1 /* ctxcsn.c -- Context CSN Management Routines */
2 /* $OpenLDAP$ */
3 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
4  *
5  * Copyright 2003-2021 The OpenLDAP Foundation.
6  * Portions Copyright 2003 IBM Corporation.
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 
18 #include "portable.h"
19 
20 #include <stdio.h>
21 
22 #include <ac/string.h>
23 #include <ac/socket.h>
24 
25 #include "lutil.h"
26 #include "slap.h"
27 #include "lutil_ldap.h"
28 
29 const struct berval slap_ldapsync_bv = BER_BVC("ldapsync");
30 const struct berval slap_ldapsync_cn_bv = BER_BVC("cn=ldapsync");
31 int slap_serverID;
32 
33 /* maxcsn->bv_val must point to a char buf[LDAP_PVT_CSNSTR_BUFSIZE] */
34 void
slap_get_commit_csn(Operation * op,struct berval * maxcsn,int * foundit)35 slap_get_commit_csn(
36 	Operation *op,
37 	struct berval *maxcsn,
38 	int *foundit
39 )
40 {
41 	struct slap_csn_entry *csne, *committed_csne = NULL;
42 	BackendDB *be = op->o_bd->bd_self;
43 	int sid = -1;
44 
45 	if ( maxcsn ) {
46 		assert( maxcsn->bv_val != NULL );
47 		assert( maxcsn->bv_len >= LDAP_PVT_CSNSTR_BUFSIZE );
48 	}
49 	if ( foundit ) {
50 		*foundit = 0;
51 	}
52 
53 	if ( !BER_BVISEMPTY( &op->o_csn )) {
54 		sid = slap_parse_csn_sid( &op->o_csn );
55 	}
56 
57 	ldap_pvt_thread_mutex_lock( &be->be_pcl_mutex );
58 
59 	LDAP_TAILQ_FOREACH( csne, be->be_pending_csn_list, ce_csn_link ) {
60 		if ( csne->ce_op == op ) {
61 			csne->ce_state = SLAP_CSN_COMMIT;
62 			if ( foundit ) *foundit = 1;
63 			break;
64 		}
65 	}
66 
67 	LDAP_TAILQ_FOREACH( csne, be->be_pending_csn_list, ce_csn_link ) {
68 		if ( sid != -1 && sid == csne->ce_sid ) {
69 			if ( csne->ce_state == SLAP_CSN_COMMIT ) committed_csne = csne;
70 			if ( csne->ce_state == SLAP_CSN_PENDING ) break;
71 		}
72 	}
73 
74 	if ( maxcsn ) {
75 		if ( committed_csne ) {
76 			if ( committed_csne->ce_csn.bv_len < maxcsn->bv_len )
77 				maxcsn->bv_len = committed_csne->ce_csn.bv_len;
78 			AC_MEMCPY( maxcsn->bv_val, committed_csne->ce_csn.bv_val,
79 				maxcsn->bv_len+1 );
80 		} else {
81 			maxcsn->bv_len = 0;
82 			maxcsn->bv_val[0] = 0;
83 		}
84 	}
85 	ldap_pvt_thread_mutex_unlock( &be->be_pcl_mutex );
86 }
87 
88 void
slap_rewind_commit_csn(Operation * op)89 slap_rewind_commit_csn( Operation *op )
90 {
91 	struct slap_csn_entry *csne;
92 	BackendDB *be = op->o_bd->bd_self;
93 
94 	ldap_pvt_thread_mutex_lock( &be->be_pcl_mutex );
95 
96 	LDAP_TAILQ_FOREACH( csne, be->be_pending_csn_list, ce_csn_link ) {
97 		if ( csne->ce_op == op ) {
98 			csne->ce_state = SLAP_CSN_PENDING;
99 			break;
100 		}
101 	}
102 
103 	ldap_pvt_thread_mutex_unlock( &be->be_pcl_mutex );
104 }
105 
106 void
slap_graduate_commit_csn(Operation * op)107 slap_graduate_commit_csn( Operation *op )
108 {
109 	struct slap_csn_entry *csne;
110 	BackendDB *be;
111 
112 	if ( op == NULL ) return;
113 	if ( op->o_bd == NULL ) return;
114 	be = op->o_bd->bd_self;
115 
116 	ldap_pvt_thread_mutex_lock( &be->be_pcl_mutex );
117 
