]> git.sur5r.net Git - openldap/blobdiff - servers/slapd/overlays/syncprov.c
Fix overlay aux_operational, add contextCSN as operational attribute
[openldap] / servers / slapd / overlays / syncprov.c
index a02ca2e8c5d8209d74b1ce407e7164006af87584..f6f414aa1c44b3f20818abcbbb33764ca41e86a4 100644 (file)
 
 #ifdef SLAPD_OVER_SYNCPROV
 
+#include <ac/string.h>
+#include "lutil.h"
 #include "slap.h"
 
+/* A modify request on a particular entry */
+typedef struct modinst {
+       struct modinst *mi_next;
+       Operation *mi_op;
+} modinst;
+
+typedef struct modtarget {
+       struct modinst *mt_mods;
+       struct modinst *mt_tail;
+       Operation *mt_op;
+       ldap_pvt_thread_mutex_t mt_mutex;
+} modtarget;
+
+/* A queued result of a persistent search */
+typedef struct syncres {
+       struct syncres *s_next;
+       struct berval s_dn;
+       struct berval s_ndn;
+       struct berval s_uuid;
+       struct berval s_csn;
+       char s_mode;
+       char s_isreference;
+} syncres;
+
 /* Record of a persistent search */
 typedef struct syncops {
        struct syncops *s_next;
        struct berval   s_base;         /* ndn of search base */
        ID              s_eid;          /* entryID of search base */
        Operation       *s_op;          /* search op */
+       long    s_sid;
+       long    s_rid;
+       struct berval s_filterstr;
+       int             s_flags;        /* search status */
+       int             s_inuse;        /* reference count */
+       struct syncres *s_res;
+       struct syncres *s_restail;
+       ldap_pvt_thread_mutex_t s_mutex;
 } syncops;
 
+static int     sync_cid;
+
+/* A received sync control */
+typedef struct sync_control {
+       struct sync_cookie sr_state;
+       int sr_rhint;
+} sync_control;
+
+/* o_sync_mode uses data bits of o_sync */
+#define        o_sync  o_ctrlflag[sync_cid]
+#define        o_sync_mode     o_ctrlflag[sync_cid]
+
+#define SLAP_SYNC_NONE                                 (LDAP_SYNC_NONE<<SLAP_CONTROL_SHIFT)
+#define SLAP_SYNC_REFRESH                              (LDAP_SYNC_REFRESH_ONLY<<SLAP_CONTROL_SHIFT)
+#define SLAP_SYNC_PERSIST                              (LDAP_SYNC_RESERVED<<SLAP_CONTROL_SHIFT)
+#define SLAP_SYNC_REFRESH_AND_PERSIST  (LDAP_SYNC_REFRESH_AND_PERSIST<<SLAP_CONTROL_SHIFT)
+
+#define        PS_IS_REFRESHING        0x01
+
 /* Record of which searches matched at premodify step */
 typedef struct syncmatches {
        struct syncmatches *sm_next;
        syncops *sm_op;
 } syncmatches;
 
+/* The main state for this overlay */
 typedef struct syncprov_info_t {
-       Entry           *si_e;  /* cached ldapsync context */
        syncops         *si_ops;
-       int             si_chkops;      /* checkpointing */
-       int             si_chktime;
-       int             si_numops;      /* number of ops since last checkpoint */
-       time_t  si_chklast;     /* time of last checkpoint */
-       ldap_pvt_thread_mutext_t si_e_mutex;
-       ldap_pvt_thread_mutext_t si_ops_mutex;
-       ldap_pvt_thread_mutext_t si_chk_mutex;
+       struct berval   si_ctxcsn;      /* ldapsync context */
+       int             si_gotcsn;      /* is our ctxcsn up to date? */
+       Avlnode *si_mods;       /* entries being modified */
+       ldap_pvt_thread_mutex_t si_csn_mutex;
+       ldap_pvt_thread_mutex_t si_ops_mutex;
+       ldap_pvt_thread_mutex_t si_mods_mutex;
+       char            si_ctxcsnbuf[LDAP_LUTIL_CSNSTR_BUFSIZE];
 } syncprov_info_t;
 
 typedef struct opcookie {
        slap_overinst *son;
        syncmatches *smatches;
+       struct berval sdn;      /* DN of entry, for deletes */
+       struct berval sndn;
+       struct berval suuid;    /* UUID of entry */
+       struct berval sctxcsn;
+       int sreference; /* Is the entry a reference? */
 } opcookie;
 
