xref: /netbsd-src/external/bsd/openldap/dist/servers/slapd/back-meta/candidates.c (revision cac8e449158efc7261bebc8657cbb0125a2cfdde)
1 /* $OpenLDAP: pkg/ldap/servers/slapd/back-meta/candidates.c,v 1.28.2.5 2008/02/11 23:26:46 kurt Exp $ */
2 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
3  *
4  * Copyright 1999-2008 The OpenLDAP Foundation.
5  * Portions Copyright 2001-2003 Pierangelo Masarati.
6  * Portions Copyright 1999-2003 Howard Chu.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted only as authorized by the OpenLDAP
11  * Public License.
12  *
13  * A copy of this license is available in the file LICENSE in the
14  * top-level directory of the distribution or, alternatively, at
15  * <http://www.OpenLDAP.org/license.html>.
16  */
17 /* ACKNOWLEDGEMENTS:
18  * This work was initially developed by the Howard Chu for inclusion
19  * in OpenLDAP Software and subsequently enhanced by Pierangelo
20  * Masarati.
21  */
22 
23 #include "portable.h"
24 
25 #include <stdio.h>
26 #include "ac/string.h"
27 
28 #include "slap.h"
29 #include "../back-ldap/back-ldap.h"
30 #include "back-meta.h"
31 
32 /*
33  * The meta-directory has one suffix, called <suffix>.
34  * It handles a pool of target servers, each with a branch suffix
35  * of the form <branch X>,<suffix>
36  *
37  * When the meta-directory receives a request with a dn that belongs
38  * to a branch, the corresponding target is invoked. When the dn
39  * does not belong to a specific branch, all the targets that
40  * are compatible with the dn are selected as candidates, and
41  * the request is spawned to all the candidate targets
42  *
43  * A request is characterized by a dn. The following cases are handled:
44  * 	- the dn is the suffix: <dn> == <suffix>,
45  * 		all the targets are candidates (search ...)
46  * 	- the dn is a branch suffix: <dn> == <branch X>,<suffix>, or
47  * 	- the dn is a subtree of a branch suffix:
48  * 		<dn> == <rdn>,<branch X>,<suffix>,
49  * 		the target is the only candidate.
50  *
51  * A possible extension will include the handling of multiple suffixes
52  */
53 
54 
55 /*
56  * returns 1 if suffix is candidate for dn, otherwise 0
57  *
58  * Note: this function should never be called if dn is the <suffix>.
59  */
60 int
61 meta_back_is_candidate(
62 	metatarget_t	*mt,
63 	struct berval	*ndn,
64 	int		scope )
65 {
66 	if ( dnIsSuffix( ndn, &mt->mt_nsuffix ) ) {
67 		if ( mt->mt_subtree_exclude ) {
68 			int	i;
69 
70 			for ( i = 0; !BER_BVISNULL( &mt->mt_subtree_exclude[ i ] ); i++ ) {
71 				if ( dnIsSuffix( ndn, &mt->mt_subtree_exclude[ i ] ) ) {
72 					return META_NOT_CANDIDATE;
73 				}
74 			}
75 		}
76 
77 		switch ( mt->mt_scope ) {
78 		case LDAP_SCOPE_SUBTREE:
79 		default:
80 			return META_CANDIDATE;
81 
82 		case LDAP_SCOPE_SUBORDINATE:
83 			if ( ndn->bv_len > mt->mt_nsuffix.bv_len ) {
84 				return META_CANDIDATE;
85 			}
86 			break;
87 
88 		/* nearly useless; not allowed by config */
89 		case LDAP_SCOPE_ONELEVEL:
90 			if ( ndn->bv_len > mt->mt_nsuffix.bv_len ) {
91 				struct berval	rdn = *ndn;
92 
93 				rdn.bv_len -= mt->mt_nsuffix.bv_len
94 					+ STRLENOF( "," );
95 				if ( dnIsOneLevelRDN( &rdn ) ) {
96 					return META_CANDIDATE;
97 				}
98 			}
99 			break;
100 
101 		/* nearly useless; not allowed by config */
102 		case LDAP_SCOPE_BASE:
103 			if ( ndn->bv_len == mt->mt_nsuffix.bv_len ) {
104 				return META_CANDIDATE;
105 			}
106 			break;
107 		}
108 
109 		return META_NOT_CANDIDATE;
110 	}
111 
112 	if ( scope == LDAP_SCOPE_SUBTREE && dnIsSuffix( &mt->mt_nsuffix, ndn ) ) {
113 		/*
114 		 * suffix longer than dn, but common part matches
115 		 */
116 		return META_CANDIDATE;
117 	}
118 
119 	return META_NOT_CANDIDATE;
120 }
121 
122 /*
123  * meta_back_select_unique_candidate
124  *
125  * returns the index of the candidate in case it is unique, otherwise
126  * META_TARGET_NONE if none matches, or
127  * META_TARGET_MULTIPLE if more than one matches
128  * Note: ndn MUST be normalized.
