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Diffstat (limited to 'bin/tests/system/chain/ans4/ans.py')
-rwxr-xr-x | bin/tests/system/chain/ans4/ans.py | 386 |
1 files changed, 386 insertions, 0 deletions
diff --git a/bin/tests/system/chain/ans4/ans.py b/bin/tests/system/chain/ans4/ans.py new file mode 100755 index 0000000..839067f --- /dev/null +++ b/bin/tests/system/chain/ans4/ans.py @@ -0,0 +1,386 @@ +# Copyright (C) Internet Systems Consortium, Inc. ("ISC") +# +# SPDX-License-Identifier: MPL-2.0 +# +# 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 https://mozilla.org/MPL/2.0/. +# +# See the COPYRIGHT file distributed with this work for additional +# information regarding copyright ownership. + +############################################################################ +# ans.py: See README.anspy for details. +############################################################################ + +from __future__ import print_function +import os +import sys +import signal +import socket +import select +from datetime import datetime, timedelta +import functools + +import dns, dns.message, dns.query +from dns.rdatatype import * +from dns.rdataclass import * +from dns.rcode import * +from dns.name import * + +############################################################################ +# set up the RRs to be returned in the next answer +# +# the message contains up to two pipe-separated ('|') fields. +# +# the first field of the message is a comma-separated list +# of actions indicating what to put into the answer set +# (e.g., a dname, a cname, another cname, etc) +# +# supported actions: +# - cname (cname from the current name to a new one in the same domain) +# - dname (dname to a new domain, plus a synthesized cname) +# - xname ("external" cname, to a new name in a new domain) +# +# example: xname, dname, cname represents a CNAME to an external +# domain which is then answered by a DNAME and synthesized +# CNAME pointing to yet another domain, which is then answered +# by a CNAME within the same domain, and finally an answer +# to the query. each RR in the answer set has a corresponding +# RRSIG. these signatures are not valid, but will exercise the +# response parser. +# +# the second field is a comma-separated list of which RRs in the +# answer set to include in the answer, in which order. if prepended +# with 's', the number indicates which signature to include. +# +# examples: for the answer set "cname, cname, cname", an rr set +# '1, s1, 2, s2, 3, s3, 4, s4' indicates that all four RRs should +# be included in the answer, with siagntures, in the original +# order, while 4, s4, 3, s3, 2, s2, 1, s1' indicates the order +# should be reversed, 's3, s3, s3, s3' indicates that the third +# RRSIG should be repeated four times and everything else should +# be omitted, and so on. +# +# if there is no second field (i.e., no pipe symbol appears in +# the line) , the default is to send all answers and signatures. +# if a pipe symbol exists but the second field is empty, then +# nothing is sent at all. +############################################################################ +actions = [] +rrs = [] + + +def ctl_channel(msg): + global actions, rrs + + msg = msg.splitlines().pop(0) + print("received control message: %s" % msg) + + msg = msg.split(b"|") + if len(msg) == 0: + return + + actions = [x.strip() for x in msg[0].split(b",")] + n = functools.reduce( + lambda n, act: (n + (2 if act == b"dname" else 1)), [0] + actions + ) + + if len(msg) == 1: + rrs = [] + for i in range(n): + for b in [False, True]: + rrs.append((i, b)) + return + + rlist = [x.strip() for x in msg[1].split(b",")] + rrs = [] + for item in rlist: + if item[0] == b"s"[0]: + i = int(item[1:].strip()) - 1 + if i > n: + print("invalid index %d" + (i + 1)) + continue + rrs.append((int(item[1:]) - 1, True)) + else: + i = int(item) - 1 + if i > n: + print("invalid index %d" % (i + 1)) + continue + rrs.append((i, False)) + + +############################################################################ +# Respond to a DNS query. +############################################################################ +def create_response(msg): + m = dns.message.from_wire(msg) + qname = m.question[0].name.to_text() + labels = qname.lower().split(".") + wantsigs = True if m.ednsflags & dns.flags.DO else False + + # get qtype + rrtype = m.question[0].rdtype + typename = dns.rdatatype.to_text(rrtype) + + # for 'www.example.com.'... + # - name is 'www' + # - domain is 'example.com.' + # - sld is 'example' + # - tld is 'com.' + name = labels.pop(0) + domain = ".".join(labels) + sld = labels.pop(0) + tld = ".".join(labels) + + print("query: " + qname + "/" + typename) + print("domain: " + domain) + + # default answers, depending on QTYPE. + # currently only A, AAAA, TXT and NS are supported. + ttl = 86400 + additionalA = "10.53.0.4" + additionalAAAA = "fd92:7065:b8e:ffff::4" + if typename == "A": + final = "10.53.0.4" + elif typename == "AAAA": + final = "fd92:7065:b8e:ffff::4" + elif typename == "TXT": + final = "Some\ text\ here" + elif typename == "NS": + domain = qname + final = "ns1.