-/* Refresh - find entries between cookie CSN and current CSN at start
- * of operation.
+typedef struct fbase_cookie {
+       struct berval *fdn;     /* DN of a modified entry, for scope testing */
+       syncops *fss;   /* persistent search we're testing against */
+       int fbase;      /* if TRUE we found the search base and it's still valid */
+       int fscope;     /* if TRUE then fdn is within the psearch scope */
+} fbase_cookie;
+
+static AttributeName csn_anlist[2];
+static AttributeName uuid_anlist[2];
+
+/* Build a LDAPsync intermediate state control */
+static int
+syncprov_state_ctrl(
+       Operation       *op,
+       SlapReply       *rs,
+       Entry           *e,
+       int                     entry_sync_state,
+       LDAPControl     **ctrls,
+       int                     num_ctrls,
+       int                     send_cookie,
+       struct berval   *cookie)
+{
+       Attribute* a;
+       int ret;
+       int res;
+       const char *text = NULL;
+
+       BerElementBuffer berbuf;
+       BerElement *ber = (BerElement *)&berbuf;
+
+       struct berval entryuuid_bv      = BER_BVNULL;
+
+       ber_init2( ber, 0, LBER_USE_DER );
+       ber_set_option( ber, LBER_OPT_BER_MEMCTX, &op->o_tmpmemctx );
+
+       ctrls[num_ctrls] = slap_sl_malloc ( sizeof ( LDAPControl ), op->o_tmpmemctx );
+
+       for ( a = e->e_attrs; a != NULL; a = a->a_next ) {
+               AttributeDescription *desc = a->a_desc;
+               if ( desc == slap_schema.si_ad_entryUUID ) {
+                       entryuuid_bv = a->a_nvals[0];
+                       break;
+               }
+       }
+
+       if ( send_cookie && cookie ) {
+               ber_printf( ber, "{eOON}",
+                       entry_sync_state, &entryuuid_bv, cookie );
+       } else {
+               ber_printf( ber, "{eON}",
+                       entry_sync_state, &entryuuid_bv );
+       }
+
+       ctrls[num_ctrls]->ldctl_oid = LDAP_CONTROL_SYNC_STATE;
+       ctrls[num_ctrls]->ldctl_iscritical = (op->o_sync == SLAP_CONTROL_CRITICAL);
+       ret = ber_flatten2( ber, &ctrls[num_ctrls]->ldctl_value, 1 );
+
+       ber_free_buf( ber );
+
+       if ( ret < 0 ) {
+               Debug( LDAP_DEBUG_TRACE,
+                       "slap_build_sync_ctrl: ber_flatten2 failed\n",
+                       0, 0, 0 );
+               send_ldap_error( op, rs, LDAP_OTHER, "internal error" );
+               return ret;
+       }
+
+       return LDAP_SUCCESS;
+}
+
+/* Build a LDAPsync final state control */
+static int
+syncprov_done_ctrl(
+       Operation       *op,
+       SlapReply       *rs,
+       LDAPControl     **ctrls,
+       int                     num_ctrls,
+       int                     send_cookie,
+       struct berval *cookie,
+       int                     refreshDeletes )
+{
+       int ret;
+       BerElementBuffer berbuf;
+       BerElement *ber = (BerElement *)&berbuf;
+
+       ber_init2( ber, NULL, LBER_USE_DER );
+       ber_set_option( ber, LBER_OPT_BER_MEMCTX, &op->o_tmpmemctx );
+
+       ctrls[num_ctrls] = ch_malloc ( sizeof ( LDAPControl ) );
+
+       ber_printf( ber, "{" );
+       if ( send_cookie && cookie ) {
+               ber_printf( ber, "O", cookie );
+       }
+       if ( refreshDeletes == LDAP_SYNC_REFRESH_DELETES ) {
+               ber_printf( ber, "b", refreshDeletes );
+       }
+       ber_printf( ber, "N}" );        
+
+       ctrls[num_ctrls]->ldctl_oid = LDAP_CONTROL_SYNC_DONE;
+       ctrls[num_ctrls]->ldctl_iscritical = (op->o_sync == SLAP_CONTROL_CRITICAL);
+       ret = ber_flatten2( ber, &ctrls[num_ctrls]->ldctl_value, 1 );
+
+       ber_free_buf( ber );
+
+       if ( ret < 0 ) {
+               Debug( LDAP_DEBUG_TRACE,
+                       "syncprov_done_ctrl: ber_flatten2 failed\n",
+                       0, 0, 0 );
+               send_ldap_error( op, rs, LDAP_OTHER, "internal error" );
+               return ret;
+       }
+
+       return LDAP_SUCCESS;
+}
+
+#if 0
+/* Generate state based on session log - not implemented yet */
+static int
+syncprov_state_ctrl_from_slog(
+       Operation       *op,
+       SlapReply       *rs,
+       struct slog_entry *slog_e,
+       int                     entry_sync_state,
+       LDAPControl     **ctrls,
+       int                     num_ctrls,
+       int                     send_cookie,
+       struct berval   *cookie)
+{
+       Attribute* a;
+       int ret;
+       int res;
+       const char *text = NULL;
+
+       BerElementBuffer berbuf;
+       BerElement *ber = (BerElement *)&berbuf;
+
+       struct berval entryuuid_bv      = BER_BVNULL;
+
+       ber_init2( ber, NULL, LBER_USE_DER );
+       ber_set_option( ber, LBER_OPT_BER_MEMCTX, &op->o_tmpmemctx );
+
+       ctrls[num_ctrls] = ch_malloc ( sizeof ( LDAPControl ) );
+
+       entryuuid_bv = slog_e->sl_uuid;
+
+       if ( send_cookie && cookie ) {
+               ber_printf( ber, "{eOON}",
+                       entry_sync_state, &entryuuid_bv, cookie );
+       } else {
+               ber_printf( ber, "{eON}",
+                       entry_sync_state, &entryuuid_bv );
+       }
+
+       ctrls[num_ctrls]->ldctl_oid = LDAP_CONTROL_SYNC_STATE;
+       ctrls[num_ctrls]->ldctl_iscritical = (op->o_sync == SLAP_CONTROL_CRITICAL);
+       ret = ber_flatten2( ber, &ctrls[num_ctrls]->ldctl_value, 1 );
+
+       ber_free_buf( ber );
+
+       if ( ret < 0 ) {
+               Debug( LDAP_DEBUG_TRACE,
+                       "slap_build_sync_ctrl: ber_flatten2 failed\n",
+                       0, 0, 0 );
+               send_ldap_error( op, rs, LDAP_OTHER, "internal error" );
+               return ret;
+       }
+
+       return LDAP_SUCCESS;
+}
+#endif
+
+static int
+syncprov_sendinfo(
+       Operation       *op,
+       SlapReply       *rs,
+       int                     type,
+       struct berval *cookie,
+       int                     refreshDone,
+       BerVarray       syncUUIDs,
+       int                     refreshDeletes )
+{
+       BerElementBuffer berbuf;
+       BerElement *ber = (BerElement *)&berbuf;
+       struct berval rspdata;
+
+       int ret;
+
+       ber_init2( ber, NULL, LBER_USE_DER );
+       ber_set_option( ber, LBER_OPT_BER_MEMCTX, &op->o_tmpmemctx );
+
+       if ( type ) {
+               switch ( type ) {
+               case LDAP_TAG_SYNC_NEW_COOKIE:
+                       ber_printf( ber, "tO", type, cookie );
+                       break;
+               case LDAP_TAG_SYNC_REFRESH_DELETE:
+               case LDAP_TAG_SYNC_REFRESH_PRESENT:
+                       ber_printf( ber, "t{", type );
+                       if ( cookie ) {
+                               ber_printf( ber, "O", cookie );
+                       }
+                       if ( refreshDone == 0 ) {
+                               ber_printf( ber, "b", refreshDone );
+                       }
+                       ber_printf( ber, "N}" );
+                       break;
+               case LDAP_TAG_SYNC_ID_SET:
+                       ber_printf( ber, "t{", type );
+                       if ( cookie ) {
+                               ber_printf( ber, "O", cookie );
+                       }
+                       if ( refreshDeletes == 1 ) {
+                               ber_printf( ber, "b", refreshDeletes );
+                       }
+                       ber_printf( ber, "[W]", syncUUIDs );
+                       ber_printf( ber, "N}" );
+                       break;
+               default:
+                       Debug( LDAP_DEBUG_TRACE,
+                               "syncprov_sendinfo: invalid syncinfo type (%d)\n",
+                               type, 0, 0 );
+                       return LDAP_OTHER;
+               }
+       }
+
+       ret = ber_flatten2( ber, &rspdata, 0 );
+
+       if ( ret < 0 ) {
+               Debug( LDAP_DEBUG_TRACE,
+                       "syncprov_sendinfo: ber_flatten2 failed\n",
+                       0, 0, 0 );
+               send_ldap_error( op, rs, LDAP_OTHER, "internal error" );
+               return ret;
+       }
+
+       rs->sr_rspoid = LDAP_SYNC_INFO;
+       rs->sr_rspdata = &rspdata;
+       send_ldap_intermediate( op, rs );
+       rs->sr_rspdata = NULL;
+       ber_free_buf( ber );
+
+       return LDAP_SUCCESS;
+}
+
+/* Find a modtarget in an AVL tree */
+static int
+sp_avl_cmp( const void *c1, const void *c2 )
+{
+       const modtarget *m1, *m2;
+       int rc;
+
+       m1 = c1; m2 = c2;
+       rc = m1->mt_op->o_req_ndn.bv_len - m2->mt_op->o_req_ndn.bv_len;
+
+       if ( rc ) return rc;
+       return ber_bvcmp( &m1->mt_op->o_req_ndn, &m2->mt_op->o_req_ndn );
+}
+
+/* syncprov_findbase:
+ *   finds the true DN of the base of a search (with alias dereferencing) and
+ * checks to make sure the base entry doesn't get replaced with a different
+ * entry (e.g., swapping trees via ModDN, or retargeting an alias). If a
+ * change is detected, any persistent search on this base must be terminated /
+ * reloaded.
+ *   On the first call, we just save the DN and entryID. On subsequent calls
+ * we compare the DN and entryID with the saved values.
  */
+static int
+findbase_cb( Operation *op, SlapReply *rs )
+{
+       slap_callback *sc = op->o_callback;
+
+       if ( rs->sr_type == REP_SEARCH && rs->sr_err == LDAP_SUCCESS ) {
+               fbase_cookie *fc = sc->sc_private;
+
+               /* If no entryID, we're looking for the first time.
+                * Just store whatever we got.
+                */
+               if ( fc->fss->s_eid == NOID ) {
+                       fc->fbase = 1;
+                       fc->fss->s_eid = rs->sr_entry->e_id;
+                       ber_dupbv( &fc->fss->s_base, &rs->sr_entry->e_nname );
+
+               } else if ( rs->sr_entry->e_id == fc->fss->s_eid &&
+                       dn_match( &rs->sr_entry->e_nname, &fc->fss->s_base )) {
+
+               /* OK, the DN is the same and the entryID is the same. Now
+                * see if the fdn resides in the scope.
+                */
+                       fc->fbase = 1;
+                       switch ( fc->fss->s_op->ors_scope ) {
+                       case LDAP_SCOPE_BASE:
+                               fc->fscope = dn_match( fc->fdn, &rs->sr_entry->e_nname );
+                               break;
+                       case LDAP_SCOPE_ONELEVEL: {
+                               struct berval pdn;
+                               dnParent( fc->fdn, &pdn );
+                               fc->fscope = dn_match( &pdn, &rs->sr_entry->e_nname );
+                               break; }
+                       case LDAP_SCOPE_SUBTREE:
+                               fc->fscope = dnIsSuffix( fc->fdn, &rs->sr_entry->e_nname );
+                               break;
+#ifdef LDAP_SCOPE_SUBORDINATE
+                       case LDAP_SCOPE_SUBORDINATE:
+                               fc->fscope = dnIsSuffix( fc->fdn, &rs->sr_entry->e_nname ) &&
+                                       !dn_match( fc->fdn, &rs->sr_entry->e_nname );
+                               break;
+#endif
+                       }
+               }
+       }
+       return LDAP_SUCCESS;
+}
+
+static int
+syncprov_findbase( Operation *op, fbase_cookie *fc )
+{
+       opcookie *opc = op->o_callback->sc_private;
+       slap_overinst *on = opc->son;
+       syncprov_info_t         *si = on->on_bi.bi_private;
+
+       slap_callback cb = {0};
+       Operation fop;
+       SlapReply frs = { REP_RESULT };
+       int rc;
+
+       fop = *op;
+
+       cb.sc_response = findbase_cb;
+       cb.sc_private = fc;
+
+       fop.o_sync_mode &= SLAP_CONTROL_MASK;   /* turn off sync mode */
+       fop.o_callback = &cb;
+       fop.o_tag = LDAP_REQ_SEARCH;
+       fop.ors_scope = LDAP_SCOPE_BASE;
+       fop.ors_deref = fc->fss->s_op->ors_deref;
+       fop.ors_slimit = 1;
+       fop.ors_tlimit = SLAP_NO_LIMIT;
+       fop.ors_attrs = slap_anlist_no_attrs;
+       fop.ors_attrsonly = 1;
+       fop.ors_filter = fc->fss->s_op->ors_filter;
+       fop.ors_filterstr = fc->fss->s_op->ors_filterstr;
+
+       fop.o_req_ndn = fc->fss->s_op->o_req_ndn;
+
+       fop.o_bd->bd_info = on->on_info->oi_orig;
+       rc = fop.o_bd->be_search( &fop, &frs );
+       fop.o_bd->bd_info = (BackendInfo *)on;
+
+       if ( fc->fbase ) return LDAP_SUCCESS;
+
+       /* If entryID has changed, then the base of this search has
+        * changed. Invalidate the psearch.
+        */
+       return LDAP_NO_SUCH_OBJECT;
+}
+
+/* syncprov_findcsn:
+ *   This function has three different purposes, but they all use a search
+ * that filters on entryCSN so they're combined here.
+ * 1: when the current contextCSN is unknown (i.e., at server start time)
+ * and a syncrepl search has arrived with a cookie, we search for all entries
+ * with CSN >= the cookie CSN, and store the maximum as our contextCSN. Also,
+ * we expect to find the cookie CSN in the search results, and note if we did
+ * or not. If not, we assume the cookie is stale. (This may be too restrictive,
+ * notice case 2.)
+ *
+ * 2: when the current contextCSN is known and we have a sync cookie, we search
+ * for one entry with CSN <= the cookie CSN. (Used to search for =.) If an
+ * entry is found, the cookie CSN is valid, otherwise it is stale. Case 1 is
+ * considered a special case of case 2, and both are generally called the
+ * "find CSN" task.
+ *
+ * 3: during a refresh phase, we search for all entries with CSN <= the cookie
+ * CSN, and generate Present records for them. We always collect this result
+ * in SyncID sets, even if there's only one match.
+ */
+#define        FIND_CSN        1
+#define        FIND_PRESENT    2
+
+typedef struct fcsn_cookie {
+       struct berval maxcsn;
+       int gotmatch;
+} fcsn_cookie;
+
+static int
+findcsn_cb( Operation *op, SlapReply *rs )
+{
+       slap_callback *sc = op->o_callback;
+
+       if ( rs->sr_type == REP_SEARCH && rs->sr_err == LDAP_SUCCESS ) {
+               /* If the private pointer is set, it points to an fcsn_cookie
+                * and we want to record the maxcsn and match state.
+                */
+               if ( sc->sc_private ) {
+                       int i;
+                       fcsn_cookie *fc = sc->sc_private;
+                       sync_control *srs = op->o_controls[sync_cid];
+                       Attribute *a = attr_find(rs->sr_entry->e_attrs,
+                               slap_schema.si_ad_entryCSN );
+                       i = ber_bvcmp( &a->a_vals[0], srs->sr_state.ctxcsn );
+                       if ( i == 0 ) fc->gotmatch = 1;
+                       i = ber_bvcmp( &a->a_vals[0], &fc->maxcsn );
+                       if ( i > 0 ) {
+                               fc->maxcsn.bv_len = a->a_vals[0].bv_len;
+                               strcpy(fc->maxcsn.bv_val, a->a_vals[0].bv_val );
+                       }
+               } else {
+               /* Otherwise, if the private pointer is not set, we just
+                * want to know if any entry matched the filter.
+                */
+                       sc->sc_private = (void *)1;
+               }
+       }
+       return LDAP_SUCCESS;
+}
+
+/* Build a list of entryUUIDs for sending in a SyncID set */
+
+typedef struct fpres_cookie {
+       int num;
+       BerVarray uuids;
+} fpres_cookie;
+
+static int
+findpres_cb( Operation *op, SlapReply *rs )
+{
+       slap_callback *sc = op->o_callback;
+       fpres_cookie *pc = sc->sc_private;
+       int ret = SLAP_CB_CONTINUE;
+
+       if ( rs->sr_type == REP_SEARCH ) {
+               ret = slap_build_syncUUID_set( op, &pc->uuids, rs->sr_entry );
+               if ( ret > 0 ) {
+                       pc->num++;
+                       ret = LDAP_SUCCESS;
+                       if ( pc->num == SLAP_SYNCUUID_SET_SIZE ) {
+                               ret = syncprov_sendinfo( op, rs, LDAP_TAG_SYNC_ID_SET, NULL,
+                                       0, pc->uuids, 0 );
+                               ber_bvarray_free_x( pc->uuids, op->o_tmpmemctx );
+                               pc->uuids = NULL;
+                               pc->num = 0;
+                       }
+               } else {
+                       ret = LDAP_OTHER;
+               }
+       } else if ( rs->sr_type == REP_RESULT ) {
+               ret = rs->sr_err;
+               if ( pc->num ) {
+                       ret = syncprov_sendinfo( op, rs, LDAP_TAG_SYNC_ID_SET, NULL,
+                               0, pc->uuids, 0 );
+                       ber_bvarray_free_x( pc->uuids, op->o_tmpmemctx );
+                       pc->uuids = NULL;
+                       pc->num = 0;
+               }
+       }
+       return ret;
+}
+
+
+static int
+syncprov_findcsn( Operation *op, int mode )
+{
+       slap_overinst           *on = (slap_overinst *)op->o_bd->bd_info;
+       syncprov_info_t         *si = on->on_bi.bi_private;
+
+       slap_callback cb = {0};
+       Operation fop;
+       SlapReply frs = { REP_RESULT };
+       char buf[LDAP_LUTIL_CSNSTR_BUFSIZE + STRLENOF("(entryCSN<=)")];
+       char cbuf[LDAP_LUTIL_CSNSTR_BUFSIZE];
+       struct berval fbuf;
+       Filter cf;
+       AttributeAssertion eq;
+       int rc;
+       fcsn_cookie fcookie;
+       fpres_cookie pcookie;
+       int locked = 0;
+       sync_control *srs = op->o_controls[sync_cid];
+
+       if ( srs->sr_state.ctxcsn->bv_len >= LDAP_LUTIL_CSNSTR_BUFSIZE ) {
+               return LDAP_OTHER;
+       }
+
+       fop = *op;
+       fop.o_sync_mode &= SLAP_CONTROL_MASK;   /* turn off sync_mode */
+
+       fbuf.bv_val = buf;
+       if ( mode == FIND_CSN ) {
+               if ( !si->si_gotcsn ) {
+                       /* If we don't know the current ctxcsn, find it */
+                       ldap_pvt_thread_mutex_lock( &si->si_csn_mutex );
+                       locked = 1;
+               }
+               if ( !si->si_gotcsn ) {
+                       cf.f_choice = LDAP_FILTER_GE;
+                       fop.ors_attrsonly = 0;
+                       fop.ors_attrs = csn_anlist;
+                       fop.ors_slimit = SLAP_NO_LIMIT;
+                       cb.sc_private = &fcookie;
+                       fcookie.maxcsn.bv_val = cbuf;
+                       fcookie.maxcsn.bv_len = 0;
+                       fcookie.gotmatch = 0;
+                       fbuf.bv_len = sprintf( buf, "(entryCSN>=%s)", srs->sr_state.ctxcsn->bv_val );
+               } else {
+                       if ( locked ) {
+                               ldap_pvt_thread_mutex_unlock( &si->si_csn_mutex );
+                               locked = 0;
+                       }
+                       cf.f_choice = LDAP_FILTER_LE;
+                       fop.ors_attrsonly = 1;
+                       fop.ors_attrs = slap_anlist_no_attrs;
+                       fop.ors_slimit = 1;
+                       cb.sc_private = NULL;
+                       fbuf.bv_len = sprintf( buf, "(entryCSN<=%s)", srs->sr_state.ctxcsn->bv_val );
+               }
+               cb.sc_response = findcsn_cb;
+
+       } else if ( mode == FIND_PRESENT ) {
+               cf.f_choice = LDAP_FILTER_LE;
+               fop.ors_attrsonly = 0;
+               fop.ors_attrs = uuid_anlist;
+               fop.ors_slimit = SLAP_NO_LIMIT;
+               /* We want pure entries, not referrals */
+               fop.o_managedsait = SLAP_CONTROL_CRITICAL;
+               cb.sc_private = &pcookie;
+               cb.sc_response = findpres_cb;
+               pcookie.num = 0;
+               pcookie.uuids = NULL;
+               fbuf.bv_len = sprintf( buf, "(entryCSN<=%s)", srs->sr_state.ctxcsn->bv_val );
+       }
+       cf.f_ava = &eq;
+       cf.f_av_desc = slap_schema.si_ad_entryCSN;
+       cf.f_av_value = *srs->sr_state.ctxcsn;
+       cf.f_next = NULL;
+
+       fop.o_callback = &cb;
+       fop.ors_tlimit = SLAP_NO_LIMIT;
+       fop.ors_filter = &cf;
+       fop.ors_filterstr = fbuf;
+
+       fop.o_bd->bd_info = on->on_info->oi_orig;
+       rc = fop.o_bd->be_search( &fop, &frs );
+       fop.o_bd->bd_info = (BackendInfo *)on;
+
+       if ( mode == FIND_CSN ) {
+               if ( !si->si_gotcsn ) {
+                       strcpy(si->si_ctxcsnbuf, fcookie.maxcsn.bv_val);
+                       si->si_ctxcsn.bv_len = fcookie.maxcsn.bv_len;
+                       si->si_gotcsn = 1;
+                       ldap_pvt_thread_mutex_unlock( &si->si_csn_mutex );
+                       if ( fcookie.gotmatch ) return LDAP_SUCCESS;
+                       
+               } else {
+                       if ( cb.sc_private ) return LDAP_SUCCESS;
+               }
+       } else if ( mode == FIND_PRESENT ) {
+               return LDAP_SUCCESS;
+       }
+
+       /* If matching CSN was not found, invalidate the context. */
+       return LDAP_NO_SUCH_OBJECT;
+}
+
+/* Queue a persistent search response if still in Refresh stage */
+static int
+syncprov_qresp( opcookie *opc, syncops *so, int mode )
+{
+       syncres *sr;
+
+       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 );
+       sr->s_next = NULL;
+       sr->s_dn.bv_val = (char *)(sr + 1);
+       sr->s_mode = mode;
+       sr->s_isreference = opc->sreference;
+       sr->s_ndn.bv_val = lutil_strcopy( sr->s_dn.bv_val, opc->sdn.bv_val );
+       *(sr->s_ndn.bv_val++) = '\0';
+       sr->s_uuid.bv_val = lutil_strcopy( sr->s_ndn.bv_val, opc->sndn.bv_val );
+       *(sr->s_uuid.bv_val++) = '\0';
+       sr->s_csn.bv_val = lutil_strcopy( sr->s_uuid.bv_val, opc->suuid.bv_val );
+
+       if ( !so->s_res ) {
+               so->s_res = sr;
+       } else {
+               so->s_restail->s_next = sr;
+       }
+       so->s_restail = sr;
+       ldap_pvt_thread_mutex_unlock( &so->s_mutex );
+       return LDAP_SUCCESS;
+}
+
+/* Send a persistent search response */
+static int
+syncprov_sendresp( Operation *op, opcookie *opc, syncops *so, Entry *e, int mode, int queue )
+{
+       slap_overinst *on = opc->son;
+       syncprov_info_t *si = on->on_bi.bi_private;
+
+       SlapReply rs = { REP_SEARCH };
+       LDAPControl *ctrls[2];
+       struct berval cookie;
+       Entry e_uuid = {0};
+       Attribute a_uuid = {0};
+       Operation sop = *so->s_op;
+       Opheader ohdr;
+
+       ohdr = *sop.o_hdr;
+       sop.o_hdr = &ohdr;
+       sop.o_tmpmemctx = op->o_tmpmemctx;
+       sop.o_bd = op->o_bd;
+       sop.o_controls = op->o_controls;
+
+       if ( queue && (so->s_flags & PS_IS_REFRESHING) ) {
+               ldap_pvt_thread_mutex_lock( &so->s_mutex );
+               if ( so->s_flags & PS_IS_REFRESHING )
+                       return syncprov_qresp( opc, so, mode );
+               ldap_pvt_thread_mutex_unlock( &so->s_mutex );
+       }
+
+       ctrls[1] = NULL;
+       slap_compose_sync_cookie( op, &cookie, &opc->sctxcsn,
+               so->s_sid, so->s_rid );
+
+       e_uuid.e_attrs = &a_uuid;
+       a_uuid.a_desc = slap_schema.si_ad_entryUUID;
+       a_uuid.a_nvals = &opc->suuid;
+       rs.sr_err = syncprov_state_ctrl( &sop, &rs, &e_uuid,
+               mode, ctrls, 0, 1, &cookie );
+
+       rs.sr_entry = e;
+       rs.sr_ctrls = ctrls;
+       switch( mode ) {
+       case LDAP_SYNC_ADD:
+               if ( opc->sreference ) {
+                       rs.sr_ref = get_entry_referrals( &sop, e );
+                       send_search_reference( &sop, &rs );
+                       ber_bvarray_free( rs.sr_ref );
+                       break;
+               }
+               /* fallthru */
+       case LDAP_SYNC_MODIFY:
+               rs.sr_attrs = sop.ors_attrs;
+               send_search_entry( &sop, &rs );
+               break;
+       case LDAP_SYNC_DELETE:
+               e_uuid.e_attrs = NULL;
+               e_uuid.e_name = opc->sdn;
+               e_uuid.e_nname = opc->sndn;
+               rs.sr_entry = &e_uuid;
+               if ( opc->sreference ) {
+                       struct berval bv;
+                       bv.bv_val = NULL;
+                       bv.bv_len = 0;
+                       rs.sr_ref = &bv;
+                       send_search_reference( &sop, &rs );
+               } else {
+                       send_search_entry( &sop, &rs );
+               }
+               break;
+       default:
+               assert(0);
+       }
+       free( rs.sr_ctrls[0] );
+       return rs.sr_err;
+}
 
