]> git.sur5r.net Git - openldap/blobdiff - servers/slapd/overlays/syncprov.c
ITS#5428
[openldap] / servers / slapd / overlays / syncprov.c
index d785e17b08ecb5fa5387577fb3012c10ce0f9f98..9d7a9ad72154672bf4a44414170eb5de9a5fc551 100644 (file)
@@ -2,7 +2,7 @@
 /* syncprov.c - syncrepl provider */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 2004-2007 The OpenLDAP Foundation.
+ * Copyright 2004-2008 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -585,11 +585,7 @@ syncprov_findcsn( Operation *op, find_csn_t mode )
        char cbuf[LDAP_LUTIL_CSNSTR_BUFSIZE];
        struct berval maxcsn;
        Filter cf;
-#ifdef LDAP_COMP_MATCH
-       AttributeAssertion eq = { NULL, BER_BVNULL, NULL };
-#else
-       AttributeAssertion eq = { NULL, BER_BVNULL };
-#endif
+       AttributeAssertion eq = ATTRIBUTEASSERTION_INIT;
        fpres_cookie pcookie;
        sync_control *srs = NULL;
        struct slap_limits_set fc_limits;
@@ -628,8 +624,11 @@ again:
                                maxid = i;
                        }
                }
-               fop.ors_filterstr.bv_len = sprintf( buf, "(entryCSN>=%s)",
-                       cf.f_av_value.bv_val );
+               fop.ors_filterstr.bv_len = snprintf( buf, sizeof( buf ),
+                       "(entryCSN>=%s)", cf.f_av_value.bv_val );
+               if ( fop.ors_filterstr.bv_len < 0 || fop.ors_filterstr.bv_len >= sizeof( buf ) ) {
+                       return LDAP_OTHER;
+               }
                fop.ors_attrsonly = 0;
                fop.ors_attrs = csn_anlist;
                fop.ors_slimit = SLAP_NO_LIMIT;
@@ -653,16 +652,19 @@ again:
                /* Look for exact match the first time */
                if ( findcsn_retry ) {
                        cf.f_choice = LDAP_FILTER_EQUALITY;
-                       fop.ors_filterstr.bv_len = sprintf( buf, "(entryCSN=%s)",
-                               cf.f_av_value.bv_val );
+                       fop.ors_filterstr.bv_len = snprintf( buf, sizeof( buf ),
+                               "(entryCSN=%s)", cf.f_av_value.bv_val );
                /* On retry, look for <= */
                } else {
                        cf.f_choice = LDAP_FILTER_LE;
                        fop.ors_limit = &fc_limits;
                        memset( &fc_limits, 0, sizeof( fc_limits ));
                        fc_limits.lms_s_unchecked = 1;
-                       fop.ors_filterstr.bv_len = sprintf( buf, "(entryCSN<=%s)",
-                               cf.f_av_value.bv_val );
+                       fop.ors_filterstr.bv_len = snprintf( buf, sizeof( buf ),
+                               "(entryCSN<=%s)", cf.f_av_value.bv_val );
+               }
+               if ( fop.ors_filterstr.bv_len < 0 || fop.ors_filterstr.bv_len >= sizeof( buf ) ) {
+                       return LDAP_OTHER;
                }
                fop.ors_attrsonly = 1;
                fop.ors_attrs = slap_anlist_no_attrs;
@@ -694,7 +696,7 @@ again:
                break;
        }
 
-       fop.o_bd->bd_info = on->on_info->oi_orig;
+       fop.o_bd->bd_info = (BackendInfo *)on->on_info;
        fop.o_bd->be_search( &fop, &frs );
        fop.o_bd->bd_info = (BackendInfo *)on;
 
@@ -774,6 +776,8 @@ syncprov_sendresp( Operation *op, opcookie *opc, syncops *so,
        BER_BVZERO( &csns[1] );
        slap_compose_sync_cookie( op, &cookie, csns, so->s_rid, so->s_sid );
 
+       Debug( LDAP_DEBUG_SYNC, "syncprov_sendresp: cookie=%s\n", cookie.bv_val, 0, 0 );
+
        e_uuid.e_attrs = &a_uuid;
        a_uuid.a_desc = slap_schema.si_ad_entryUUID;
        a_uuid.a_nvals = &opc->suuid;
@@ -833,8 +837,10 @@ syncprov_sendresp( Operation *op, opcookie *opc, syncops *so,
 
 /* Play back queued responses */
 static int
-syncprov_qplay( Operation *op, slap_overinst *on, syncops *so )
+syncprov_qplay( Operation *op, struct re_s *rtask )
 {
+       syncops *so = rtask->arg;
+       slap_overinst *on = LDAP_SLIST_FIRST(&so->s_op->o_extra)->oe_key;
        syncres *sr;
        Entry *e;
        opcookie opc;
@@ -849,10 +855,10 @@ syncprov_qplay( Operation *op, slap_overinst *on, syncops *so )
                        so->s_res = sr->s_next;
                if ( !so->s_res )
                        so->s_restail = NULL;
-               ldap_pvt_thread_mutex_unlock( &so->s_mutex );
-
+               /* Exit loop with mutex held */
                if ( !sr || so->s_op->o_abandon )
                        break;
+               ldap_pvt_thread_mutex_unlock( &so->s_mutex );
 
                opc.sdn = sr->s_dn;
                opc.sndn = sr->s_ndn;
@@ -879,9 +885,24 @@ syncprov_qplay( Operation *op, slap_overinst *on, syncops *so )
 
                ch_free( sr );
 