129  */
130 int
131 meta_back_select_unique_candidate(
132 	metainfo_t	*mi,
133 	struct berval	*ndn )
134 {
135 	int	i, candidate = META_TARGET_NONE;
136 
137 	for ( i = 0; i < mi->mi_ntargets; i++ ) {
138 		metatarget_t	*mt = mi->mi_targets[ i ];
139 
140 		if ( meta_back_is_candidate( mt, ndn, LDAP_SCOPE_BASE ) ) {
141 			if ( candidate == META_TARGET_NONE ) {
142 				candidate = i;
143 
144 			} else {
145 				return META_TARGET_MULTIPLE;
146 			}
147 		}
148 	}
149 
150 	return candidate;
151 }
152 
153 /*
154  * meta_clear_unused_candidates
155  *
156  * clears all candidates except candidate
157  */
158 int
159 meta_clear_unused_candidates(
160 	Operation	*op,
161 	int		candidate )
162 {
163 	metainfo_t	*mi = ( metainfo_t * )op->o_bd->be_private;
164 	int		i;
165 	SlapReply	*candidates = meta_back_candidates_get( op );
166 
167 	for ( i = 0; i < mi->mi_ntargets; ++i ) {
168 		if ( i == candidate ) {
169 			continue;
170 		}
171 		META_CANDIDATE_RESET( &candidates[ i ] );
172 	}
173 
174 	return 0;
175 }
176 
177 /*
178  * meta_clear_one_candidate
179  *
180  * clears the selected candidate
181  */
182 int
183 meta_clear_one_candidate(
184 	Operation	*op,
185 	metaconn_t	*mc,
186 	int		candidate )
187 {
188 	metasingleconn_t	*msc = &mc->mc_conns[ candidate ];
189 
190 	if ( msc->msc_ld != NULL ) {
191 
192 #ifdef DEBUG_205
193 		char	buf[ BUFSIZ ];
194 
195 		snprintf( buf, sizeof( buf ), "meta_clear_one_candidate ldap_unbind_ext[%d] mc=%p ld=%p",
196 			candidate, (void *)mc, (void *)msc->msc_ld );
197 		Debug( LDAP_DEBUG_ANY, "### %s %s\n",
198 			op ? op->o_log_prefix : "", buf, 0 );
199 #endif /* DEBUG_205 */
200 
201 		ldap_unbind_ext( msc->msc_ld, NULL, NULL );
202 		msc->msc_ld = NULL;
203 	}
204 
205 	if ( !BER_BVISNULL( &msc->msc_bound_ndn ) ) {
206 		ber_memfree_x( msc->msc_bound_ndn.bv_val, NULL );
207 		BER_BVZERO( &msc->msc_bound_ndn );
208 	}
209 
210 	if ( !BER_BVISNULL( &msc->msc_cred ) ) {
211 		memset( msc->msc_cred.bv_val, 0, msc->msc_cred.bv_len );
212 		ber_memfree_x( msc->msc_cred.bv_val, NULL );
213 		BER_BVZERO( &msc->msc_cred );
214 	}
215 
216 	msc->msc_mscflags = 0;
217 
218 	return 0;
219 }
220 
221