xref: /netbsd-src/external/bsd/openldap/dist/servers/slapd/back-mdb/id2entry.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: id2entry.c,v 1.2 2020/08/11 13:15:40 christos Exp $	*/
2 
3 /* id2entry.c - routines to deal with the id2entry database */
4 /* $OpenLDAP$ */
5 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
6  *
7  * Copyright 2000-2020 The OpenLDAP Foundation.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted only as authorized by the OpenLDAP
12  * Public License.
13  *
14  * A copy of this license is available in the file LICENSE in the
15  * top-level directory of the distribution or, alternatively, at
16  * <http://www.OpenLDAP.org/license.html>.
17  */
18 
19 #include <sys/cdefs.h>
20 __RCSID("$NetBSD: id2entry.c,v 1.2 2020/08/11 13:15:40 christos Exp $");
21 
22 #include "portable.h"
23 
24 #include <stdio.h>
25 #include <ac/string.h>
26 #include <ac/errno.h>
27 
28 #include "back-mdb.h"
29 
30 typedef struct Ecount {
31 	ber_len_t len;
32 	int nattrs;
33 	int nvals;
34 	int offset;
35 } Ecount;
36 
37 static int mdb_entry_partsize(struct mdb_info *mdb, MDB_txn *txn, Entry *e,
38 	Ecount *eh);
39 static int mdb_entry_encode(Operation *op, Entry *e, MDB_val *data,
40 	Ecount *ec);
41 static Entry *mdb_entry_alloc( Operation *op, int nattrs, int nvals );
42 
43 #define ADD_FLAGS	(MDB_NOOVERWRITE|MDB_APPEND)
44 
45 static int mdb_id2entry_put(
46 	Operation *op,
47 	MDB_txn *txn,
48 	MDB_cursor *mc,
49 	Entry *e,
50 	int flag )
51 {
52 	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
53 	Ecount ec;
54 	MDB_val key, data;
55 	int rc, prev_ads = mdb->mi_numads;
56 
57 	/* We only store rdns, and they go in the dn2id database. */
58 
59 	key.mv_data = &e->e_id;
60 	key.mv_size = sizeof(ID);
61 
62 	rc = mdb_entry_partsize( mdb, txn, e, &ec );
63 	if (rc) {
64 		rc = LDAP_OTHER;
65 		goto fail;
66 	}
67 
68 	flag |= MDB_RESERVE;
69 
70 	if (e->e_id < mdb->mi_nextid)
71 		flag &= ~MDB_APPEND;
72 
73 again:
74 	data.mv_size = ec.len;
75 	if ( mc )
76 		rc = mdb_cursor_put( mc, &key, &data, flag );
77 	else
78 		rc = mdb_put( txn, mdb->mi_id2entry, &key, &data, flag );
79 	if (rc == MDB_SUCCESS) {
80 		rc = mdb_entry_encode( op, e, &data, &ec );
81 		if( rc != LDAP_SUCCESS )
82 			goto fail;
83 	}
84 	if (rc) {
85 		/* Was there a hole from slapadd? */
86 		if ( (flag & MDB_NOOVERWRITE) && data.mv_size == 0 ) {
87 			flag &= ~ADD_FLAGS;
88 			goto again;
89 		}
90 		Debug( LDAP_DEBUG_ANY,
91 			"mdb_id2entry_put: mdb_put failed: %s(%d) \"%s\"\n",
92 			mdb_strerror(rc), rc,
93 			e->e_nname.bv_val );
94 		if ( rc != MDB_KEYEXIST )
95 			rc = LDAP_OTHER;
96 	}
97 fail:
98 	if (rc) {
99 		mdb_ad_unwind( mdb, prev_ads );
100 	}
101 	return rc;
102 }
103 
104 /*
105  * This routine adds (or updates) an entry on disk.
106  * The cache should be already be updated.
