openldap/servers/slapd/back-bdb2/alias.c
1999-03-05 10:25:55 +00:00

320 lines
9.0 KiB
C

/*
* Copyright (c) 1998 Will Ballantyne, ITSD, Government of BC
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and that due credit is given
* to ITSD, Government of BC. The name of ITSD
* may not be used to endorse or promote products derived from this
* software without specific prior written permission. This software
* is provided ``as is'' without express or implied warranty.
*/
#include "portable.h"
#include <stdio.h>
#include <string.h>
#include <ac/socket.h> /* Get struct sockaddr for slap.h */
#include "slap.h"
#include "back-bdb2.h"
#include "proto-back-bdb2.h"
/*
* given an alias object, dereference it to its end point.
* Entry returned has reader lock or is NULL. Starting entry is not released.
*/
Entry *bdb2i_derefAlias_r ( BackendDB *be,
Connection *conn,
Operation *op,
Entry *e)
{
/* to free cache entries */
struct ldbminfo *li = (struct ldbminfo *) be->be_private;
Attribute *a;
int depth;
char *matched;
Entry *origDN = e;
if (!e) return NULL; /* be sure we have a starting entry */
Debug( LDAP_DEBUG_TRACE, "<= checking for alias for dn %s\n", e->e_dn, 0, 0 );
/*
* try to deref fully, up to a maximum depth. If the max depth exceeded
* then send an error
*/
for ( depth = 0;
( ( a = attr_find( e->e_attrs, "aliasedobjectname" ) ) != NULL) &&
( depth < be->be_maxDerefDepth );
++depth)
{
/*
* make sure there is a defined aliasedobjectname.
* can only have one value so just use first value (0) in the attr list.
*/
if (a->a_vals[0] && a->a_vals[0]->bv_val) {
char *newDN, *oldDN;
Debug( LDAP_DEBUG_TRACE, "<= %s is an alias for %s\n",
e->e_dn, a->a_vals[0]->bv_val, 0 );
newDN = ch_strdup (a->a_vals[0]->bv_val);
oldDN = ch_strdup (e->e_ndn);
/*
* release past lock if not original
*/
if ( (depth > 0) && e ) {
bdb2i_cache_return_entry_r(&li->li_cache, e);
}
/* make sure new and old DN are not same to avoid loops */
dn_normalize_case (newDN);
if ( strcmp (newDN, oldDN) == 0 ) {
Debug( LDAP_DEBUG_TRACE,
"<= %s alias is same as current %s\n",
oldDN, newDN, 0 );
send_ldap_result( conn, op, LDAP_ALIAS_DEREF_PROBLEM, "",
"Circular alias" );
free (newDN);
free (oldDN);
break;
}
/* make sure new and original are not same to avoid deadlocks */
if ( strcmp (newDN, origDN->e_ndn) == 0 ) {
Debug( LDAP_DEBUG_TRACE,
"<= %s alias is same as original %s\n",
oldDN, origDN->e_ndn, 0 );
send_ldap_result( conn, op, LDAP_ALIAS_DEREF_PROBLEM, "",
"Circular alias" );
free (newDN);
free (oldDN);
break;
}
/*
* ok, so what happens if there is an alias in the DN of a dereferenced
* alias object?
*/
if ( (e = bdb2i_dn2entry_r( be, newDN, &matched )) == NULL ) {
/* could not deref return error */
Debug( LDAP_DEBUG_TRACE,
"<= %s is a dangling alias to %s\n",
oldDN, newDN, 0 );
send_ldap_result( conn, op, LDAP_ALIAS_DEREF_PROBLEM, "",
"Dangling Alias" );
if(matched != NULL) free(matched);
free (newDN);
free (oldDN);
break;
}
free (newDN);
free (oldDN);
}
else {
/*
* there was an aliasedobjectname defined but no data.
* this can't happen, right?
*/
Debug( LDAP_DEBUG_TRACE,
"<= %s has no data in aliasedobjectname attribute\n",
(e && e->e_dn) ? e->e_dn : "(null)", 0, 0 );
send_ldap_result( conn, op, LDAP_ALIAS_PROBLEM, "",
"Alias missing aliasedobjectname" );
break;
}
}
/*
* warn if we pulled out due to exceeding the maximum deref depth
*/
if ( depth >= be->be_maxDerefDepth ) {
Debug( LDAP_DEBUG_TRACE,
"<= deref(\"%s\") exceeded maximum deref depth (%d) at \"%s\"\n",
origDN->e_dn ? origDN->e_dn : "(null)",
be->be_maxDerefDepth,
(e && e->e_ndn) ? e->e_ndn : "(null)");
send_ldap_result( conn, op, LDAP_ALIAS_DEREF_PROBLEM, "",
"Maximum alias dereference depth exceeded" );
}
return e;
}
/*
* given a DN fully deref it and return the real DN or original DN if it fails
* This involves finding the last matched part then reconstructing forward
* e.g.
