openldap/servers/slapd/back-meta/candidates.c
Pierangelo Masarati 74fa239a20 This is the commit of:
- librewrite, for string rewriting; it may be used in back-ldap
    by configuring with '--enable-rewrite'. It must be used in
    back-meta. There's a text file, 'libraries/librewrite/RATIONALE',
    that explains the usage and the features. More comprehensive
    documentation will follow.
  - enhancements of back-ldap (ITS#989,ITS#998,ITS#1002,ITS#1054 and ITS#1137)
    including dn rewriting, a fix to group acl matching and so
  - back-meta: a new backend that proxies a set of remote servers
    by spawning queries. It uses portions of back-ldap and the rewrite
    capabilities of librewrite. It can be compiled by configuring
    with `--enable-ldap --enable-rewrite --enable-meta'.
    There's a text file, 'servers/slapd/back-meta/Documentation', that
    describes the main features and config statements.

Note: someone (Kurt?) should run 'autoconf' and commit 'configure' as
my autoconf version must be different: my configures contain a number
of differences and I didn't feel comfortable in adding them :)
2001-05-12 00:51:28 +00:00

285 lines
7.0 KiB
C

/*
* Copyright 1998-2001 The OpenLDAP Foundation, All Rights Reserved.
* COPYING RESTRICTIONS APPLY, see COPYRIGHT file
*
* Copyright 2001, Pierangelo Masarati, All rights reserved. <ando@sys-net.it>
*
* This work has been developed to fulfill the requirements
* of SysNet s.n.c. <http:www.sys-net.it> and it has been donated
* to the OpenLDAP Foundation in the hope that it may be useful
* to the Open Source community, but WITHOUT ANY WARRANTY.
*
* Permission is granted to anyone to use this software for any purpose
* on any computer system, and to alter it and redistribute it, subject
* to the following restrictions:
*
* 1. The author and SysNet s.n.c. are not responsible for the consequences
* of use of this software, no matter how awful, even if they arise from
* flaws in it.
*
* 2. The origin of this software must not be misrepresented, either by
* explicit claim or by omission. Since few users ever read sources,
* credits should appear in the documentation.
*
* 3. Altered versions must be plainly marked as such, and must not be
* misrepresented as being the original software. Since few users
* ever read sources, credits should appear in the documentation.
* SysNet s.n.c. cannot be responsible for the consequences of the
* alterations.
*
* 4. This notice may not be removed or altered.
*
*
* This software is based on the backend back-ldap, implemented
* by Howard Chu <hyc@highlandsun.com>, and modified by Mark Valence
* <kurash@sassafras.com>, Pierangelo Masarati <ando@sys-net.it> and other
* contributors. The contribution of the original software to the present
* implementation is acknowledged in this copyright statement.
*
* A special acknowledgement goes to Howard for the overall architecture
* (and for borrowing large pieces of code), and to Mark, who implemented
* from scratch the attribute/objectclass mapping.
*
* The original copyright statement follows.
*
* Copyright 1999, Howard Chu, All rights reserved. <hyc@highlandsun.com>
*
* Permission is granted to anyone to use this software for any purpose
* on any computer system, and to alter it and redistribute it, subject
* to the following restrictions:
*
* 1. The author is not responsible for the consequences of use of this
* software, no matter how awful, even if they arise from flaws in it.
*
* 2. The origin of this software must not be misrepresented, either by
* explicit claim or by omission. Since few users ever read sources,
* credits should appear in the documentation.
*
* 3. Altered versions must be plainly marked as such, and must not be
* misrepresented as being the original software. Since few users
* ever read sources, credits should appear in the
* documentation.
*
* 4. This notice may not be removed or altered.
*
*/
#include "portable.h"
