mirror of
https://gitlab.isc.org/isc-projects/bind9
synced 2025-08-30 05:57:52 +00:00
Add a hung fetch check while chasing DS in the forward system test
Implement TCP support in the `ans11` Python-based DNS server. Implement a control command channel in `ans11` to support an optional silent mode of operation, which, when enabled, will ignore incoming queries. In the added check, make the `ans11` the NS server of "a.root-servers.nil." for `ns3`, so it uses `ans11` (in silent mode) for the regular (non-forwarded) name resolutions. This will trigger the "hung fetch" scenario, which was causing `named` to crash.
This commit is contained in:
Aram Sargsyan
Michal Nowak
parent
84914a0610
commit
848094d6f7
@ -15,6 +15,7 @@ import sys
|
||||
import signal
|
||||
import socket
|
||||
import select
|
||||
import struct
|
||||
from datetime import datetime, timedelta
|
||||
import time
|
||||
import functools
|
||||
@ -30,6 +31,66 @@ def logquery(type, qname):
|
||||
with open("qlog", "a") as f:
|
||||
f.write("%s %s\n", type, qname)
|
||||
|
||||
# Create a UDP listener
|
||||
def udp_listen(ip, port, is_ipv6 = False):
|
||||
try:
|
||||
udp = socket.socket(socket.AF_INET6 if is_ipv6 else socket.AF_INET,
|
||||
socket.SOCK_DGRAM)
|
||||
try:
|
||||
udp.bind((ip, port))
|
||||
except:
|
||||
udp.close()
|
||||
udp = None
|
||||
except:
|
||||
udp = None
|
||||
|
||||
if udp is None and not is_ipv6:
|
||||
raise socket.error("Can not create an IPv4 UDP listener")
|
||||
|
||||
return udp
|
||||
|
||||
# Create a TCP listener
|
||||
def tcp_listen(ip, port, is_ipv6 = False):
|
||||
try:
|
||||
tcp = socket.socket(socket.AF_INET6 if is_ipv6 else socket.AF_INET,
|
||||
socket.SOCK_STREAM)
|
||||
try:
|
||||
tcp.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
|
||||
tcp.bind((ip, port))
|
||||
tcp.listen(100)
|
||||
except:
|
||||
tcp.close()
|
||||
tcp = None
|
||||
except:
|
||||
tcp = None
|
||||
|
||||
if tcp is None and not is_ipv6:
|
||||
raise socket.error("Can not create an IPv4 TCP listener")
|
||||
|
||||
return tcp
|
||||
|
||||
############################################################################
|
||||
# Control channel - send "1" or "0" to enable or disable the "silent" mode.
|
||||
############################################################################
|
||||
silent = False
|
||||
def ctrl_channel(msg):
|
||||
global silent
|
||||
|
||||
msg = msg.splitlines().pop(0)
|
||||
print("Received control message: %s" % msg)
|
||||
|
||||
if len(msg) != 1:
|
||||
return
|
||||
|
||||
if silent:
|
||||
if msg == b'0':
|
||||
silent = False
|
||||
print("Silent mode was disabled")
|
||||
else:
|
||||
if msg == b'1':
|
||||
silent = True
|
||||
print("Silent mode was enabled")