-               if ( rc )
+               if ( rc ) {
+                       /* Exit loop with mutex held */
+                       ldap_pvt_thread_mutex_lock( &so->s_mutex );
                        break;
+               }
+       }
+
+       /* wait until we get explicitly scheduled again */
+       ldap_pvt_thread_mutex_lock( &slapd_rq.rq_mutex );
+       ldap_pvt_runqueue_stoptask( &slapd_rq, rtask );
+       if ( rc == 0 ) {
+               ldap_pvt_runqueue_resched( &slapd_rq, rtask, 1 );
+       } else {
+               /* bail out on any error */
+               ldap_pvt_runqueue_remove( &slapd_rq, rtask );
        }
+       ldap_pvt_thread_mutex_unlock( &slapd_rq.rq_mutex );
+       ldap_pvt_thread_mutex_unlock( &so->s_mutex );
        return rc;
 }
 
@@ -891,7 +912,6 @@ syncprov_qtask( void *ctx, void *arg )
 {
        struct re_s *rtask = arg;
        syncops *so = rtask->arg;
-       slap_overinst *on = so->s_op->o_private;
        OperationBuffer opbuf;
        Operation *op;
        BackendDB be;
@@ -913,25 +933,14 @@ syncprov_qtask( void *ctx, void *arg )
        be = *so->s_op->o_bd;
        be.be_flags |= SLAP_DBFLAG_OVERLAY;
        op->o_bd = &be;
-       op->o_private = NULL;
+       LDAP_SLIST_FIRST(&op->o_extra) = NULL;
        op->o_callback = NULL;
 
-       rc = syncprov_qplay( op, on, so );
+       rc = syncprov_qplay( op, rtask );
 
        /* decrement use count... */
        syncprov_free_syncop( so );
 
-       /* wait until we get explicitly scheduled again */
-       ldap_pvt_thread_mutex_lock( &slapd_rq.rq_mutex );
-       ldap_pvt_runqueue_stoptask( &slapd_rq, rtask );
-       if ( rc == 0 ) {
-               ldap_pvt_runqueue_resched( &slapd_rq, rtask, 1 );
-       } else {
-               /* bail out on any error */
-               ldap_pvt_runqueue_remove( &slapd_rq, rtask );
-       }
-       ldap_pvt_thread_mutex_unlock( &slapd_rq.rq_mutex );
-
 #if 0  /* FIXME: connection_close isn't exported from slapd.
                 * should it be?
                 */
@@ -978,15 +987,18 @@ static int
 syncprov_qresp( opcookie *opc, syncops *so, int mode )
 {
        syncres *sr;
-       int sid;
+       int sid, srsize;
 
        /* Don't send changes back to their originator */
        sid = slap_parse_csn_sid( &opc->sctxcsn );
        if ( sid >= 0 && sid == so->s_sid )
                return LDAP_SUCCESS;
 
-       sr = ch_malloc(sizeof(syncres) + opc->suuid.bv_len + 1 +
-               opc->sdn.bv_len + 1 + opc->sndn.bv_len + 1 + opc->sctxcsn.bv_len + 1 );
+       srsize = sizeof(syncres) + opc->suuid.bv_len + 1 +
+               opc->sdn.bv_len + 1 + opc->sndn.bv_len + 1;
+       if ( opc->sctxcsn.bv_len )
+               srsize += opc->sctxcsn.bv_len + 1;
+       sr = ch_malloc( srsize );
        sr->s_next = NULL;
        sr->s_dn.bv_val = (char *)(sr + 1);
        sr->s_dn.bv_len = opc->sdn.bv_len;
@@ -999,9 +1011,13 @@ syncprov_qresp( opcookie *opc, syncops *so, int mode )
                 opc->sndn.bv_val ) + 1;
        sr->s_uuid.bv_len = opc->suuid.bv_len;
        AC_MEMCPY( sr->s_uuid.bv_val, opc->suuid.bv_val, opc->suuid.bv_len );
-       sr->s_csn.bv_val = sr->s_uuid.bv_val + sr->s_uuid.bv_len + 1;
+       if ( opc->sctxcsn.bv_len ) {
+               sr->s_csn.bv_val = sr->s_uuid.bv_val + sr->s_uuid.bv_len + 1;
+               strcpy( sr->s_csn.bv_val, opc->sctxcsn.bv_val );
+       } else {
+               sr->s_csn.bv_val = NULL;
+       }
        sr->s_csn.bv_len = opc->sctxcsn.bv_len;
-       strcpy( sr->s_csn.bv_val, opc->sctxcsn.bv_val );
 
        ldap_pvt_thread_mutex_lock( &so->s_mutex );
        if ( !so->s_res ) {
@@ -1198,7 +1214,7 @@ syncprov_matchops( Operation *op, opcookie *opc, int saveit )
                }
 