#include <stdio.h>
#include "slap.h"
#include "../back-ldap/back-ldap.h"
#include "back-meta.h"
/*
* The meta-directory has one suffix, called <suffix>.
* It handles a pool of target servers, each with a branch suffix
* of the form <branch X>,<suffix>
*
* When the meta-directory receives a request with a dn that belongs
* to a branch, the corresponding target is invoked. When the dn
* does not belong to a specific branch, all the targets that
* are compatible with the dn are selected as candidates, and
* the request is spawned to all the candidate targets
*
* A request is characterized by a dn. The following cases are handled:
* - the dn is the suffix: <dn> == <suffix>,
* all the targets are candidates (search ...)
* - the dn is a branch suffix: <dn> == <branch X>,<suffix>, or
* - the dn is a subtree of a branch suffix:
* <dn> == <rdn>,<branch X>,<suffix>,
* the target is the only candidate.
*
* A possible extension will include the handling of multiple suffixes
*/
/*
* returns 1 if suffix is candidate for dn, otherwise 0
*
* Note: this function should never be called if dn is the <suffix>.
*/
int
meta_back_is_candidate(
const char *nsuffix,
const char *ndn,
int ndnlen
)
{
int len = strlen( nsuffix );
if ( len > ndnlen ) {
/*
* suffix longer than dn
*/
if ( ! DN_SEPARATOR( nsuffix[ ( len - ndnlen ) - 1 ] ) ) {
/*
* not a separator begins the possible common part
*/
return META_NOT_CANDIDATE;
}
if ( strcmp( &nsuffix[ len - ndnlen] , ndn ) == 0 ) {
/*
* Got it!
*/
return META_CANDIDATE;
}
}
if ( len < ndnlen && ! DN_SEPARATOR( ndn[ ( ndnlen - len ) - 1 ] ) ) {
/*
* not a separator begins the possible common part
*/
return META_NOT_CANDIDATE;
}
if ( strcmp( nsuffix, &ndn[ ndnlen - len ] ) == 0 ) {
/*
* Got it!
*/
return META_CANDIDATE;
}
return META_NOT_CANDIDATE;
}
/*
* meta_back_count_candidates
*
* returns a count of the possible candidate targets
* Note: dn MUST be normalized
*/
int
meta_back_count_candidates(
struct metainfo *li,
const char *ndn
)
{
int i, cnt = 0, ndnlen = strlen( ndn );
/*
* I know assertions should not check run-time values;
* at present I didn't find a place for such checks
* after config.c
*/
assert( li->targets != NULL );
assert( li->ntargets != 0 );
for ( i = 0; i < li->ntargets; ++i ) {
if ( meta_back_is_candidate( li->targets[ i ]->suffix,
ndn, ndnlen ) ) {
++cnt;
}
}
return cnt;
}
/*
* meta_back_is_candidate_unique
*
* checks whether a candidate is unique
* Note: dn MUST be normalized
*/
int
meta_back_is_candidate_unique(
struct metainfo *li,
const char *ndn
)
{
return ( meta_back_count_candidates( li, ndn ) == 1 );
}
/*
* meta_back_select_unique_candidate
*
* returns the index of the candidate in case it is unique, otherwise -1
* Note: dn MUST be normalized.
* Note: if defined, the default candidate is returned in case of no match.
*/
int
meta_back_select_unique_candidate(
struct metainfo *li,
const char *ndn
)
{
int i, ndnlen;
switch ( meta_back_count_candidates( li, ndn ) ) {
case 1:
break;
case 0:
default:
return ( li->defaulttarget == META_DEFAULT_TARGET_NONE
? -1 : li->defaulttarget );
}
ndnlen = strlen( ndn );
for ( i = 0; i < li->ntargets; ++i ) {
if ( meta_back_is_candidate( li->targets[ i ]->suffix,
ndn, ndnlen ) ) {
return i;
}
}
return -1;
}
/*
* meta_clear_unused_candidates
*
* clears all candidates except candidate
*/
int
meta_clear_unused_candidates(
struct metainfo *li,
struct metaconn *lc,
int candidate,
int reallyclean
)
{
int i;
for ( i = 0; i < li->ntargets; ++i ) {
if ( i == candidate ) {
continue;
}
meta_clear_one_candidate( lc->conns[ i ], reallyclean );
}
return 0;
}
/*
* meta_clear_one_candidate
*
* clears the selected candidate
*/
int
meta_clear_one_candidate(
struct metasingleconn *lsc,
int reallyclean
)
{
lsc->candidate = META_NOT_CANDIDATE;
if ( !reallyclean ) {
return 0;
}
if ( lsc->ld ) {
ldap_unbind( lsc->ld );
lsc->ld = NULL;
}
if ( lsc->bound_dn != NULL ) {
free( lsc->bound_dn );
lsc->bound_dn = NULL;
}
return 0;
}