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Ensure delegations inside mirror zones are properly handled for non-recursive queries

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When a resolver is a regular slave (i.e. not a mirror) for some zone,
non-recursive queries for names below that slaved zone will return a
delegation sourced from it.  This behavior is suboptimal for mirror
zones as their contents should rather be treated as validated, cached
DNS responses.  Modify query_delegation() and query_zone_delegation() to
permit clients allowed cache access to check its contents for a better
answer when responding to non-recursive queries.
This commit is contained in:
Michał Kępień
2018-06-28 13:38:39 +02:00
parent c9accfde28
commit 179d5faa28
6 changed files with 60 additions and 2 deletions
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33
bin/tests/system/mirror/tests.sh
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@@ -216,5 +216,38 @@ grep "query 'foo.example/A/IN'" ns1/named.run > /dev/null && ret=1
if [ $ret != 0 ]; then echo_i "failed"; fi
status=`expr $status + $ret`
n=`expr $n + 1`
echo_i "checking that non-recursive queries for names below mirror zone get responded from cache ($n)"
ret=0
# Issue a non-recursive query for an RRset which is expected to be in cache.
$DIG $DIGOPTS @10.53.0.3 +norec foo.example. A > dig.out.ns3.test$n 2>&1 || ret=1
# Check response code and flags in the answer.
grep "NOERROR" dig.out.ns3.test$n > /dev/null || ret=1
grep "flags:.* ad" dig.out.ns3.test$n > /dev/null || ret=1
# Ensure the response is not a delegation.
grep "ANSWER: 0" dig.out.ns3.test$n > /dev/null && ret=1
grep "foo.example.*IN.*A.*127.0.0.1" dig.out.ns3.test$n > /dev/null || ret=1
if [ $ret != 0 ]; then echo_i "failed"; fi
status=`expr $status + $ret`
n=`expr $n + 1`
echo_i "checking that delegations from cache which improve mirror zone delegations are properly handled ($n)"
ret=0
# First, issue a recursive query in order to cache an RRset which is not within
# the mirror zone's bailiwick.
$DIG $DIGOPTS @10.53.0.3 sub.example. NS > dig.out.ns3.test$n.1 2>&1 || ret=1
# Ensure the child-side NS RRset is returned.
grep "NOERROR" dig.out.ns3.test$n.1 > /dev/null || ret=1
grep "ANSWER: 1" dig.out.ns3.test$n.1 > /dev/null || ret=1
grep "sub.example.*IN.*NS" dig.out.ns3.test$n.1 > /dev/null || ret=1
# Issue a non-recursive query for something below the cached zone cut.
$DIG $DIGOPTS @10.53.0.3 +norec foo.sub.example. A > dig.out.ns3.test$n.2 2>&1 || ret=1
# Ensure the cached NS RRset is returned in a delegation.
grep "NOERROR" dig.out.ns3.test$n.2 > /dev/null || ret=1
grep "ANSWER: 0" dig.out.ns3.test$n.2 > /dev/null || ret=1
grep "sub.example.*IN.*NS" dig.out.ns3.test$n.2 > /dev/null || ret=1
if [ $ret != 0 ]; then echo_i "failed"; fi
status=`expr $status + $ret`
echo_i "exit status: $status"
[ $status -eq 0 ] || exit 1