From 21a7fde6ba34c62f4859a4c19de4f49ec1bab474 Mon Sep 17 00:00:00 2001
From: Evan Hunt <each@isc.org>
Date: Mon, 11 Mar 2013 15:54:03 -0700
Subject: [PATCH] [master] handle servfail at DLZ zone apex

3522.	[bug]		DLZ lookups could fail to return SERVFAIL when
			they ought to. [RT #32685]
---
 CHANGES                               |  3 +++
 bin/tests/system/dlzexternal/driver.c | 18 ++++++++++++++++--
 bin/tests/system/dlzexternal/tests.sh |  7 +++++++
 lib/dns/sdlz.c                        |  8 ++++++--
 4 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/CHANGES b/CHANGES
index 82a83fe1f3..d66584e5f5 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+3522.	[bug]		DLZ lookups could fail to return SERVFAIL when
+			they ought to. [RT #32685]
+
 3521.	[bug]		Address memory leak in opensslecdsa_link.c. [RT #32249]
 
 3520.	[bug]		'mctx' was not being referenced counted in some places
diff --git a/bin/tests/system/dlzexternal/driver.c b/bin/tests/system/dlzexternal/driver.c
index 765f32fad1..fa0021cdaa 100644
--- a/bin/tests/system/dlzexternal/driver.c
+++ b/bin/tests/system/dlzexternal/driver.c
@@ -233,7 +233,7 @@ dlz_create(const char *dlzname, unsigned int argc, char *argv[],
 	struct dlz_example_data *state;
 	const char *helper_name;
 	va_list ap;
-	char soa_data[200];
+	char soa_data[1024];
 	const char *extra;
 	isc_result_t result;
 	int n;
@@ -359,6 +359,18 @@ dlz_findzonedb(void *dbdata, const char *name,
 	    strncmp(addrbuf, "10.53.0.1", 9) == 0)
 		return (ISC_R_NOMORE);
 
+	/*
+	 * For bigcname.domain, return success so it appears to be
+	 * the zone origin; this regression tests a bug in which
+	 * zone origin nodes could fail to return SERVFAIL to the client.
+	 */
+	if (strcasecmp(name, "bigcname.domain") == 0)
+		return (ISC_R_SUCCESS);
+
+	/*
+	 * Return success if we have an exact match between the
+	 * zone name and the qname
+	 */
 	if (strcasecmp(state->zone_name, name) == 0)
 		return (ISC_R_SUCCESS);
 
@@ -418,7 +430,9 @@ dlz_lookup(const char *zone, const char *name, void *dbdata,
 			return (result);
 	}
 
-	if (strcmp(name, "too-long") == 0) {
+	if (strcmp(name, "too-long") == 0 ||
+	    strcmp(zone, "bigcname.domain") == 0)
+	{
 		for (i = 0; i < 511; i++)
 			buf[i] = 'x';
 		buf[i] = '\0';
diff --git a/bin/tests/system/dlzexternal/tests.sh b/bin/tests/system/dlzexternal/tests.sh
index c8beb537ff..5cc9348671 100644
--- a/bin/tests/system/dlzexternal/tests.sh
+++ b/bin/tests/system/dlzexternal/tests.sh
@@ -143,4 +143,11 @@ grep "status: SERVFAIL" dig.out.ns1.6 > /dev/null || ret=1
 [ "$ret" -eq 0 ] || echo "I:failed"
 status=`expr $status + $ret`
 
+ret=0
+echo "I:testing zone returning oversized data at zone origin"
+$DIG $DIGOPTS txt bigcname.domain > dig.out.ns1.7 2>&1 || ret=1
+grep "status: SERVFAIL" dig.out.ns1.7 > /dev/null || ret=1
+[ "$ret" -eq 0 ] || echo "I:failed"
+status=`expr $status + $ret`
+
 exit $status
diff --git a/lib/dns/sdlz.c b/lib/dns/sdlz.c
index 555605c319..9197f923ef 100644
--- a/lib/dns/sdlz.c
+++ b/lib/dns/sdlz.c
@@ -613,7 +613,10 @@ findnodeext(dns_db_t *db, dns_name_t *name, isc_boolean_t create,
 
 	MAYBE_UNLOCK(sdlz->dlzimp);
 
-	if (result != ISC_R_SUCCESS && !isorigin && !create) {
+	if (result == ISC_R_NOTFOUND && (isorigin || create))
+		result = ISC_R_SUCCESS;
+
+	if (result != ISC_R_SUCCESS) {
 		destroynode(node);
 		return (result);
 	}
@@ -625,7 +628,8 @@ findnodeext(dns_db_t *db, dns_name_t *name, isc_boolean_t create,
 				      sdlz->dbdata, node);
 		MAYBE_UNLOCK(sdlz->dlzimp);
 		if (result != ISC_R_SUCCESS &&
-		    result != ISC_R_NOTIMPLEMENTED) {
+		    result != ISC_R_NOTIMPLEMENTED)
+		{
 			destroynode(node);
 			return (result);
 		}