%s" % domain + else: + final = None + + # RRSIG rdata - won't validate but will exercise response parsing + t = datetime.now() + delta = timedelta(30) + t1 = t - delta + t2 = t + delta + inception = t1.strftime("%Y%m%d000000") + expiry = t2.strftime("%Y%m%d000000") + sigdata = "OCXH2De0yE4NMTl9UykvOsJ4IBGs/ZIpff2rpaVJrVG7jQfmj50otBAp A0Zo7dpBU4ofv0N/F2Ar6LznCncIojkWptEJIAKA5tHegf/jY39arEpO cevbGp6DKxFhlkLXNcw7k9o7DSw14OaRmgAjXdTFbrl4AiAa0zAttFko Tso=" + + # construct answer set. + answers = [] + sigs = [] + curdom = domain + curname = name + i = 0 + + for action in actions: + if name != "test": + continue + if action == b"xname": + owner = curname + "." + curdom + newname = "cname%d" % i + i += 1 + newdom = "domain%d.%s" % (i, tld) + i += 1 + target = newname + "." + newdom + print("add external CNAME %s to %s" % (owner, target)) + answers.append(dns.rrset.from_text(owner, ttl, IN, CNAME, target)) + rrsig = "CNAME 5 3 %d %s %s 12345 %s %s" % ( + ttl, + expiry, + inception, + domain, + sigdata, + ) + print("add external RRISG(CNAME) %s to %s" % (owner, target)) + sigs.append(dns.rrset.from_text(owner, ttl, IN, RRSIG, rrsig)) + curname = newname + curdom = newdom + continue + + if action == b"cname": + owner = curname + "." + curdom + newname = "cname%d" % i + target = newname + "." + curdom + i += 1 + print("add CNAME %s to %s" % (owner, target)) + answers.append(dns.rrset.from_text(owner, ttl, IN, CNAME, target)) + rrsig = "CNAME 5 3 %d %s %s 12345 %s %s" % ( + ttl, + expiry, + inception, + domain, + sigdata, + ) + print("add RRSIG(CNAME) %s to %s" % (owner, target)) + sigs.append(dns.rrset.from_text(owner, ttl, IN, RRSIG, rrsig)) + curname = newname + continue + + if action == b"dname": + owner = curdom + newdom = "domain%d.%s" % (i, tld) + i += 1 + print("add DNAME %s to %s" % (owner, newdom)) + answers.append(dns.rrset.from_text(owner, ttl, IN, DNAME, newdom)) + rrsig = "DNAME 5 3 %d %s %s 12345 %s %s" % ( + ttl, + expiry, + inception, + domain, + sigdata, + ) + print("add RRSIG(DNAME) %s to %s" % (owner, newdom)) + sigs.append(dns.rrset.from_text(owner, ttl, IN, RRSIG, rrsig)) + owner = curname + "." + curdom + target = curname + "." + newdom + print("add synthesized CNAME %s to %s" % (owner, target)) + answers.append(dns.rrset.from_text(owner, ttl, IN, CNAME, target)) + rrsig = "CNAME 5 3 %d %s %s 12345 %s %s" % ( + ttl, + expiry, + inception, + domain, + sigdata, + ) + print("add synthesized RRSIG(CNAME) %s to %s" % (owner, target)) + sigs.append(dns.rrset.from_text(owner, ttl, IN, RRSIG, rrsig)) + curdom = newdom + continue + + # now add the final answer + owner = curname + "." + curdom + answers.append(dns.rrset.from_text(owner, ttl, IN, rrtype, final)) + rrsig = "%s 5 3 %d %s %s 12345 %s %s" % ( + typename, + ttl, + expiry, + inception, + domain, + sigdata, + ) + sigs.append(dns.rrset.from_text(owner, ttl, IN, RRSIG, rrsig)) + + # prepare the response and convert to wire format + r = dns.message.make_response(m) + + if name != "test": + r.answer.append(answers[-1]) + if wantsigs: + r.answer.append(sigs[-1]) + else: + for i, sig in rrs: + if sig and not wantsigs: + continue + elif sig: + r.answer.append(sigs[i]) + else: + r.answer.append(answers[i]) + + if typename != "NS": + r.authority.append( + dns.rrset.from_text(domain, ttl, IN, "NS", ("ns1.%s" % domain)) + ) + r.additional.append( + dns.rrset.from_text(("ns1.%s" % domain), 86400, IN, A, additionalA) + ) + r.additional.append( + dns.rrset.from_text(("ns1.%s" % domain), 86400, IN, AAAA, additionalAAAA) + ) + + r.flags |= dns.flags.AA + r.use_edns() + return r.to_wire() + + +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 = "10.53.0.4" +ip6 = "fd92:7065:b8e:ffff::4" + +try: + port = int(os.environ["PORT"]) +except: + port = 5300 + +try: + ctrlport = int(os.environ["EXTRAPORT1"]) +except: + ctrlport = 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 + +ctrl_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) +ctrl_socket.bind((ip4, ctrlport)) +ctrl_socket.listen(5) + +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("Control channel on %s port %d" % (ip4, ctrlport)) +print("Ctrl-c to quit") + +if havev6: + input = [query4_socket, query6_socket, ctrl_socket] +else: + input = [query4_socket, ctrl_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 == ctrl_socket: + # Handle control channel input + conn, addr = s.accept() + print("Control channel connected") + while True: + msg = conn.recv(65535) + if not msg: + break + ctl_channel(msg) + conn.close() + if s == query4_socket or s == query6_socket: + print("Query received on %s" % (ip4 if s == query4_socket else ip6)) + # Handle incoming queries + msg = s.recvfrom(65535) + rsp = create_response(msg[0]) + if rsp: + s.sendto(rsp, msg[1]) + if not running: + break |