 static void
-syncprov_matchops( Operation *op, opcookie *opc )
+syncprov_free_syncop( syncops *so )
+{
+       syncres *sr, *srnext;
+
+       ldap_pvt_thread_mutex_lock( &so->s_mutex );
+       so->s_inuse--;
+       if ( so->s_inuse > 0 ) {
+               ldap_pvt_thread_mutex_unlock( &so->s_mutex );
+               return;
+       }
+       ldap_pvt_thread_mutex_unlock( &so->s_mutex );
+       filter_free( so->s_op->ors_filter );
+       ch_free( so->s_op );
+       ch_free( so->s_base.bv_val );
+       for ( sr=so->s_res; sr; sr=srnext ) {
+               srnext = sr->s_next;
+               ch_free( sr );
+       }
+       ldap_pvt_thread_mutex_destroy( &so->s_mutex );
+       ch_free( so );
+}
+
+static int
+syncprov_drop_psearch( syncops *so )
+{
+       ldap_pvt_thread_mutex_lock( &so->s_op->o_conn->c_mutex );
+       so->s_op->o_conn->c_n_ops_executing--;
+       so->s_op->o_conn->c_n_ops_completed++;
+       ldap_pvt_thread_mutex_unlock( &so->s_op->o_conn->c_mutex );
+       syncprov_free_syncop( so );
+}
+
+static int
+syncprov_op_abandon( Operation *op, SlapReply *rs )
 {
        slap_overinst           *on = (slap_overinst *)op->o_bd->bd_info;
        syncprov_info_t         *si = on->on_bi.bi_private;
+       syncops *so, *soprev;
+
+       ldap_pvt_thread_mutex_lock( &si->si_ops_mutex );
+       for ( so=si->si_ops, soprev = (syncops *)&si->si_ops; so;
+               soprev=so, so=so->s_next ) {
+               if ( so->s_op->o_connid == op->o_connid &&
+                       so->s_op->o_msgid == op->orn_msgid ) {
+                               so->s_op->o_abandon = 1;
+                               soprev->s_next = so->s_next;
+                               break;
+               }
+       }
+       ldap_pvt_thread_mutex_unlock( &si->si_ops_mutex );
+       if ( so ) {
+               /* Is this really a Cancel exop? */
+               if ( op->o_tag != LDAP_REQ_ABANDON ) {
+                       rs->sr_err = LDAP_CANCELLED;
+                       send_ldap_result( so->s_op, rs );
+               }
+               syncprov_drop_psearch( so );
+       }
+       return SLAP_CB_CONTINUE;
+}
+
+/* Find which persistent searches are affected by this operation */
+static void
+syncprov_matchops( Operation *op, opcookie *opc, int saveit )
+{
+       slap_overinst *on = opc->son;
+       syncprov_info_t         *si = on->on_bi.bi_private;
 