                /* check if current o_req_dn is in scope and matches filter */
-               if ( fc.fscope && test_filter( op, e, ss->s_op->ors_filter ) ==
+               if ( fc.fscope && test_filter( ss->s_op, e, ss->s_op->ors_filter ) ==
                        LDAP_COMPARE_TRUE ) {
                        if ( saveit ) {
                                sm = op->o_tmpalloc( sizeof(syncmatches), op->o_tmpmemctx );
@@ -1290,7 +1306,9 @@ syncprov_checkpoint( Operation *op, SlapReply *rs, slap_overinst *on )
        Operation opm;
        SlapReply rsm = { 0 };
        slap_callback cb = {0};
+       BackendDB be;
 
+       mod.sml_numvals = si->si_numcsns;
        mod.sml_values = si->si_ctxcsn;
        mod.sml_nvalues = NULL;
        mod.sml_desc = slap_schema.si_ad_contextCSN;
@@ -1304,8 +1322,12 @@ syncprov_checkpoint( Operation *op, SlapReply *rs, slap_overinst *on )
        opm.o_callback = &cb;
        opm.orm_modlist = &mod;
        opm.orm_no_opattrs = 1;
-       opm.o_req_dn = op->o_bd->be_suffix[0];
-       opm.o_req_ndn = op->o_bd->be_nsuffix[0];
+       if ( SLAP_GLUE_SUBORDINATE( op->o_bd )) {
+               be = *on->on_info->oi_origdb;
+               opm.o_bd = &be;
+       }
+       opm.o_req_dn = opm.o_bd->be_suffix[0];
+       opm.o_req_ndn = opm.o_bd->be_nsuffix[0];
        opm.o_bd->bd_info = on->on_info->oi_orig;
        opm.o_managedsait = SLAP_CONTROL_NONCRITICAL;
        opm.o_no_schema_check = 1;
@@ -1313,7 +1335,6 @@ syncprov_checkpoint( Operation *op, SlapReply *rs, slap_overinst *on )
        if ( mod.sml_next != NULL ) {
                slap_mods_free( mod.sml_next, 1 );
        }
-       opm.orm_no_opattrs = 0;
 }
 
 static void
@@ -1483,11 +1504,7 @@ syncprov_playlog( Operation *op, SlapReply *rs, sessionlog *sl,
                SlapReply frs = { REP_RESULT };
                int rc;
                Filter mf, af;
-#ifdef LDAP_COMP_MATCH
-               AttributeAssertion eq = { NULL, BER_BVNULL, NULL };
-#else
-               AttributeAssertion eq;
-#endif
+               AttributeAssertion eq = ATTRIBUTEASSERTION_INIT;
                slap_callback cb = {0};
 
                fop = *op;
@@ -1511,7 +1528,7 @@ syncprov_playlog( Operation *op, SlapReply *rs, sessionlog *sl,
                fop.ors_filter = &af;
 
                cb.sc_response = playlog_cb;
-               fop.o_bd->bd_info = on->on_info->oi_orig;
+               fop.o_bd->bd_info = (BackendInfo *)on->on_info;
 
                for ( i=ndel; i<num; i++ ) {
                        if ( uuids[i].bv_len == 0 ) continue;
@@ -1532,10 +1549,16 @@ syncprov_playlog( Operation *op, SlapReply *rs, sessionlog *sl,
        if ( ndel ) {
                struct berval cookie;
 
-               slap_compose_sync_cookie( op, &cookie, delcsn, srs->sr_state.rid,
-                       srs->sr_state.sid );
+               if ( delcsn[0].bv_len ) {
+                       slap_compose_sync_cookie( op, &cookie, delcsn, srs->sr_state.rid,
+                               srs->sr_state.sid );
+               }
+
+               Debug( LDAP_DEBUG_SYNC, "syncprov_playlog: cookie=%s\n", cookie.bv_val, 0, 0 );
+
                uuids[ndel].bv_val = NULL;
-               syncprov_sendinfo( op, rs, LDAP_TAG_SYNC_ID_SET, &cookie, 0, uuids, 1 );
+               syncprov_sendinfo( op, rs, LDAP_TAG_SYNC_ID_SET,
+                       delcsn[0].bv_len ? &cookie : NULL, 0, uuids, 1 );
                op->o_tmpfree( cookie.bv_val, op->o_tmpmemctx );
        }
        op->o_tmpfree( uuids, op->o_tmpmemctx );
@@ -1553,7 +1576,7 @@ syncprov_op_response( Operation *op, SlapReply *rs )
        {
                struct berval maxcsn = BER_BVNULL;
                char cbuf[LDAP_LUTIL_CSNSTR_BUFSIZE];
-               int do_check = 0;
+               int do_check = 0, have_psearches;
 
                /* Update our context CSN */
                cbuf[0] = '\0';
@@ -1596,8 +1619,12 @@ syncprov_op_response( Operation *op, SlapReply *rs )
                        }
                        if ( si->si_chktime &&
                                (op->o_time - si->si_chklast >= si->si_chktime )) {
-                               do_check = 1;
-                               si->si_chklast = op->o_time;
+                               if ( si->si_chklast ) {
+                                       do_check = 1;
+                                       si->si_chklast = op->o_time;
+                               } else {
+                                       si->si_chklast = 1;
+                               }
                        }
                }
                ldap_pvt_thread_rdwr_wunlock( &si->si_csn_rwlock );
@@ -1612,7 +1639,10 @@ syncprov_op_response( Operation *op, SlapReply *rs )
                opc->sctxcsn.bv_val = cbuf;
 
