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bind9/bin/tests/system/qmin/ans2/ans.py
Diego Fronza 55c0fa2bf6 Added test for the proposed fix 
The test works as follows:

1. Client wants to resolve unusual ip6.arpa. name:

   test1.test2.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.9.0.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. IN TXT

2. Query is sent to ns7, a qmin enabled resolver.

3. ns7 do the first stage in query minimization for the name and send a new
   query to root (ns1):

  _.1.0.0.2.ip6.arpa.        IN  A

4. ns1 delegates ip6.arpa. to ns2.good.:

    ;; AUTHORITY SECTION:
    ;ip6.arpa.      20  IN  NS  ns2.good.

    ;; ADDITIONAL SECTION:
    ;ns2.good.      20  IN  A   10.53.0.2

5. ns7 do a second round in minimizing the name and send a new query
   to ns2.good. (10.53.0.2):

   _.8.2.6.0.1.0.0.2.ip6.arpa.    IN  A

6. ans2 delegates 8.2.6.0.1.0.0.2.ip6.arpa. to ns3.good.:

    ;; AUTHORITY SECTION:
    ;8.2.6.0.1.0.0.2.ip6.arpa. 60   IN  NS  ns3.good.

    ;; ADDITIONAL SECTION:
    ;ns3.good.      60  IN  A   10.53.0.3

7. ns7 do a third round in minimizing the name and send a new query to
   ns3.good.:

    _.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. IN A

8. ans3 delegates 1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. to ns4.good.:

    ;; AUTHORITY SECTION:
    ;1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. 60 IN    NS  ns4.good.

    ;; ADDITIONAL SECTION:
    ;ns4.good.      60  IN  A   10.53.0.4

9. ns7 do fourth round in minimizing the name and send a new query to
   ns4.good.:

	_.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa.    IN A

10. ns4.good. doesn't know such name, but answers stating it is authoritative for
    the domai:

	;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id:  53815
	...
	;; AUTHORITY SECTION:
	1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. 60 IN    SOA ns4.good.  ...

11. ns7 do another minimization on name:
   _.9.0.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa
   sends to ns4.good. and gets the same SOA response stated in item #10

12. ns7 do another minimization on name:
	_.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.9.0.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa
	sends to ns4.good. and gets the same SOA response stated in item #10.

13. ns7 do the last query minimization name for the ip6.arpa. QNAME.
	After all IPv6 labels are exausted the algorithm falls back to the
	original QNAME:
	test1.test2.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.9.0.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa

    ns7 sends a new query with the original QNAME to ans4.

14. Finally ans4 answers with the expected response:
	;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id:  40969
	;; flags: qr aa; QUESTION: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
	;; OPT PSEUDOSECTION:
	; EDNS: version: 0, flags:; udp: 8192
	;; QUESTION SECTION:
	;test1.test2.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.9.0.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. IN TXT

	;; ANSWER SECTION:
	;test1.test2.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.9.0.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. 1    IN TXT "long_ip6_name"