-       syncops *ss;
+       fbase_cookie fc;
+       syncops *ss, *sprev, *snext;
+       Entry *e;
+       Attribute *a;
+       int rc;
+       struct berval newdn;
+
+       fc.fdn = &op->o_req_ndn;
+       /* compute new DN */
+       if ( op->o_tag == LDAP_REQ_MODRDN && !saveit ) {
+               struct berval pdn;
+               if ( op->orr_nnewSup ) pdn = *op->orr_nnewSup;
+               else dnParent( fc.fdn, &pdn );
+               build_new_dn( &newdn, &pdn, &op->orr_nnewrdn, op->o_tmpmemctx );
+               fc.fdn = &newdn;
+       }
+       if ( op->o_tag != LDAP_REQ_ADD ) {
+               op->o_bd->bd_info = (BackendInfo *)on->on_info;
+               rc = be_entry_get_rw( op, fc.fdn, NULL, NULL, 0, &e );
+               op->o_bd->bd_info = (BackendInfo *)on;
+               if ( rc ) return;
+       } else {
+               e = op->ora_e;
+       }
 
-       for (ss = si->si_ops; ss; ss=ss->s_next)
+       if ( saveit ) {
+               ber_dupbv_x( &opc->sdn, &e->e_name, op->o_tmpmemctx );
+               ber_dupbv_x( &opc->sndn, &e->e_nname, op->o_tmpmemctx );
+               opc->sreference = is_entry_referral( e );
+       }
+       if ( saveit || op->o_tag == LDAP_REQ_ADD ) {
+               a = attr_find( e->e_attrs, slap_schema.si_ad_entryUUID );
+               if ( a )
+                       ber_dupbv_x( &opc->suuid, &a->a_nvals[0], op->o_tmpmemctx );
+       }
+
+       ldap_pvt_thread_mutex_lock( &si->si_ops_mutex );
+       for (ss = si->si_ops, sprev = (syncops *)&si->si_ops; ss;
+               sprev = ss, ss=snext)
        {
+               syncmatches *sm;
+               int found = 0;
+
+               snext = ss->s_next;
                /* validate base */
+               fc.fss = ss;
+               fc.fbase = 0;
+               fc.fscope = 0;
+
+               /* If the base of the search is missing, signal a refresh */
+               rc = syncprov_findbase( op, &fc );
+               if ( rc != LDAP_SUCCESS ) {
+                       SlapReply rs = {REP_RESULT};
+                       send_ldap_error( ss->s_op, &rs, LDAP_SYNC_REFRESH_REQUIRED,
+                               "search base has changed" );
+                       sprev->s_next = snext;
+                       syncprov_drop_psearch( ss );
+                       continue;
+               }
+
+               /* If we're sending results now, look for this op in old matches */
+               if ( !saveit ) {
+                       syncmatches *old;
+                       for ( sm=opc->smatches, old=(syncmatches *)&opc->smatches; sm;
+                               old=sm, sm=sm->sm_next ) {
+                               if ( sm->sm_op == ss ) {
+                                       found = 1;
+                                       old->sm_next = sm->sm_next;
+                                       op->o_tmpfree( sm, op->o_tmpmemctx );
+                                       break;
+                               }
+                       }
+               }
+
                /* check if current o_req_dn is in scope and matches filter */
+               if ( fc.fscope && test_filter( op, e, ss->s_op->ors_filter ) ==
+                       LDAP_COMPARE_TRUE ) {
+                       if ( saveit ) {
+                               sm = op->o_tmpalloc( sizeof(syncmatches), op->o_tmpmemctx );
+                               sm->sm_next = opc->smatches;
+                               sm->sm_op = ss;
+                               ss->s_inuse++;
+                               opc->smatches = sm;
+                       } else {
+                               /* if found send UPDATE else send ADD */
+                               syncprov_sendresp( op, opc, ss, e,
+                                       found ? LDAP_SYNC_MODIFY : LDAP_SYNC_ADD, 1 );
+                       }
+               } else if ( !saveit && found ) {
+                       /* send DELETE */
+                       syncprov_sendresp( op, opc, ss, NULL, LDAP_SYNC_DELETE, 1 );
+               }
+       }
+       ldap_pvt_thread_mutex_unlock( &si->si_ops_mutex );
+       if ( op->o_tag != LDAP_REQ_ADD ) {
+               op->o_bd->bd_info = (BackendInfo *)on->on_info;
+               be_entry_release_r( op, e );
+               op->o_bd->bd_info = (BackendInfo *)on;
        }
 }
 
+static int
+syncprov_op_cleanup( Operation *op, SlapReply *rs )
+{
+       slap_callback *cb = op->o_callback;
+       opcookie *opc = cb->sc_private;
+       slap_overinst *on = opc->son;
+       syncprov_info_t         *si = on->on_bi.bi_private;
+       syncmatches *sm, *snext;
+       modtarget *mt, mtdummy;
+
+       for (sm = opc->smatches; sm; sm=snext) {
+               snext = sm->sm_next;
+               syncprov_free_syncop( sm->sm_op );
+               op->o_tmpfree( sm, op->o_tmpmemctx );
+       }
+
+       /* Remove op from lock table */
+       mtdummy.mt_op = op;
+       ldap_pvt_thread_mutex_lock( &si->si_mods_mutex );
+       mt = avl_find( si->si_mods, &mtdummy, sp_avl_cmp );
+       if ( mt ) {
+               modinst *mi = mt->mt_mods;
+               
+               /* If there are more, promote the next one */
+               ldap_pvt_thread_mutex_lock( &mt->mt_mutex );
+               if ( mi->mi_next ) {
+                       mt->mt_mods = mi->mi_next;
+                       mt->mt_op = mt->mt_mods->mi_op;
+                       ldap_pvt_thread_mutex_unlock( &mt->mt_mutex );
+               } else {
+                       avl_delete( &si->si_mods, mt, sp_avl_cmp );
+                       ldap_pvt_thread_mutex_unlock( &mt->mt_mutex );
+                       ldap_pvt_thread_mutex_destroy( &mt->mt_mutex );
+                       ch_free( mt );
+               }
+       }
+       ldap_pvt_thread_mutex_unlock( &si->si_mods_mutex );
+       op->o_callback = cb->sc_next;
+       op->o_tmpfree(cb, op->o_tmpmemctx);
+}
+
 static int
 syncprov_op_response( Operation *op, SlapReply *rs )
 {
-       slap_callback *sc = op->o_callback;
-       opcookie *opc = (opcookie *)(cb+1);
+       opcookie *opc = op->o_callback->sc_private;
        slap_overinst *on = opc->son;
        syncprov_info_t         *si = on->on_bi.bi_private;
+       syncmatches *sm;
 