* ou=MyOU,o=MyAliasedOrg,c=MyCountry where o=MyAliasedOrg is an alias for o=MyOrg
* loop starts with newDN = ou=MyOU,o=MyAliasedOrg,c=MyCountry
* dn2entry_r on newDN gives null entry and o=MyAliasedOrg,c=MyCountry matched
* dn2entry_r on matched gives o=MyAliasedOrg,c=MyCountry entry
* remainder is ou=MyOU
* dereferencing o=MyAliasedOrg,c=MyCountry yields entry o=MyOrg,c=MyCountry
* release lock on o=MyAliasedOrg,c=MyCountry entry
* reconstructed dn is ou=MyOU,o=MyOrg,c=MyCountry
* release lock on o=MyOrg,c=MyCountry entry
*/
char *bdb2i_derefDN ( BackendDB *be,
Connection *conn,
Operation *op,
char *dn
)
{
struct ldbminfo *li = (struct ldbminfo *) be->be_private;
char *matched = 0;
char *newDN = NULL;
int depth, i;
Entry *eMatched;
Entry *eDeref;
Entry *eNew;
if (!dn) return NULL;
Debug( LDAP_DEBUG_TRACE,
"<= dereferencing dn: \"%s\"\n",
dn, 0, 0 );
newDN = ch_strdup ( dn );
/* while we don't have a matched dn, deref the DN */
for ( depth = 0;
( (eMatched = bdb2i_dn2entry_r( be, newDN, &matched )) == NULL) &&
(depth < be->be_maxDerefDepth);
++depth ) {
if ((matched != NULL) && *matched) {
char *submatch;
/*
* make sure there actually is an entry for the matched part
*/
if ( (eMatched = bdb2i_dn2entry_r( be, matched, &submatch )) != NULL) {
char *remainder; /* part before the aliased part */
int rlen = strlen(newDN) - strlen(matched);
Debug( LDAP_DEBUG_TRACE, "<= matched %s\n", matched, 0, 0 );
remainder = ch_malloc (rlen + 1);
strncpy ( remainder, newDN, rlen );
remainder[rlen] = '\0';
Debug( LDAP_DEBUG_TRACE, "<= remainder %s\n", remainder, 0, 0 );
if ((eNew = bdb2i_derefAlias_r( be, conn, op, eMatched )) == NULL) {
free (matched);
matched = NULL;
free (newDN);
newDN = NULL;
free (remainder);
remainder = NULL;
bdb2i_cache_return_entry_r(&li->li_cache, eMatched);
eMatched = NULL;
break; /* no associated entry, dont deref */
}
else {
Debug( LDAP_DEBUG_TRACE, "<= l&g we have %s vs %s \n", matched, eNew->e_dn, 0 );
i = strcasecmp (matched, eNew->e_dn);
/* free reader lock */
bdb2i_cache_return_entry_r(&li->li_cache, eNew);
free (matched);
matched = NULL;
if (! i) {
/* newDN same as old so not an alias, no need to go further */
free (newDN);
newDN = NULL;
free (remainder);
bdb2i_cache_return_entry_r(&li->li_cache, eMatched);
eMatched = NULL;
break;
}
/*
* we have dereferenced the aliased part so put
* the new dn together
*/
free (newDN);
newDN = ch_malloc (strlen(eMatched->e_dn) + rlen + 1);
strcpy (newDN, remainder);
strcat (newDN, eMatched->e_dn);
Debug( LDAP_DEBUG_TRACE, "<= expanded to %s\n", newDN, 0, 0 );
free (remainder);
}
/* free reader lock */
bdb2i_cache_return_entry_r(&li->li_cache, eMatched);
}
else {
if(submatch != NULL) free(submatch);
break; /* there was no entry for the matched part */
}
}
else {
break; /* there was no matched part */
}
}
/* release lock if a match terminated the loop, there should be no
* outstanding locks at this point
*/
if(eMatched != NULL) {
/* free reader lock */
bdb2i_cache_return_entry_r(&li->li_cache, eMatched);
}
/*
* the final part of the DN might be an alias so try to dereference it.
* e.g. if we had started with dn = o=MyAliasedOrg,c=MyCountry the dn would match
* and the above loop complete but we would still be left with an aliased DN.
*/
if ( (eNew = bdb2i_dn2entry_r( be, newDN, &matched )) != NULL) {
if ((eDeref = bdb2i_derefAlias_r( be, conn, op, eNew )) != NULL) {
free (newDN);
newDN = ch_strdup (eDeref->e_dn);
/* free reader lock */
bdb2i_cache_return_entry_r(&li->li_cache, eDeref);
}
/* free reader lock */
bdb2i_cache_return_entry_r(&li->li_cache, eNew);
}
if (matched != NULL) free(matched);
/*
* warn if we exceeded the max depth as the resulting DN may not be dereferenced
*/
if (depth >= be->be_maxDerefDepth) {
if (newDN) {
Debug( LDAP_DEBUG_TRACE,
"<= max deref depth exceeded in derefDN for \"%s\", result \"%s\"\n",
dn, newDN, 0 );
free (newDN);
newDN = NULL;
} else {
Debug( LDAP_DEBUG_TRACE,
"<= max deref depth exceeded in derefDN for \"%s\", result NULL\n",
dn, 0, 0 );
}
send_ldap_result( conn, op, LDAP_ALIAS_DEREF_PROBLEM, "",
"Maximum alias dereference depth exceeded for base" );
}
if (newDN == NULL) {
newDN = ch_strdup ( dn );
}
Debug( LDAP_DEBUG_TRACE, "<= returning deref DN of \"%s\"\n", newDN, 0, 0 );
return newDN;
}