(cherry picked from commit 11add69198)
2020-09-02 16:52:39 +02:00

258 lines
9.5 KiB
Python
Executable File
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############################################################################
# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#
# See the COPYRIGHT file distributed with this work for additional
# information regarding copyright ownership.
############################################################################
from __future__ import print_function
import os
import sys
import signal
import socket
import select
from datetime import datetime, timedelta
import time
import functools
import dns, dns.message, dns.query, dns.flags
from dns.rdatatype import *
from dns.rdataclass import *
from dns.rcode import *
from dns.name import *
# Log query to file
def logquery(type, qname):
with open("qlog", "a") as f:
f.write("%s %s\n", type, qname)
############################################################################
# Respond to a DNS query.
# For good. it serves:
# ns2.good. IN A 10.53.0.2
# zoop.boing.good. NS ns3.good.
# ns3.good. IN A 10.53.0.3
# too.many.labels.a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z.good. A 192.0.2.2
# it responds properly (with NODATA empty response) to non-empty terminals
#
# For slow. it works the same as for good., but each response is delayed by 400 milliseconds
#
# For bad. it works the same as for good., but returns NXDOMAIN to non-empty terminals
#
# For ugly. it works the same as for good., but returns garbage to non-empty terminals
#
# For 1.0.0.2.ip6.arpa it serves
# 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.f.4.0.1.0.0.2.ip6.arpa. IN PTR nee.com.
# 8.2.6.0.1.0.0.2.ip6.arpa IN NS ns3.good
# 1.0.0.2.ip6.arpa. IN NS ns2.good
# ip6.arpa. IN NS ns2.good
############################################################################
def create_response(msg):
m = dns.message.from_wire(msg)
qname = m.question[0].name.to_text()
lqname = qname.lower()
labels = lqname.split('.')
# get qtype
rrtype = m.question[0].rdtype
typename = dns.rdatatype.to_text(rrtype)
if typename == "A" or typename == "AAAA":
typename = "ADDR"
bad = False
ugly = False
slow = False
# log this query
with open("query.log", "a") as f:
f.write("%s %s\n" % (typename, lqname))
print("%s %s" % (typename, lqname), end=" ")
r = dns.message.make_response(m)
r.set_rcode(NOERROR)
if lqname.endswith("1.0.0.2.ip6.arpa."):
# Direct query - give direct answer
if lqname.endswith("8.2.6.0.1.0.0.2.ip6.arpa."):
# Delegate to ns3
r.authority.append(dns.rrset.from_text("8.2.6.0.1.0.0.2.ip6.arpa.", 60, IN, NS, "ns3.good."))
r.additional.append(dns.rrset.from_text("ns3.good.", 60, IN, A, "10.53.0.3"))
elif lqname == "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.f.4.0.1.0.0.2.ip6.arpa." and rrtype == PTR:
# Direct query - give direct answer
r.answer.append(dns.rrset.from_text("1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.f.4.0.1.0.0.2.ip6.arpa.", 1, IN, PTR, "nee.com."))
r.flags |= dns.flags.AA
elif lqname == "1.0.0.2.ip6.arpa." and rrtype == NS:
# NS query at the apex
r.answer.append(dns.rrset.from_text("1.0.0.2.ip6.arpa.", 30, IN, NS, "ns2.good."))
r.flags |= dns.flags.AA
elif "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.f.4.0.1.0.0.2.ip6.arpa.".endswith(lqname):
# NODATA answer
r.authority.append(dns.rrset.from_text("1.0.0.2.ip6.arpa.", 30, IN, SOA, "ns2.good. hostmaster.arpa. 2018050100 1 1 1 1"))
else:
# NXDOMAIN
r.authority.append(dns.rrset.from_text("1.0.0.2.ip6.arpa.", 30, IN, SOA, "ns2.good. hostmaster.arpa. 2018050100 1 1 1 1"))
r.set_rcode(NXDOMAIN)
return r
elif lqname.endswith("ip6.arpa."):
if lqname == "ip6.arpa." and rrtype == NS:
# NS query at the apex
r.answer.append(dns.rrset.from_text("ip6.arpa.", 30, IN, NS, "ns2.good."))
r.flags |= dns.flags.AA
elif "1.0.0.2.ip6.arpa.".endswith(lqname):
# NODATA answer
r.authority.append(dns.rrset.from_text("ip6.arpa.", 30, IN, SOA, "ns2.good. hostmaster.arpa. 2018050100 1 1 1 1"))
else:
# NXDOMAIN
r.authority.append(dns.rrset.from_text("ip6.arpa.", 30, IN, SOA, "ns2.good. hostmaster.arpa. 2018050100 1 1 1 1"))
r.set_rcode(NXDOMAIN)
return r
elif lqname.endswith("bad."):
bad = True
suffix = "bad."
lqname = lqname[:-4]
elif lqname.endswith("ugly."):