                /* Handle any persistent searches */
-               if ( si->si_ops ) {
+               ldap_pvt_thread_mutex_lock( &si->si_ops_mutex );
+               have_psearches = ( si->si_ops != NULL );
+               ldap_pvt_thread_mutex_unlock( &si->si_ops_mutex );
+               if ( have_psearches ) {
                        switch(op->o_tag) {
                        case LDAP_REQ_ADD:
                        case LDAP_REQ_MODIFY:
@@ -1687,10 +1717,10 @@ syncprov_op_compare( Operation *op, SlapReply *rs )
 
                rs->sr_err = LDAP_COMPARE_FALSE;
 
-               if ( value_find_ex( op->oq_compare.rs_ava->aa_desc,
+               if ( attr_valfind( &a,
                        SLAP_MR_ATTRIBUTE_VALUE_NORMALIZED_MATCH |
                                SLAP_MR_ASSERTED_VALUE_NORMALIZED_MATCH,
-                               a.a_nvals, &op->oq_compare.rs_ava->aa_value, op->o_tmpmemctx ) == 0 )
+                               &op->oq_compare.rs_ava->aa_value, NULL, op->o_tmpmemctx ) == 0 )
                {
                        rs->sr_err = LDAP_COMPARE_TRUE;
                }
@@ -1715,12 +1745,19 @@ syncprov_op_mod( Operation *op, SlapReply *rs )
 {
        slap_overinst           *on = (slap_overinst *)op->o_bd->bd_info;
        syncprov_info_t         *si = on->on_bi.bi_private;
+       slap_callback *cb;
+       opcookie *opc;
+       int have_psearches, cbsize;
+
+       ldap_pvt_thread_mutex_lock( &si->si_ops_mutex );
+       have_psearches = ( si->si_ops != NULL );
+       ldap_pvt_thread_mutex_unlock( &si->si_ops_mutex );
+
+       cbsize = sizeof(slap_callback) + sizeof(opcookie) +
+               (have_psearches ? sizeof(modinst) : 0 );
 
-       slap_callback *cb = op->o_tmpcalloc(1, sizeof(slap_callback)+
-               sizeof(opcookie) +
-               (si->si_ops ? sizeof(modinst) : 0 ),
-               op->o_tmpmemctx);
-       opcookie *opc = (opcookie *)(cb+1);
+       cb = op->o_tmpcalloc(1, cbsize, op->o_tmpmemctx);
+       opc = (opcookie *)(cb+1);
        opc->son = on;
        cb->sc_response = syncprov_op_response;
        cb->sc_cleanup = syncprov_op_cleanup;
@@ -1731,7 +1768,7 @@ syncprov_op_mod( Operation *op, SlapReply *rs )
        /* If there are active persistent searches, lock this operation.
         * See seqmod.c for the locking logic on its own.
         */
-       if ( si->si_ops ) {
+       if ( have_psearches ) {
                modtarget *mt, mtdummy;
                modinst *mi;
 
@@ -1750,7 +1787,13 @@ syncprov_op_mod( Operation *op, SlapReply *rs )
                        /* wait for this op to get to head of list */
                        while ( mt->mt_mods != mi ) {
                                ldap_pvt_thread_mutex_unlock( &mt->mt_mutex );
-                               ldap_pvt_thread_yield();
+                               /* FIXME: if dynamic config can delete overlays or
+                                * databases we'll have to check for cleanup here.
+                                * Currently it's not an issue because there are
+                                * no dynamic config deletes...
+                                */
+                               if ( !ldap_pvt_thread_pool_pausecheck( &connection_pool ))
+                                       ldap_pvt_thread_yield();
                                ldap_pvt_thread_mutex_lock( &mt->mt_mutex );
 
                                /* clean up if the caller is giving up */
@@ -1778,7 +1821,7 @@ syncprov_op_mod( Operation *op, SlapReply *rs )
                }
        }
 
-       if (( si->si_ops || si->si_logs ) && op->o_tag != LDAP_REQ_ADD )
+       if (( have_psearches || si->si_logs ) && op->o_tag != LDAP_REQ_ADD )
                syncprov_matchops( op, opc, 1 );
 
        return SLAP_CB_CONTINUE;
@@ -1799,7 +1842,9 @@ typedef struct searchstate {
        BerVarray ss_ctxcsn;
        int *ss_sids;
        int ss_numcsns;
-       int ss_present;
+#define        SS_PRESENT      0x01
+#define        SS_CHANGED      0x02
+       int ss_flags;
 } searchstate;
 
 static int
@@ -1816,6 +1861,7 @@ syncprov_search_cleanup( Operation *op, SlapReply *rs )
 typedef struct SyncOperationBuffer {
        Operation               sob_op;
        Opheader                sob_hdr;
+       OpExtra                 sob_oe;
        AttributeName   sob_extra;      /* not always present */
        /* Further data allocated here */
 } SyncOperationBuffer;
@@ -1844,6 +1890,7 @@ syncprov_detach_op( Operation *op, syncops *so, slap_overinst *on )
        sopbuf2 = ch_calloc( 1, size );
        op2 = &sopbuf2->sob_op;
        op2->o_hdr = &sopbuf2->sob_hdr;
+       LDAP_SLIST_FIRST(&op2->o_extra) = &sopbuf2->sob_oe;
 