107  */
108 
109 
110 int mdb_id2entry_add(
111 	Operation *op,
112 	MDB_txn *txn,
113 	MDB_cursor *mc,
114 	Entry *e )
115 {
116 	return mdb_id2entry_put(op, txn, mc, e, ADD_FLAGS);
117 }
118 
119 int mdb_id2entry_update(
120 	Operation *op,
121 	MDB_txn *txn,
122 	MDB_cursor *mc,
123 	Entry *e )
124 {
125 	return mdb_id2entry_put(op, txn, mc, e, 0);
126 }
127 
128 int mdb_id2edata(
129 	Operation *op,
130 	MDB_cursor *mc,
131 	ID id,
132 	MDB_val *data )
133 {
134 	MDB_val key;
135 	int rc;
136 
137 	key.mv_data = &id;
138 	key.mv_size = sizeof(ID);
139 
140 	/* fetch it */
141 	rc = mdb_cursor_get( mc, &key, data, MDB_SET );
142 	/* stubs from missing parents - DB is actually invalid */
143 	if ( rc == MDB_SUCCESS && !data->mv_size )
144 		rc = MDB_NOTFOUND;
145 	return rc;
146 }
147 
148 int mdb_id2entry(
149 	Operation *op,
150 	MDB_cursor *mc,
151 	ID id,
152 	Entry **e )
153 {
154 	MDB_val key, data;
155 	int rc = 0;
156 
157 	*e = NULL;
158 
159 	key.mv_data = &id;
160 	key.mv_size = sizeof(ID);
161 
162 	/* fetch it */
163 	rc = mdb_cursor_get( mc, &key, &data, MDB_SET );
164 	if ( rc == MDB_NOTFOUND ) {
165 		/* Looking for root entry on an empty-dn suffix? */
166 		if ( !id && BER_BVISEMPTY( &op->o_bd->be_nsuffix[0] )) {
167 			struct berval gluebv = BER_BVC("glue");
168 			Entry *r = mdb_entry_alloc(op, 2, 4);
169 			Attribute *a = r->e_attrs;
170 			struct berval *bptr;
171 
172 			r->e_id = 0;
173 			r->e_ocflags = SLAP_OC_GLUE|SLAP_OC__END;
174 			bptr = a->a_vals;
175 			a->a_flags = SLAP_ATTR_DONT_FREE_DATA | SLAP_ATTR_DONT_FREE_VALS;
176 			a->a_desc = slap_schema.si_ad_objectClass;
177 			a->a_nvals = a->a_vals;
178 			a->a_numvals = 1;
179 			*bptr++ = gluebv;
180 			BER_BVZERO(bptr);
181 			bptr++;
182 			a->a_next = a+1;
183 			a = a->a_next;
184 			a->a_flags = SLAP_ATTR_DONT_FREE_DATA | SLAP_ATTR_DONT_FREE_VALS;
185 			a->a_desc = slap_schema.si_ad_structuralObjectClass;
186 			a->a_vals = bptr;
187 			a->a_nvals = a->a_vals;
188 			a->a_numvals = 1;
189 			*bptr++ = gluebv;
190 			BER_BVZERO(bptr);
191 			a->a_next = NULL;
192 			*e = r;
193 			return MDB_SUCCESS;
194 		}
195 	}
196 	/* stubs from missing parents - DB is actually invalid */
197 	if ( rc == MDB_SUCCESS && !data.mv_size )
198 		rc = MDB_NOTFOUND;
199 	if ( rc ) return rc;
200 
201 	rc = mdb_entry_decode( op, mdb_cursor_txn( mc ), &data, e );
202 	if ( rc ) return rc;
203 
204 	(*e)->e_id = id;
205 	(*e)->e_name.bv_val = NULL;
206 	(*e)->e_nname.bv_val = NULL;
207 
208 	return rc;
209 }
210 
211 int mdb_id2entry_delete(
212 	BackendDB *be,
213 	MDB_txn *tid,
214 	Entry *e )
215 {
216 	struct mdb_info *mdb = (struct mdb_info *) be->be_private;
217 	MDB_dbi dbi = mdb->mi_id2entry;
218 	MDB_val key;
219 	int rc;
220 
221 	key.mv_data = &e->e_id;
222 	key.mv_size = sizeof(ID);
223 
224 	/* delete from database */
225 	rc = mdb_del( tid, dbi, &key, NULL );
226 
227 	return rc;
228 }
229 
230 static Entry * mdb_entry_alloc(
231 	Operation *op,
232 	int nattrs,
233 	int nvals )
234 {
235 	Entry *e = op->o_tmpalloc( sizeof(Entry) +
236 		nattrs * sizeof(Attribute) +
237 		nvals * sizeof(struct berval), op->o_tmpmemctx );
238 	BER_BVZERO(&e->e_bv);
239 	e->e_private = e;
240 	if (nattrs) {
241 		e->e_attrs = (Attribute *)(e+1);
