class DnsServer(DatagramServer):
'''
Answers DNS queries against the registry, falling back to the recursive
resolver (if present).
'''
def __init__(self, bindaddr, registry, dns_servers=None):
DatagramServer.__init__(self, bindaddr)
self._registry = registry
self._resolver = None
if dns_servers:
self._resolver = Resolver(servers=dns_servers,
timeout=DNS_RESOLVER_TIMEOUT,
tries=1)
def handle(self, data, peer):
rec = DNSRecord.parse(data)
addr = None
if rec.q.qtype in (QTYPE.A, QTYPE.AAAA):
log.debug('Quering DNS')
addr = self._registry.resolve(rec.q.qname.idna())
if not addr:
strArr = []
for l in rec.q.qname.label:
strArr.append(str(l, 'utf-8'))
domainName = '.'.join(strArr)
addr = self._resolve(domainName)
log.debug('Sending request to %s', addr)
self.socket.sendto(self._reply(rec, addr), peer)
def _reply(self, rec, addrs=None):
reply = DNSRecord(DNSHeader(id=rec.header.id, qr=1, aa=1, ra=1),
q=rec.q)
if addrs:
if not isinstance(addrs, list):
addrs = [addrs]
for addr in addrs:
if addr:
reply.add_answer(RR(rec.q.qname, QTYPE.A, rdata=A(addr)))
return reply.pack()
def _resolve(self, name):
log.debug('resolve name=%s', name)
if not self._resolver:
return None
try:
return self._resolver.gethostbyname(name)
except socket.gaierror as e:
log.debug('Host by name could not be resolved')
msg = str(e)
if not contains(msg, 'ETIMEOUT', 'ENOTFOUND'):
print(msg)
class DnsServer(DatagramServer):
'''
Answers DNS queries against the registry, falling back to the recursive
resolver (if present).
'''
def __init__(self, bindaddr, registry, dns_servers=None):
DatagramServer.__init__(self, bindaddr)
self._registry = registry
self._resolver = None
if dns_servers:
self._resolver = Resolver(servers=dns_servers, timeout=DNS_RESOLVER_TIMEOUT, tries=1)
def handle(self, data, peer):
rec = DNSRecord.parse(data)
addr = None
if rec.q.qtype in (QTYPE.A, QTYPE.AAAA):
log.debug('Quering DNS')
addr = self._registry.resolve(rec.q.qname.idna())
if not addr:
strArr = []
for l in rec.q.qname.label:
strArr.append(str(l,'utf-8'))
domainName = '.'.join(strArr)
addr = self._resolve(domainName)
log.debug('Sending request to %s', addr)
self.socket.sendto(self._reply(rec, addr), peer)
def _reply(self, rec, addrs=None):
reply = DNSRecord(DNSHeader(id=rec.header.id, qr=1, aa=1, ra=1), q=rec.q)
if addrs:
if not isinstance(addrs, list):
addrs = [addrs]
for addr in addrs:
if addr:
reply.add_answer(RR(rec.q.qname, QTYPE.A, rdata=A(addr)))
return reply.pack()
def _resolve(self, name):
log.debug('resolve name=%s', name)
if not self._resolver:
return None
try:
return self._resolver.gethostbyname(name)
except socket.gaierror as e:
log.debug('Host by name could not be resolved')
msg = str(e)
if not contains(msg, 'ETIMEOUT', 'ENOTFOUND'):
print(msg)
class DnsServer(DatagramServer):
'''
Answers DNS queries against the registry, falling back to the recursive
resolver (if present).