        if ( rs->sr_err == LDAP_SUCCESS )
        {
-               switch(op->o_tag) {
-               case LDAP_REQ_ADD:
-                       /* for each op in si->si_ops:
-                        *   validate base
-                        *   check for scope and filter
-                        *   send ADD msg if matched
-                        */
-                        break;
-               case LDAP_REQ_DELETE:
-                       /* for each match in opc->smatches:
-                        *   send DELETE msg
-                        */
-                        break;
-               case LDAP_REQ_MODIFY:
-               case LDAP_REQ_MODRDN:
-                       /* for each op in si->si_ops:
-                        *   validate base
-                        *   check for scope and filter
-                        *   if match
-                        *     if match in opc->smatches, send UPDATE
-                        *     else send ADD
-                        *   else
-                        *     if match in opc->smatches, send DELETE
-                        */
-                        break;
-               case LDAP_REQ_EXTENDED:
-                       /* for each op in si->si_ops:
-                        *   validate base
-                        *   check for scope and filter
-                        *   send UPDATE msg if matched
-                        */
-                        break;
+               struct berval maxcsn;
+               char cbuf[LDAP_LUTIL_CSNSTR_BUFSIZE];
+
+               /* Update our context CSN */
+               cbuf[0] = '\0';
+               ldap_pvt_thread_mutex_lock( &si->si_csn_mutex );
+               slap_get_commit_csn( op, &maxcsn );
+               if ( maxcsn.bv_val ) {
+                       strcpy( cbuf, maxcsn.bv_val );
+                       if ( ber_bvcmp( &maxcsn, &si->si_ctxcsn ) > 0 ) {
+                               strcpy( si->si_ctxcsnbuf, cbuf );
+                               si->si_ctxcsn.bv_len = maxcsn.bv_len;
+                       }
+                       si->si_gotcsn = 1;
                }
+               ldap_pvt_thread_mutex_unlock( &si->si_csn_mutex );
+
+               opc->sctxcsn.bv_len = maxcsn.bv_len;
+               opc->sctxcsn.bv_val = cbuf;
+
+               /* Handle any persistent searches */
+               if ( si->si_ops ) {
+                       switch(op->o_tag) {
+                       case LDAP_REQ_ADD:
+                       case LDAP_REQ_MODIFY:
+                       case LDAP_REQ_MODRDN:
+                       case LDAP_REQ_EXTENDED:
+                               syncprov_matchops( op, opc, 0 );
+                               break;
+                       case LDAP_REQ_DELETE:
+                               /* for each match in opc->smatches:
+                                *   send DELETE msg
+                                */
+                               ldap_pvt_thread_mutex_lock( &si->si_ops_mutex );
+                               for ( sm = opc->smatches; sm; sm=sm->sm_next ) {
+                                       if ( sm->sm_op->s_op->o_abandon )
+                                               continue;
+                                       syncprov_sendresp( op, opc, sm->sm_op, NULL,
+                                               LDAP_SYNC_DELETE, 1 );
+                               }
+                               ldap_pvt_thread_mutex_unlock( &si->si_ops_mutex );
+                               break;
+                       }
+               }
+
        }
-       op->o_callback = cb->sc_next;
-       op->o_tmpfree(cb, op->o_tmpmemctx);
        return SLAP_CB_CONTINUE;
 }
 
+/* We don't use a subentry to store the context CSN any more.
+ * We expose the current context CSN as an operational attribute
+ * of the suffix entry.
+ */
 static int
 syncprov_op_compare( Operation *op, SlapReply *rs )
 {
@@ -129,46 +1061,53 @@ syncprov_op_compare( Operation *op, SlapReply *rs )
        syncprov_info_t         *si = on->on_bi.bi_private;
        int rc = SLAP_CB_CONTINUE;
 
-       if ( dn_match( &op->o_req_ndn, &si->si_e->e_nname ) )
+       if ( dn_match( &op->o_req_ndn, op->o_bd->be_nsuffix ) &&
+               op->oq_compare.rs_ava->aa_desc == slap_schema.si_ad_contextCSN )
        {
-               
-               ldap_pvt_thread_mutex_lock( &si->si_e_mutex );
+               Entry e = {0};
+               Attribute a = {0};
+               struct berval bv[2];
 
-               if ( get_assert( op ) &&
-                       ( test_filter( op, si->si_e, get_assertion( op ) ) != LDAP_COMPARE_TRUE ) )
-               {
-                       rs->sr_err = LDAP_ASSERTION_FAILED;
-                       goto return_results;
-               }
+               e.e_name = op->o_bd->be_suffix[0];
+               e.e_nname = op->o_bd->be_nsuffix[0];
 
-               rs->sr_err = access_allowed( op, si->si_e, op->oq_compare.rs_ava->aa_desc,
+               bv[1].bv_val = NULL;
+               bv[0] = si->si_ctxcsn;
+
+               a.a_desc = slap_schema.si_ad_contextCSN;
+               a.a_vals = bv;
+               a.a_nvals = a.a_vals;
+
+               ldap_pvt_thread_mutex_lock( &si->si_csn_mutex );
+
+               rs->sr_err = access_allowed( op, &e, op->oq_compare.rs_ava->aa_desc,
                        &op->oq_compare.rs_ava->aa_value, ACL_COMPARE, NULL );
                if ( ! rs->sr_err ) {
                        rs->sr_err = LDAP_INSUFFICIENT_ACCESS;
                        goto return_results;
                }
 
-               rs->sr_err = LDAP_NO_SUCH_ATTRIBUTE;
+               if ( get_assert( op ) &&
+                       ( test_filter( op, &e, get_assertion( op ) ) != LDAP_COMPARE_TRUE ) )
+               {
+                       rs->sr_err = LDAP_ASSERTION_FAILED;
+                       goto return_results;
+               }
+
+
+               rs->sr_err = LDAP_COMPARE_FALSE;
 
-               for ( a = attr_find( si->si_e->e_attrs, op->oq_compare.rs_ava->aa_desc );
-                       a != NULL;
-                       a = attr_find( a->a_next, op->oq_compare.rs_ava->aa_desc ) )
+               if ( value_find_ex( op->oq_compare.rs_ava->aa_desc,
+                       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 )
                {
-                       rs->sr_err = LDAP_COMPARE_FALSE;
-
-                       if ( value_find_ex( op->oq_compare.rs_ava->aa_desc,
-                               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 )
-                       {
-                               rs->sr_err = LDAP_COMPARE_TRUE;
-                               break;
-                       }
+                       rs->sr_err = LDAP_COMPARE_TRUE;
                }
 
 return_results:;
 
-               ldap_pvt_thread_mutex_unlock( &si->si_entry_mutex );
+               ldap_pvt_thread_mutex_unlock( &si->si_csn_mutex );
 
                send_ldap_result( op, rs );
 
@@ -178,175 +1117,454 @@ return_results:;
                rc = rs->sr_err;
        }
 
-       return SLAP_CB_CONTINUE;
+       return rc;
 }
        
 static int
-syncprov_op_add( Operation *op, SlapReply *rs )
+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;
 
-       if ( si->si_ops )
-       {
-               slap_callback *cb = op->o_tmpcalloc(1, sizeof(slap_callback)+sizeof(opcookie), op->o_tmpmemctx);
-               opcookie *opc = (opcookie *)(cb+1);
-               opc->son = on;
-               cb->sc_response = syncprov_op_response;
-               cb->sc_private = opc;
-               cb->sc_next = op->o_callback;
-               op->o_callback = cb;
+       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);
+       opc->son = on;
+       cb->sc_response = syncprov_op_response;
+       cb->sc_cleanup = syncprov_op_cleanup;
+       cb->sc_private = opc;
+       cb->sc_next = op->o_callback;
+       op->o_callback = cb;
+
+       /* If there are active persistent searches, lock this operation.
+        * See seqmod.c for the locking logic on its own.
+        */
+       if ( si->si_ops ) {
+               modtarget *mt, mtdummy;
+               modinst *mi;
+
+               mi = (modinst *)(opc+1);
+               mi->mi_op = op;
+
+               /* See if we're already modifying this entry... */
+               mtdummy.mt_op = op;
+               ldap_pvt_thread_mutex_lock( &si->si_mods_mutex );
+               mt = avl_find( si->si_mods, &mtdummy, sp_avl_cmp );
+               if ( mt ) {
+                       ldap_pvt_thread_mutex_lock( &mt->mt_mutex );
+                       ldap_pvt_thread_mutex_unlock( &si->si_mods_mutex );
+                       mt->mt_tail->mi_next = mi;
+                       mt->mt_tail = mi;
+                       /* 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();
+                               ldap_pvt_thread_mutex_lock( &mt->mt_mutex );
+                       }
+               } else {
+                       /* Record that we're modifying this entry now */
+                       mt = malloc( sizeof(modtarget) );
+                       mt->mt_mods = mi;
+                       mt->mt_tail = mi;
+                       mt->mt_op = mi->mi_op;
+                       ldap_pvt_thread_mutex_init( &mt->mt_mutex );
+                       avl_insert( &si->si_mods, mt, sp_avl_cmp, avl_dup_error );
+                       ldap_pvt_thread_mutex_unlock( &si->si_mods_mutex );
+               }
+
+               if ( op->o_tag != LDAP_REQ_ADD )
+                       syncprov_matchops( op, opc, 1 );
        }
 