242 		e->e_attrs->a_vals = (struct berval *)(e->e_attrs+nattrs);
243 	} else {
244 		e->e_attrs = NULL;
245 	}
246 
247 	return e;
248 }
249 
250 int mdb_entry_return(
251 	Operation *op,
252 	Entry *e
253 )
254 {
255 	if ( !e )
256 		return 0;
257 	if ( e->e_private ) {
258 		if ( op->o_hdr ) {
259 			op->o_tmpfree( e->e_nname.bv_val, op->o_tmpmemctx );
260 			op->o_tmpfree( e->e_name.bv_val, op->o_tmpmemctx );
261 			op->o_tmpfree( e, op->o_tmpmemctx );
262 		} else {
263 			ch_free( e->e_nname.bv_val );
264 			ch_free( e->e_name.bv_val );
265 			ch_free( e );
266 		}
267 	} else {
268 		entry_free( e );
269 	}
270 	return 0;
271 }
272 
273 int mdb_entry_release(
274 	Operation *op,
275 	Entry *e,
276 	int rw )
277 {
278 	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
279 	struct mdb_op_info *moi = NULL;
280 
281 	/* slapMode : SLAP_SERVER_MODE, SLAP_TOOL_MODE,
282 			SLAP_TRUNCATE_MODE, SLAP_UNDEFINED_MODE */
283 
284 	int release = 1;
285 	if ( slapMode & SLAP_SERVER_MODE ) {
286 		OpExtra *oex;
287 		LDAP_SLIST_FOREACH( oex, &op->o_extra, oe_next ) {
288 			release = 0;
289 			if ( oex->oe_key == mdb ) {
290 				mdb_entry_return( op, e );
291 				moi = (mdb_op_info *)oex;
292 				/* If it was setup by entry_get we should probably free it */
293 				if ( moi->moi_flag & MOI_FREEIT ) {
294 					moi->moi_ref--;
295 					if ( moi->moi_ref < 1 ) {
296 						mdb_txn_reset( moi->moi_txn );
297 						moi->moi_ref = 0;
298 						LDAP_SLIST_REMOVE( &op->o_extra, &moi->moi_oe, OpExtra, oe_next );
299 						op->o_tmpfree( moi, op->o_tmpmemctx );
300 					}
301 				}
302 				break;
303 			}
304 		}
305 	}
306 
307 	if (release)
308 		mdb_entry_return( op, e );
309 
310 	return 0;
311 }
312 
313 /* return LDAP_SUCCESS IFF we can retrieve the specified entry.
314  */
315 int mdb_entry_get(
316 	Operation *op,
317 	struct berval *ndn,
318 	ObjectClass *oc,
319 	AttributeDescription *at,
320 	int rw,
321 	Entry **ent )
322 {
323 	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
324 	struct mdb_op_info *moi = NULL;
325 	MDB_txn *txn = NULL;
326 	Entry *e = NULL;
327 	int	rc;
328 	const char *at_name = at ? at->ad_cname.bv_val : "(null)";
329 
330 	Debug( LDAP_DEBUG_ARGS,
331 		"=> mdb_entry_get: ndn: \"%s\"\n", ndn->bv_val, 0, 0 );
332 	Debug( LDAP_DEBUG_ARGS,
333 		"=> mdb_entry_get: oc: \"%s\", at: \"%s\"\n",
334 		oc ? oc->soc_cname.bv_val : "(null)", at_name, 0);
335 
336 	rc = mdb_opinfo_get( op, mdb, rw == 0, &moi );
337 	if ( rc )
338 		return LDAP_OTHER;
339 	txn = moi->moi_txn;
340 
341 	/* can we find entry */
342 	rc = mdb_dn2entry( op, txn, NULL, ndn, &e, NULL, 0 );
343 	switch( rc ) {
344 	case MDB_NOTFOUND:
345 	case 0:
346 		break;
347 	default:
348 		return (rc != LDAP_BUSY) ? LDAP_OTHER : LDAP_BUSY;
349 	}
350 	if (e == NULL) {
351 		Debug( LDAP_DEBUG_ACL,
352 			"=> mdb_entry_get: cannot find entry: \"%s\"\n",
353 				ndn->bv_val, 0, 0 );
354 		rc = LDAP_NO_SUCH_OBJECT;
355 		goto return_results;
356 	}
357 
358 	Debug( LDAP_DEBUG_ACL,
359 		"=> mdb_entry_get: found entry: \"%s\"\n",
360 		ndn->bv_val, 0, 0 );
361 
362 	if ( oc && !is_entry_objectclass( e, oc, 0 )) {
363 		Debug( LDAP_DEBUG_ACL,
364 			"<= mdb_entry_get: failed to find objectClass %s\n",