'''
def __init__(self, bindaddr, registry, dns_servers=None):
DatagramServer.__init__(self, bindaddr)
self._registry = registry
self._resolver = None
if dns_servers:
self._resolver = Resolver(servers=dns_servers,
timeout=DNS_RESOLVER_TIMEOUT,
tries=1)
def handle(self, data, peer):
rec = DNSRecord.parse(data)
addr = None
if rec.q.qtype in (QTYPE.A, QTYPE.AAAA):
addr = self._registry.resolve(rec.q.qname.idna())
if not addr:
addr = self._resolve('.'.join(rec.q.qname.label))
self.socket.sendto(self._reply(rec, addr), peer)
def _reply(self, rec, addrs=None):
reply = DNSRecord(DNSHeader(id=rec.header.id, qr=1, aa=1, ra=1),
q=rec.q)
if addrs:
if not isinstance(addrs, list):
addrs = [addrs]
for addr in addrs:
if ":" in addr:
reply.add_answer(
RR(rec.q.qname, QTYPE.AAAA, rdata=AAAA(addr)))
else:
reply.add_answer(RR(rec.q.qname, QTYPE.A, rdata=A(addr)))
return reply.pack()
def _resolve(self, name):
if not self._resolver:
return None
try:
return self._resolver.gethostbyname(name)
except socket.gaierror, e:
msg = str(e)
if not contains(msg, 'ETIMEOUT', 'ENOTFOUND'):
print msg
class DnsServer(DatagramServer):
"""
Answers DNS queries against the name table, falling back to the recursive
resolver (if present).
"""
def __init__(self, bindaddr, table, dns_servers=None):
DatagramServer.__init__(self, bindaddr)
self._table = table
self._resolver = None
if dns_servers:
self._resolver = Resolver(servers=dns_servers, timeout=DNS_RESOLVER_TIMEOUT, tries=1)
def handle(self, data, peer):
rec = DNSRecord.parse(data)
addr = None
if rec.q.qtype in (QTYPE.A, QTYPE.AAAA):
addr = self._table.get(rec.q.qname.idna())
if not addr:
addr = self._resolve(".".join(rec.q.qname.label))
self.socket.sendto(self._reply(rec, addr), peer)
def _reply(self, rec, addr=None):
reply = DNSRecord(DNSHeader(id=rec.header.id, qr=1, aa=1, ra=1), q=rec.q)
if addr:
qtype = QTYPE.A if QTYPE.A == rec.q.qtype else QTYPE.AAAA
reply.add_answer(RR(rec.q.qname, qtype, rdata=A(addr)))
rep = reply.pack()
return rep
def _resolve(self, name):
if not self._resolver:
return None
try:
return self._resolver.gethostbyname(name)
except socket.gaierror, e:
msg = str(e)
if not contains(msg, "ETIMEOUT", "ENOTFOUND"):
print msg
class DnsServer(DatagramServer):
"""
Answers DNS queries against the registry, falling back to the recursive
resolver (if present).
"""
def __init__(self, bindaddr, registry, dns_servers=None):
DatagramServer.__init__(self, bindaddr)
self._registry = registry
self._resolver = None
if dns_servers:
log.info("[namesrv] starting with failover resolver %s",
dns_servers)
self._resolver = Resolver(servers=dns_servers,
timeout=DNS_RESOLVER_TIMEOUT,
tries=1)
def handle(self, data, peer):
rec = DNSRecord.parse(data)
addrs = None
auth = False
if rec.q.qtype in (QTYPE.A, QTYPE.AAAA, QTYPE.ANY):
addrs = self._registry.resolve(rec.q.qname.idna()) or set()
if addrs:
auth = True
# answer AAAA queries for existing A records
# with an successful but empty result
if rec.q.qtype == QTYPE.AAAA:
addrs = None
else:
log.debug("[namesrv] resolved %s to %s",
rec.q.qname.idna(), addrs)
else:
addr = self._resolve('.'.join(rec.q.qname.label))
if addr:
addrs.add(addr)
log.debug("[namesrv] externally resolved %s to %s",
rec.q.qname.idna(), addrs)
if addrs:
addrs = list(addrs)
self.socket.sendto(self._reply(rec, auth, addrs), peer)
def _reply(self, rec, auth, addrs=None):
reply = DNSRecord(DNSHeader(id=rec.header.id,
qr=1,
aa=auth,
ra=bool(self._resolver)),
q=rec.q)
if addrs:
if not isinstance(addrs, list):
addrs = [addrs]
for addr in addrs[0:15]:
reply.add_answer(RR(rec.q.qname, QTYPE.A, rdata=A(addr)))
return reply.pack()
def _resolve(self, name):
if not self._resolver:
log.info("DnsServer._resolve is not set")
return None
try:
return self._resolver.gethostbyname(name)
except Exception as e:
# socket.gaierror as e:
if not contains(str(e), 'ETIMEOUT', 'ENOTFOUND'):
log.error("Exception in DnsServer._resolve", e)
return None