        /* Copy the fields we care about explicitly, leave the rest alone */
        *op2->o_hdr = *op->o_hdr;
@@ -1851,7 +1898,8 @@ syncprov_detach_op( Operation *op, syncops *so, slap_overinst *on )
        op2->o_time = op->o_time;
        op2->o_bd = on->on_info->oi_origdb;
        op2->o_request = op->o_request;
-       op2->o_private = on;
+       LDAP_SLIST_FIRST(&op2->o_extra)->oe_key = on;
+       LDAP_SLIST_NEXT(LDAP_SLIST_FIRST(&op2->o_extra), oe_next) = NULL;
 
        ptr = (char *) sopbuf2 + offsetof( SyncOperationBuffer, sob_extra );
        if ( i ) {
@@ -1902,12 +1950,10 @@ syncprov_detach_op( Operation *op, syncops *so, slap_overinst *on )
        op2->o_do_not_cache = 1;
 
        /* Add op2 to conn so abandon will find us */
-       ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
        op->o_conn->c_n_ops_executing++;
        op->o_conn->c_n_ops_completed--;
        LDAP_STAILQ_INSERT_TAIL( &op->o_conn->c_ops, op2, o_next );
        so->s_flags |= PS_IS_DETACHED;
-       ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
 
        /* Prevent anyone else from trying to send a result for this op */
        op->o_abandon = 1;
@@ -1947,16 +1993,20 @@ syncprov_search_response( Operation *op, SlapReply *rs )
                                        rs->sr_entry->e_name.bv_val, 0, 0 );
                                return LDAP_SUCCESS;
                        }
-                       /* Make sure entry is less than the snapshot'd contextCSN */
-                       for ( i=0; i<ss->ss_numcsns; i++ ) {
-                               if ( sid == ss->ss_sids[i] && ber_bvcmp( &a->a_nvals[0],
-                                       &ss->ss_ctxcsn[i] ) > 0 ) {
-                                       Debug( LDAP_DEBUG_SYNC,
-                                               "Entry %s CSN %s greater than snapshot %s\n",
-                                               rs->sr_entry->e_name.bv_val,
-                                               a->a_nvals[0].bv_val,
-                                               ss->ss_ctxcsn[i].bv_val );
-                                       return LDAP_SUCCESS;
+
+                       /* If not a persistent search */
+                       if ( !ss->ss_so ) {
+                               /* Make sure entry is less than the snapshot'd contextCSN */
+                               for ( i=0; i<ss->ss_numcsns; i++ ) {
+                                       if ( sid == ss->ss_sids[i] && ber_bvcmp( &a->a_nvals[0],
+                                               &ss->ss_ctxcsn[i] ) > 0 ) {
+                                               Debug( LDAP_DEBUG_SYNC,
+                                                       "Entry %s CSN %s greater than snapshot %s\n",
+                                                       rs->sr_entry->e_name.bv_val,
+                                                       a->a_nvals[0].bv_val,
+                                                       ss->ss_ctxcsn[i].bv_val );
+                                               return LDAP_SUCCESS;
+                                       }
                                }
                        }
 
@@ -1984,36 +2034,56 @@ syncprov_search_response( Operation *op, SlapReply *rs )
        } else if ( rs->sr_type == REP_RESULT && rs->sr_err == LDAP_SUCCESS ) {
                struct berval cookie;
 
-               slap_compose_sync_cookie( op, &cookie, ss->ss_ctxcsn,
-                       srs->sr_state.rid, srs->sr_state.sid );
+               if ( ss->ss_flags & SS_CHANGED ) {
+                       slap_compose_sync_cookie( op, &cookie, ss->ss_ctxcsn,
+                               srs->sr_state.rid, srs->sr_state.sid );
 
-               /* Is this a regular refresh? */
+                       Debug( LDAP_DEBUG_SYNC, "syncprov_search_response: cookie=%s\n", cookie.bv_val, 0, 0 );
+               }
+
+               /* Is this a regular refresh?
+                * Note: refresh never gets here if there were no changes
+                */
                if ( !ss->ss_so ) {
                        rs->sr_ctrls = op->o_tmpalloc( sizeof(LDAPControl *)*2,
                                op->o_tmpmemctx );
                        rs->sr_ctrls[1] = NULL;
                        rs->sr_err = syncprov_done_ctrl( op, rs, rs->sr_ctrls,
-                               0, 1, &cookie, ss->ss_present ?  LDAP_SYNC_REFRESH_PRESENTS :
+                               0, 1, &cookie, ( ss->ss_flags & SS_PRESENT ) ?  LDAP_SYNC_REFRESH_PRESENTS :
                                        LDAP_SYNC_REFRESH_DELETES );
                        op->o_tmpfree( cookie.bv_val, op->o_tmpmemctx );
                } else {
                /* It's RefreshAndPersist, transition to Persist phase */
-                       syncprov_sendinfo( op, rs, ss->ss_present ?
+                       syncprov_sendinfo( op, rs, ( ss->ss_flags & SS_PRESENT ) ?
                                LDAP_TAG_SYNC_REFRESH_PRESENT : LDAP_TAG_SYNC_REFRESH_DELETE,
-                               &cookie, 1, NULL, 0 );
-                       op->o_tmpfree( cookie.bv_val, op->o_tmpmemctx );
+                               ( ss->ss_flags & SS_CHANGED ) ? &cookie : NULL,
+                               1, NULL, 0 );
+                       if ( ss->ss_flags & SS_CHANGED )
+                               op->o_tmpfree( cookie.bv_val, op->o_tmpmemctx );
 
