From: Jeremy Allison <jra@samba.org>
Date: Thu, 23 Jul 2020 02:03:23 +0000 (-0700)
Subject: s3: libads: Don't re-do DNS lookups in ads_domain_func_level() if not needed.
X-Git-Tag: talloc-2.3.2~819
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cf0cfa03ac6fd4c4e2c7d86079796079754f3cf2;p=thirdparty%2Fsamba.git

s3: libads: Don't re-do DNS lookups in ads_domain_func_level() if not needed.

ADS_STRUCT may be being reused after a
DC lookup from ads_find_dc(), so ads->ldap.ss may already have a
good address (even if ads->server.ldap_server == NULL).
Only re-initialize the ADS_STRUCT and redo the ads_find_fc()
DNS lookups if we have to.

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

Autobuild-User(master): Andreas Schneider <asn@cryptomilk.org>
Autobuild-Date(master): Tue Aug 18 09:46:28 UTC 2020 on sn-devel-184
---

diff --git a/source3/libads/ldap.c b/source3/libads/ldap.c
index 04d699c348a..2fc9b2009b6 100755
--- a/source3/libads/ldap.c
+++ b/source3/libads/ldap.c
@@ -3351,11 +3351,28 @@ ADS_STATUS ads_domain_func_level(ADS_STRUCT *ads, uint32_t *val)
         /* establish a new ldap tcp session if necessary */
 
 	if ( !ads->ldap.ld ) {
-		if ( (ads_s = ads_init( ads->server.realm, ads->server.workgroup, 
-			ads->server.ldap_server, ADS_SASL_PLAIN )) == NULL )
-		{
-			status = ADS_ERROR_NT(NT_STATUS_NO_MEMORY);
-			goto done;
+		/*
+		 * ADS_STRUCT may be being reused after a
+		 * DC lookup, so ads->ldap.ss may already have a
+		 * good address. If not, re-initialize the passed-in
+		 * ADS_STRUCT with the given server.XXXX parameters.
+		 *
+		 * Note that this doesn't depend on
+		 * ads->server.ldap_server != NULL,
+		 * as the case where ads->server.ldap_server==NULL and
+		 * ads->ldap.ss != zero_address is precisely the DC
+		 * lookup case where ads->ldap.ss was found by going
+		 * through ads_find_dc() again we want to avoid repeating.
+		 */
+		if (is_zero_addr(&ads->ldap.ss)) {
+			ads_s = ads_init(ads->server.realm,
+					 ads->server.workgroup,
+					 ads->server.ldap_server,
+					 ADS_SASL_PLAIN );
+			if (ads_s == NULL ) {
+				status = ADS_ERROR_NT(NT_STATUS_NO_MEMORY);
+				goto done;
+			}
 		}
 		ads_s->auth.flags = ADS_AUTH_ANON_BIND;
 		status = ads_connect( ads_s );