|
||||
|
||||
############################################################################
|
||||
# Respond to a DNS query.
|
||||
############################################################################
|
||||
@ -79,18 +140,17 @@ ip6 = "fd92:7065:b8e:ffff::11"
|
||||
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
|
||||
try: ctrlport=int(os.environ['EXTRAPORT1'])
|
||||
except: ctrlport=5300
|
||||
|
||||
ctrl4_tcp = tcp_listen(ip4, ctrlport)
|
||||
query4_udp = udp_listen(ip4, port)
|
||||
query6_udp = udp_listen(ip6, port, is_ipv6=True)
|
||||
query4_tcp = tcp_listen(ip4, port)
|
||||
query6_tcp = tcp_listen(ip6, port, is_ipv6=True)
|
||||
|
||||
havev6 = query6_udp is not None and query6_tcp is not None
|
||||
|
||||
signal.signal(signal.SIGTERM, sigterm)
|
||||
|
||||
f = open('ans.pid', 'w')
|
||||
@ -100,15 +160,19 @@ f.close()
|
||||
|
||||
running = True
|
||||
|
||||
print ("Listening on %s port %d" % (ip4, ctrlport))
|
||||
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]
|
||||
input = [ctrl4_tcp, query4_udp, query6_udp, query4_tcp, query6_tcp]
|
||||
else:
|
||||
input = [query4_socket]
|
||||
input = [ctrl4_tcp, query4_udp, query4_tcp]
|
||||
|
||||
hung_conns = []
|
||||
|
||||
while running:
|
||||
try:
|
||||
@ -121,16 +185,71 @@ while running:
|
||||
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=" ")
|
||||
if s == ctrl4_tcp:
|
||||
print("Control channel connected")
|
||||
conn = None
|
||||
try:
|
||||
# Handle control channel input
|
||||
conn, addr = s.accept()
|
||||
msg = conn.recv(1)
|
||||
if msg:
|
||||
ctrl_channel(msg)
|
||||
conn.close()
|
||||
except s.timeout:
|
||||
pass
|
||||
if conn:
|
||||
conn.close()
|
||||
elif s == query4_tcp or s == query6_tcp:
|
||||
print("TCP query received on %s" %
|
||||
(ip4 if s == query4_tcp else ip6), end=" ")
|
||||
conn = None
|
||||
try:
|
||||
# Handle incoming queries
|
||||
conn, addr = s.accept()
|
||||
if not silent:
|
||||
# get TCP message length
|
||||
msg = conn.recv(2)
|
||||
if len(msg) != 2:
|
||||
print("NO RESPONSE (can not read the message length)")
|
||||
conn.close()
|
||||
continue
|
||||
length = struct.unpack('>H', msg[:2])[0]
|
||||
msg = conn.recv(length)
|
||||
if len(msg) != length:
|
||||
print("NO RESPONSE (can not read the message)")
|
||||
conn.close()
|
||||
continue
|
||||
rsp = create_response(msg)
|
||||
if rsp:
|
||||
print(dns.rcode.to_text(rsp.rcode()))
|
||||
wire = rsp.to_wire()
|
||||
conn.send(struct.pack('>H', len(wire)))
|
||||
conn.send(wire)
|
||||
else:
|
||||
print("NO RESPONSE (can not create a response)")
|
||||
else:
|
||||
# Do not respond and hang the connection.
|
||||
print("NO RESPONSE (silent mode)")
|
||||
hung_conns.append(conn)
|
||||
continue
|
||||
except socket.error as e:
|
||||
print("NO RESPONSE (error: %s)" % str(e))
|
||||
if conn:
|
||||
conn.close()
|
||||
elif s == query4_udp or s == query6_udp:
|
||||
print("UDP query received on %s" %
|
||||
(ip4 if s == query4_udp 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])
|
||||
if not silent:
|
||||
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 (can not create a response)")
|
||||
else:
|
||||
print("NO RESPONSE")
|
||||
# Do not respond.
|
||||
print("NO RESPONSE (silent mode)")
|
||||
if not running:
|
||||
break
|
||||
|
||||
@ -15,7 +15,7 @@
|
||||
rm -f ./dig.out.*
|
||||
rm -f ./*/named.conf
|
||||
rm -f ./*/named.memstats
|
||||
rm -f ./*/named.run ./*/named.run.prev
|
||||
rm -f ./*/named.run ./*/named.run.prev ./*/ans.run
|
||||
rm -f ./*/named_dump.db
|
||||
rm -f ./ns*/named.lock
|
||||
rm -f ./ns*/managed-keys.bind*
|
||||
|
||||
21
bin/tests/system/forward/ns3/root2.db
Normal file
21
bin/tests/system/forward/ns3/root2.db
Normal file
@ -0,0 +1,21 @@
|
||||
; 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.
|
||||
|
||||
$TTL 300
|
||||
. IN SOA gson.nominum.com. a.root.servers.nil. (
|
||||
2000042100 ; serial
|
||||
600 ; refresh
|
||||
600 ; retry
|
||||
1200 ; expire
|
||||
600 ; minimum
|
||||
)
|
||||
. NS a.root-servers.nil.