                        /* Detach this Op from frontend control */
                        ldap_pvt_thread_mutex_lock( &ss->ss_so->s_mutex );
+                       ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
+
+                       /* But not if this connection was closed along the way */
+                       if ( op->o_abandon ) {
+                               ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
+                               ldap_pvt_thread_mutex_unlock( &ss->ss_so->s_mutex );
+                               syncprov_free_syncop( ss->ss_so );
+                               return SLAPD_ABANDON;
 
-                       /* Turn off the refreshing flag */
-                       ss->ss_so->s_flags ^= PS_IS_REFRESHING;
+                       } else {
+                               /* Turn off the refreshing flag */
+                               ss->ss_so->s_flags ^= PS_IS_REFRESHING;
+
+                               syncprov_detach_op( op, ss->ss_so, on );
 
-                       syncprov_detach_op( op, ss->ss_so, on );
+                               ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
 
-                       /* If there are queued responses, fire them off */
-                       if ( ss->ss_so->s_res )
-                               syncprov_qstart( ss->ss_so );
+                               /* If there are queued responses, fire them off */
+                               if ( ss->ss_so->s_res )
+                                       syncprov_qstart( ss->ss_so );
+                       }
                        ldap_pvt_thread_mutex_unlock( &ss->ss_so->s_mutex );
 
                        return LDAP_SUCCESS;
@@ -2029,7 +2099,7 @@ syncprov_op_search( Operation *op, SlapReply *rs )
        slap_overinst           *on = (slap_overinst *)op->o_bd->bd_info;
        syncprov_info_t         *si = (syncprov_info_t *)on->on_bi.bi_private;
        slap_callback   *cb;
-       int gotstate = 0, nochange = 0, do_present;
+       int gotstate = 0, changed = 0, do_present = 0;
        syncops *sop = NULL;
        searchstate *ss;
        sync_control *srs;
@@ -2044,8 +2114,6 @@ syncprov_op_search( Operation *op, SlapReply *rs )
                return rs->sr_err;
        }
 
-       do_present = si->si_nopres ? 0 : 1;
-
        srs = op->o_controls[slap_cids.sc_LDAPsync];
        op->o_managedsait = SLAP_CONTROL_NONCRITICAL;
 
@@ -2113,6 +2181,9 @@ syncprov_op_search( Operation *op, SlapReply *rs )
                if ( !numcsns )
                        goto no_change;
 
+               if ( !si->si_nopres )
+                       do_present = SS_PRESENT;
+
                /* If there are SIDs we don't recognize in the cookie, drop them */
                for (i=0; i<srs->sr_state.numcsns; ) {
                        for (j=0; j<numcsns; j++) {
@@ -2143,21 +2214,21 @@ syncprov_op_search( Operation *op, SlapReply *rs )
 
                /* If nothing has changed, shortcut it */
                if ( srs->sr_state.numcsns == numcsns ) {
-                       int i, j, changed = 0;
+                       int i, j;
                        for ( i=0; i<srs->sr_state.numcsns; i++ ) {
                                for ( j=0; j<numcsns; j++ ) {
                                        if ( srs->sr_state.sids[i] != sids[j] )
                                                continue;
                                        if ( !bvmatch( &srs->sr_state.ctxcsn[i], &ctxcsn[j] ))
-                                               changed = 1;
+                                               changed = SS_CHANGED;
                                        break;
                                }
                                if ( changed )
                                        break;
                        }
                        if ( !changed ) {
-no_change:             nochange = 1;
-                               if ( !(op->o_sync_mode & SLAP_SYNC_PERSIST) ) {
+                               do_present = 0;
+no_change:             if ( !(op->o_sync_mode & SLAP_SYNC_PERSIST) ) {
                                        LDAPControl     *ctrls[2];
 
                                        ctrls[0] = NULL;
@@ -2172,6 +2243,9 @@ no_change:                nochange = 1;
                                }
                                goto shortcut;
                        }
+               } else {
+                       /* consumer doesn't have the right number of CSNs */
+                       changed = SS_CHANGED;
                }
                /* Do we have a sessionlog for this search? */
                sl=si->si_logs;
@@ -2195,6 +2269,8 @@ no_change:                nochange = 1;
                        if ( si->si_usehint && srs->sr_rhint == 0 ) {
                                if ( ctxcsn )
                                        ber_bvarray_free_x( ctxcsn, op->o_tmpmemctx );
+                               if ( sids )
+                                       op->o_tmpfree( sids, op->o_tmpmemctx );
                                send_ldap_error( op, rs, LDAP_SYNC_REFRESH_REQUIRED, "sync cookie is stale" );
                                return rs->sr_err;
                        }
@@ -2205,10 +2281,15 @@ no_change:              nochange = 1;
                                LDAP_SUCCESS ) {
                                if ( ctxcsn )
                                        ber_bvarray_free_x( ctxcsn, op->o_tmpmemctx );
+                               if ( sids )
+                                       op->o_tmpfree( sids, op->o_tmpmemctx );
                                send_ldap_result( op, rs );
                                return rs->sr_err;
                        }
                }
+       } else {
+               /* No consumer state, assume something has changed */
+               changed = SS_CHANGED;
        }
 