365 			oc->soc_cname.bv_val, 0, 0 );
366 		rc = LDAP_NO_SUCH_ATTRIBUTE;
367 		goto return_results;
368 	}
369 
370 	/* NOTE: attr_find() or attrs_find()? */
371 	if ( at && attr_find( e->e_attrs, at ) == NULL ) {
372 		Debug( LDAP_DEBUG_ACL,
373 			"<= mdb_entry_get: failed to find attribute %s\n",
374 			at->ad_cname.bv_val, 0, 0 );
375 		rc = LDAP_NO_SUCH_ATTRIBUTE;
376 		goto return_results;
377 	}
378 
379 return_results:
380 	if( rc != LDAP_SUCCESS ) {
381 		/* free entry */
382 		mdb_entry_release( op, e, rw );
383 	} else {
384 		*ent = e;
385 	}
386 
387 	Debug( LDAP_DEBUG_TRACE,
388 		"mdb_entry_get: rc=%d\n",
389 		rc, 0, 0 );
390 	return(rc);
391 }
392 
393 static void
394 mdb_reader_free( void *key, void *data )
395 {
396 	MDB_txn *txn = data;
397 
398 	if ( txn ) mdb_txn_abort( txn );
399 }
400 
401 /* free up any keys used by the main thread */
402 void
403 mdb_reader_flush( MDB_env *env )
404 {
405 	void *data;
406 	void *ctx = ldap_pvt_thread_pool_context();
407 
408 	if ( !ldap_pvt_thread_pool_getkey( ctx, env, &data, NULL ) ) {
409 		ldap_pvt_thread_pool_setkey( ctx, env, NULL, 0, NULL, NULL );
410 		mdb_reader_free( env, data );
411 	}
412 }
413 
414 extern MDB_txn *mdb_tool_txn;
415 
416 int
417 mdb_opinfo_get( Operation *op, struct mdb_info *mdb, int rdonly, mdb_op_info **moip )
418 {
419 	int rc, renew = 0;
420 	void *data;
421 	void *ctx;
422 	mdb_op_info *moi = NULL;
423 	OpExtra *oex;
424 
425 	assert( op != NULL );
426 
427 	if ( !mdb || !moip ) return -1;
428 
429 	/* If no op was provided, try to find the ctx anyway... */
430 	if ( op ) {
431 		ctx = op->o_threadctx;
432 	} else {
433 		ctx = ldap_pvt_thread_pool_context();
434 	}
435 
436 	if ( op ) {
437 		LDAP_SLIST_FOREACH( oex, &op->o_extra, oe_next ) {
438 			if ( oex->oe_key == mdb ) break;
439 		}
440 		moi = (mdb_op_info *)oex;
441 	}
442 
443 	if ( !moi ) {
444 		moi = *moip;
445 
446 		if ( !moi ) {
447 			if ( op ) {
448 				moi = op->o_tmpalloc(sizeof(struct mdb_op_info),op->o_tmpmemctx);
449 			} else {
450 				moi = ch_malloc(sizeof(mdb_op_info));
451 			}
452 			moi->moi_flag = MOI_FREEIT;
453 			*moip = moi;
454 		}
455 		LDAP_SLIST_INSERT_HEAD( &op->o_extra, &moi->moi_oe, oe_next );
456 		moi->moi_oe.oe_key = mdb;
457 		moi->moi_ref = 0;
458 		moi->moi_txn = NULL;
459 	}
460 
461 	if ( !rdonly ) {
462 		/* This op started as a reader, but now wants to write. */
463 		if ( moi->moi_flag & MOI_READER ) {
464 			moi = *moip;
465 			LDAP_SLIST_INSERT_HEAD( &op->o_extra, &moi->moi_oe, oe_next );
466 		} else {
467 		/* This op is continuing an existing write txn */
468 			*moip = moi;
469 		}
470 		moi->moi_ref++;
471 		if ( !moi->moi_txn ) {
472 			if (( slapMode & SLAP_TOOL_MODE ) && mdb_tool_txn ) {
473 				moi->moi_txn = mdb_tool_txn;
474 			} else {
475 				rc = mdb_txn_begin( mdb->mi_dbenv, NULL, 0, &moi->moi_txn );
476 				if (rc) {
477 					Debug( LDAP_DEBUG_ANY, "mdb_opinfo_get: err %s(%d)\n",
478 						mdb_strerror(rc), rc, 0 );
479 				}
480 				return rc;
481 			}
482 		}
483 		return 0;
484 	}
485 
486 	/* OK, this is a reader */
487 	if ( !moi->moi_txn ) {
488 		if (( slapMode & SLAP_TOOL_MODE ) && mdb_tool_txn ) {
489 			moi->moi_txn = mdb_tool_txn;
490 			goto ok;
491 		}
492 		if ( !ctx ) {
