don't leak callbacks if stuff cannot be registered; provide a means to dispose of...

[openldap] / servers / slapd / backover.c

diff --git a/servers/slapd/backover.c b/servers/slapd/backover.c
index 3128840ce9f541c2f470526ae947ab698f1d2327..9a7b4df76114a88412287ed5cc529d32c0f85138 100644 (file)
--- a/servers/slapd/backover.c
+++ b/servers/slapd/backover.c
@@ -210,10 +210,13 @@ over_db_destroy(
 
        rc = over_db_func( be, db_destroy );
 
-       for (next = on->on_next; on; on=next) {
-               next = on->on_next;
-               free( on );
+       if ( on ) {
+               for (next = on->on_next; on; on=next) {
+                       next = on->on_next;
+                       free( on );
+               }
        }
+
        free( oi );
        return rc;
 }
@@ -235,6 +238,11 @@ over_back_response ( Operation *op, SlapReply *rs )
                        if ( rc != SLAP_CB_CONTINUE ) break;
                }
        }
+       /* Bypass the remaining on_response layers, but allow
+        * normal execution to continue.
+        */
+       if ( rc == SLAP_CB_BYPASS )
+               rc = SLAP_CB_CONTINUE;
        op->o_bd = be;
        return rc;
 }
@@ -490,6 +498,8 @@ int overlay_op_walk(
                        if ( rc != SLAP_CB_CONTINUE ) break;
                }
        }
+       if ( rc == SLAP_CB_BYPASS )
+               rc = SLAP_CB_CONTINUE;
 
        func = &oi->oi_orig->bi_op_bind;
        if ( func[which] && rc == SLAP_CB_CONTINUE ) {
@@ -932,14 +942,77 @@ overlay_destroy_one( BackendDB *be, slap_overinst *on )
        }
 }
 
+void
+overlay_insert( BackendDB *be, slap_overinst *on2, slap_overinst ***prev,
+       int idx )
+{
+       slap_overinfo *oi = (slap_overinfo *)be->bd_info;
+
+       if ( idx == -1 ) {
+               on2->on_next = oi->oi_list;
+               oi->oi_list = on2;
+       } else {
+               int i;
+               slap_overinst *on, *otmp1 = NULL, *otmp2;
+
+               /* Since the list is in reverse order and is singly linked,
+                * we reverse it to find the idx insertion point. Adding
+                * on overlay at a specific point should be a pretty
+                * infrequent occurrence.
+                */
+               for ( on = oi->oi_list; on; on=otmp2 ) {
+                       otmp2 = on->on_next;
+                       on->on_next = otmp1;
+                       otmp1 = on;
+               }
+               oi->oi_list = NULL;
+               /* advance to insertion point */
+               for ( i=0, on = otmp1; i<idx; i++ ) {
+                       otmp1 = on->on_next;
+                       on->on_next = oi->oi_list;
+                       oi->oi_list = on;
+               }
+               /* insert */
+               on2->on_next = oi->oi_list;
+               oi->oi_list = on2;
+               if ( otmp1 ) {
+                       *prev = &otmp1->on_next;
+                       /* replace remainder of list */
+                       for ( on=otmp1; on; on=otmp1 ) {
+                               otmp1 = on->on_next;
+                               on->on_next = oi->oi_list;
+                               oi->oi_list = on;
+                       }
+               }
+       }
+}
+
+void
+overlay_move( BackendDB *be, slap_overinst *on, int idx )
+{
+       slap_overinfo *oi = (slap_overinfo *)be->bd_info;
+       slap_overinst **onp;
+
+       for (onp = &oi->oi_list; *onp; onp= &(*onp)->on_next) {
+               if ( *onp == on ) {
+                       *onp = on->on_next;
+                       break;
+               }
+       }
+       overlay_insert( be, on, &onp, idx );
+}
+
 /* add an overlay to a particular backend. */
 int
-overlay_config( BackendDB *be, const char *ov )
+overlay_config( BackendDB *be, const char *ov, int idx, BackendInfo **res )
 {
-       slap_overinst *on = NULL, *on2 = NULL;
+       slap_overinst *on = NULL, *on2 = NULL, **prev;
        slap_overinfo *oi = NULL;
        BackendInfo *bi = NULL;
 
+       if ( res )
+               *res = NULL;
+
        on = overlay_find( ov );
        if ( !on ) {
                Debug( LDAP_DEBUG_ANY, "overlay \"%s\" not found\n", ov, 0, 0 );
@@ -1039,24 +1112,44 @@ overlay_config( BackendDB *be, const char *ov )
                oi = be->bd_info->bi_private;
        }
 
-       /* Insert new overlay on head of list. Overlays are executed
-        * in reverse of config order...
+       /* Insert new overlay into list. By default overlays are
+        * added to head of list and executed in LIFO order.
         */
        on2 = ch_calloc( 1, sizeof(slap_overinst) );
        *on2 = *on;
        on2->on_info = oi;
-       on2->on_next = oi->oi_list;
-       oi->oi_list = on2;
+
+       prev = &oi->oi_list;
+       /* Do we need to find the insertion point? */
+       if ( idx >= 0 ) {
+               int i;
+
+               /* count current overlays */
+               for ( i=0, on=oi->oi_list; on; on=on->on_next, i++ );
+
+               /* are we just appending a new one? */
+               if ( idx >= i )
+                       idx = -1;
+       }
+       overlay_insert( be, on2, &prev, idx );
 
        /* Any initialization needed? */
-       if ( on->on_bi.bi_db_init ) {
+       if ( on2->on_bi.bi_db_init ) {
                int rc;
                be->bd_info = (BackendInfo *)on2;
                rc = on2->on_bi.bi_db_init( be );
                be->bd_info = (BackendInfo *)oi;
-               if ( rc ) return rc;
+               if ( rc ) {
+                       *prev = on2->on_next;
+                       ch_free( on2 );
+                       on2 = NULL;
+                       return rc;
+               }
        }
 
+       if ( res )
+               *res = &on2->on_bi;
+
        return 0;
 }