 shortcut:
@@ -2220,7 +2301,7 @@ shortcut:
        }
 
        /* If something changed, find the changes */
-       if ( gotstate && !nochange ) {
+       if ( gotstate && changed ) {
                Filter *fand, *fava;
 
                fand = op->o_tmpalloc( sizeof(Filter), op->o_tmpmemctx );
@@ -2247,7 +2328,7 @@ shortcut:
        ss = (searchstate *)(cb+1);
        ss->ss_on = on;
        ss->ss_so = sop;
-       ss->ss_present = do_present;
+       ss->ss_flags = do_present | changed;
        ss->ss_ctxcsn = ctxcsn;
        ss->ss_numcsns = numcsns;
        ss->ss_sids = sids;
@@ -2261,7 +2342,7 @@ shortcut:
         * the refresh phase, just invoke the response callback to transition
         * us into persist phase
         */
-       if ( nochange ) {
+       if ( !changed ) {
                rs->sr_err = LDAP_SUCCESS;
                rs->sr_nentries = 0;
                send_ldap_result( op, rs );
@@ -2278,6 +2359,12 @@ syncprov_operational(
        slap_overinst           *on = (slap_overinst *)op->o_bd->bd_info;
        syncprov_info_t         *si = (syncprov_info_t *)on->on_bi.bi_private;
 
+       /* This prevents generating unnecessarily; frontend will strip
+        * any statically stored copy.
+        */
+       if ( op->o_sync != SLAP_CONTROL_NONE )
+               return SLAP_CB_CONTINUE;
+
        if ( rs->sr_entry &&
                dn_match( &rs->sr_entry->e_nname, op->o_bd->be_nsuffix )) {
 
@@ -2301,17 +2388,22 @@ syncprov_operational(
                                }
 
                                if ( !ap ) {
-                                       if ( !rs->sr_flags & REP_ENTRY_MODIFIABLE ) {
+                                       if ( !(rs->sr_flags & REP_ENTRY_MODIFIABLE) ) {
                                                rs->sr_entry = entry_dup( rs->sr_entry );
                                                rs->sr_flags |=
                                                        REP_ENTRY_MODIFIABLE|REP_ENTRY_MUSTBEFREED;
                                                a = attr_find( rs->sr_entry->e_attrs,
                                                        slap_schema.si_ad_contextCSN );
                                        }
-                                       free( a->a_vals );
+                                       if ( a->a_nvals != a->a_vals ) {
+                                               ber_bvarray_free( a->a_nvals );
+                                       }
+                                       a->a_nvals = NULL;
+                                       ber_bvarray_free( a->a_vals );
+                                       a->a_vals = NULL;
+                                       a->a_numvals = 0;
                                }
-                               ber_bvarray_dup_x( &a->a_vals, si->si_ctxcsn, NULL );
-                               a->a_nvals = a->a_vals;
+                               attr_valadd( a, si->si_ctxcsn, si->si_ctxcsn, si->si_numcsns );
                        }
                        ldap_pvt_thread_rdwr_runlock( &si->si_csn_rwlock );
                }
@@ -2370,10 +2462,14 @@ sp_cf_gen(ConfigArgs *c)
                case SP_CHKPT:
                        if ( si->si_chkops || si->si_chktime ) {
                                struct berval bv;
-                               bv.bv_len = sprintf( c->msg, "%d %d",
-                                       si->si_chkops, si->si_chktime );
-                               bv.bv_val = c->msg;
-                               value_add_one( &c->rvalue_vals, &bv );
+                               bv.bv_len = snprintf( c->cr_msg, sizeof( c->cr_msg ),
+                                       "%d %d", si->si_chkops, si->si_chktime );
+                               if ( bv.bv_len < 0 || bv.bv_len >= sizeof( c->cr_msg ) ) {
+                                       rc = 1;
+                               } else {
+                                       bv.bv_val = c->cr_msg;
+                                       value_add_one( &c->rvalue_vals, &bv );
+                               }
                        } else {
                                rc = 1;
                        }
@@ -2431,31 +2527,31 @@ sp_cf_gen(ConfigArgs *c)
        switch ( c->type ) {
        case SP_CHKPT:
                if ( lutil_atoi( &si->si_chkops, c->argv[1] ) != 0 ) {
-                       snprintf( c->msg, sizeof( c->msg ), "%s unable to parse checkpoint ops # \"%s\"",
+                       snprintf( c->cr_msg, sizeof( c->cr_msg ), "%s unable to parse checkpoint ops # \"%s\"",
                                c->argv[0], c->argv[1] );
                        Debug( LDAP_DEBUG_CONFIG|LDAP_DEBUG_NONE,
-                               "%s: %s\n", c->log, c->msg, 0 );
+                               "%s: %s\n", c->log, c->cr_msg, 0 );
                        return ARG_BAD_CONF;
                }
                if ( si->si_chkops <= 0 ) {
-                       snprintf( c->msg, sizeof( c->msg ), "%s invalid checkpoint ops # \"%d\"",
+                       snprintf( c->cr_msg, sizeof( c->cr_msg ), "%s invalid checkpoint ops # \"%d\"",
                                c->argv[0], si->si_chkops );
                        Debug( LDAP_DEBUG_CONFIG|LDAP_DEBUG_NONE,
-                               "%s: %s\n", c->log, c->msg, 0 );
+                               "%s: %s\n", c->log, c->cr_msg, 0 );
                        return ARG_BAD_CONF;
                }
                if ( lutil_atoi( &si->si_chktime, c->argv[2] ) != 0 ) {
-                       snprintf( c->msg, sizeof( c->msg ), "%s unable to parse checkpoint time \"%s\"",
+                       snprintf( c->cr_msg, sizeof( c->cr_msg ), "%s unable to parse checkpoint time \"%s\"",
                                c->argv[0], c->argv[1] );
                        Debug( LDAP_DEBUG_CONFIG|LDAP_DEBUG_NONE,
-                               "%s: %s\n", c->log, c->msg, 0 );
+                               "%s: %s\n", c->log, c->cr_msg, 0 );
                        return ARG_BAD_CONF;
                }
                if ( si->si_chktime <= 0 ) {
-                       snprintf( c->msg, sizeof( c->msg ), "%s invalid checkpoint time \"%d\"",
+                       snprintf( c->cr_msg, sizeof( c->cr_msg ), "%s invalid checkpoint time \"%d\"",
                                c->argv[0], si->si_chkops );
                        Debug( LDAP_DEBUG_CONFIG|LDAP_DEBUG_NONE,
-                               "%s: %s\n", c->log, c->msg, 0 );
+                               "%s: %s\n", c->log, c->cr_msg, 0 );
                        return ARG_BAD_CONF;
                }
                si->si_chktime *= 60;
@@ -2465,10 +2561,10 @@ sp_cf_gen(ConfigArgs *c)
                int size = c->value_int;
 
