(FP, [FILENAME]) to slurp in the - configuration data. + 1. Call parse(FILENAME) to slurp in the configuration data. 2. Call resolve() to collect the hostnames which need to be resolved and actually do the name resolution. - 3. Call get(SECTION, ITEM) to collect the results, or items(SECTION) to + 3. Call sections() to get a list of the configuration sections, or + section(NAME) to find a named section. + + 4. Call get(ITEM) on a section to collect the results, or items() to iterate over them. """ @@ -141,100 +373,99 @@ class MyConfigParser (CP.RawConfigParser): """ Initialize a new, empty configuration parser. """ - CP.RawConfigParser.__init__(me) + me._sectmap = dict() me._resolver = BulkResolver() - def resolve(me): - """ - Works out all of the hostnames which need resolving and resolves them. - - Until you call this, attempts to fetch configuration items which need to - resolve hostnames will fail! - """ - for sec in me.sections(): - for key, value in me.items(sec, resolvep = False): - for match in r_resolve.finditer(value): - me._resolver.prepare(match.group(1)) - me._resolver.run() - - def _expand(me, sec, string, resolvep): + def parse(me, f): """ - Expands $(...) and (optionally) $[...] placeholders in STRING. - - The SEC is the configuration section from which to satisfy $(...) - requests. RESOLVEP is a boolean switch: do we bother to tax the resolver - or not? This is turned off by the resolve() method while it's collecting - hostnames to be resolved. + Parse configuration from a file F. """ - string = r_ref.sub \ - (lambda m: me.get(sec, m.group(1), resolvep), string) - if resolvep: - string = r_resolve.sub(lambda m: me._resolver.lookup(m.group(1)), - string) - return string - def has_option(me, sec, key): - """ - Decide whether section SEC has a configuration key KEY. + ## Initial parser state. + sect = None + key = None + val = None + lno = 0 + + ## An unpleasant hack. Python makes it hard to capture a value in a + ## variable and examine it in a single action, and this is the best that + ## I came up with. + m = [None] + def match(rx): m[0] = rx.match(line); return m[0] + + ## Commit a key's value when we've determined that there are no further + ## continuation lines. + def flush(): + if key is not None: sect._itemmap[key] = val.getvalue() + + ## Work through all of the input lines. + for line in f: + lno += 1 + + if match(RX_COMMENT): + ## A comment or a blank line. Nothing doing. (This means that we + ## leave out blank lines which look like they might be continuation + ## lines.) + + pass + + elif match(RX_GRPHDR): + ## A section header. Flush out any previous value and set up the new + ## group. + + flush() + name = m[0].group(1) + try: sect = me._sectmap[name] + except KeyError: sect = me._sectmap[name] = ConfigSection(name, me) + key = None + + elif match(RX_ASSGN): + ## A new assignment. Flush out the old one, and set up to store this + ## one. + + if sect is None: + raise ConfigSyntaxError(f.name, lno, 'no active section to update') + flush() + key = m[0].group(1) + val = StringIO(); val.write(m[0].group(2)) + + elif match(RX_CONT): + ## A continuation line. Accumulate the value. + + if key is None: + raise ConfigSyntaxError(f.name, lno, 'no config value to continue') + val.write('\n'); val.write(m[0].group(1)) - This version of the method properly handles the @inherit key. - """ - return CP.RawConfigParser.has_option(me, sec, key) or \ - (CP.RawConfigParser.has_option(me, sec, '@inherit') and - me.has_option(CP.RawConfigParser.get(me, sec, '@inherit'), key)) - - def _get(me, basesec, sec, key, resolvep): - """ - Low-level option-fetching method. + else: + ## Something else. - Fetch the value for the named KEY from section SEC, or maybe - (recursively) the section which SEC inherits from. + raise ConfigSyntaxError(f.name, lno, 'incomprehensible line') - The result is expanded, by _expend; RESOLVEP is passed to _expand to - control whether $[...] should be expanded in the result. + ## Don't forget to commit any final value material. + flush() - The BASESEC is the section for which the original request was made. This - will be different from SEC if we're recursing up the inheritance chain. + def section(me, name): + """Return a ConfigSection with the given NAME.""" + try: return me._sectmap[name] + except KeyError: raise MissingSectionException(name) - We also provide the default value for `name' here. - """ - try: - raw = CP.RawConfigParser.get(me, sec, key) - except CP.NoOptionError: - if key == 'name': - raw = basesec - elif CP.RawConfigParser.has_option(me, sec, '@inherit'): - raw = me._get(basesec, - CP.RawConfigParser.get(me, sec, '@inherit'), - key, - resolvep) - else: - raise - return me._expand(basesec, raw, resolvep) + def sections(me): + """Yield the known sections.""" + return me._sectmap.itervalues() - def get(me, sec, key, resolvep = True): - """ - Retrieve the value of KEY from section SEC. - """ - return me._get(sec, sec, key, resolvep) - - def items(me, sec, resolvep = True): + def resolve(me): """ - Return a list of (NAME, VALUE) items in section SEC. + Works out all of the hostnames which need resolving and resolves them. - This extends the default method by handling the inheritance chain. + Until you call this, attempts to fetch configuration items which need to + resolve hostnames will fail! """ - d = {} - basesec = sec - while sec: - next = None - for key, value in CP.RawConfigParser.items(me, sec): - if key == '@inherit': - next = value - elif not key.startswith('@') and key not in d: - d[key] = me._expand(basesec, value, resolvep) - sec = next - return d.items() + for sec in me.sections(): + for key in sec.items(): + value = sec.get(key, resolvep = False) + for match in RX_RESOLVE.finditer(value): + me._resolver.prepare(match.group(1)) + me._resolver.run() ###-------------------------------------------------------------------------- ### Command-line handling. @@ -291,7 +522,7 @@ def getconf(args): """ conf = MyConfigParser() for f in inputiter(args): - conf.readfp(f) + conf.parse(f) conf.resolve() return conf @@ -302,22 +533,24 @@ def output(conf, cdb): This is where the special `user' and `auto' database entries get set. """ auto = [] - for sec in conf.sections(): - if sec.startswith('@'): + for sec in sorted(conf.sections(), key = lambda sec: sec.name): + if sec.name.startswith('@'): continue - elif sec.startswith('$'): - label = sec + elif sec.name.startswith('$'): + label = sec.name else: - label = 'P%s' % sec - if conf.has_option(sec, 'auto') and \ - conf.get(sec, 'auto') in ('y', 'yes', 't', 'true', '1', 'on'): - auto.append(sec) - if conf.has_option(sec, 'user'): - cdb.add('U%s' % conf.get(sec, 'user'), sec) - url = M.URLEncode(laxp = True, semip = True) - for key, value in conf.items(sec): + label = 'P%s' % sec.name + try: a = sec.get('auto') + except MissingKeyException: pass + else: + if a in ('y', 'yes', 't', 'true', '1', 'on'): auto.append(sec.name) + try: u = sec.get('user') + except MissingKeyException: pass + else: cdb.add('U%s' % u) + url = M.URLEncode(semip = True) + for key in sorted(sec.items()): if not key.startswith('@'): - url.encode(key, ' '.join(M.split(value)[0])) + url.encode(key, sec.get(key)) cdb.add(label, url.result) cdb.add('%AUTO', ' '.join(auto)) cdb.finish()