493 			/* Shouldn't happen unless we're single-threaded */
494 			rc = mdb_txn_begin( mdb->mi_dbenv, NULL, MDB_RDONLY, &moi->moi_txn );
495 			if (rc) {
496 				Debug( LDAP_DEBUG_ANY, "mdb_opinfo_get: err %s(%d)\n",
497 					mdb_strerror(rc), rc, 0 );
498 			}
499 			return rc;
500 		}
501 		if ( ldap_pvt_thread_pool_getkey( ctx, mdb->mi_dbenv, &data, NULL ) ) {
502 			rc = mdb_txn_begin( mdb->mi_dbenv, NULL, MDB_RDONLY, &moi->moi_txn );
503 			if (rc) {
504 				Debug( LDAP_DEBUG_ANY, "mdb_opinfo_get: err %s(%d)\n",
505 					mdb_strerror(rc), rc, 0 );
506 				return rc;
507 			}
508 			data = moi->moi_txn;
509 			if ( ( rc = ldap_pvt_thread_pool_setkey( ctx, mdb->mi_dbenv,
510 				data, mdb_reader_free, NULL, NULL ) ) ) {
511 				mdb_txn_abort( moi->moi_txn );
512 				moi->moi_txn = NULL;
513 				Debug( LDAP_DEBUG_ANY, "mdb_opinfo_get: thread_pool_setkey failed err (%d)\n",
514 					rc, 0, 0 );
515 				return rc;
516 			}
517 		} else {
518 			moi->moi_txn = data;
519 			renew = 1;
520 		}
521 		moi->moi_flag |= MOI_READER;
522 	}
523 ok:
524 	if ( moi->moi_ref < 1 ) {
525 		moi->moi_ref = 0;
526 	}
527 	if ( renew ) {
528 		rc = mdb_txn_renew( moi->moi_txn );
529 		assert(!rc);
530 	}
531 	moi->moi_ref++;
532 	if ( *moip != moi )
533 		*moip = moi;
534 
535 	return 0;
536 }
537 
538 /* Count up the sizes of the components of an entry */
539 static int mdb_entry_partsize(struct mdb_info *mdb, MDB_txn *txn, Entry *e,
540 	Ecount *eh)
541 {
542 	ber_len_t len;
543 	int i, nat = 0, nval = 0, nnval = 0;
544 	Attribute *a;
545 
546 	len = 4*sizeof(int);	/* nattrs, nvals, ocflags, offset */
547 	for (a=e->e_attrs; a; a=a->a_next) {
548 		/* For AttributeDesc, we only store the attr index */
549 		nat++;
550 		if (a->a_desc->ad_index >= MDB_MAXADS) {
551 			Debug( LDAP_DEBUG_ANY, "mdb_entry_partsize: too many AttributeDescriptions used\n",
552 				0, 0, 0 );
553 			return LDAP_OTHER;
554 		}
555 		if (!mdb->mi_adxs[a->a_desc->ad_index]) {
556 			int rc = mdb_ad_get(mdb, txn, a->a_desc);
557 			if (rc)
558 				return rc;
559 		}
560 		len += 2*sizeof(int);	/* AD index, numvals */
561 		nval += a->a_numvals + 1;	/* empty berval at end */
562 		for (i=0; i<a->a_numvals; i++) {
563 			len += a->a_vals[i].bv_len + 1 + sizeof(int);	/* len */
564 		}
565 		if (a->a_nvals != a->a_vals) {
566 			nval += a->a_numvals + 1;
567 			nnval++;
568 			for (i=0; i<a->a_numvals; i++) {
569 				len += a->a_nvals[i].bv_len + 1 + sizeof(int);;
570 			}
571 		}
572 	}
573 	/* padding */
574 	len = (len + sizeof(ID)-1) & ~(sizeof(ID)-1);
575 	eh->len = len;
576 	eh->nattrs = nat;
577 	eh->nvals = nval;
578 	eh->offset = nat + nval - nnval;
579 	return 0;
580 }
581 
582 #define HIGH_BIT (1U<<(sizeof(unsigned int)*CHAR_BIT-1))
583 
584 /* Flatten an Entry into a buffer. The buffer starts with the count of the
585  * number of attributes in the entry, the total number of values in the
586  * entry, and the e_ocflags. It then contains a list of integers for each
587  * attribute. For each attribute the first integer gives the index of the
588  * matching AttributeDescription, followed by the number of values in the
589  * attribute. If the high bit of the attr index is set, the attribute's
590  * values are already sorted.