        return SLAP_CB_CONTINUE;
 }
 
 static int
-syncprov_op_delete( Operation *op, SlapReply *rs )
+syncprov_op_extended( Operation *op, SlapReply *rs )
 {
-       slap_overinst           *on = (slap_overinst *)op->o_bd->bd_info;
-       syncprov_info_t         *si = on->on_bi.bi_private;
-
-       if ( si->si_ops )
-       {
-               slap_callback *cb = op->o_tmpcalloc(1, sizeof(slap_callback)+sizeof(opcookie), op->o_tmpmemctx);
-               opcookie *opc = (opcookie *)(cb+1);
-               opc->son = on;
-               cb->sc_response = syncprov_op_response;
-               cb->sc_private = opc;
-               cb->sc_next = op->o_callback;
-               op->o_callback = cb;
-
-               syncprov_matchops( op, opc );
-       }
+       if ( exop_is_write( op ))
+               return syncprov_op_mod( op, rs );
 
        return SLAP_CB_CONTINUE;
 }
 
+typedef struct searchstate {
+       slap_overinst *ss_on;
+       syncops *ss_so;
+} searchstate;
+
 static int
-syncprov_op_modify( Operation *op, SlapReply *rs )
+syncprov_search_cleanup( Operation *op, SlapReply *rs )
 {
-       slap_overinst           *on = (slap_overinst *)op->o_bd->bd_info;
-       syncprov_info_t         *si = on->on_bi.bi_private;
-
-       if ( si->si_ops )
-       {
-               slap_callback *cb = op->o_tmpcalloc(1, sizeof(slap_callback)+sizeof(opcookie), op->o_tmpmemctx);
-               opcookie *opc = (opcookie *)(cb+1);
-               opc->son = on;
-               cb->sc_response = syncprov_op_response;
-               cb->sc_private = opc;
-               cb->sc_next = op->o_callback;
-               op->o_callback = cb;
-
-               syncprov_matchops( op, opc );
+       searchstate *ss = op->o_callback->sc_private;
+       if ( rs->sr_ctrls ) {
+               free( rs->sr_ctrls[0] );
+               op->o_tmpfree( rs->sr_ctrls, op->o_tmpmemctx );
        }
+       return 0;
+}
 
-       return SLAP_CB_CONTINUE;
+static void
+syncprov_detach_op( Operation *op, syncops *so )
+{
+       Operation *op2;
+       int i, alen = 0;
+       size_t size;
+       char *ptr;
+
+       /* count the search attrs */
+       for (i=0; op->ors_attrs && op->ors_attrs[i].an_name.bv_val; i++) {
+               alen += op->ors_attrs[i].an_name.bv_len + 1;
+       }
+       /* Make a new copy of the operation */
+       size = sizeof(Operation) + sizeof(Opheader) +
+               (i ? ( (i+1) * sizeof(AttributeName) + alen) : 0) +
+               op->o_req_dn.bv_len + 1 +
+               op->o_req_ndn.bv_len + 1 +
+               op->o_ndn.bv_len + 1 +
+               so->s_filterstr.bv_len + 1;
+       op2 = (Operation *)ch_malloc( size );
+       *op2 = *op;
+       op2->o_hdr = (Opheader *)(op2+1);
+       *op2->o_hdr = *op->o_hdr;
+       if ( i ) {
+               op2->ors_attrs = (AttributeName *)(op2->o_hdr + 1);
+               ptr = (char *)(op2->ors_attrs+i+1);
+               for (i=0; op->ors_attrs[i].an_name.bv_val; i++) {
+                       op2->ors_attrs[i] = op->ors_attrs[i];
+                       op2->ors_attrs[i].an_name.bv_val = ptr;
+                       ptr = lutil_strcopy( ptr, op->ors_attrs[i].an_name.bv_val ) + 1;
+               }
+               op2->ors_attrs[i].an_name.bv_val = NULL;
+               op2->ors_attrs[i].an_name.bv_len = 0;
+       } else {
+               ptr = (char *)(op2->o_hdr + 1);
+       }
+       op2->o_ndn.bv_val = ptr;
+       ptr = lutil_strcopy(ptr, op->o_ndn.bv_val) + 1;
+       op2->o_dn = op2->o_ndn;
+       op2->o_req_dn.bv_val = ptr;
+       ptr = lutil_strcopy(ptr, op->o_req_dn.bv_val) + 1;
+       op2->o_req_ndn.bv_val = ptr;
+       ptr = lutil_strcopy(ptr, op->o_req_ndn.bv_val) + 1;
+       op2->ors_filterstr.bv_val = ptr;
+       strcpy( ptr, so->s_filterstr.bv_val );
+       op2->ors_filterstr.bv_len = so->s_filterstr.bv_len;
+       op2->ors_filter = str2filter( ptr );
+       op2->o_controls = NULL;
+       op2->o_callback = NULL;
+       so->s_op = op2;
+
+       /* Increment number of ops so that idletimeout ignores 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_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
 }
 
 static int
-syncprov_op_modrdn( Operation *op, SlapReply *rs )
+syncprov_search_response( Operation *op, SlapReply *rs )
 {
-       slap_overinst           *on = (slap_overinst *)op->o_bd->bd_info;
+       searchstate *ss = op->o_callback->sc_private;
+       slap_overinst *on = ss->ss_on;
        syncprov_info_t         *si = on->on_bi.bi_private;
+       sync_control *srs = op->o_controls[sync_cid];
+
+       if ( rs->sr_type == REP_SEARCH || rs->sr_type == REP_SEARCHREF ) {
+               int i;
+               if ( srs->sr_state.ctxcsn ) {
+                       Attribute *a = attr_find( rs->sr_entry->e_attrs,
+                               slap_schema.si_ad_entryCSN );
+                       /* Don't send the ctx entry twice */
+                       if ( bvmatch( &a->a_nvals[0], srs->sr_state.ctxcsn ))
+                               return LDAP_SUCCESS;
+               }
+               rs->sr_ctrls = op->o_tmpalloc( sizeof(LDAPControl *)*2,
+                       op->o_tmpmemctx );
+               rs->sr_ctrls[1] = NULL;
+               rs->sr_err = syncprov_state_ctrl( op, rs, rs->sr_entry,
+                       LDAP_SYNC_ADD, rs->sr_ctrls, 0, 0, NULL );
+       } else if ( rs->sr_type == REP_RESULT && rs->sr_err == LDAP_SUCCESS ) {
+               struct berval cookie;
+
+               slap_compose_sync_cookie( op, &cookie,
+                       &op->ors_filter->f_and->f_ava->aa_value,
+                       srs->sr_state.sid, srs->sr_state.rid );
+
+               /* Is this a regular refresh? */
+               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, LDAP_SYNC_REFRESH_PRESENTS );
+               } else {
+                       int locked = 0;
+               /* It's RefreshAndPersist, transition to Persist phase */
+                       syncprov_sendinfo( op, rs, rs->sr_nentries ?
+                               LDAP_TAG_SYNC_REFRESH_PRESENT : LDAP_TAG_SYNC_REFRESH_DELETE,
+                               &cookie, 1, NULL, 0 );
+                       /* Flush any queued persist messages */
+                       if ( ss->ss_so->s_res ) {
+                               syncres *sr, *srnext;
+                               Entry *e;
+                               opcookie opc;
+
+                               opc.son = on;
+                               ldap_pvt_thread_mutex_lock( &ss->ss_so->s_mutex );
+                               locked = 1;
+                               for (sr = ss->ss_so->s_res; sr; sr=srnext) {
+                                       int rc = LDAP_SUCCESS;
+                                       srnext = sr->s_next;
+                                       opc.sdn = sr->s_dn;
+                                       opc.sndn = sr->s_ndn;
+                                       opc.suuid = sr->s_uuid;
+                                       opc.sctxcsn = sr->s_csn;
+                                       opc.sreference = sr->s_isreference;
+                                       e = NULL;
+                                       
+                                       if ( sr->s_mode != LDAP_SYNC_DELETE ) {
+                                               op->o_bd->bd_info = (BackendInfo *)on->on_info;
+                                               rc = be_entry_get_rw( op, &opc.sndn, NULL, NULL, 0, &e );
+                                               op->o_bd->bd_info = (BackendInfo *)on;
+                                       }
+                                       if ( rc == LDAP_SUCCESS )
+                                               syncprov_sendresp( op, &opc, ss->ss_so, e,
+                                                       sr->s_mode, 0 );
+
+                                       if ( e ) {
+                                               op->o_bd->bd_info = (BackendInfo *)on->on_info;
+                                               be_entry_release_r( op, e );
+                                               op->o_bd->bd_info = (BackendInfo *)on;
+                                       }
+                                       ch_free( sr );
+                               }
+                               ss->ss_so->s_res = NULL;
+                               ss->ss_so->s_restail = NULL;
+                       }
 
-       if ( si->si_ops )
-       {
-               slap_callback *cb = op->o_tmpcalloc(1, sizeof(slap_callback)+sizeof(opcookie), op->o_tmpmemctx);
-               opcookie *opc = (opcookie *)(cb+1);
-               opc->son = on;
-               cb->sc_response = syncprov_op_response;
-               cb->sc_private = opc;
-               cb->sc_next = op->o_callback;
-               op->o_callback = cb;
+                       /* Turn off the refreshing flag */
+                       ss->ss_so->s_flags ^= PS_IS_REFRESHING;
+                       if ( locked )
+                               ldap_pvt_thread_mutex_unlock( &ss->ss_so->s_mutex );
+
+                       /* Detach this Op from frontend control */
+                       syncprov_detach_op( op, ss->ss_so );
 
-               syncprov_matchops( op, opc );
+                       return LDAP_SUCCESS;
+               }
        }
 
        return SLAP_CB_CONTINUE;
 }
 
 static int
-syncprov_op_extended( Operation *op, SlapReply *rs )
+syncprov_op_search( Operation *op, SlapReply *rs )
 {
        slap_overinst           *on = (slap_overinst *)op->o_bd->bd_info;
-       syncprov_info_t         *si = on->on_bi.bi_private;
+       syncprov_info_t         *si = (syncprov_info_t *)on->on_bi.bi_private;
+       slap_callback   *cb;
+       int gotstate = 0, nochange = 0;
+       Filter *fand, *fava;
+       syncops *sop = NULL;
+       searchstate *ss;
+       sync_control *srs;
+
+       if ( !(op->o_sync_mode & SLAP_SYNC_REFRESH) ) return SLAP_CB_CONTINUE;
+
+       if ( op->ors_deref & LDAP_DEREF_SEARCHING ) {
+               send_ldap_error( op, rs, LDAP_PROTOCOL_ERROR, "illegal value for derefAliases" );
+               return rs->sr_err;
+       }
 
