Commit 3814b5f1 authored by Howard Chu's avatar Howard Chu
Browse files

Range check cleanup, added alias processing comments

parent fbc6a7e8
......@@ -186,6 +186,9 @@ int bdb_idl_insert( ID *ids, ID id )
#endif
if (BDB_IDL_IS_RANGE( ids )) {
/* if already in range, treat as a dup */
if (id >= BDB_IDL_FIRST(ids) && id <= BDB_IDL_LAST(ids))
return -1;
if (id < BDB_IDL_FIRST(ids))
ids[1] = id;
else if (id > BDB_IDL_LAST(ids))
......
......@@ -29,8 +29,11 @@ static void send_pagerequest_response(
Operation *op,
SlapReply *rs,
ID lastid,
int tentries );
int tentries );
/* Dereference aliases for a single alias entry. Return the final
* dereferenced entry on success, NULL on any failure.
*/
static Entry * deref_base (
BackendDB *be,
SlapReply *rs,
......@@ -50,25 +53,38 @@ static Entry * deref_base (
rs->sr_text = "maximum deref depth exceeded";
while (BDB_IDL_N(tmp) < be->be_max_deref_depth) {
/* Remember the last entry we looked at, so we can
* report broken links
*/
*matched = e;
if ( visited ) {
x = bdb_idl_search(visited, e->e_id);
if (x > 0 && x <= visited[0] && visited[x] == e->e_id) {
e = NULL;
break;
}
bdb_idl_insert( visited, e->e_id );
/* If this is part of a subtree or onelevel search,
* have we seen this ID before? If so, quit.
*/
if ( visited && bdb_idl_insert( visited, e->e_id ) ) {
e = NULL;
break;
}
/* If we've seen this ID during this deref iteration,
* we've hit a loop.
*/
if ( bdb_idl_insert( tmp, e->e_id ) ) {
rs->sr_err = LDAP_ALIAS_PROBLEM;
rs->sr_text = "circular alias";
e = NULL;
break;
}
/* If there was a problem getting the aliasedObjectName,
* get_alias_dn will have set the error status.
*/
if ( get_alias_dn(e, &ndn, &rs->sr_err, &rs->sr_text) ) {
e = NULL;
break;
}
rs->sr_err = bdb_dn2entry_r( be, NULL, &ndn, &e,
NULL, 0, locker, &lockr );
if (!e) {
......@@ -76,9 +92,17 @@ static Entry * deref_base (
rs->sr_text = "aliasedObject not found";
break;
}
/* Free the previous entry, continue to work with the
* one we just retrieved.
*/
bdb_cache_return_entry_r( bdb->bi_dbenv, &bdb->bi_cache,
*matched, lock);
*lock = lockr;
/* We found a regular entry. Return this to the caller. The
* entry is still locked for Read.
*/
if (!is_entry_alias(e)) {
rs->sr_err = LDAP_SUCCESS;
rs->sr_text = NULL;
......@@ -88,6 +112,10 @@ static Entry * deref_base (
return e;
}
/* Look for and dereference all aliases within the search scope. Adds
* the dereferenced entries to the "ids" list. Requires "stack" to be
* able to hold 8 levels of IDLs.
*/
static int search_aliases(
Operation *op,
SlapReply *rs,
......@@ -108,13 +136,18 @@ static int search_aliases(
DB_LOCK locka, lockr;
int first = 1;
aliases = stack;
curscop = aliases + BDB_IDL_UM_SIZE;
subscop = curscop + BDB_IDL_UM_SIZE;
visited = subscop + BDB_IDL_UM_SIZE;
newsubs = visited + BDB_IDL_UM_SIZE;
oldsubs = newsubs + BDB_IDL_UM_SIZE;
tmp = oldsubs + BDB_IDL_UM_SIZE;
aliases = stack; /* IDL of all aliases in the database */
curscop = aliases + BDB_IDL_UM_SIZE; /* Aliases in the current scope */
subscop = curscop + BDB_IDL_UM_SIZE; /* The current scope */
visited = subscop + BDB_IDL_UM_SIZE; /* IDs we've seen in this search */
newsubs = visited + BDB_IDL_UM_SIZE; /* New subtrees we've added */
oldsubs = newsubs + BDB_IDL_UM_SIZE; /* Subtrees added previously */
tmp = oldsubs + BDB_IDL_UM_SIZE; /* Scratch space for deref_base() */
/* A copy of subscop, because subscop gets clobbered by
* the bdb_idl_union/intersection routines
*/
subscop2 = tmp + BDB_IDL_UM_SIZE;
af.f_choice = LDAP_FILTER_EQUALITY;
......@@ -141,6 +174,11 @@ static int search_aliases(
ido = bdb_idl_first( oldsubs, &cursoro );
for (;;) {
/* Set curscop to only the aliases in the current scope. Start with
* all the aliases, obtain the IDL for the current scope, and then
* get the intersection of these two IDLs. Make sure to save a copy
* of the scope IDL since it gets clobbered.