591  * If the high bit of numvals is set, the attribute also has normalized
592  * values present. (Note - a_numvals is an unsigned int, so this means
593  * it's possible to receive an attribute that we can't encode due to size
594  * overflow. In practice, this should not be an issue.) Then the length
595  * of each value is listed. If there are normalized values, their lengths
596  * come next. This continues for each attribute. After all of the lengths
597  * for the last attribute, the actual values are copied, with a NUL
598  * terminator after each value. The buffer is padded to the sizeof(ID).
599  * The entire buffer size is precomputed so that a single malloc can be
600  * performed.
601  */
602 static int mdb_entry_encode(Operation *op, Entry *e, MDB_val *data, Ecount *eh)
603 {
604 	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
605 	ber_len_t i;
606 	Attribute *a;
607 	unsigned char *ptr;
608 	unsigned int *lp, l;
609 
610 	Debug( LDAP_DEBUG_TRACE, "=> mdb_entry_encode(0x%08lx): %s\n",
611 		(long) e->e_id, e->e_dn, 0 );
612 
613 	/* make sure e->e_ocflags is set */
614 	if (is_entry_referral(e))
615 		;	/* empty */
616 
617 	lp = (unsigned int *)data->mv_data;
618 	*lp++ = eh->nattrs;
619 	*lp++ = eh->nvals;
620 	*lp++ = (unsigned int)e->e_ocflags;
621 	*lp++ = eh->offset;
622 	ptr = (unsigned char *)(lp + eh->offset);
623 
624 	for (a=e->e_attrs; a; a=a->a_next) {
625 		if (!a->a_desc->ad_index)
626 			return LDAP_UNDEFINED_TYPE;
627 		l = mdb->mi_adxs[a->a_desc->ad_index];
628 		if (a->a_flags & SLAP_ATTR_SORTED_VALS)
629 			l |= HIGH_BIT;
630 		*lp++ = l;
631 		l = a->a_numvals;
632 		if (a->a_nvals != a->a_vals)
633 			l |= HIGH_BIT;
634 		*lp++ = l;
635 		if (a->a_vals) {
636 			for (i=0; a->a_vals[i].bv_val; i++);
637 			assert( i == a->a_numvals );
638 			for (i=0; i<a->a_numvals; i++) {
639 				*lp++ = a->a_vals[i].bv_len;
640 				memcpy(ptr, a->a_vals[i].bv_val,
641 					a->a_vals[i].bv_len);
642 				ptr += a->a_vals[i].bv_len;
643 				*ptr++ = '\0';
644 			}
645 			if (a->a_nvals != a->a_vals) {
646 				for (i=0; i<a->a_numvals; i++) {
647 					*lp++ = a->a_nvals[i].bv_len;
648 					memcpy(ptr, a->a_nvals[i].bv_val,
649 						a->a_nvals[i].bv_len);
650 					ptr += a->a_nvals[i].bv_len;
651 					*ptr++ = '\0';
652 				}
653 			}
654 		}
655 	}
656 
657 	Debug( LDAP_DEBUG_TRACE, "<= mdb_entry_encode(0x%08lx): %s\n",
658 		(long) e->e_id, e->e_dn, 0 );
659 
660 	return 0;
661 }
662 
663 /* Retrieve an Entry that was stored using entry_encode above.