-       if ( si->si_ops )
-       {
-               int i, doit = 0;
+       srs = op->o_controls[sync_cid];
+
+       /* If this is a persistent search, set it up right away */
+       if ( op->o_sync_mode & SLAP_SYNC_PERSIST ) {
+               syncops so = {0};
+               fbase_cookie fc;
+               opcookie opc;
+               slap_callback sc;
+
+               fc.fss = &so;
+               fc.fbase = 0;
+               so.s_eid = NOID;
+               so.s_op = op;
+               so.s_flags = PS_IS_REFRESHING;
+               /* syncprov_findbase expects to be called as a callback... */
+               sc.sc_private = &opc;
+               opc.son = on;
+               cb = op->o_callback;
+               op->o_callback = &sc;
+               rs->sr_err = syncprov_findbase( op, &fc );
+               op->o_callback = cb;
 
-               for ( i=0; write_exop[i]; i++ )
-               {
-                       if ( !ber_bvcmp( write_exop[i], &op->oq_extended.rs_reqoid ))
-                       {
-                               doit = 1;
-                               break;
-                       }
+               if ( rs->sr_err != LDAP_SUCCESS ) {
+                       send_ldap_result( op, rs );
+                       return rs->sr_err;
                }
-               if ( doit )
-               {
-                       slap_callback *cb = op->o_tmpcalloc(1,
-                               sizeof(slap_callback)+sizeof(opcookie), op->o_tmpmemctx);
-                       opcookie *opc = (opcookie *)(cb+1);
-                       opc->son = on;
-                       cb->sc_response = syncprov_op_response;
-                       cb->sc_private = opc;
-                       cb->sc_next = op->o_callback;
-                       op->o_callback = cb;
+               sop = ch_malloc( sizeof( syncops ));
+               *sop = so;
+               ldap_pvt_thread_mutex_init( &sop->s_mutex );
+               ldap_pvt_thread_mutex_lock( &si->si_ops_mutex );
+               sop->s_sid = srs->sr_state.sid;
+               sop->s_rid = srs->sr_state.rid;
+               sop->s_next = si->si_ops;
+               sop->s_inuse = 1;
+               si->si_ops = sop;
+               ldap_pvt_thread_mutex_unlock( &si->si_ops_mutex );
+       }
+
+       /* If we have a cookie, handle the PRESENT lookups
+        */
+       if ( srs->sr_state.ctxcsn ) {
+               /* Is the CSN in a valid format? */
+               if ( srs->sr_state.ctxcsn->bv_len >= LDAP_LUTIL_CSNSTR_BUFSIZE ) {
+                       send_ldap_error( op, rs, LDAP_OTHER, "invalid sync cookie" );
+                       return rs->sr_err;
                }
+               /* Is the CSN still present in the database? */
+               if ( syncprov_findcsn( op, FIND_CSN ) != LDAP_SUCCESS ) {
+                       /* No, so a reload is required */
+#if 0          /* the consumer doesn't seem to send this hint */
+                       if ( op->o_sync_rhint == 0 ) {
+                               send_ldap_error( op, rs, LDAP_SYNC_REFRESH_REQUIRED, "sync cookie is stale" );
+                               return rs->sr_err;
+                       }
+#endif
+               } else {
+                       gotstate = 1;
+                       /* If just Refreshing and nothing has changed, shortcut it */
+                       if ( bvmatch( srs->sr_state.ctxcsn, &si->si_ctxcsn )) {
+                               nochange = 1;
+                               if ( !(op->o_sync_mode & SLAP_SYNC_PERSIST) ) {
+                                       LDAPControl     *ctrls[2];
+
+                                       ctrls[0] = NULL;
+                                       ctrls[1] = NULL;
+                                       syncprov_done_ctrl( op, rs, ctrls, 0, 0,
+                                               NULL, LDAP_SYNC_REFRESH_DELETES );
+                                       rs->sr_ctrls = ctrls;
+                                       rs->sr_err = LDAP_SUCCESS;
+                                       send_ldap_result( op, rs );
+                                       return rs->sr_err;
+                               }
+                               goto shortcut;
+                       } else 
+                       /* If context has changed, check for Present UUIDs */
+                       if ( syncprov_findcsn( op, FIND_PRESENT ) != LDAP_SUCCESS ) {
+                               send_ldap_result( op, rs );
+                               return rs->sr_err;
+                       }
+               }
+       }
+
+       /* If we didn't get a cookie and we don't know our contextcsn, try to
+        * find it anyway.
+        */
+       if ( !gotstate && !si->si_gotcsn ) {
+               struct berval bv = BER_BVC("1"), *old;
+               
+               old = srs->sr_state.ctxcsn;
+               srs->sr_state.ctxcsn = &bv;
+               syncprov_findcsn( op, FIND_CSN );
+               srs->sr_state.ctxcsn = old;
+       }
+
+       /* Append CSN range to search filter, save original filter
+        * for persistent search evaluation
+        */
+       if ( sop ) {
+               sop->s_filterstr= op->ors_filterstr;
        }
 
+       fand = op->o_tmpalloc( sizeof(Filter), op->o_tmpmemctx );
+       fand->f_choice = LDAP_FILTER_AND;
+       fand->f_next = NULL;
+       fava = op->o_tmpalloc( sizeof(Filter), op->o_tmpmemctx );
+       fava->f_choice = LDAP_FILTER_LE;
+       fava->f_ava = op->o_tmpalloc( sizeof(AttributeAssertion), op->o_tmpmemctx );
+       fava->f_ava->aa_desc = slap_schema.si_ad_entryCSN;
+       ldap_pvt_thread_mutex_lock( &si->si_csn_mutex );
+       ber_dupbv_x( &fava->f_ava->aa_value, &si->si_ctxcsn, op->o_tmpmemctx );
+       ldap_pvt_thread_mutex_unlock( &si->si_csn_mutex );
+       fand->f_and = fava;
+       if ( gotstate ) {
+               fava->f_next = op->o_tmpalloc( sizeof(Filter), op->o_tmpmemctx );
+               fava = fava->f_next;
+               fava->f_choice = LDAP_FILTER_GE;
+               fava->f_ava = op->o_tmpalloc( sizeof(AttributeAssertion), op->o_tmpmemctx );
+               fava->f_ava->aa_desc = slap_schema.si_ad_entryCSN;
+               ber_dupbv_x( &fava->f_ava->aa_value, srs->sr_state.ctxcsn, op->o_tmpmemctx );
+       }
+       fava->f_next = op->ors_filter;
+       op->ors_filter = fand;
+       filter2bv_x( op, op->ors_filter, &op->ors_filterstr );
+
+shortcut:
+       /* Let our callback add needed info to returned entries */
+       cb = op->o_tmpcalloc(1, sizeof(slap_callback)+sizeof(searchstate), op->o_tmpmemctx);
+       ss = (searchstate *)(cb+1);
+       ss->ss_on = on;
+       ss->ss_so = sop;
+       cb->sc_response = syncprov_search_response;
+       cb->sc_cleanup = syncprov_search_cleanup;
+       cb->sc_private = ss;
+       cb->sc_next = op->o_callback;
+       op->o_callback = cb;
+
+       op->o_sync_mode &= SLAP_CONTROL_MASK;
+
+       /* If this is a persistent search and no changes were reported during
+        * the refresh phase, just invoke the response callback to transition
+        * us into persist phase
+        */
+       if ( nochange ) {
+               rs->sr_err = LDAP_SUCCESS;
+               rs->sr_nentries = 0;
+               send_ldap_result( op, rs );
+               return rs->sr_err;
+       }
        return SLAP_CB_CONTINUE;
 }
 
 static int
-syncprov_response( Operation *op, SlapReply *rs )
+syncprov_operational(
+       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;
 
-       /* If the operation succeeded and we're checkpointing */
-       if ( rs->sr_err == LDAP_SUCCESS && ( si->si_chkops || si->si_chktime ))
-       {
-               int do_check = 0;
-
-               switch ( op->o_tag ) {
-               case LDAP_REQ_EXTENDED:
-                       /* if not PASSWD_MODIFY, break */
-                       /* else fallthru */
-               case LDAP_REQ_ADD:
-               case LDAP_REQ_MODIFY:
-               case LDAP_REQ_MODRDN:
-               case LDAP_REQ_DELETE:
-                       ldap_pvt_thread_mutex_lock( &si->si_chk_mutex );
-                       if ( si->si_chkops )
-                       {
-                               si->si_numops++;
-                               if ( si->si_numops >= si->si_chkops )
-                               {
-                                       do_check = 1;
-                                       si->si_numops = 0;
-                               }
-                       }
-                       if ( si->si_chktime )
-                       {
-                               if ( op->o_time - si->si_chklast >= si->si_chktime )
-                               {
-                                       do_check = 1;
-                                       si->si_chklast = op->o_time;
-                               }
-                       }
-                       ldap_pvt_thread_mutex_unlock( &si->si_chk_mutex );
-                       if ( do_check )
-                       {
-                               /* write cn=ldapsync to underlying db */
-                       }
-                       break;
+       if ( rs->sr_entry &&
+               dn_match( &rs->sr_entry->e_nname, op->o_bd->be_nsuffix )) {
+
+               Attribute **ap;
+
+               for ( ap = &rs->sr_operational_attrs; *ap; ap=&(*ap)->a_next ) ;
+
+               if ( SLAP_OPATTRS( rs->sr_attr_flags ) ||
+                       ad_inlist( slap_schema.si_ad_contextCSN, rs->sr_attrs )) {
+                       
+                       Attribute *a = ch_malloc( sizeof(Attribute));
+                       a->a_desc = slap_schema.si_ad_contextCSN;
+                       a->a_vals = ch_malloc( 2 * sizeof(struct berval));
+
+                       ldap_pvt_thread_mutex_lock( &si->si_csn_mutex );
+                       ber_dupbv( &a->a_vals[0], &si->si_ctxcsn );
+                       ldap_pvt_thread_mutex_unlock( &si->si_csn_mutex );
+
+                       a->a_vals[1].bv_val = NULL;
+                       a->a_nvals = a->a_vals;
+                       a->a_next = NULL;
+                       a->a_flags = 0;
+
+                       *ap = a;
                }
        }
-       return SLAP_CB_CONTINUE;
+       return LDAP_SUCCESS;
 }
 
 static int
@@ -361,10 +1579,11 @@ syncprov_db_config(
        slap_overinst           *on = (slap_overinst *)be->bd_info;
        syncprov_info_t         *si = (syncprov_info_t *)on->on_bi.bi_private;
 
