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Commit 0f168a4b authored by Michał Kępień's avatar Michał Kępień Committed by Evan Hunt
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dig: return a non-zero exit code for failed TCP EOF retries 

dig retries a TCP query when a server closes the connection prematurely.
However, dig's exit code remains unaffected even if the second attempt
to get a response also fails with the same error for the same lookup,
which should not be the case.  Ensure the exit code is updated
appropriately when a retry triggered by a TCP EOF condition fails.
parent 91d12180
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Showing with 263 additions and 9 deletions
bin/dig/dighost.c
View file @ 0f168a4b
......@@ -2991,6 +2991,27 @@ connect_timeout(isc_task_t *task, isc_event_t *event) {
UNLOCK_LOOKUP;
}
/*%
* Called when a peer closes a TCP socket prematurely.
*/
static void
requeue_or_update_exitcode(dig_lookup_t *lookup) {
if (lookup->eoferr == 0U) {
/*
* Peer closed the connection prematurely for the first time
* for this lookup. Try again, keeping track of this failure.
*/
dig_lookup_t *requeued_lookup = requeue_lookup(lookup, true);
requeued_lookup->eoferr++;
} else {
/*
* Peer closed the connection prematurely and it happened
* previously for this lookup. Indicate an error.
*/
exitcode = 9;
}
}
/*%
* Event handler for the TCP recv which gets the length header of TCP
* packets. Start the next recv of length bytes.
......@@ -3002,7 +3023,7 @@ tcp_length_done(isc_task_t *task, isc_event_t *event) {
isc_region_t r;
isc_result_t result;
dig_query_t *query = NULL;
dig_lookup_t *l, *n;
dig_lookup_t *l;
uint16_t length;
REQUIRE(event->ev_type == ISC_SOCKEVENT_RECVDONE);
......@@ -3041,9 +3062,8 @@ tcp_length_done(isc_task_t *task, isc_event_t *event) {
sockcount--;
debug("sockcount=%d", sockcount);
INSIST(sockcount >= 0);
if (sevent->result == ISC_R_EOF && l->eoferr == 0U) {
n = requeue_lookup(l, true);
n->eoferr++;
if (sevent->result == ISC_R_EOF) {
requeue_or_update_exitcode(l);
}
isc_event_free(&event);
clear_query(query);
......@@ -3544,9 +3564,8 @@ recv_done(isc_task_t *task, isc_event_t *event) {
debug("sockcount=%d", sockcount);
INSIST(sockcount >= 0);
}
if (sevent->result == ISC_R_EOF && l->eoferr == 0U) {
n = requeue_lookup(l, true);
n->eoferr++;
if (sevent->result == ISC_R_EOF) {
requeue_or_update_exitcode(l);
}
isc_event_free(&event);
clear_query(query);
......
bin/tests/system/digdelv/ans5/ans.pl 0 → 100644
View file @ 0f168a4b
#!/usr/bin/perl
#
# 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.
# This is a TCP-only DNS server whose aim is to facilitate testing how dig
# copes with prematurely closed TCP connections.
#
# This server can be configured (through a separate control socket) with a
# series of responses to send for subsequent incoming TCP DNS queries. Only
# one query is handled before closing each connection. In order to keep things
# simple, the server is not equipped with any mechanism for handling malformed
# queries.
#
# Available response types are defined in the %response_types hash in the
# getAnswerSection() function below. Each RR returned is generated dynamically
# based on the QNAME found in the incoming query.
use IO::File;
use Net::DNS;
use Net::DNS::Packet;
use strict;
# Ignore SIGPIPE so we won't fail if peer closes a TCP socket early
local $SIG{PIPE} = 'IGNORE';
# Flush logged output after every line
local $| = 1;
my $server_addr = "10.53.0.5";
if (@ARGV > 0) {
$server_addr = @ARGV[0];
}
my $mainport = int($ENV{'PORT'});
if (!$mainport) { $mainport = 5300; }
my $ctrlport = int($ENV{'EXTRAPORT1'});
if (!$ctrlport) { $ctrlport = 5301; }
my $ctlsock = IO::Socket::INET->new(LocalAddr => "$server_addr",
LocalPort => $ctrlport, Proto => "tcp", Listen => 5, Reuse => 1) or die "$!";
my $tcpsock = IO::Socket::INET->new(LocalAddr => "$server_addr",
LocalPort => $mainport, Proto => "tcp", Listen => 5, Reuse => 1) or die "$!";
my $pidf = new IO::File "ans.pid", "w" or die "cannot open pid file: $!";
print $pidf "$$\n" or die "cannot write pid file: $!";
$pidf->close or die "cannot close pid file: $!";;
sub rmpid { unlink "ans.pid"; exit 1; };
$SIG{INT} = \&rmpid;
$SIG{TERM} = \&rmpid;
my @response_sequence = ("complete_axfr");
my $connection_counter = 0;