ugly = True
suffix = "ugly."
lqname = lqname[:-5]
elif lqname.endswith("good."):
suffix = "good."
lqname = lqname[:-5]
elif lqname.endswith("slow."):
slow = True
suffix = "slow."
lqname = lqname[:-5]
elif lqname.endswith("fwd."):
suffix = "fwd."
lqname = lqname[:-4]
else:
r.set_rcode(REFUSED)
return r
# Good/bad/ugly differs only in how we treat non-empty terminals
if lqname.endswith("zoop.boing."):
r.authority.append(dns.rrset.from_text("zoop.boing." + suffix, 1, IN, NS, "ns3." + suffix))
elif lqname == "many.labels.a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z." and rrtype == A:
r.answer.append(dns.rrset.from_text(lqname + suffix, 1, IN, A, "192.0.2.2"))
r.flags |= dns.flags.AA
elif lqname == "" and rrtype == NS:
r.answer.append(dns.rrset.from_text(suffix, 30, IN, NS, "ns2." + suffix))
r.flags |= dns.flags.AA
elif lqname == "ns2." and rrtype == A:
r.answer.append(dns.rrset.from_text("ns2."+suffix, 30, IN, A, "10.53.0.2"))
r.flags |= dns.flags.AA
elif lqname == "ns2." and rrtype == AAAA:
r.answer.append(dns.rrset.from_text("ns2."+suffix, 30, IN, AAAA, "fd92:7065:b8e:ffff::2"))
r.flags |= dns.flags.AA
elif lqname == "ns3." and rrtype == A:
r.answer.append(dns.rrset.from_text("ns3."+suffix, 30, IN, A, "10.53.0.3"))
r.flags |= dns.flags.AA
elif lqname == "ns3." and rrtype == AAAA:
r.answer.append(dns.rrset.from_text("ns3."+suffix, 30, IN, AAAA, "fd92:7065:b8e:ffff::3"))
r.flags |= dns.flags.AA
elif lqname == "ns4." and rrtype == A:
r.answer.append(dns.rrset.from_text("ns4."+suffix, 30, IN, A, "10.53.0.4"))
r.flags |= dns.flags.AA
elif lqname == "ns4." and rrtype == AAAA:
r.answer.append(dns.rrset.from_text("ns4."+suffix, 30, IN, AAAA, "fd92:7065:b8e:ffff::4"))
r.flags |= dns.flags.AA
elif lqname == "a.bit.longer.ns.name." and rrtype == A:
r.answer.append(dns.rrset.from_text("a.bit.longer.ns.name."+suffix, 1, IN, A, "10.53.0.4"))
r.flags |= dns.flags.AA
elif lqname == "a.bit.longer.ns.name." and rrtype == AAAA:
r.answer.append(dns.rrset.from_text("a.bit.longer.ns.name."+suffix, 1, IN, AAAA, "fd92:7065:b8e:ffff::4"))
r.flags |= dns.flags.AA
else:
r.authority.append(dns.rrset.from_text(suffix, 1, IN, SOA, "ns2." + suffix + " hostmaster.arpa. 2018050100 1 1 1 1"))
if bad or not \
("icky.icky.icky.ptang.zoop.boing.".endswith(lqname) or \
"many.labels.a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z.".endswith(lqname) or \
"a.bit.longer.ns.name.".endswith(lqname)):
r.set_rcode(NXDOMAIN)
if ugly:
r.set_rcode(FORMERR)
if slow:
time.sleep(0.2)
return r
def sigterm(signum, frame):
print ("Shutting down now...")
os.remove('ans.pid')
running = False
sys.exit(0)
############################################################################
# Main
#
# Set up responder and control channel, open the pid file, and start
# the main loop, listening for queries on the query channel or commands
# on the control channel and acting on them.
############################################################################
ip4 = "10.53.0.2"
ip6 = "fd92:7065:b8e:ffff::2"
try: port=int(os.environ['PORT'])
except: port=5300
query4_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
query4_socket.bind((ip4, port))
havev6 = True
try:
query6_socket = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
try:
query6_socket.bind((ip6, port))
except:
query6_socket.close()
havev6 = False
except:
havev6 = False
signal.signal(signal.SIGTERM, sigterm)
f = open('ans.pid', 'w')
pid = os.getpid()
print (pid, file=f)
f.close()
running = True
print ("Listening on %s port %d" % (ip4, port))
if havev6:
print ("Listening on %s port %d" % (ip6, port))
print ("Ctrl-c to quit")
if havev6:
input = [query4_socket, query6_socket]
else:
input = [query4_socket]
while running:
try:
inputready, outputready, exceptready = select.select(input, [], [])
except select.error as e:
break
except socket.error as e:
break
except KeyboardInterrupt:
break
for s in inputready:
if s == query4_socket or s == query6_socket:
print ("Query received on %s" %
(ip4 if s == query4_socket else ip6), end=" ")
# Handle incoming queries
msg = s.recvfrom(65535)
rsp = create_response(msg[0])
if rsp:
print(dns.rcode.to_text(rsp.rcode()))
s.sendto(rsp.to_wire(), msg[1])
else:
print("NO RESPONSE")
if not running:
break
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