from __future__ import nested_scopes
import os
import copy
import operator
import time
from twisted.protocols import dns
from twisted.internet import defer
from twisted.python import failure
import common
def getSerial(filename = '/tmp/twisted-names.serial'):
"""Return a monotonically increasing (across program runs) integer.
State is stored in the given file. If it does not exist, it is
created with rw-/---/--- permissions.
"""
serial = time.strftime('%Y%m%d')
o = os.umask(0177)
try:
if not os.path.exists(filename):
f = file(filename, 'w')
f.write(serial + ' 0')
f.close()
finally:
os.umask(o)
serialFile = file(filename, 'r')
lastSerial, ID = serialFile.readline().split()
ID = (lastSerial == serial) and (int(ID) + 1) or 0
serialFile.close()
serialFile = file(filename, 'w')
serialFile.write('%s %d' % (serial, ID))
serialFile.close()
serial = serial + ('%02d' % (ID,))
return serial
class FileAuthority(common.ResolverBase):
"""An Authority that is loaded from a file."""
soa = None
records = None
def __init__(self, filename):
common.ResolverBase.__init__(self)
self.loadFile(filename)
self._cache = {}
def __setstate__(self, state):
self.__dict__ = state
def _lookup(self, name, cls, type, timeout = None):
cnames = []
results = []
authority = []
additional = []
default_ttl = max(self.soa[1].minimum, self.soa[1].expire)
try:
for record in self.records[name.lower()]:
if record.ttl is not None:
ttl = record.ttl
else:
ttl = default_ttl
if record.TYPE == type or type == dns.ALL_RECORDS:
results.append(
dns.RRHeader(name, record.TYPE, dns.IN, ttl, record, auth=True)
)
elif record.TYPE == dns.NS and type != dns.ALL_RECORDS:
authority.append(
dns.RRHeader(name, record.TYPE, dns.IN, ttl, record, auth=True)
)
if record.TYPE == dns.CNAME:
cnames.append(
dns.RRHeader(name, record.TYPE, dns.IN, ttl, record, auth=True)
)
if not results:
results = cnames
for record in results + authority:
if record.type == dns.NS or record.type == dns.CNAME:
n = str(record.payload.name)
for rec in self.records.get(n.lower(), ()):
if rec.TYPE == dns.A:
additional.append(
dns.RRHeader(n, dns.A, dns.IN, rec.ttl or default_ttl, rec, auth=True)
)
return defer.succeed((results, authority, additional))
except KeyError:
if name.lower().endswith(self.soa[0].lower()):
return defer.fail(failure.Failure(dns.AuthoritativeDomainError(name)))
return defer.fail(failure.Failure(dns.DomainError(name)))
def lookupZone(self, name, timeout = 10):
if self.soa[0].lower() == name.lower():
default_ttl = max(self.soa[1].minimum, self.soa[1].expire)
if self.soa[1].ttl is not None:
soa_ttl = self.soa[1].ttl
else:
soa_ttl = default_ttl
results = [dns.RRHeader(self.soa[0], dns.SOA, dns.IN, soa_ttl, self.soa[1], auth=True)]
for (k, r) in self.records.items():
for rec in r:
if rec.ttl is not None:
ttl = rec.ttl
else:
ttl = default_ttl
if rec.TYPE != dns.SOA:
results.append(dns.RRHeader(k, rec.TYPE, dns.IN, ttl, rec, auth=True))
results.append(results[0])
return defer.succeed((results, (), ()))
return defer.fail(failure.Failure(dns.DomainError(name)))
def _cbAllRecords(self, results):
ans, auth, add = [], [], []
for res in results:
if res[0]:
ans.extend(res[1][0])
auth.extend(res[1][1])
add.extend(res[1][2])
return ans, auth, add
class PySourceAuthority(FileAuthority):
"""A FileAuthority that is built up from Python source code."""