# Return the next answer type to send, incrementing the connection counter and
# making sure the latter does not exceed the size of the array holding the
# configured response sequence.
sub getNextResponseType {
my $response_type = $response_sequence[$connection_counter];
$connection_counter++;
$connection_counter %= scalar(@response_sequence);
return $response_type;
}
# Return an array of resource records comprising the answer section of a given
# response type.
sub getAnswerSection {
my ($response_type, $qname) = @_;
my %response_types = (
no_response => [],
partial_axfr => [
Net::DNS::RR->new("$qname 300 IN SOA . . 0 0 0 0 300"),
Net::DNS::RR->new("$qname NS ."),
],
complete_axfr => [
Net::DNS::RR->new("$qname 300 IN SOA . . 0 0 0 0 300"),
Net::DNS::RR->new("$qname NS ."),
Net::DNS::RR->new("$qname 300 IN SOA . . 0 0 0 0 300"),
],
);
return $response_types{$response_type};
}
# Generate a Net::DNS::Packet containing the response to send on the current
# TCP connection. If the answer section of the response is determined to be
# empty, no data will be sent on the connection at all (immediate EOF).
sub generateResponse {
my ($buf) = @_;
my $request;
if ($Net::DNS::VERSION > 0.68) {
$request = new Net::DNS::Packet(\$buf, 0);
$@ and die $@;
} else {
my $err;
($request, $err) = new Net::DNS::Packet(\$buf, 0);
$err and die $err;
}
my @questions = $request->question;
my $qname = $questions[0]->qname;
my $qtype = $questions[0]->qtype;
my $qclass = $questions[0]->qclass;
my $id = $request->header->id;
my $packet = new Net::DNS::Packet($qname, $qtype, $qclass);
$packet->header->qr(1);
$packet->header->aa(1);
$packet->header->id($id);
my $response_type = getNextResponseType();
my $answers = getAnswerSection($response_type, $qname);
for my $rr (@$answers) {
$packet->push("answer", $rr);
}
print " Sending \"$response_type\" response\n";
return $packet->data if @$answers;
}
my $rin;
my $rout;
for (;;) {
$rin = '';
vec($rin, fileno($ctlsock), 1) = 1;
vec($rin, fileno($tcpsock), 1) = 1;
select($rout = $rin, undef, undef, undef);
if (vec($rout, fileno($ctlsock), 1)) {
my $conn = $ctlsock->accept;
@response_sequence = split(' ', $conn->getline);
$connection_counter = 0;
print "Response sequence set to: @response_sequence\n";
$conn->close;
} elsif (vec($rout, fileno($tcpsock), 1)) {
my $buf;
my $lenbuf;
my $conn = $tcpsock->accept;
my $n = $conn->sysread($lenbuf, 2);
die unless $n == 2;
my $len = unpack("n", $lenbuf);
$n = $conn->sysread($buf, $len);
die unless $n == $len;
print "TCP request\n";
my $response = generateResponse($buf);
if ($response) {
$len = length($response);
$n = $conn->syswrite(pack("n", $len), 2);
$n = $conn->syswrite($response, $len);
print " Sent: $n chars via TCP\n";
} else {
print " No response sent\n";
}
$conn->close;
}
}
bin/tests/system/digdelv/tests.sh
View file @ 0f168a4b
......@@ -18,7 +18,7 @@ status=0
n=0
sendcmd() {
"$PERL" "$SYSTEMTESTTOP/send.pl" 10.53.0.4 "$EXTRAPORT1"
"$PERL" "$SYSTEMTESTTOP/send.pl" "${1}" "$EXTRAPORT1"
}
dig_with_opts() {
......@@ -247,7 +247,7 @@ if [ -x "$DIG" ] ; then
echo_i "checking dig preserves origin on TCP retries ($n)"
ret=0
# Ask ans4 to still accept TCP connections, but not respond to queries
echo "//" | sendcmd
echo "//" | sendcmd 10.53.0.4
dig_with_opts -d +tcp @10.53.0.4 +retry=1 +time=1 +domain=bar foo > dig.out.test$n 2>&1 && ret=1
test "$(grep -c "trying origin bar" dig.out.test$n)" -eq 2 || ret=1
grep "using root origin" < dig.out.test$n > /dev/null && ret=1
......@@ -524,6 +524,66 @@ if [ -x "$DIG" ] ; then
grep "Dump of all outstanding memory allocations" dig.out.test$n > /dev/null && ret=1
if [ $ret -ne 0 ]; then echo_i "failed"; fi
status=$((status+ret))
n=$((n+1))
echo_i "checking exit code for a retry upon TCP EOF (immediate -> immediate) ($n)"