+#if 0
        if ( strcasecmp( argv[ 0 ], "syncprov-checkpoint" ) == 0 ) {
                if ( argc != 3 ) {
                        fprintf( stderr, "%s: line %d: wrong number of arguments in "
-                               "\"syncprov-checkpint <ops> <minutes>\"\n", fname, lineno );
+                               "\"syncprov-checkpoint <ops> <minutes>\"\n", fname, lineno );
                        return -1;
                }
                si->si_chkops = atoi( argv[1] );
@@ -373,40 +1592,9 @@ syncprov_db_config(
        } else {
                return SLAP_CONF_UNKNOWN;
        }
+#endif
 
-       return 0;
-}
-
-/* Read any existing cn=ldapsync context from the underlying db.
- * Then search for any entries newer than that. If no value exists,
- * just generate it. Cache whatever result.
- */
-static int
-syncprov_db_open(
-       BackendDB *be
-)
-{
-       slap_overinst   *on = (slap_overinst *) be->bd_info;
-       syncprov_info_t *si = (syncprov_info_t *)on->on_bi.bi_private;
-
-       return 0;
-}
-
-/* Write the current cn=ldapsync context into the underlying db.
- */
-static int
-syncprov_db_close(
-       BackendDB *be
-)
-{
-       slap_overinst   *on = (slap_overinst *) be->bd_info;
-       syncprov_info_t *si = (syncprov_info_t *)on->on_bi.bi_private;
-
-       /* for si->si_ops:
-        *   send DONE messages
-        *   free si_ops
-        */
-       return 0;
+       return SLAP_CONF_UNKNOWN;
 }
 
 static int
@@ -419,10 +1607,15 @@ syncprov_db_init(
 
        si = ch_calloc(1, sizeof(syncprov_info_t));
        on->on_bi.bi_private = si;
-
-       ldap_pvt_thread_mutex_init( &si->si_e_mutex );
+       ldap_pvt_thread_mutex_init( &si->si_csn_mutex );
        ldap_pvt_thread_mutex_init( &si->si_ops_mutex );
-       ldap_pvt_thread_mutex_init( &si->si_chk_mutex );
+       si->si_ctxcsn.bv_val = si->si_ctxcsnbuf;
+
+       csn_anlist[0].an_desc = slap_schema.si_ad_entryCSN;
+       csn_anlist[0].an_name = slap_schema.si_ad_entryCSN->ad_cname;
+
+       uuid_anlist[0].an_desc = slap_schema.si_ad_entryUUID;
+       uuid_anlist[0].an_name = slap_schema.si_ad_entryUUID->ad_cname;
 
        return 0;
 }
@@ -436,20 +1629,115 @@ syncprov_db_destroy(
        syncprov_info_t *si = (syncprov_info_t *)on->on_bi.bi_private;
 
        if ( si ) {
-               if ( si->si_e ) {
-                       entry_free( si->si_e );
-
-               }
-               ldap_pvt_thread_mutex_destroy( &si->si_chk_mutex );
                ldap_pvt_thread_mutex_destroy( &si->si_ops_mutex );
-               ldap_pvt_thread_mutex_destroy( &si->si_e_mutex );
-
+               ldap_pvt_thread_mutex_destroy( &si->si_csn_mutex );
                ch_free( si );
        }
 
        return 0;
 }
 
+static int syncprov_parseCtrl (
+       Operation *op,
+       SlapReply *rs,
+       LDAPControl *ctrl )
+{
+       ber_tag_t tag;
+       BerElement *ber;
+       ber_int_t mode;
+       ber_len_t len;
+       struct berval cookie = BER_BVNULL;
+       sync_control *sr;
+       int rhint = 0;
+
+       if ( op->o_sync != SLAP_CONTROL_NONE ) {
+               rs->sr_text = "Sync control specified multiple times";
+               return LDAP_PROTOCOL_ERROR;
+       }
+
+       if ( op->o_pagedresults != SLAP_CONTROL_NONE ) {
+               rs->sr_text = "Sync control specified with pagedResults control";
+               return LDAP_PROTOCOL_ERROR;
+       }
+
+       if ( ctrl->ldctl_value.bv_len == 0 ) {
+               rs->sr_text = "Sync control value is empty (or absent)";
+               return LDAP_PROTOCOL_ERROR;
+       }
+
+       /* Parse the control value
+        *      syncRequestValue ::= SEQUENCE {
+        *              mode   ENUMERATED {
+        *                      -- 0 unused
+        *                      refreshOnly             (1),
+        *                      -- 2 reserved
+        *                      refreshAndPersist       (3)
+        *              },
+        *              cookie  syncCookie OPTIONAL
+        *      }
+        */
+
+       ber = ber_init( &ctrl->ldctl_value );
+       if( ber == NULL ) {
+               rs->sr_text = "internal error";
+               return LDAP_OTHER;
+       }
+
+       if ( (tag = ber_scanf( ber, "{i" /*}*/, &mode )) == LBER_ERROR ) {
+               rs->sr_text = "Sync control : mode decoding error";
+               return LDAP_PROTOCOL_ERROR;
+       }
+
+       switch( mode ) {
+       case LDAP_SYNC_REFRESH_ONLY:
+               mode = SLAP_SYNC_REFRESH;
+               break;
+       case LDAP_SYNC_REFRESH_AND_PERSIST:
+               mode = SLAP_SYNC_REFRESH_AND_PERSIST;
+               break;
+       default:
+               rs->sr_text = "Sync control : unknown update mode";
+               return LDAP_PROTOCOL_ERROR;
+       }
+
+       tag = ber_peek_tag( ber, &len );
+
+       if ( tag == LDAP_TAG_SYNC_COOKIE ) {
+               if (( ber_scanf( ber, /*{*/ "o", &cookie )) == LBER_ERROR ) {
+                       rs->sr_text = "Sync control : cookie decoding error";
+                       return LDAP_PROTOCOL_ERROR;
+               }
+       }
+       if ( tag == LDAP_TAG_RELOAD_HINT ) {
+               if (( ber_scanf( ber, /*{*/ "b", &rhint )) == LBER_ERROR ) {
+                       rs->sr_text = "Sync control : rhint decoding error";
+                       return LDAP_PROTOCOL_ERROR;
+               }
+       }
+       if (( ber_scanf( ber, /*{*/ "}")) == LBER_ERROR ) {
+                       rs->sr_text = "Sync control : decoding error";
+                       return LDAP_PROTOCOL_ERROR;
+       }
+       sr = op->o_tmpcalloc( 1, sizeof(struct sync_control), op->o_tmpmemctx );
+       sr->sr_rhint = rhint;
+       if (!BER_BVISNULL(&cookie)) {
+               ber_bvarray_add( &sr->sr_state.octet_str, &cookie );
+               slap_parse_sync_cookie( &sr->sr_state );
+       }
+
+       op->o_controls[sync_cid] = sr;
+
+       (void) ber_free( ber, 1 );
+
+       op->o_sync = ctrl->ldctl_iscritical
+               ? SLAP_CONTROL_CRITICAL
+               : SLAP_CONTROL_NONCRITICAL;
+
+       op->o_sync_mode |= mode;        /* o_sync_mode shares o_sync */
+
+       return LDAP_SUCCESS;
+}
+
 /* This overlay is set up for dynamic loading via moduleload. For static
  * configuration, you'll need to arrange for the slap_overinst to be
  * initialized and registered by some other function inside slapd.
@@ -460,22 +1748,36 @@ static slap_overinst             syncprov;
 int
 syncprov_init()
 {
+       int rc;
+
+       rc = register_supported_control( LDAP_CONTROL_SYNC,
+               SLAP_CTRL_HIDE|SLAP_CTRL_SEARCH, NULL,
+               syncprov_parseCtrl, &sync_cid );
+       if ( rc != LDAP_SUCCESS ) {
+               fprintf( stderr, "Failed to register control %d\n", rc );
+               return rc;
+       }
+
        syncprov.on_bi.bi_type = "syncprov";
        syncprov.on_bi.bi_db_init = syncprov_db_init;
        syncprov.on_bi.bi_db_config = syncprov_db_config;
        syncprov.on_bi.bi_db_destroy = syncprov_db_destroy;
-       syncprov.on_bi.bi_db_open = syncprov_db_open;
-       syncprov.on_bi.bi_db_close = syncprov_db_close;
 
-       syncprov.on_bi.bi_op_add = syncprov_op_add;
+       syncprov.on_bi.bi_op_abandon = syncprov_op_abandon;
+       syncprov.on_bi.bi_op_cancel = syncprov_op_abandon;
+
+       syncprov.on_bi.bi_op_add = syncprov_op_mod;
        syncprov.on_bi.bi_op_compare = syncprov_op_compare;
-       syncprov.on_bi.bi_op_delete = syncprov_op_delete;
-       syncprov.on_bi.bi_op_modify = syncprov_op_modify;
-       syncprov.on_bi.bi_op_modrdn = syncprov_op_modrdn;
+       syncprov.on_bi.bi_op_delete = syncprov_op_mod;
+       syncprov.on_bi.bi_op_modify = syncprov_op_mod;
+       syncprov.on_bi.bi_op_modrdn = syncprov_op_mod;
        syncprov.on_bi.bi_op_search = syncprov_op_search;
        syncprov.on_bi.bi_extended = syncprov_op_extended;
+       syncprov.on_bi.bi_operational = syncprov_operational;
 
+#if 0
        syncprov.on_response = syncprov_response;
+#endif
 
        return overlay_register( &syncprov );
 }