                if ( size < 0 ) {
-                       snprintf( c->msg, sizeof( c->msg ), "%s size %d is negative",
+                       snprintf( c->cr_msg, sizeof( c->cr_msg ), "%s size %d is negative",
                                c->argv[0], size );
                        Debug( LDAP_DEBUG_CONFIG|LDAP_DEBUG_NONE,
-                               "%s: %s\n", c->log, c->msg, 0 );
+                               "%s: %s\n", c->log, c->cr_msg, 0 );
                        return ARG_BAD_CONF;
                }
                sl = si->si_logs;
@@ -2513,7 +2609,7 @@ syncprov_db_otask(
 static int
 syncprov_db_open(
        BackendDB *be,
-       ConfigArgs *ca
+       ConfigReply *cr
 )
 {
        slap_overinst   *on = (slap_overinst *) be->bd_info;
@@ -2557,11 +2653,9 @@ syncprov_db_open(
 
                a = attr_find( e->e_attrs, slap_schema.si_ad_contextCSN );
                if ( a ) {
-                       int i;
                        ber_bvarray_dup_x( &si->si_ctxcsn, a->a_vals, NULL );
-                       for ( i = 0; !BER_BVISNULL( &a->a_vals[i] ); i++ );
-                       si->si_numcsns = i;
-                       si->si_sids = slap_parse_csn_sids( si->si_ctxcsn, i, NULL );
+                       si->si_numcsns = a->a_numvals;
+                       si->si_sids = slap_parse_csn_sids( si->si_ctxcsn, a->a_numvals, NULL );
                }
                overlay_entry_release_ov( op, e, 0, on );
                if ( si->si_ctxcsn ) {
@@ -2607,7 +2701,7 @@ out:
 static int
 syncprov_db_close(
        BackendDB *be,
-       ConfigArgs *ca
+       ConfigReply *cr
 )
 {
     slap_overinst   *on = (slap_overinst *) be->bd_info;
@@ -2638,7 +2732,7 @@ syncprov_db_close(
 static int
 syncprov_db_init(
        BackendDB *be,
-       ConfigArgs *ca
+       ConfigReply *cr
 )
 {
        slap_overinst   *on = (slap_overinst *)be->bd_info;
@@ -2671,7 +2765,7 @@ syncprov_db_init(
 static int
 syncprov_db_destroy(
        BackendDB *be,
-       ConfigArgs *ca
+       ConfigReply *cr
 )
 {
        slap_overinst   *on = (slap_overinst *)be->bd_info;
@@ -2790,10 +2884,14 @@ static int syncprov_parseCtrl (
        sr->sr_rhint = rhint;
        if (!BER_BVISNULL(&cookie)) {
                ber_dupbv_x( &sr->sr_state.octet_str, &cookie, op->o_tmpmemctx );
+               /* If parse fails, pretend no cookie was sent */
                if ( slap_parse_sync_cookie( &sr->sr_state, op->o_tmpmemctx ) ||
                        sr->sr_state.rid == -1 ) {
-                       rs->sr_text = "Sync control : cookie parsing error";
-                       return LDAP_PROTOCOL_ERROR;
+                       if ( sr->sr_state.ctxcsn ) {
+                               ber_bvarray_free_x( sr->sr_state.ctxcsn, op->o_tmpmemctx );
+                               sr->sr_state.ctxcsn = NULL;
+                       }
+                       sr->sr_state.numcsns = 0;
                }
        }