ret=0
echo "no_response no_response" | sendcmd 10.53.0.5
dig_with_opts @10.53.0.5 example AXFR +tries=1 > dig.out.test$n 2>&1 && ret=1
# Sanity check: ensure ans5 behaves as expected.
[ `grep "communications error.*end of file" dig.out.test$n | wc -l` -eq 2 ] || ret=1
if [ $ret -ne 0 ]; then echo_i "failed"; fi
status=$((status+ret))
n=$((n+1))
echo_i "checking exit code for a retry upon TCP EOF (partial AXFR -> partial AXFR) ($n)"
ret=0
echo "partial_axfr partial_axfr" | sendcmd 10.53.0.5
dig_with_opts @10.53.0.5 example AXFR +tries=1 > dig.out.test$n 2>&1 && ret=1
# Sanity check: ensure ans5 behaves as expected.
[ `grep "communications error.*end of file" dig.out.test$n | wc -l` -eq 2 ] || ret=1
if [ $ret -ne 0 ]; then echo_i "failed"; fi
status=$((status+ret))
n=$((n+1))
echo_i "checking exit code for a retry upon TCP EOF (immediate -> partial AXFR) ($n)"
ret=0
echo "no_response partial_axfr" | sendcmd 10.53.0.5
dig_with_opts @10.53.0.5 example AXFR +tries=1 > dig.out.test$n 2>&1 && ret=1
# Sanity check: ensure ans5 behaves as expected.
[ `grep "communications error.*end of file" dig.out.test$n | wc -l` -eq 2 ] || ret=1
if [ $ret -ne 0 ]; then echo_i "failed"; fi
status=$((status+ret))
n=$((n+1))
echo_i "checking exit code for a retry upon TCP EOF (partial AXFR -> immediate) ($n)"
ret=0
echo "partial_axfr no_response" | sendcmd 10.53.0.5
dig_with_opts @10.53.0.5 example AXFR +tries=1 > dig.out.test$n 2>&1 && ret=1
# Sanity check: ensure ans5 behaves as expected.
[ `grep "communications error.*end of file" dig.out.test$n | wc -l` -eq 2 ] || ret=1
if [ $ret -ne 0 ]; then echo_i "failed"; fi
status=$((status+ret))
n=$((n+1))
echo_i "checking exit code for a retry upon TCP EOF (immediate -> complete AXFR) ($n)"
ret=0
echo "no_response complete_axfr" | sendcmd 10.53.0.5
dig_with_opts @10.53.0.5 example AXFR +tries=1 > dig.out.test$n 2>&1 || ret=1
# Sanity check: ensure ans5 behaves as expected.
[ `grep "communications error.*end of file" dig.out.test$n | wc -l` -eq 1 ] || ret=1
if [ $ret -ne 0 ]; then echo_i "failed"; fi
status=$((status+ret))
n=$((n+1))
echo_i "checking exit code for a retry upon TCP EOF (partial AXFR -> complete AXFR) ($n)"
ret=0
echo "partial_axfr complete_axfr" | sendcmd 10.53.0.5
dig_with_opts @10.53.0.5 example AXFR +tries=1 > dig.out.test$n 2>&1 || ret=1
# Sanity check: ensure ans5 behaves as expected.
[ `grep "communications error.*end of file" dig.out.test$n | wc -l` -eq 1 ] || ret=1
if [ $ret -ne 0 ]; then echo_i "failed"; fi
status=$((status+ret))
else
echo_i "$DIG is needed, so skipping these dig tests"
fi
......
util/copyrights
View file @ 0f168a4b
......@@ -493,6 +493,7 @@
./bin/tests/system/dialup/tests.sh SH 2000,2001,2004,2007,2012,2016,2018,2019
./bin/tests/system/digcomp.pl PERL 2000,2001,2004,2007,2012,2013,2016,2018,2019
./bin/tests/system/digdelv/ans4/startme X 2017,2018,2019
./bin/tests/system/digdelv/ans5/ans.pl PERL 2019
./bin/tests/system/digdelv/clean.sh SH 2015,2016,2018,2019
./bin/tests/system/digdelv/ns2/sign.sh SH 2018,2019
./bin/tests/system/digdelv/prereq.sh SH 2018,2019
......
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