118 	LDAP_TAILQ_FOREACH( csne, be->be_pending_csn_list, ce_csn_link ) {
119 		if ( csne->ce_op == op ) {
120 			LDAP_TAILQ_REMOVE( be->be_pending_csn_list,
121 				csne, ce_csn_link );
122 			Debug( LDAP_DEBUG_SYNC, "slap_graduate_commit_csn: removing %p %s\n",
123 				csne, csne->ce_csn.bv_val );
124 			if ( op->o_csn.bv_val == csne->ce_csn.bv_val ) {
125 				BER_BVZERO( &op->o_csn );
126 			}
127 			ch_free( csne->ce_csn.bv_val );
128 			ch_free( csne );
129 			break;
130 		}
131 	}
132 
133 	ldap_pvt_thread_mutex_unlock( &be->be_pcl_mutex );
134 
135 	return;
136 }
137 
138 static struct berval ocbva[] = {
139 	BER_BVC("top"),
140 	BER_BVC("subentry"),
141 	BER_BVC("syncProviderSubentry"),
142 	BER_BVNULL
143 };
144 
145 Entry *
slap_create_context_csn_entry(Backend * be,struct berval * context_csn)146 slap_create_context_csn_entry(
147 	Backend *be,
148 	struct berval *context_csn )
149 {
150 	Entry* e;
151 
152 	struct berval bv;
153 
154 	e = entry_alloc();
155 
156 	attr_merge( e, slap_schema.si_ad_objectClass,
157 		ocbva, NULL );
158 	attr_merge_one( e, slap_schema.si_ad_structuralObjectClass,
159 		&ocbva[1], NULL );
160 	attr_merge_one( e, slap_schema.si_ad_cn,
161 		(struct berval *)&slap_ldapsync_bv, NULL );
162 
163 	if ( context_csn ) {
164 		attr_merge_one( e, slap_schema.si_ad_contextCSN,
165 			context_csn, NULL );
166 	}
167 
168 	BER_BVSTR( &bv, "{}" );
169 	attr_merge_one( e, slap_schema.si_ad_subtreeSpecification, &bv, NULL );
170 
171 	build_new_dn( &e->e_name, &be->be_nsuffix[0],
172 		(struct berval *)&slap_ldapsync_cn_bv, NULL );
173 	ber_dupbv( &e->e_nname, &e->e_name );
174 
175 	return e;
176 }
177 
178 void
slap_queue_csn(Operation * op,struct berval * csn)179 slap_queue_csn(
180 	Operation *op,
181 	struct berval *csn )
182 {
183 	struct slap_csn_entry *pending;
184 	BackendDB *be = op->o_bd->bd_self;
185 
186 	pending = (struct slap_csn_entry *) ch_calloc( 1,
187 			sizeof( struct slap_csn_entry ));
188 
189 	Debug( LDAP_DEBUG_SYNC, "slap_queue_csn: queueing %p %s\n", pending, csn->bv_val );
190 
191 	ber_dupbv( &pending->ce_csn, csn );
192 	ber_bvreplace_x( &op->o_csn, &pending->ce_csn, op->o_tmpmemctx );
193 	pending->ce_sid = slap_parse_csn_sid( csn );
194 	pending->ce_op = op;
195 	pending->ce_state = SLAP_CSN_PENDING;
196 
197 	ldap_pvt_thread_mutex_lock( &be->be_pcl_mutex );
198 	LDAP_TAILQ_INSERT_TAIL( be->be_pending_csn_list,
199 		pending, ce_csn_link );
200 	ldap_pvt_thread_mutex_unlock( &be->be_pcl_mutex );
201 }
202 
203 int
slap_get_csn(Operation * op,struct berval * csn,int manage_ctxcsn)204 slap_get_csn(
205 	Operation *op,
206 	struct berval *csn,
207 	int manage_ctxcsn )
208 {
209 	if ( csn == NULL ) return LDAP_OTHER;
210 
211 	csn->bv_len = ldap_pvt_csnstr( csn->bv_val, csn->bv_len, slap_serverID, 0 );
212 	Debug( LDAP_DEBUG_SYNC, "slap_get_csn: %s generated new csn=%s manage=%d\n",
213 		op->o_log_prefix, csn->bv_val, manage_ctxcsn );
214 	if ( manage_ctxcsn )
215 		slap_queue_csn( op, csn );
216 
217 	return LDAP_SUCCESS;
218 }
219