664  *
665  * Note: everything is stored in a single contiguous block, so
666  * you can not free individual attributes or names from this
667  * structure. Attempting to do so will likely corrupt memory.
668  */
669 
670 int mdb_entry_decode(Operation *op, MDB_txn *txn, MDB_val *data, Entry **e)
671 {
672 	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
673 	int i, j, nattrs, nvals;
674 	int rc;
675 	Attribute *a;
676 	Entry *x;
677 	const char *text;
678 	unsigned int *lp = (unsigned int *)data->mv_data;
679 	unsigned char *ptr;
680 	BerVarray bptr;
681 
682 	Debug( LDAP_DEBUG_TRACE,
683 		"=> mdb_entry_decode:\n",
684 		0, 0, 0 );
685 
686 	nattrs = *lp++;
687 	nvals = *lp++;
688 	x = mdb_entry_alloc(op, nattrs, nvals);
689 	x->e_ocflags = *lp++;
690 	if (!nvals) {
691 		goto done;
692 	}
693 	a = x->e_attrs;
694 	bptr = a->a_vals;
695 	i = *lp++;
696 	ptr = (unsigned char *)(lp + i);
697 
698 	for (;nattrs>0; nattrs--) {
699 		int have_nval = 0;
700 		a->a_flags = SLAP_ATTR_DONT_FREE_DATA | SLAP_ATTR_DONT_FREE_VALS;
701 		i = *lp++;
702 		if (i & HIGH_BIT) {
703 			i ^= HIGH_BIT;
704 			a->a_flags |= SLAP_ATTR_SORTED_VALS;
705 		}
706 		if (i > mdb->mi_numads) {
707 			rc = mdb_ad_read(mdb, txn);
708 			if (rc)
709 				return rc;
710 			if (i > mdb->mi_numads) {
711 				Debug( LDAP_DEBUG_ANY,
712 					"mdb_entry_decode: attribute index %d not recognized\n",
713 					i, 0, 0 );
714 				return LDAP_OTHER;
715 			}
716 		}
717 		a->a_desc = mdb->mi_ads[i];
718 		a->a_numvals = *lp++;
719 		if (a->a_numvals & HIGH_BIT) {
720 			a->a_numvals ^= HIGH_BIT;
721 			have_nval = 1;
722 		}
723 		a->a_vals = bptr;
724 		for (i=0; i<a->a_numvals; i++) {
725 			bptr->bv_len = *lp++;;
726 			bptr->bv_val = (char *)ptr;
727 			ptr += bptr->bv_len+1;
728 			bptr++;
729 		}
730 		bptr->bv_val = NULL;
731 		bptr->bv_len = 0;
732 		bptr++;
733 
734 		if (have_nval) {
735 			a->a_nvals = bptr;
736 			for (i=0; i<a->a_numvals; i++) {
737 				bptr->bv_len = *lp++;
738 				bptr->bv_val = (char *)ptr;
739 				ptr += bptr->bv_len+1;
740 				bptr++;
741 			}
742 			bptr->bv_val = NULL;
743 			bptr->bv_len = 0;
744 			bptr++;
745 		} else {
746 			a->a_nvals = a->a_vals;
747 		}
748 		/* FIXME: This is redundant once a sorted entry is saved into the DB */
749 		if (( a->a_desc->ad_type->sat_flags & SLAP_AT_SORTED_VAL )
750 			&& !(a->a_flags & SLAP_ATTR_SORTED_VALS)) {
751 			rc = slap_sort_vals( (Modifications *)a, &text, &j, NULL );
752 			if ( rc == LDAP_SUCCESS ) {
753 				a->a_flags |= SLAP_ATTR_SORTED_VALS;
754 			} else if ( rc == LDAP_TYPE_OR_VALUE_EXISTS ) {
755 				/* should never happen */
756 				Debug( LDAP_DEBUG_ANY,
757 					"mdb_entry_decode: attributeType %s value #%d provided more than once\n",
758 					a->a_desc->ad_cname.bv_val, j, 0 );
759 				return rc;
760 			}
761 		}
762 		a->a_next = a+1;
763 		a = a->a_next;
764 	}
765 	a[-1].a_next = NULL;
766 done:
767 
768 	Debug(LDAP_DEBUG_TRACE, "<= mdb_entry_decode\n",
769 		0, 0, 0 );
770 	*e = x;
771 	return 0;
772 }
773