*/
BDB_IDL_CPY( curscop, aliases );
rs->sr_err = bdb_filter_candidates( op->o_bd, sf, subscop, NULL, NULL );
if (first) {
......@@ -152,6 +190,7 @@ static int search_aliases(
rs->sr_err = bdb_idl_intersection(curscop, subscop);
BDB_IDL_CPY(subscop, subscop2);
/* Dereference all of the aliases in the current scope. */
cursora = 0;
for (ida = bdb_idl_first(curscop, &cursora); ida != NOID;
ida = bdb_idl_next(curscop, &cursora))
......@@ -161,34 +200,56 @@ static int search_aliases(
if (rs->sr_err != LDAP_SUCCESS) {
continue;
}
/* This should only happen if the curscop IDL has maxed out and
* turned into a range that spans IDs indiscriminately
*/
if (!is_entry_alias(a)) {
bdb_cache_return_entry_r (bdb->bi_dbenv, &bdb->bi_cache,
a, &lockr);
continue;
}
/* Actually dereference the alias */
BDB_IDL_ZERO(tmp);
a = deref_base( op->o_bd, rs, a, &matched, locker, &lockr,
tmp, visited );
if (a) {
if (bdb_idl_insert(subscop, a->e_id) == 0
&& op->ors_scope == LDAP_SCOPE_SUBTREE)
{
/* If the target was not already in our current search scope,
* make note of it in the newsubs list.
* FIXME: Somehow we have to propagate these new scopes back
* up to bdb_search.
*/
if (bdb_idl_insert(subscop, a->e_id) == 0) {
bdb_idl_insert(newsubs, a->e_id);
}
bdb_cache_return_entry_r( bdb->bi_dbenv, &bdb->bi_cache,
a, &lockr);
} else if (matched) {
/* ignore errors */
/* Alias could not be dereferenced, or it deref'd to
* an ID we've already seen. Ignore it.
*/
bdb_cache_return_entry_r( bdb->bi_dbenv, &bdb->bi_cache,
matched, &lockr );
rs->sr_text = NULL;
}
}
/* All of the deref'd aliases have been added to subscop. Add these
* to our candidate list.
*/
bdb_idl_union( ids, subscop );
/* If this is a OneLevel search, we're done; oldsubs only had one
* ID in it. For a Subtree search, oldsubs may be a list of scope IDs.
*/
if (op->ors_scope != LDAP_SCOPE_SUBTREE) break;
nextido:
ido = bdb_idl_next( oldsubs, &cursoro );
/* If we're done processing the old scopes, did we add any new
* scopes in this iteration? If so, go back and do those now.
*/
if (ido == NOID) {
if (BDB_IDL_IS_ZERO(newsubs)) break;
BDB_IDL_CPY(oldsubs, newsubs);
......@@ -196,6 +257,12 @@ nextido:
cursoro = 0;
ido = bdb_idl_first( oldsubs, &cursoro );
}
/* Find the entry corresponding to the next scope. If it can't
* be found, ignore it and move on. This should never happen;
* we should never see the ID of an entry that doesn't exist.
* Set the name so that the scope's IDL can be retrieved.
*/
rs->sr_err = bdb_id2entry_r(op->o_bd, NULL, ido, &e, locker, &locka);
if (rs->sr_err != LDAP_SUCCESS) goto nextido;
sf->f_dn = &e->e_nname;
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment