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add a system test for the prefetch bug

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Ensure that if prefetch is triggered as a result of a query
restart, it won't have the TRYSTALE_ONTIMEOUT flag set.
This commit is contained in:
Evan Hunt
2021-05-27 19:55:12 -07:00
parent c0dc5937c7
commit 8c047feb3a
4 changed files with 119 additions and 6 deletions
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40
bin/tests/system/serve-stale/ans2/ans.pl
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@@ -26,7 +26,12 @@ sub rmpid { unlink "ans.pid"; exit 1; };
$SIG{INT} = \&rmpid;
$SIG{TERM} = \&rmpid;
# If send_response is set, the server will respond, otherwise the query will
# be dropped.
my $send_response = 1;
# If slow_response is set, a lookup for the CNAME target (target.example) is
# delayed. Other lookups will not be delayed.
my $slow_response = 0;
my $localaddr = "10.53.0.2";
@@ -49,6 +54,8 @@ my $TXT = "data.example 2 IN TXT \"A text record with a 2 second ttl\"";
my $LONGTXT = "longttl.example 600 IN TXT \"A text record with a 600 second ttl\"";
my $CAA = "othertype.example 2 IN CAA 0 issue \"ca1.example.net\"";
my $negSOA = "example 2 IN SOA . . 0 0 0 0 300";
my $CNAME = "cname.example 7 IN CNAME target.example";
my $TARGET = "target.example 9 IN A $localaddr";
sub reply_handler {
my ($qname, $qclass, $qtype) = @_;
@@ -75,6 +82,15 @@ sub reply_handler {
}
$rcode = "NOERROR";
return ($rcode, \@ans, \@auth, \@add, { aa => 1 });
} elsif ($qname eq "slowdown" ) {
if ($qtype eq "TXT") {
$send_response = 1;
$slow_response = 1;
my $rr = new Net::DNS::RR("$qname 0 $qclass TXT \"$send_response\"");
push @ans, $rr;
}
$rcode = "NOERROR";
return ($rcode, \@ans, \@auth, \@add, { aa => 1 });
}
# If we are not responding to queries we are done.
@@ -118,7 +134,7 @@ sub reply_handler {
}
$rcode = "NOERROR";
} elsif ($qname eq "a-only.example") {
if ($qtype eq "A") {
if ($qtype eq "A") {
my $rr = new Net::DNS::RR("a-only.example 2 IN A $localaddr");
push @ans, $rr;
} else {
@@ -126,6 +142,28 @@ sub reply_handler {
push @auth, $rr;
}
$rcode = "NOERROR";
} elsif ($qname eq "cname.example") {
if ($qtype eq "A") {
my $rr = new Net::DNS::RR($CNAME);
push @ans, $rr;
} else {
my $rr = new Net::DNS::RR($negSOA);
push @auth, $rr;
}
$rcode = "NOERROR";
} elsif ($qname eq "target.example") {
if ($slow_response) {
print " Sleeping 3 seconds\n";
sleep(3);
}
if ($qtype eq "A") {
my $rr = new Net::DNS::RR($TARGET);
push @ans, $rr;
} else {
my $rr = new Net::DNS::RR($negSOA);
push @auth, $rr;
}
$rcode = "NOERROR";
} elsif ($qname eq "longttl.example") {
if ($qtype eq "TXT") {
my $rr = new Net::DNS::RR($LONGTXT);

2
bin/tests/system/serve-stale/clean.sh
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@@ -7,7 +7,7 @@
# See the COPYRIGHT file distributed with this work for additional
# information regarding copyright ownership.
rm -f dig.out.test*
rm -f dig.out*
rm -f ns*/named.conf
rm -f ns*/root.bk
rm -f rndc.out.test*

7
bin/tests/system/serve-stale/ns3/named8.conf.in
View File

@@ -29,11 +29,12 @@ options {
recursion yes;
stale-answer-enable yes;
stale-cache-enable yes;
stale-answer-client-timeout 1800;
stale-answer-client-timeout 1800;
prefetch 2 8;
dns64 2001:aaaa::/96 {
clients { any; };
mapped { any; };
};
mapped { any; };
};
};
zone "." {

76
bin/tests/system/serve-stale/tests.sh
View File

@@ -2244,12 +2244,14 @@ status=$((status+ret))
n=$((n+1))
echo_i "check DNS64 processing of a stale negative answer ($n)"
ret=0
# configure ns3 with dns64
copy_setports ns3/named8.conf.in ns3/named.conf
rndc_reload ns3 10.53.0.3
# flush cache, enable ans2 responses
# flush cache, enable ans2 responses, make sure serve-stale is on
$RNDCCMD 10.53.0.3 flush > rndc.out.test$n.1 2>&1 || ret=1
$DIG -p ${PORT} @10.53.0.2 txt enable > /dev/null
$RNDCCMD 10.53.0.3 serve-stale on > rndc.out.test$n.2 2>&1 || ret=1
# prime the cache with an AAAA NXRRSET response
$DIG -p ${PORT} @10.53.0.3 a-only.example AAAA > dig.out.1.test$n
grep "status: NOERROR" dig.out.1.test$n > /dev/null || ret=1
@@ -2269,5 +2271,77 @@ grep "2001:aaaa" dig.out.2.test$n > /dev/null || ret=1
if [ $ret != 0 ]; then echo_i "failed"; fi
status=$((status+ret))
###########################################################
# Test serve-stale's interaction with prefetch processing #
###########################################################
echo_i "test serve-stale's interaction with prefetch processing"
# Test case for #2733, ensuring that prefetch queries do not trigger
# a lookup due to stale-answer-client-timeout.
#
# 1. Cache the following records:
# cname.example 7 IN CNAME target.example.
# target.example 9 IN A <addr>.
# 2. Let the CNAME RRset expire.
# 3. Query for 'cname.example/A'.
#
# This starts recursion because cname.example/CNAME is expired.
# The authoritative server is up so likely it will respond before
# stale-answer-client-timeout is triggered.
# The 'target.example/A' RRset is found in cache with a positive value
# and is eligble for prefetching.
# A prefetch is done for 'target.example/A', our ans2 server will
# delay the request.
# The 'prefetch_done()' callback should have the right event type
# (DNS_EVENT_FETCHDONE).
# flush cache
n=$((n+1))
echo_i "flush cache ($n)"
ret=0
$RNDCCMD 10.53.0.3 flushtree example > rndc.out.test$n.1 2>&1 || ret=1
if [ $ret != 0 ]; then echo_i "failed"; fi
status=$((status+ret))
# prime the cache with CNAME and A; CNAME expires sooner
n=$((n+1))
echo_i "prime cache cname.example (stale-answer-client-timeout 1.8) ($n)"
ret=0
$DIG -p ${PORT} @10.53.0.3 cname.example A > dig.out.test$n
grep "status: NOERROR" dig.out.test$n > /dev/null || ret=1
grep "ANSWER: 2," dig.out.test$n > /dev/null || ret=1
grep "cname\.example\..*7.*IN.*CNAME.*target\.example\." dig.out.test$n > /dev/null || ret=1
grep "target\.example\..*9.*IN.*A" dig.out.test$n > /dev/null || ret=1
if [ $ret != 0 ]; then echo_i "failed"; fi
status=$((status+ret))
# wait for the CNAME to be stale; A will still be valid and in prefetch window.
# (the longer TTL is needed, otherwise data won't be prefetch-eligible.)
sleep 7
# re-enable auth responses, but with a delay answering the A
n=$((n+1))
echo_i "delay responses from authoritative server ($n)"
ret=0
$DIG -p ${PORT} @10.53.0.2 txt slowdown > dig.out.test$n
grep "ANSWER: 1," dig.out.test$n > /dev/null || ret=1
grep "TXT.\"1\"" dig.out.test$n > /dev/null || ret=1
if [ $ret != 0 ]; then echo_i "failed"; fi
status=$((status+ret))
# resend the query and wait in the background; we should get a stale answer
n=$((n+1))
echo_i "check prefetch processing of a stale CNAME target ($n)"
ret=0
$DIG -p ${PORT} @10.53.0.3 cname.example A > dig.out.test$n &
sleep 2
wait
grep "status: NOERROR" dig.out.test$n > /dev/null || ret=1
grep "ANSWER: 2," dig.out.test$n > /dev/null || ret=1
grep "cname\.example\..*7.*IN.*CNAME.*target\.example\." dig.out.test$n > /dev/null || ret=1
grep "target\.example\..*[1-2].*IN.*A" dig.out.test$n > /dev/null || ret=1
if [ $ret != 0 ]; then echo_i "failed"; fi
status=$((status+ret))
echo_i "exit status: $status"
[ $status -eq 0 ] || exit 1