From: Michał Kępień <michal@isc.org>
Date: Mon, 26 Feb 2018 11:30:48 +0000 (+0100)
Subject: Fix MX checks for dynamic updates
X-Git-Tag: v9.13.0~133^2~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=857a40c87bb80669ecc5cf1c51301d967e7aba53;p=thirdparty%2Fbind9.git

Fix MX checks for dynamic updates

The check_mx() function in lib/ns/update.c incorrectly tests whether the
DNS_RDATA_CHECKMX/DNS_RDATA_CHECKMXFAIL flags are set for each applied
MX record update as these flags are never set in code paths related to
dynamic updates; they can only be set when loading a zone from a master
file (DNS_ZONEOPT_CHECKMX -> DNS_MASTER_CHECKMX -> DNS_RDATA_CHECKMX).
This flaw allows MX records containing IP addresses to be added to a
zone even when "check-mx fail;" is used.

Ensure correct behavior by modifying the relevant tests in check_mx() so
that they use DNS_ZONEOPT_CHECKMX/DNS_ZONEOPT_CHECKMXFAIL instead.
---

diff --git a/bin/tests/system/nsupdate/ns1/named.conf.in b/bin/tests/system/nsupdate/ns1/named.conf.in
index fbd24a1ba35..e7b6adb39e1 100644
--- a/bin/tests/system/nsupdate/ns1/named.conf.in
+++ b/bin/tests/system/nsupdate/ns1/named.conf.in
@@ -43,6 +43,7 @@ zone "example.nil" {
 	type master;
 	file "example.db";
 	check-integrity no;
+	check-mx ignore;
 	update-policy {
 		grant ddns-key.example.nil subdomain example.nil ANY;
 	};
@@ -62,6 +63,7 @@ zone "other.nil" {
 	type master;
 	file "other.db";
 	check-integrity no;
+	check-mx warn;
 	update-policy local;
 	allow-query-on { 10.53.0.1; 127.0.0.1; };
 	allow-transfer { any; };
@@ -76,6 +78,7 @@ zone "update.nil" {
 	type master;
 	file "update.db";
 	check-integrity no;
+	check-mx fail;
 	allow-update { any; };
 	allow-transfer { any; };
 	also-notify { othermasters; };
diff --git a/bin/tests/system/nsupdate/tests.sh b/bin/tests/system/nsupdate/tests.sh
index 263f57e3ad1..ae5c8c592c8 100755
--- a/bin/tests/system/nsupdate/tests.sh
+++ b/bin/tests/system/nsupdate/tests.sh
@@ -162,6 +162,38 @@ grep ns5.other.nil dig.out.ns1 > /dev/null 2>&1 || ret=1
 grep ns6.other.nil dig.out.ns1 > /dev/null 2>&1 || ret=1
 [ $ret = 0 ] || { echo_i "failed"; status=1; }
 
+ret=0
+echo_i "ensure 'check-mx ignore' allows adding MX records containing an address without a warning"
+$NSUPDATE -k ns1/ddns.key > nsupdate.out 2>&1 << END || ret=1
+server 10.53.0.1 ${PORT}
+update add mx03.example.nil 600 IN MX 10 10.53.0.1
+send
+END
+grep REFUSED nsupdate.out > /dev/null 2>&1 && ret=1
+grep "mx03.example.nil/MX:.*MX is an address" ns1/named.run > /dev/null 2>&1 && ret=1
+[ $ret = 0 ] || { echo_i "failed"; status=1; }
+
+ret=0
+echo_i "ensure 'check-mx warn' allows adding MX records containing an address with a warning"
+$NSUPDATE -4 -l -p ${PORT} -k ns1/session.key > nsupdate.out 2>&1 << END || ret=1
+update add mx03.other.nil 600 IN MX 10 10.53.0.1
+send
+END
+grep REFUSED nsupdate.out > /dev/null 2>&1 && ret=1
+grep "mx03.other.nil/MX:.*MX is an address" ns1/named.run > /dev/null 2>&1 || ret=1
+[ $ret = 0 ] || { echo_i "failed"; status=1; }
+
+ret=0
+echo_i "ensure 'check-mx fail' prevents adding MX records containing an address with a warning"
+$NSUPDATE > nsupdate.out 2>&1 << END && ret=1
+server 10.53.0.1 ${PORT}
+update add mx03.update.nil 600 IN MX 10 10.53.0.1
+send
+END
+grep REFUSED nsupdate.out > /dev/null 2>&1 || ret=1
+grep "mx03.update.nil/MX:.*MX is an address" ns1/named.run > /dev/null 2>&1 || ret=1
+[ $ret = 0 ] || { echo_i "failed"; status=1; }
+
 ret=0
 echo_i "check SIG(0) key is accepted"
 key=`$KEYGEN -q -r $RANDFILE -a NSEC3RSASHA1 -b 1024 -T KEY -n ENTITY xxx`
diff --git a/lib/ns/update.c b/lib/ns/update.c
index 8ad98a1c724..05e60d592d9 100644
--- a/lib/ns/update.c
+++ b/lib/ns/update.c
@@ -1737,7 +1737,7 @@ check_mx(ns_client_t *client, dns_zone_t *zone,
 		dns_name_format(&mx.mx, namebuf, sizeof(namebuf));
 		dns_name_format(&t->name, ownerbuf, sizeof(ownerbuf));
 		isaddress = ISC_FALSE;
-		if ((options & DNS_RDATA_CHECKMX) != 0 &&
+		if ((options & DNS_ZONEOPT_CHECKMX) != 0 &&
 		    strlcpy(tmp, namebuf, sizeof(tmp)) < sizeof(tmp)) {
 			if (tmp[strlen(tmp) - 1] == '.')
 				tmp[strlen(tmp) - 1] = '\0';
@@ -1746,7 +1746,7 @@ check_mx(ns_client_t *client, dns_zone_t *zone,
 				isaddress = ISC_TRUE;
 		}
 
-		if (isaddress && (options & DNS_RDATA_CHECKMXFAIL) != 0) {
+		if (isaddress && (options & DNS_ZONEOPT_CHECKMXFAIL) != 0) {
 			update_log(client, zone, ISC_LOG_ERROR,
 				   "%s/MX: '%s': %s",
 				   ownerbuf, namebuf,