-#!/usr/bin/env python
+#!/usr/bin/env python3
#
# Unix SMB/CIFS implementation.
# Copyright (C) Volker Lendecke 2017
import sys
import select
import socket
+import time
from samba.dcerpc import dns
import samba.ndr as ndr
import socketserver
sserver = socketserver
+DNS_REQUEST_TIMEOUT = 10
+
class DnsHandler(sserver.BaseRequestHandler):
+ dns_qtype_strings = dict((v, k) for k, v in vars(dns).items() if k.startswith('DNS_QTYPE_'))
+ def dns_qtype_string(self, qtype):
+ "Return a readable qtype code"
+ return self.dns_qtype_strings[qtype]
+
+ dns_rcode_strings = dict((v, k) for k, v in vars(dns).items() if k.startswith('DNS_RCODE_'))
+ def dns_rcode_string(self, rcode):
+ "Return a readable error code"
+ return self.dns_rcode_strings[rcode]
+
def dns_transaction_udp(self, packet, host):
"send a DNS query and read the reply"
s = None
try:
send_packet = ndr.ndr_pack(packet)
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0)
- s.settimeout(5)
+ s.settimeout(DNS_REQUEST_TIMEOUT)
s.connect((host, 53))
s.sendall(send_packet, 0)
recv_packet = s.recv(2048, 0)
s.close()
return None
+ def get_pdc_ipv4_addr(self, lookup_name):
+ """Maps a DNS realm to the IPv4 address of the PDC for that testenv"""
+
+ realm_to_ip_mappings = self.server.realm_to_ip_mappings
+
+ # sort the realms so we find the longest-match first
+ testenv_realms = sorted(realm_to_ip_mappings.keys(), key=len)
+ testenv_realms.reverse()
+
+ for realm in testenv_realms:
+ if lookup_name.endswith(realm):
+ # return the corresponding IP address for this realm's PDC
+ return realm_to_ip_mappings[realm]
+
+ return None
+
def forwarder(self, name):
lname = name.lower()
+ # check for special cases used by tests (e.g. dns_forwarder.py)
if lname.endswith('an-address-that-will-not-resolve'):
return 'ignore'
if lname.endswith('dsfsdfs'):
return 'fail'
- if lname.endswith('adnonssdom.samba.example.com'):
- return '127.0.0.17'
- if lname.endswith('adnontlmdom.samba.example.com'):
- return '127.0.0.18'
- if lname.endswith('samba2000.example.com'):
- return '127.0.0.25'
- if lname.endswith('samba2003.example.com'):
- return '127.0.0.26'
- if lname.endswith('samba2008r2.example.com'):
- return '127.0.0.27'
- if lname.endswith('addom.samba.example.com'):
- return '127.0.0.30'
- if lname.endswith('sub.samba.example.com'):
- return '127.0.0.31'
- if lname.endswith('chgdcpassword.samba.example.com'):
- return '127.0.0.32'
- if lname.endswith('backupdom.samba.example.com'):
- return '127.0.0.40'
- if lname.endswith('renamedom.samba.example.com'):
- return '127.0.0.42'
- if lname.endswith('labdom.samba.example.com'):
- return '127.0.0.43'
- if lname.endswith('samba.example.com'):
- return '127.0.0.21'
- return None
+ if lname.endswith("torture1", 0, len(lname)-2):
+ # CATCH TORTURE100, TORTURE101, ...
+ return 'torture'
+ if lname.endswith('_none_.example.com'):
+ return 'torture'
+ if lname.endswith('torturedom.samba.example.com'):
+ return 'torture'
+
+ # return the testenv PDC matching the realm being requested
+ return self.get_pdc_ipv4_addr(lname)
def handle(self):
+ start = time.monotonic()
data, sock = self.request
query = ndr.ndr_unpack(dns.name_packet, data)
name = query.questions[0].name
return
elif forwarder is 'fail':
pass
- elif forwarder is not None:
- response = self.dns_transaction_udp(query, forwarder)
- else:
+ elif forwarder in ['torture', None]:
response = query
response.operation |= dns.DNS_FLAG_REPLY
response.operation |= dns.DNS_FLAG_RECURSION_AVAIL
response.operation |= dns.DNS_RCODE_NXDOMAIN
+ else:
+ response = self.dns_transaction_udp(query, forwarder)
if response is None:
response = query
send_packet = ndr.ndr_pack(response)
- print("dns_hub: sending %s to address %s for name %s\n" %
- (forwarder, self.client_address, name))
+ end = time.monotonic()
+ tdiff = end - start
+ errcode = response.operation & dns.DNS_RCODE
+ if tdiff > (DNS_REQUEST_TIMEOUT/5):
+ debug = True
+ else:
+ debug = False
+ if debug:
+ print("dns_hub: forwarder[%s] client[%s] name[%s][%s] %s response.operation[0x%x] tdiff[%s]\n" %
+ (forwarder, self.client_address, name,
+ self.dns_qtype_string(query.questions[0].question_type),
+ self.dns_rcode_string(errcode), response.operation, tdiff))
try:
sock.sendto(send_packet, self.client_address)
except socket.error as err:
- print("Error sending %s to address %s for name %s: %s\n" %
- (forwarder, self.client_address, name, err))
+ print("dns_hub: Error sending response to client[%s] for name[%s] tdiff[%s]: %s\n" %
+ (self.client_address, name, tdiff, err))
class server_thread(threading.Thread):
timeout = int(sys.argv[1]) * 1000
timeout = min(timeout, 2**31 - 1) # poll with 32-bit int can't take more
host = sys.argv[2]
+
server = sserver.UDPServer((host, int(53)), DnsHandler)
+
+ # we pass in the realm-to-IP mappings as a comma-separated key=value
+ # string. Convert this back into a dictionary that the DnsHandler can use
+ realm_mapping = dict(kv.split('=') for kv in sys.argv[3].split(','))
+ server.realm_to_ip_mappings = realm_mapping
+
+ print("dns_hub will proxy DNS requests for the following realms:")
+ for realm, ip in server.realm_to_ip_mappings.items():
+ print(" {0} ==> {1}".format(realm, ip))
+
t = server_thread(server)
t.start()
p = select.poll()
git.samba.org / kai / samba-autobuild / .git / blobdiff