def loadFile(self, filename):
g, l = self.setupConfigNamespace(), {}
execfile(filename, g, l)
if not l.has_key('zone'):
raise ValueError, "No zone defined in " + filename
self.records = {}
for rr in l['zone']:
if isinstance(rr[1], dns.Record_SOA):
self.soa = rr
self.records.setdefault(rr[0].lower(), []).append(rr[1])
def wrapRecord(self, type):
return lambda name, *arg, **kw: (name, type(*arg, **kw))
def setupConfigNamespace(self):
r = {}
items = dns.__dict__.iterkeys()
for record in [x for x in items if x.startswith('Record_')]:
type = getattr(dns, record)
f = self.wrapRecord(type)
r[record[len('Record_'):]] = f
return r
class BindAuthority(FileAuthority):
"""An Authority that loads BIND configuration files"""
def loadFile(self, filename):
self.origin = os.path.basename(filename) + '.' lines = open(filename).readlines()
lines = self.stripComments(lines)
lines = self.collapseContinuations(lines)
self.parseLines(lines)
def stripComments(self, lines):
return [
a.find(';') == -1 and a or a[:a.find(';')] for a in [
b.strip() for b in lines
]
]
def collapseContinuations(self, lines):
L = []
state = 0
for line in lines:
if state == 0:
if line.find('(') == -1:
L.append(line)
else:
L.append(line[:line.find('(')])
state = 1
else:
if line.find(')') != -1:
L[-1] += ' ' + line[:line.find(')')]
state = 0
else:
L[-1] += ' ' + line
lines = L
L = []
for line in lines:
L.append(line.split())
return filter(None, L)
def parseLines(self, lines):
TTL = 60 * 60 * 3
ORIGIN = self.origin
self.records = {}
for (line, index) in zip(lines, range(len(lines))):
if line[0] == '$TTL':
TTL = dns.str2time(line[1])
elif line[0] == '$ORIGIN':
ORIGIN = line[1]
elif line[0] == '$INCLUDE': raise NotImplementedError('$INCLUDE directive not implemented')
elif line[0] == '$GENERATE':
raise NotImplementedError('$GENERATE directive not implemented')
else:
self.parseRecordLine(ORIGIN, TTL, line)
def addRecord(self, owner, ttl, type, domain, cls, rdata):
if not domain.endswith('.'):
domain = domain + '.' + owner
else:
domain = domain[:-1]
f = getattr(self, 'class_%s' % cls, None)
if f:
f(ttl, type, domain, rdata)
else:
raise NotImplementedError, "Record class %r not supported" % cls
def class_IN(self, ttl, type, domain, rdata):
record = getattr(dns, 'Record_%s' % type, None)
if record:
r = record(*rdata)
r.ttl = ttl
self.records.setdefault(domain.lower(), []).append(r)
print 'Adding IN Record', domain, ttl, r
if type == 'SOA':
self.soa = (domain, r)
else:
raise NotImplementedError, "Record type %r not supported" % type
def parseRecordLine(self, origin, ttl, line):
MARKERS = dns.QUERY_CLASSES.values() + dns.QUERY_TYPES.values()
cls = 'IN'
owner = origin
if line[0] == '@':
line = line[1:]
owner = origin
elif not line[0].isdigit() and line[0] not in MARKERS:
owner = line[0]
line = line[1:]
if line[0].isdigit() or line[0] in MARKERS:
domain = owner
owner = origin
else:
domain = line[0]
line = line[1:]
if line[0] in dns.QUERY_CLASSES.values():
cls = line[0]
line = line[1:]
if line[0].isdigit():
ttl = int(line[0])
line = line[1:]
elif line[0].isdigit():
ttl = int(line[0])
line = line[1:]
if line[0] in dns.QUERY_CLASSES.values():
cls = line[0]
line = line[1:]
type = line[0]
rdata = line[1:]
self.addRecord(owner, ttl, type, domain, cls, rdata)