|
||||
a.root-servers.nil. A 10.53.0.11
|
||||
@ -17,7 +17,7 @@ dig_with_opts() (
|
||||
)
|
||||
|
||||
sendcmd() (
|
||||
send 10.53.0.6 "$EXTRAPORT1"
|
||||
send "$1" "$EXTRAPORT1"
|
||||
)
|
||||
|
||||
rndccmd() {
|
||||
@ -185,7 +185,7 @@ n=$((n+1))
|
||||
echo_i "checking that a forwarder timeout prevents it from being reused in the same fetch context ($n)"
|
||||
ret=0
|
||||
# Make ans6 receive queries without responding to them.
|
||||
echo "//" | sendcmd
|
||||
echo "//" | sendcmd 10.53.0.6
|
||||
# Query for a record in a zone which is forwarded to a non-responding forwarder
|
||||
# and is delegated from the root to check whether the forwarder will be retried
|
||||
# when a delegation is encountered after falling back to full recursive
|
||||
@ -235,25 +235,47 @@ grep "status: SERVFAIL" dig.out.$n > /dev/null || ret=1
|
||||
if [ $ret != 0 ]; then echo_i "failed"; fi
|
||||
status=$((status+ret))
|
||||
|
||||
n=$((n+1))
|
||||
echo_i "checking switch from forwarding to normal resolution while chasing DS ($n)"
|
||||
ret=0
|
||||
copy_setports ns3/named2.conf.in ns3/named.conf
|
||||
rndccmd 10.53.0.3 reconfig 2>&1 | sed 's/^/ns3 /' | cat_i
|
||||
sleep 1
|
||||
sendcmd << EOF
|
||||
# Prepare ans6 for the chasing DS tests.
|
||||
sendcmd 10.53.0.6 << EOF
|
||||
/ns1.sld.tld/A/
|
||||
300 A 10.53.0.2
|
||||
/sld.tld/NS/
|
||||
300 NS ns1.sld.tld.
|
||||
/sld.tld/
|
||||
EOF
|
||||
|
||||
n=$((n+1))
|
||||
echo_i "checking switch from forwarding to normal resolution while chasing DS ($n)"
|
||||
ret=0
|
||||
copy_setports ns3/named2.conf.in ns3/named.conf
|
||||
rndccmd 10.53.0.3 reconfig 2>&1 | sed 's/^/ns3 /' | cat_i
|
||||
sleep 1
|
||||
nextpart ns3/named.run >/dev/null
|
||||
dig_with_opts @$f1 xxx.yyy.sld.tld ds > dig.out.$n.f1 || ret=1
|
||||
grep "status: SERVFAIL" dig.out.$n.f1 > /dev/null || ret=1
|
||||
if [ $ret != 0 ]; then echo_i "failed"; fi
|
||||
status=$((status+ret))
|
||||
|
||||
# See [GL #3129].
|
||||
# Enable silent mode for ans11.
|
||||
echo "1" | sendcmd 10.53.0.11
|
||||
n=$((n+1))
|
||||
echo_i "checking the handling of hung DS fetch while chasing DS ($n)"
|
||||
ret=0
|
||||
copy_setports ns3/named2.conf.in ns3/tmp
|
||||
sed 's/root.db/root2.db/' ns3/tmp > ns3/named.conf
|
||||
rm -f ns3/tmp
|
||||
rndccmd 10.53.0.3 reconfig 2>&1 | sed 's/^/ns3 /' | cat_i
|
||||
rndccmd 10.53.0.3 flush 2>&1 | sed 's/^/ns3 /' | cat_i
|
||||
sleep 1
|
||||
nextpart ns3/named.run >/dev/null
|
||||
dig_with_opts @$f1 xxx.yyy.sld.tld ds > dig.out.$n.f1 || ret=1
|
||||
grep "status: SERVFAIL" dig.out.$n.f1 > /dev/null || ret=1
|
||||
# Disable silent mode for ans11.
|
||||
echo "0" | sendcmd 10.53.0.11
|
||||
if [ $ret != 0 ]; then echo_i "failed"; fi
|
||||
status=$((status+ret))
|
||||
|
||||
#
|
||||
# Check various spoofed response scenarios. The same tests will be
|
||||
# run twice, with "forward first" and "forward only" configurations.
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user