From e841247c9086053d774d66e4fbb058d0ead706b2 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@openldap.org>
Date: Mon, 16 Feb 2009 00:12:38 +0000
Subject: [PATCH] Fix corrupted CSN issue

---
 servers/slapd/ctxcsn.c            | 16 ++++++++++++++--
 servers/slapd/overlays/syncprov.c | 14 ++++++++------
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/servers/slapd/ctxcsn.c b/servers/slapd/ctxcsn.c
index 1f8c0505c7..873721600f 100644
--- a/servers/slapd/ctxcsn.c
+++ b/servers/slapd/ctxcsn.c
@@ -30,6 +30,7 @@ const struct berval slap_ldapsync_bv = BER_BVC("ldapsync");
 const struct berval slap_ldapsync_cn_bv = BER_BVC("cn=ldapsync");
 int slap_serverID;
 
+/* maxcsn->bv_val must point to a char buf[LDAP_LUTIL_CSNSTR_BUFSIZE] */
 void
 slap_get_commit_csn(
 	Operation *op,
@@ -41,7 +42,8 @@ slap_get_commit_csn(
 	BackendDB *be = op->o_bd->bd_self;
 
 	if ( maxcsn ) {
-		BER_BVZERO( maxcsn );
+		assert( maxcsn->bv_val != NULL );
+		assert( maxcsn->bv_len >= LDAP_LUTIL_CSNSTR_BUFSIZE );
 	}
 	if ( foundit ) {
 		*foundit = 0;
@@ -62,7 +64,17 @@ slap_get_commit_csn(
 		if ( csne->ce_state == SLAP_CSN_PENDING ) break;
 	}
 
-	if ( committed_csne && maxcsn ) *maxcsn = committed_csne->ce_csn;
+	if ( maxcsn ) {
+		if ( committed_csne ) {
+			if ( committed_csne->ce_csn.bv_len < maxcsn->bv_len )
+				maxcsn->bv_len = committed_csne->ce_csn.bv_len;
+			AC_MEMCPY( maxcsn->bv_val, committed_csne->ce_csn.bv_val,
+				maxcsn->bv_len+1 );
+		} else {
+			maxcsn->bv_len = 0;
+			maxcsn->bv_val[0] = 0;
+		}
+	}
 	ldap_pvt_thread_mutex_unlock( &be->be_pcl_mutex );
 }
 
diff --git a/servers/slapd/overlays/syncprov.c b/servers/slapd/overlays/syncprov.c
index aab00da1ff..427c9a421d 100644
--- a/servers/slapd/overlays/syncprov.c
+++ b/servers/slapd/overlays/syncprov.c
@@ -1628,15 +1628,17 @@ syncprov_op_response( Operation *op, SlapReply *rs )
 
 	if ( rs->sr_err == LDAP_SUCCESS )
 	{
-		struct berval maxcsn = BER_BVNULL;
+		struct berval maxcsn;
 		char cbuf[LDAP_LUTIL_CSNSTR_BUFSIZE];
 		int do_check = 0, have_psearches, foundit;
 
 		/* Update our context CSN */
 		cbuf[0] = '\0';
+		maxcsn.bv_val = cbuf;
+		maxcsn.bv_len = sizeof(cbuf);
 		ldap_pvt_thread_rdwr_wlock( &si->si_csn_rwlock );
 		slap_get_commit_csn( op, &maxcsn, &foundit );
-		if ( BER_BVISNULL( &maxcsn ) && SLAP_GLUE_SUBORDINATE( op->o_bd )) {
+		if ( BER_BVISEMPTY( &maxcsn ) && SLAP_GLUE_SUBORDINATE( op->o_bd )) {
 			/* syncrepl queues the CSN values in the db where
 			 * it is configured , not where the changes are made.
 			 * So look for a value in the glue db if we didn't
@@ -1644,16 +1646,17 @@ syncprov_op_response( Operation *op, SlapReply *rs )
 			 */
 			BackendDB *be = op->o_bd;
 			op->o_bd = select_backend( &be->be_nsuffix[0], 1);
+			maxcsn.bv_val = cbuf;
+			maxcsn.bv_len = sizeof(cbuf);
 			slap_get_commit_csn( op, &maxcsn, &foundit );
 			op->o_bd = be;
 		}
-		if ( !BER_BVISNULL( &maxcsn ) ) {
+		if ( !BER_BVISEMPTY( &maxcsn ) ) {
 			int i, sid;
 #ifdef CHECK_CSN
 			Syntax *syn = slap_schema.si_ad_contextCSN->ad_type->sat_syntax;
 			assert( !syn->ssyn_validate( syn, &maxcsn ));
 #endif
-			strcpy( cbuf, maxcsn.bv_val );
 			sid = slap_parse_csn_sid( &maxcsn );
 			for ( i=0; i<si->si_numcsns; i++ ) {
 				if ( sid == si->si_sids[i] ) {
@@ -1709,8 +1712,7 @@ syncprov_op_response( Operation *op, SlapReply *rs )
 
 		/* only update consumer ctx if this is the greatest csn */
 		if ( bvmatch( &maxcsn, &op->o_csn )) {
-			opc->sctxcsn.bv_len = maxcsn.bv_len;
-			opc->sctxcsn.bv_val = cbuf;
+			opc->sctxcsn = maxcsn;
 		}
 
 		/* Handle any persistent searches */
-- 
2.39.5